Dissertations / Theses on the topic 'Z-cluster'

We present a detailed study of the colours of late-type galaxy discs for ten of the EDisCS galaxy clusters with 0.5 less than or similar to z less than or similar to 0.8. Our cluster sample contains 172 spiral galaxies, and our control sample is composed of 96 field disc galaxies. We deconvolved their ground-based V and I images obtained with FORS2 at the VLT with initial spatial resolutions between 0.4 and 0.8 arcsec to achieve a final resolution of 0.1 arcsec with 0.05 arcsec pixels, which is close to the resolution of the ACS at the HST. After removing the central region of each galaxy to avoid pollution by the bulges, we measured the V - I colours of the discs. We find that 50% of cluster spiral galaxies have disc V - I colours redder by more than 1 sigma of the mean colours of their field counterparts. This is well above the 16% expected for a normal distribution centred on the field disc properties. The prominence of galaxies with red discs depends neither on the mass of their parent cluster nor on the distance of the galaxies to the cluster cores. Passive spiral galaxies constitute 20% of our sample. These systems are not abnormally dusty. They are are made of old stars and are located on the cluster red sequences. Another 24% of our sample is composed of galaxies that are still active and star forming, but less so than galaxies with similar morphologies in the field. These galaxies are naturally located in the blue sequence of their parent cluster colour-magnitude diagrams. The reddest of the discs in clusters must have stopped forming stars more than similar to 5 Gyr ago. Some of them are found among infalling galaxies, suggesting preprocessing. Our results confirm that galaxies are able to continue forming stars for some significant period of time after being accreted into clusters, and suggest that star formation can decline on seemingly long (1 to 5 Gyr) timescales.

We present an investigation into the environments of quasars with respect to galaxy clus- ters, and environment evolution with redshift and luminosity. The positions of quasars with respect to clusters have been studied using cluster and quasar catalogues available, covering the redshift range 0.2 < z < 1.2. The 2D projected separations and the 3D separations have been found and the orientation of the quasar with respect to the major axis of the closest cluster calculated, introducing new information to previous work. The positions of quasars with respect to clusters of galaxies will give an indication of the large scale environment of quasars and potentially clues as to which formation mechanisms are likely to dominate at various redshifts. For example, galaxy mergers are most likely to occur in galaxy group environments and will create luminous quasars. Galaxy harassment is more likely to occur on the outskirts of galaxy clusters and create lower luminosity AGN. Secular processes such as bar instability can also create AGN and are likely to be the cause of nuclear activity in isolated galaxies. The aim of this work is to study the large scale environment over a large redshift range and study the evolution as well as any change in environment with quasar luminosity and redshift. Another aim of this work is to study the orientation of a quasar with respect to a galaxy cluster. If galaxy clusters lie orientated along filaments, the position of a quasar with respect to a cluster will give an indication as to where quasars lie with respect to the filament and therefore the large scale structure. There is a deficit of quasars lying close to cluster centres for 0.4 < z < 0.8, indicating a preference for less dense environments, in agreement with previous work. Studying the separations as a function of cluster richness, there was a change in quasars lying closer to poorer clusters for z < 0.2 (Lietzen et al. 2009) to lying closer to richer clusters for 0.2 < z < 0.4, though more clusters at low redshifts will be needed to confirm this. There is no obvious relation between the orientation angle between a quasar and the major axis of the closest galaxy cluster and 2D projected separations. Using faint (Mr > −23.0 mag) and bright (Mr < −23.0 mag) quasars, there is no difference between the two magnitude samples for the 2D separations or the cluster richness, in contrast to Strand et al. (2008) who found brighter quasars lying in denser environments than dimmer quasars. These is no change with redshift (over 0 < z < 1.2) in the positions of the quasars with respect to the cluster or the cluster richness as a function of absolute quasar magnitude. There is also no preferred orientation between the quasar and the cluster major axis for bright or faint quasars. Spectra of a selection of 680 star forming galaxies, red galaxies, and AGN were taken by Luis Campusano and Ilona S¨ochting and 515 redshifts calculated. Though few of these galaxies turned out to be cluster members as was originally intended, it was possible to use these galaxies to study the environments of quasars with respect to star-forming galaxies and galaxy clusters. The objects were classified (33 classed as AGN), and star formation rates calculated and compared. Three AGN and 10 star forming galaxies lie at the same redshift (z = 0.29) as three galaxy clusters. The three galaxy clusters have the same orientation angle and may be part of a filament along with the star forming galaxies and AGN. Further study will investigate the relation between AGN positions and filaments of structure. A sample of quasar spectra taken by Lutz Haberzettl using Hectospec on the MMT were taken to increase the number of quasars used in this study. However, when studying the spectra, a number of high redshift quasars showed evidence of ultra-strong UV Feii emission in their spectra. The redshifts of these quasars were too high to be included in the main body of the study. However, a significantly large number of ultra-strong UV Feii emitting quasars have been found in the direction of three LQGs in the redshift range 1.1 < z < 1.6, including the Clowes-Campusano Large Quasar Group (CCLQG). Ly� fluorescence can increase the UV Feii emission. However, Ly� emission from other quasars was found to be negligible compared to emission from the quasar’s central source. Though there has been no previous indication that the LQG environment is unique, the high level of iron emission may indicate a difference in environment. Plans for future work based on these results are outlined.

2002/2003
Il lavoro di questa tesi è basato sull'analisi dell'ammasso di galassie ABCG 209, a zrv 0.2, che e' caratterizzato da una forte evoluzione dinamica. Lo studio si basa su dati ottici nuovi (EMMI-NTT: immagini nelle bande B, V e R, e spettri MOS) acquisiti in ottobre 2001 all'osservatorio europeo del sud (ESO) in Cile. Sono stati analizzati, inoltre, dati ottici di archivio (immagini a grande campo nelle bande B ed R del CFHR12k), dati X-ray (Chandra) e osservazioni (VLA). Lo scopo principale di questa analisi è lo studio della relazione tra la dinamica degli ammassi e la storia di formazione stellare delle galassie, al fine di capire i complessi meccanisn1i della formazione e dell'evoluzione degli ammassi. Sulla base di 112 spettri di galassie di ammasso è stata studiata la dinamica interna di ABCG 209. Questa analisi ha mostrato che l'ammasso è caratterizzato da un valore particolarmente alto della dispersione di velocità lungo la linea di vista: av = 1250-1400 km s- 1 , che implica un valore della massa viriale pari a M = 1.6-2.2 x 1015 h- 1 M0 all'interno di un raggio viriale, Rvir· Inoltre, l'ammasso presenta un'elongazione lungo la direzione SE-NW, come mostrato da: a) la presenza di un gradiente di velocità; b) l'elongaziòne della distribuzione spaziale delle galassie di ammasso selezionate in base alla sequenza della colore-magnitudine; c) l'elongazione dei contorni dell'emissione X; d) l'allungamento della galassia centrale dominante (cD). La presenza di sottostrutture è indicata sia dalla non-gaussianità della distribuzione delle velocità, che presenta due sottogruppi spazialmente segregati a z = 0.199 e z = 0.215, sia dal test di Dressler & Schectrnan in 3 dimensioni, che utilizza contemporaneamente l'informazione in ascensione retta e declinazione, e quella in velocità. Infine le galassie selezionate in base alla colore-magnitudine presentano una segregazione in luminosità, ovvero le galassie brillanti R < 19.5 sono concentrate intorno alla galassia cD, mentre quelle deboli R > 19.5 mostrano dei sottogruppi, dei quali quello più ad est coincide con il picco secondario dell'emissione X. Lo studio della funzione di luminosità (LF) nelle bande B, V ed R, ha mostrato che l'ammasso presenta caratteristiche intermedie tra un ammasso ricco rilassato ed un ammasso irregolare, dinamic; unente giovane. Questi risultati suggeriscono che ABCG 209 è un ammasso che si sta ancora evolvendo dinamicamente, in cui vi è stato un merging di due o più sottogruppi lungo la direzione SE-NW, in un piano non parallelo a quello del cielo. Il merging potrebbe essere in uno stadio avanzato in cui le galassie luminose tracciano la struttura del sottogruppo che ospitava la galassie centrale dominante prima del rnerging. L'elongazione e l'asimmetria della distribuzione di galassie e dell'emissione X, e la forma della funzione di luminosità indicano, infine, che l'ammasso non è ancora rilassato. L'effetto dell'ambiente (valutato in termini di densità superficiale locale delle galassie con magnitudini R < 23.0) sulle proprietà globali dell'ammasso è stato esaminato mediante l'analisi delle funzioni di luminosità, delle relazioni colore-magnitudine, e dei colori medi dell'ammasso, usando immagini a grande campo (30'x42') nelle bande B ed R. La funzione di luminosità dipende fortemente dall'ambiente, in particolare la slope diventa sempre più ripida andando dalle regioni ad alta densità a quelle a bassa densità (livelli di confidenza maggiori di 3o-). Inoltre la sequenza della relazione colore-magnitudine è 0.022 ± 0.014 mag più rossa nelle regioni a densità alta rispetto a quelle a densità intermedia, e la frazione di galassie blu decresce monotonicamente con la densità, in accordo con altri studi. Tutti questi risultati sono comprensibili sulla base della relazione densità-morfologia, per la quale la frazione di galassie early-type, caratterizzate da colori rossi e funzioni di luminosità piatte, decresce lentamente e monotonicamente dalle regioni ad alta densità a quelle a bassa densità; mentre la frazione di galassie late-type, che sono blu ed hanno funzioni di luminosità ripide, cresce. L'analisi dei colori medi delle galassie luminose (R < 21) in funzione della loro posizione spaziale mostra chiaramente i complessi effetti dell'ambiente e dell'evoluzione dinamica dell'ammasso sulle galassie che lo costituiscono. Le galassie più rosse sono concentrate attorno alla cD e in una regione a 5 arcmin dal centro, coincidente con la sottostruttura prevista dal weak lensing. L'effetto di una direzione preferenziale SE-NW per ABCG 209 è evidente nella presenza di galassie blu brillanti vicino alla cD lungo perpendicolarmente alla direzione di allungamento, e quindi non affette dal merging, e nell'estensione delle galassie rosse a SE che potrebbe indicare un gruppo di galassie che sta cadendo sull'amn1asso lungo il filamento. L'allungamento dell'ammasso lungo la direzione SE-NW sen1bra anche legato alla struttura a larga scala in cui ABCG 209 è vicino a due ammassi ricchi ABCG 222 az= 0.211 e ABCG 223 a z = 0.2070, che si trovano a 1.5° (15 Mpc) a NW lungo questo asse preferenziale. La dinamica degli ammassi e la struttura a larga scala hanno una forte influenza sull'evoluzione delle galassie. Per questo motivo è stato fatto uno studio dettagliato delle proprietà spettroscopiche di 102 galassie membro dell'ammasso. Sono state individuati cinque differenti tipi di galassie: i) galassie che evolvono passivamente (E), che hanno colori rossi e non presentano nel loro spettro righe di emissione, ii) galassie con righe di emissione (ELG), che sono blu, iii-iv) galassie con profonde righe di assorbimento H5, che possono essere divise in due gruppi: blu (HDSblue) e rosse (HDSred), in base al loro colore B-R ed al break a 4000 A v) e infine galassie a spirale anemiche (Ab-spirals), che hanno proprietà spettrali uguali a quelle della galassie passive, ma sono sistemi a disco. Queste differenti classi spettrali sono fortemente segregate nello spazio delle fasi, in accordo con il test di Kolmogorov & Smirnov in 2 dimensioni. Le galassie che evolvono passivamente rappresentano il 74% delle galassie di ammasso esaminate. Questa popolazione si è formata molto presto, durante il collasso iniziale dell'ammasso. Queste galassie si trovano principalmente nella regione ad alta densità ed hanno una dispersione di velocità consistente con quella totale dell'ammasso. Questo risultato è comprensibile sulla base del modello cos1nologico di formazione della struttura a larga scala, secondo il quale le galassie early-type si formano nelle regioni di più alta densità, corrispondenti alle zone centrali degli ammassi. Le galassie HDSred sono distribuite lungo l'allungamento dell'ammasso, principalmente in regioni a densità intermedia ed hanno una bassa dispersione di velocità, che suggerisce che questa popolazione sia il nucleo di un gruppo che è caduto sull'ammasso. Sulla base dei modelli di evoluzione delle galassie, la presenza di forti righe di assorbimento H 6 nei loro spettri, indica che queste galassie hanno sperimentato un piccolo burst di formazione stellare pochi Gyrs fa. In particolare sulla base di un modello di starburst l'aver osservato [H6] > 3.0 A implica che il burst deve essere avvenuto non più di 2 Gyrs fa. Le galassie HDSblue si trovano in regioni a densità intermedia, 1na lungo una direzione perpendicolare a quella di allungamento dell'ammasso, vicine al picco secondario dell'emissione X, ed in una regione in cui l'intracluster medium è particolarmente denso. Queste galassie sono caratterizzate da un'alta dispersione di velocità. Le galassie con righe di emissione si trovano principalmente nelle regioni a bassa densità e hanno alta dispersione di velocità. Sia la posizione spaziale, che la dispersione di velocità di queste ultime due classi di galassie indicano che queste potrebbero essere due popolazioni recentemente cadute nell'ammasso dal campo. Tutti questi risultati indicano uno scenario evolutivo in cui ABCG 209 è caratterizzato principalmente dalla sovrapposizione di due componenti: una popolazione di galassie vecchie che si sono forrr1ate molto presto (zJ ;G 3), ed una popolazione più giovane di galassie che sono state accresciute dal campo. Inoltre, l'ammasso potrebbe aver sperimentato un merging con un gruppo l o 2 Gyrs fa, come indicato anche precedentemente dall'analisi dinamica. Questo studio dettagliato ha mostrato chiaramente l'importanza di avere dati multi-banda e di un approccio multi-direzionale nello studio di questi sistemi così complessi. E', a questo punto, fondamentale estendere questo tipo di analisi ad altri ammassi a redshifts maggiori, e con differenti proprietà dinamiche. Per rispondere definitivamente alla domanda se gli ammassi sono generalmente giovani o vecchi è necessario avere informazioni sulle proprietà di un gran numero di ammassi e contemporaneamente studiare in dettaglio le componenti appartenenti a diverse strutture ed ambienti in un singolo ammasso.
The thesis work is focused on the analysis of the galaxy clusters ABCG 209, at zrv 0.2, which is characterized by a strong dynamical evolution. The data sample used is based mainly on new optical data (EMMI-NTT: B, V and R band images and MOS spectra), acquired in October 2001 at the European Southern Observatory in Chile. Archive optical data ( CFHR12k: B and R images), and X-ray (Chandra) and radio (VLA) observations are also analysed. The n1ain goal of this analysis is the investigation of the connection between internal cluster clynamics and star formation history, aimed at understanding the complex mechanisms of cluster formation and evolution. The internal dynamics of the cluster was studied through a spectroscopic survey of 112 cluster Inembers. The dynamical analysis has pointed out that ABCG 209 is characterized by a very high value of the line of sight velocity dispersion: av = 1250-1400 km s- 1that results in a virial mass of M = 1.6-2.2 x 1015 h-1 M0 within Rvir· A preferential SE-NW direction is indicated by: a) the presence of a velocity gradient in the velocity field; b) the elongation in the spatial distribution of colour-selected cluster members; c) the elongation of the X-ray contour levels in the Chandra image; d) the elongation of the cD galaxy. T h ere is evidence of substructure, as shown by i) significant cleviation of the velocity distribution from a Gaussian, with evidence for two secondary clumps at z = 0.199 and z = 0.215, which appear spatially segregated from the main cluster, ii) the Dressler & Schectman test and iii) the two-dimensional distribution of the colour-selected members shows a strong luminosity segregation: bright galaxies R < 19.5 are centered around the cD galaxy, while faint galaxies R > 19.5 show some clumps. The main one, Eastern with respect to the cD galaxy, is well coincident with the secondary X -ray peak. ' The study of the galaxy luminosity function (LF) in B, V and R bands has pointed out that ABCG 209 is a cluster with intermediate characteristic between a dynamically-evolved, rich clusters and clusters with central dominant galaxies having bright characteristic luminosities and shallow faint-end slopes and less evolved clusters, characterized by steep faint-end slopes, thus reconciling the asynnnetric properties of X-ray emission with the non flat-LF shape of irregular systen1s. This observational scenario suggests that ABCG 209 is undergoing a strong dynan1ical evolution with the Inerging of two or more subclumps along the SE-NW direction in a plane which is not parallel to the plane of sky. The merging might be in a more advanced status, where luminous galaxies trace the remnant of the core-halo structure of a pre-merging clump hosting the cD galaxy. The elongation and asymmetry of the galaxy distribution (of the X-ray emission) and the shape of the LFs show that ABCG 209 is not yet a fully relaxed system. The effect of cluster environment (as measured in terms of the local surface density of R < 23.0 galaxies) o n the global properties of the cluster galaxies is examined through the analysis of the L Fs, colour-magnitude relations, and average colours by using wide field (30'x42') B- and R-band images. The faint-end slope of the LF, a, shows a strong dependence on environment, becoming steeper at > 3a significance level from high- to low-density environments. The red sequence is found to be 0.022 ± 0.014 mag redder in the high-density region than for the intermediate-density region by fixing the slope. In contrast no correlation between the slope of the red sequence and environment was observed. Studying the effect of the cluster environment on galaxy star-formation, we find that the blue galaxy fraction decreases monotonically with density, in agreement with other studies. The observed trends of steepening of the faint-end slope, faintening of the characteristic luminosity, and increasing blue galaxy fraction, from high- to low-density environments, are manifestations of the morphology-density relation, where the fraction of early-type galaxies decreases smoothly and monotonically from the cluster core to the periphery, while the fraction of late-type galaxies increases in the same manner. The observed trends in the composite LF reflect this morphology-density relation: the galaxy population in the cluster core is dominateci by early-type galaxies and so the cornposite LF resembles that of this type of galaxy, with a shallow faint-end slope and a bright characteristic lun1inosity; whereas in lower density regions the fraction ~f late-type galaxies increases, and so the composite LF increasingly resembles that of the late-type, with a steep faint-end slope and a fainter characteristic magnitude. The analysis of the mean colour of luminous (R < 21) cluster galaxies as a function of their spatial position shows clearly the complex effects of the cluster environment and dynamics on their constituent galaxies. The reddest galaxies are concentrateci around the cD galaxy (main cluster) and a more diffuse region 5 arcmin to the north is coincident with the structure predicted from weak lensing analysis. The effect of the preferential SE-NW direction for ABCG 209 is apparent in the presence of bright blue galaxies near the cD galaxy perpendicular to the axis and hence unaffected by the cluster merger, and an extension of red galaxies to the SE which may indicate the irifall of galaxies into the cluster along a filament. This preferential SE-NW direction appears also related to the large-scale structure in which ABCG 209 is embedded, with two rich (Abell class R=3) clusters ABCG 222 at z = 0.211 and ABCG 223 at z = 0.2070 are located 1.5° (15M pc) to the NW along this preferential axis. Cluster dynamics and large-scale structure clearly have a strong influence on galaxy evolution, so we have performed a detailed study of spectroscopic properties of 102 luminous member galaxies. W e find five different galaxy types: i) passive evolving galaxies (E), which exhibit red colours and no emission lines, ii) emission line galaxies (ELG), which are blue and have prominent emission lines, iiiiv) strong Hc5 galaxies, that are characterized by the presence of strong Hc5 equivalent width and can be divided into blue (HDSblue) and red (HDSred), according to the break at 4000 A and the B-R colours, v) and finally anemie spirals (Ab-spirals), that have spectral properties equal to passive evolving galaxies, but are disk-dominateci systems. These different spectral classes are strongly segregated in the phase-space, as indicated by the two dimensionai Kolmogorov-Smirnov test. Passive evolving galaxies represent the I"V 74% of the cluster members. This population formed very early, during the initial collapse of the cluster. They lie mainly in high density regions and ha ve a velocity dispersion fully consistent with those of the whole cluster. This result is understandable in terms of cosmological models of structure formation, in which early-type galaxies form in the highestdensity regions corresponding to the cores of rich clusters. HDSred galaxies are distributed along the elongation of the cluster mainly in intermediate density regions and have a significant low velocity dispersion, suggesting that this population could be the remnant of an infalling group. According to the evolution models, the presence of a strong Hc5 absorption line in their spectra indicates that these galaxies have experimented a short starburst of star formation in the past few Gyrs. In the starburst nwdel [Hc5] and Dn(4000) declines on a timescale of I"V 2Gyr after the burst has ceased, irregardless of their SFR before the burst. Thus the fact that we see these galaxies, detecting [Hc5] > 3.0 A implies that the burst has occurred no more than 2 Gyr ago. HDSblue galaxies are found in intermediate density regions in a direction perpendicular to the cluster elongation, dose to the secondary peak of the X-ray flux andina region where the intracluster Inedium (ICM) is dense. Moreover galaxies belonging to this class seem to be aligned Thus the burst in the star formation seen in these galaxies could be due to the interaction with the hot dense ICM. They have high velocity dispersion. ELGs lie in low density regions and have high line-of-sight velocity dispersion. Both the spatial position and the velocity dispersion suggest that these two populations of galaxies have recently fallen into the cluster from the field. All these results support an evolutionary scenario in which ABCG 209 is characterized by a sum of two components: an old galaxy population, formed very earlier (zJ ;:G 3), and a younger population of infalling galaxies. Moreover this cluster may have experimented l or 2 Gyrs ago a merging with an infalling galaxy group, as indicated also by the previous dynamical analysis. This detailed study has showed clearly the importance to have multi-band data and to perform a n1ulti-directional analysis, in order to precisely characterize the different cluster components. It is now fundamental to extend this kind of analysis to other clusters at higher redshift and with different dynamical properties. To address the issue if clusters are generally young or old one needs to have measurements of subclustering properties of a large sample of clusters and at the same time it is fundamental to precisely characterize cluster components belonging to different structures and environments inside a single cluster.
XVI Ciclo
1976
Versione digitalizzata della tesi di dottorato cartacea.

A fundamental pursuit of astronomy is to understand how galaxies form and evolve. What drives the decline in the cosmic star formation rate density? Why are high redshift galaxies clumpy and turbulent? How can we explain the emergence of the Hubble sequence? To answer these questions we must unravel a complex interplay of different processes, including gas accretion, star formation, feedback, and environmental effects. Studying the gas kinematics of galaxies can provide valuable insight. In this thesis we use integral field spectroscopy to probe the evolution of star-forming field and cluster galaxies over the past 8 billion years. We first present a multi-wavelength analysis of 27 dusty starburst galaxies in a massive cluster at z~0.4. It is thought that starbursts represent an intermediate phase in the transition from spirals to S0s in dense environments. We combine H-alpha kinematics with far-infrared imaging and millimetre spectroscopy, and find that most galaxies are rotationally supported, with high angular momentum and large cold gas reservoirs. It appears that the starbursts have only recently been accreted to the cluster. To complete the transition to S0s, they must undergo a dynamical heating of the disk, increase in concentration, and reduce their angular momentum by ~40%. We conclude that the most likely way to achieve this is via multiple tidal interactions with other cluster members. We next study the velocity dispersion properties of 472 galaxies observed as part of the KMOS Redshift One Spectroscopic Survey (KROSS). Most galaxies at this epoch are rotationally supported, but dynamically hot and highly turbulent. In order to make robust kinematic measurements, we model the effects of beam smearing using a series of mock KMOS data cubes. We then combine KROSS with data from the SAMI survey (z~0.05) and an intermediate redshift MUSE sample (z~0.5), and find that while there is a weak trend between velocity dispersion and stellar mass, at fixed mass there is a strong increase in velocity dispersion with redshift. At all redshifts, galaxies appear to follow the same weak trend of increasing velocity dispersion with star formation rate. We also test the predictions of two analytic models which suggest that turbulence in the ISM is driven by gravitational instabilities or stellar feedback. However we find that further observations are required to rule-out either model. Finally, to understand the role of galaxy kinematics in “crystallising” the Hubble sequence, we study the HST images of 231 KROSS galaxies. We quantify differences in morphology using the asymmetry parameter. This metric correlates very well with our visual interpretation of “clumpiness”, however there are no strong trends as a function of galaxy kinematics. On average, the velocity dispersion of clumps is consistent with the underlying disk, and there is no evidence to suggest that these star-forming regions are preferentially located towards the outskirts of the galaxy. We propose that adaptive optics assisted IFU observations would provide further insight, allowing us to test clump evolution theories and to study the radial distribution of angular momentum.

This thesis describes searching for high-risk clusters of portals in the Ingress game by using data mining techniques. The work contains background for descibed problematics and methods and experiments used to search for theese information.

This thesis describes searching for high-risk clusters of portals in the Ingress game by using data mining techniques. The work contains background for descibed problematics and methods and experiments used to search for theese information.

We present an extremely deep CO(1-0) observation of a confirmed z = 1.62 galaxy cluster. We detect two spectroscopically confirmed cluster members in CO(1-0) with signal-to-noise ratio >5. Both galaxies have log (M-star/M-circle dot) > 11 and are gas rich, with M-mol/(M-star + M-mol) similar to 0.17-0.45. One of these galaxies lies on the star formation rate (SFR)-M-star sequence, while the other lies an order of magnitude below. We compare the cluster galaxies to other SFR-selected galaxies with CO measurements and find that they have CO luminosities consistent with expectations given their infrared luminosities. We also find that they have gas fractions and star formation efficiencies (SFE) comparable to what is expected from published field galaxy scaling relations. The galaxies are compact in their stellar light distribution, at the extreme end for all high-redshift star-forming galaxies. However, their SFE is consistent with other field galaxies at comparable compactness. This is similar to two other sources selected in a blind CO survey of the HDF-N. Despite living in a highly quenched protocluster core, the molecular gas properties of these two galaxies, one of which may be in the process of quenching, appear entirely consistent with field scaling relations between the molecular gas content, stellar mass, star formation rate, and redshift. We speculate that these cluster galaxies cannot have any further substantive gas accretion if they are to become members of the dominant passive population in z < 1 clusters.

This thesis investigates the reconstruction of Z(→ee)γ events with the ATLAS detector at the LHC. The capabilities of the detector are explored for the initial run scenario with a proton-proton centre of mass collision energy of √s = 7TeV, and an integrated luminosity of \(\char{cmsy10}{0x4C}\) = 1 fb⁻¹. Monte Carlo simulations are used to predict the expected precision of a differential cross-section measurement for initial state radiation Z + γ events, both with respect to the transverse momentum of the photon, p_T(γ), and the three body eeγ invariant mass. A bin-by-bin correction is used to account for the signal selection efficiency and purity, and to correct the measured (simulated) distribution back to the theoretical prediction. The main backgrounds are found to be from the final state radiation Z + γ process, and from jets faking photons in Z → ee events. The possible QCD multijet background is studied using a fake-rate method, and found to be negligible for the particle identification cuts used in the analysis. The main systematic uncertainties on the differential cross-section measurements are explored with Monte Carlo simulations, and found to be of a similar scale to the statistical errors for the chosen distribution binning. The three body eeγ invariant mass distribution was then used as the basis of an exclusion study on new particles decaying to the Z(ee)γ final state. Under the assumption that the measured data agrees with the Standard Model prediction, exclusion limits were placed at 95% confidence level on the cross-section times branching ratio for a new scalar (modelled by SM Higgs process), or vector (based on a low-scale technicolor process) particle hypothesis, for particles in the mass range 200 to 900GeV. Limits of the order \(\char{cmsy10}{0x4f}\)(0.01) - \(\char{cmsy10}{0x4f}\)(0.1) pb on the cross section times branching ratios are predicted, which would improve on the equivalent limits previously calculated by the DØ experiment at the Tevatron collider, albeit in a different √s region, where cross-sections will generally be higher for new massive particles. In addition to the Zγ measurements, a digital timing calibration procedure was developed for the Cluster Processor (CP) subsystem of the level-1 calorimeter trigger. This work was essential to providing a repeatable and robust mechanism for timing in the digital processing in the CP system, a necessary ingredient for a robust and reliable trigger system; a pre-requisite of any physics analysis. This calibration procedure is described here.

Le but de cette thèse est de décrire le chemin métabolique permettant de remplacer l’adénine (A) par la 2-aminoadénine (Z) dans le génome de bactériophages Siphoviridae. La 2-aminoadénine et la thymine (T) forment la paire Z:T, liée par trois liaisons hydrogène. Avec la paire G:C classique, ils forment un ADN « ZTGC » qui est résistant aux enzymes de réstriction de l’hôte. En premier lieu, mes travaux se sont focalisés sur le cyanophage S-2L, décrit comme porteur de 2-aminoadénine. J’ai d’abord étudié la primase-polymérase, PrimPol, responsable de la réplication de l’ADN chez ces phages, et qui possède la capacité surprenante d’incorporer à la fois le dATP et le dZTP. J’ai ensuite caractérisé une triphosphatase dATP-spécifique, appelée DatZ, conservée chez tous les bactériophages Siphoviridae, responsable de la dégradation spécifique du dATP. J’ai également mis en évidence que PurZ, l’enzyme-clé pour la production de la diaminopurine est non seulement une ATPase mais aussi une dATPase. J’ai identifié une nucléotide pyrophosphatase, appelée MazZ, composant essentiel du chemin de biosynthèse de Z, qui convertit dGTP en dGMP, en générant ainsi un des substrats de PurZ. Structures cristallographiques de haute résolution de tous les 4 enzymes avec leurs ligands respectifs expliquent les spécificités observées dans les tests catalytiques – ou leur absence. Enfin, j’ai caractérisé une structure d’une ADN polymérase Z-spécifique de famille A, PolZ, trouvée dans le vibriophage φVC8, mais absente dans S-2L. J’ai résolu sa structure cristallographique en modes polymérase et exonuléase « couplé-ouvert » et « couplé-fermé », permettant de decrire son activité au niveau atomique
The subject for this thesis is to dissect the enzymatic pathway allowing a non-canonical base 2-aminoadenine, or diaminopurine (Z) to replace adenine (A) in the genomes of a number of Siphoviridae bacteriophages. 2-aminoadenine and thymine (T) form the Z:T pair bound by fully saturated triple hydrogen bond. Together with the standard G:C pair they form ZTGC-DNA which is resistant to host’s restriction enzymes. I first focus on cyanophage S-2L, the originally-described bearer of 2-aminoadenine. I identify a DNA primase-polymerase, PrimPol, responsible for its replication, with surprisingly similar activity towards dATP and dZTP. This prompted the characterization of a dATP-specific triphosphatase, DatZ. Its activity and conservation between the phages of interest explains the mechanism behind adenine removal. Secondly, I find that PurZ of phage S-2L’s, a key enzyme in diaminopurine production, is not only an ATPase but also a dATPase. I identify a nucleotide pyrophosphatase, MazZ, as an essential component of the conserved Z biosynthetic pathway, that converts dGTP into dGMP, thus generating one of the substrates of PurZ. High resolution crystallographic structures of all 4 enzymes with their respective ligands explain the specificities observed in catalytic tests - or lack thereof. Finally, I characterized the structure of a Z-specific family A DNA polymerase, PolZ, found in a related vibriophage φVC8 but absent in S-2L. Its crystallographic structure in polymerase-exonuclease “coupled-open” and “coupled-close” states offers an explanation for the observed specificity

This master's thesis deals with development of a module for a data mining system, which is being developed on FIT. The first part describes the general knowledge discovery process and cluster analysis including cluster validation; it also describes Oracle Data Mining including algorithms, which it uses for clustering. At the end it deals with the system and the technologies it uses, such as NetBeans Platform and DMSL. The second part describes design of a clustering module and a module used to compare its results. It also deals with visualization of cluster analysis results and shows the achievements.

This thesis deals with the design and implementation of a cluster analysis module for currently developing datamining system DataMiner on FIT BUT. So far, the system lacked cluster analysis module. The main objective of the thesis was therefore to extend the system of such a module. Together with me, Pavel Riedl worked on the module. We have created a common part for all the algorithms so that the system can be easily extended to other clustering algorithms. In the second part, I extended the clustering module by adding three density based clustering aglorithms - DBSCAN, OPTICS and DENCLUE. Algorithms have been implemented and appropriate sample data was chosen to verify theirs functionality.

This master's thesis deals with with FIT-Miner, the system for knowledge discovery in databases. The first part of this paper describes the data-mining process, mixture model's issues and FIT-Miner system. Second part deals with design, implementation and testing of created module, which is used for cluster analysis with Expectation-Maximalization algorithm. The end of the paper is focused to design of modules using Java Store Procedures Technology.

We directly detect dust emission in an optically detected, multiply imaged galaxy lensed by the Frontier Fields cluster MACSJ0717.5+3745. We detect two images of the same galaxy at 1.1 mm with the AzTEC camera on the Large Millimeter Telescope leaving no ambiguity in the counterpart identification. This galaxy, MACS0717_Az9, is at z > 4 and the strong lensing model (mu = 7.5) allows us to calculate an intrinsic IR luminosity of 9.7 x 10(10) L-circle dot and an obscured star formation rate of 14.6 +/- 4.5 M-circle dot yr(-1). The unobscured star formation rate from the UV is only 4.1 +/- 0.3 M-circle dot yr(-1), which means the total star formation rate (18.7 +/- 4.5 M-circle dot yr(-1)) is dominated (75%-80%) by the obscured component. With an intrinsic stellar mass of only 6.9 x 10(9) M circle dot, MACS0717_Az9 is one of only a handful of z. >. 4 galaxies at these lower masses that is detected in dust emission. This galaxy lies close to the estimated star formation sequence at this epoch. However, it does not lie on the dust obscuration relation (IRX-beta) for local starburst galaxies and is instead consistent with the Small Magellanic Cloud attenuation law. This remarkable lower mass galaxy, showing signs of both low metallicity and high dust content, may challenge our picture of dust production in the early universe.

The chemistry of transition metal clusters has been a fast developing area of organometallic research in recent years. Compared to mononuclear metal complexes, polynuclear clusters offer more opportunities to study cooperative effects and electron reservoir properties between contiguous metal centers, in addition to functioning as storehouses for the release of catalytically active small fragments capable of exhibiting heterosite subtrate activation. Theoretically, metal clusters are intermediates between mononuclear complexes and metal surfaces, i.e., they serve as a bridge between molecular and solid-state chemistry. Transition metal clusters are ideal candidates to study M-M interactions stretching from the single bond to the collective metallic behavior found in a three-dimensional network of metal atoms. The reaction between the redox-active diphoshpine ligand bpcd and RU(CO) has been examined under a variety of conditions. The disubstituted cluster Ru3(CO)10(bpcd)(2) has been synthesized and shown to contain a chealating bpcd ligand, on the basis of IR and 31P NMR data. The cluster 2 (chelating isomer) undergoes cluster fragmentation at ambient temperatures in the dark to give the binuclear compound 3 and Ru3(CO)12, with no evidence for the formation of 4. Both 3 and 4 have been isolated and fully characterized in solution by IR and NMR spectroscopy, and the solid-state structure of each new binuclear compound has been established by X-ray diffraction analysis. Independent experiments reveal that dinuclear 3 is converted to 4 by 366 nm light with a quantum efficiency of .0364.

This master"s thesis deals with the knowledge discovery in multimedia databases. It contains general principles of knowledge discovery in databases, especially methods of cluster analysis used for data mining in large and multidimensional databases are described here. The next chapter contains introduction to multimedia databases, focusing on the extraction of low level features from images and video data. The practical part is then an implementation of the methods BIRCH, DBSCAN and k-means for cluster analysis. Final part is dedicated to experiments above TRECVid 2008 dataset and description of achievements.

The correlation between NMR chemical shifts of interstitial atoms and electronic structures of boron- and carbon-centered hexazirconium halide clusters was investigated by density functional theory (DFT) calculation. The influences of bridging halide and terminal ligand variations on electronic structure were examined respectively. Inverse proportionality was found between the chemical shifts and the calculated energy gaps between two Kohn-Sham orbitals of t1u symmetry, which arose from the bonding and antibonding interaction between the zirconium cage bonding orbitals and the interstitial 2p orbitals. Chemical shielding properties of the interstitial atoms were calculated with Gauge Including Atomic Orbital (GIAO) method. Stepwise ligand substitution of terminal chlorides on [(Zr6CCl12)Cl6]4-cluster by tri(n-butyl)-phosphine oxide (Bu3PO) was conducted with the aid of TlPF6. Composition of the reaction mixtures was analyzed by use of both 13C and 31P NMR. A preliminary scheme for synthesis and separation of [(Zr6CCl12)Cl6-x(Bu3PO)x]x-4 (x = 3 ?? 5) mixture based on solubility difference was reevaluated. Three 1,10-phenanthroline based bidentate ligands, namely, 2,9-Bis(diphenyl-phosphinyl)-1,10-phenanthroline, 2,9-Bis(diethoxyphosphoryl)-1,10-phenanthroline, and 2,9-Bis(di-n-butoxyphosphoryl)-1,10-phenantholine, were synthesized for bridge-chelating the hexazirconium clusters. Coordination chemistry of these ligands with the [Zr6BCl12] and [Zr6CCl12] clusters was subject to preliminary investigation.

This thesis presents optical CCD imaging taken as part of the follow-up programme to the Massive Cluster Survey, a ROSAT All-Sky Survey based cluster survey aiming to discover X-ray luminous galaxy clusters at redshifts above 0.3. A data-reduction pipeline is developed to process the V, R and I band imaging of 111 clusters observed with the University of Hawaii 2.2 metre telescope and 57 with the ESQ NTT. The galaxian population is examined and all clusters but one contain enough galaxies to account for the X-ray flux. The cluster red-sequence is used to constrain the star-formation epoch to high {z > 1.7) redshift and as a basis for photometric redshifts. The symmetry properties of the clusters are examined to probe merger activity, the cluster selection exhibiting no bias towards, or against, merging clusters. The BCG population is examined. The degree to which the BCG dominates the cluster galaxy population displays no trend with either redshift or cluster X-ray luminosity, indicative of considerable previous as well as ongoing evolution. A quarter of the BCG population show bluer colours than would be expected for an elliptical galaxy at the appropriate redshift, some with known line emission, proving that BCGs are not purely passively evolving galaxies. Multi-object spectroscopy of two clusters is used to confirm these as being massive. Colour-magnitude diagrams of spectroscopically selected galaxies are used to determine that the major source of error in the photometry to is the flux limit of the imaging not the techniques applied. The Veron-Cetty Veron AGN catalogue is cross-correlated with the Abell catalogue to reveal a sample of AGN in clusters which are found to be distributed within clusters as ordinary galaxies, making contamination to the observed X-ray flux a possibility. A search for gravitationally lensed galaxies reveals such objects in 23% of the clusters imaged.

This thesis presents new and unique wide-field imaging and spectroscopic observations of 21 X-ray selected rich clusters of galaxies in the redshift range 0.07 < z < 0.16 from the Las Campanas Observatory (LCO) / Anglo-Australian Telescope (AAT) Rich Cluster Survey (LARCS). Mosaic two colour broad-band CCD imaging extending to 10 Mpc at the mean redshift of the survey have been taken at LCO; comprising over 50Gb of raw data. A reduction pipeline is developed for these data and catalogues are constructed for these clusters. Four of these fields are compared to the APM catalogue (Maddox et al. 1990) to confirm their photometric accuracy. In making the comparison several populations of galaxies are discovered to be absent from the APM.A statistical background correction technique is developed to examine the photometric properties of cluster members. Eleven clusters are combined together to investigate environmental trends in the stellar populations of the combined sample. It is found that the modal colours of galaxies lying on the colour-magnitude relation in the clusters become bluer by d (B - R)/dr(_p) = -0.022 ±0.004 with radius or d (B - R)/dlog(_10) (Σ) = -0.076 ± 0.009 with local galaxy density. The 2dF spectroscope at the A AT is used to make spectroscopic follow-up observations of three clusters. A reduction pipeline for these data is developed and redshifts for the galaxies are determined. The spectral catalogues are used to define cluster membership and confirm the photometric environmental trends. Spectral line strengths are used to classify the galaxy population and examine environmental trends across the clusters. The cluster cores are found to be predominantly passive compared to the field. A comparison of the two cluster membership assignment techniques underscores the need for spectroscopy to define the cluster population.

We present a stacked weak-lensing analysis of 27 richness selected galaxy clusters at 0.40 <= z <= 0.62 in the COnstrain Dark Energy with X-ray galaxy clusters (CODEX) survey. The fields were observed in five bands with the Canada-France-Hawaii Telescope (CFHT). We measure the stacked surface mass density profile with a 14 sigma significance in the radial range 0.1 < R Mpc h(-1) < 2.5. The profile is well described by the halo model, with the main halo term following a Navarro-Frenk-White profile (NFW) profile and including the off-centring effect. We select the background sample using a conservative colour-magnitude method to reduce the potential systematic errors and contamination by cluster member galaxies. We perform a Bayesian analysis for the stacked profile and constrain the best-fitting NFW parameters M-200c = 6.6(- 0.8)(+1.0) x 10(14) h(-1)M(circle dot) and c(200c) = 3.7(+0.7) (-0.6). The off-centring effect was modelled based on previous observational results found for redMaPPer Sloan Digital Sky Survey clusters. Our constraints on M(200)c and c(200)c allow us to investigate the consistency with numerical predictions and select a concentration-mass relation to describe the high richness CODEX sample. Comparing our best-fitting values forM(200c) and c(200c) with other observational surveys at different redshifts, we find no evidence for evolution in the concentration-mass relation, though it could be mitigated by particular selection functions. Similar to previous studies investigating the X-ray luminosity-mass relation, our data suggest a lower evolution than expected from self-similarity.

The aim of the thesis is to classify european countries in terms of their business climate using the method of cluster analysis over the years 2008-2013. Changes in classification during this period are associated with events of global significance (e.g. World financial crisis) or local importance (reforms, EU strategy...). Data base consists of indicators describing administrative, financial and law environment for doing business and are publicated by World Bank. Clusters indicate both geographic conditionality and specific attributes of these clusters, which suggest countries with better/worse conditions in some of the areas. Particular attention is given to development in the Czech republic. There was significant change in classificiation between 2008 and 2009 and subsequently became stable. The results of analysis correspond to the existing rankings and indicators of business demography. Potentials for improvement which might leed to stabel economic development according to the conducted analysis are outlined in the end of the thesis (f.e. implementation of unified administrative points, electronization and further simplification of bureaucratic processes).

Association rules mining is one of several ways of knowledge discovery in databases. Paradoxically, data mining itself can produce such great amounts of association rules that there is a new knowledge management problem: there can easily be thousands or even more association rules holding in a data set. The goal of this work is to design a new method for association rules post-processing. The method should be software and domain independent. The output of the new method should be structured description of the whole set of discovered association rules. The output should help user to work with discovered rules. The path to reach the goal I used is: to split association rules into clusters. Each cluster should contain rules, which are more similar each other than to rules from another cluster. The output of the method is such cluster definition and description. The main contribution of this Ph.D. thesis is the described new Multicriterial clustering association rules method. Secondary contribution is the discussion of already published association rules post-processing methods. The output of the introduced new method are clusters of rules, which cannot be reached by any of former post-processing methods. According user expectations clusters are more relevant and more effective than any former association rules clustering results. The method is based on two orthogonal clustering of the same set of association rules. One clustering is based on interestingness measures (confidence, support, interest, etc.). Second clustering is inspired by document clustering in information retrieval. The representation of rules in vectors like documents is fontal in this thesis. The thesis is organized as follows. Chapter 2 identify the role of association rules in the KDD (knowledge discovery in databases) process, using KDD methodologies (CRISP-DM, SEMMA, GUHA, RAMSYS). Chapter 3 define association rule and introduce characteristics of association rules (including interestingness measuress). Chapter 4 introduce current association rules post-processing methods. Chapter 5 is the introduction to cluster analysis. Chapter 6 is the description of the new Multicriterial clustering association rules method. Chapter 7 consists of several experiments. Chapter 8 discuss possibilities of usage and development of the new method.

The aim of the first part of this thesis is to explain the theoretical basis of transmission electron microscopy and to mention fundamental parts of transmission electron microscopes. The next part of this work is focused on possible methods of image segmentation, the use of neural networks in the detection of objects in an image and the subsequent clustering of results. The theoretical part of the thesis is concluded with an explanation of some already published methods of automatic detection of biological structures in microscopic images and theoretical design of the algorithm, which will be subsequently developed. The process of training neural networks in order to automatically detect biological structures in an image is described at the beginning of the practical part. This is followed by an evaluation of the results achieved by these networks. Subsequently, cluster analysis methods are applied to these results, the products of which are compared with each other and also with the results obtained by already published methods.

Master thesis deals with dividing destricts of the Czech Republic in to clusters acording to demographic indicators during the year 2011. After the theoretical introduction with exploratory data analyiss, factor analysis and cluster analysis is described practical implementation of agglomerative hierarchical clustering. Within the frame cluster analysis we compare results calculated by four methods of clustering, which are the single linkage method, the complete linkage method, the average linkage method and Ward's method. At the conclusion we select the method which divides destricts of the Czech Republic in to the clusters the best. Master thesis includes a prezentations of discovere results with the help of dendrograms and cartograms. The analysis were carried out with the help of the statistical program STATISTICA.

The main purpose of this master's thesis is to propose and implement a SAP CAR (customer activity repository) solution as an application into the current enterprise information system. Following the analysis of the existing system, there will be a solution created, which is fulfilling the customer demands and at the same time it is feasible under given conditions and in the current environment. This project is closely related with addressing the disaster recovery issue for making the system highly available. The final design is implemented, tested and then handed over to the customer.

The thesis is focused on an introduction of data mining. Data mining is focused on finding of a hidden data correlation. Interest in this area is dated back to the 60th the 20th century. Data analysis was first used in marketing. However, later it expanded to more areas, and some of its options are still unused. One of methodologies is useful used for creating of this process. Methodology offers a concise guide on how you can create a data mining procedure. The data mining analysis contains a wide range of algorithms for data modification. The interest in data mining causes that number of data mining software is increasing. This thesis contains overviews some of this programs, some examples and assessment.

We present a detailed, multi-wavelength study of star formation (SF) and active galactic nucleus (AGN) activity in 11 near-infrared (IR) selected, spectroscopically confirmed massive (greater than or similar to 10(14)M(circle dot)) galaxy clusters at 1 < z < 1.75. Using new deep Herschel/PACS imaging, we characterize the optical to far-IR spectral energy distributions (SEDs) for IR-luminous cluster galaxies, finding that they can, on average, be well described by field galaxy templates. Identification and decomposition of AGNs through SED fittings allows us to include the contribution to cluster SF from AGN host galaxies. We quantify the star-forming fraction, dust-obscured SF rates (SFRs) and specific SFRs for cluster galaxies as a function of cluster-centric radius and redshift. In good agreement with previous studies, we find that SF in cluster galaxies at z greater than or similar to 1.4 is largely consistent with field galaxies at similar epochs, indicating an era before significant quenching in the cluster cores (r < 0.5 Mpc). This is followed by a transition to lower SF activity as environmental quenching dominates by z similar to 1. Enhanced SFRs are found in lower mass (10.1< logM(kappa)/M-circle dot < 10.8) cluster galaxies. We find significant variation in SF from cluster to cluster within our uniformly selected sample, indicating that caution should be taken when evaluating individual clusters. We examine AGNs in clusters from z = 0.5-2, finding an excess AGN fraction at z greater than or similar to 1, suggesting environmental triggering of AGNs during this epoch. We argue that our results-a transition from field-like to quenched SF, enhanced SF in lower mass galaxies in the cluster cores, and excess AGNs-are consistent with a co-evolution between SF and AGNs in clusters and an increased merger rate in massive halos at high redshift.

We study the galaxy populations in 74 Sunyaev-Zeldovich effect selected clusters from the South Pole Telescope survey, which have been imaged in the science verification phase of the Dark Energy Survey. The sample extends up to z similar to 1.1 with 4 x 10(14)M(circle dot) <= M-200 <= 3 x 10(15)M(circle dot). Using the band containing the 4000 angstrom break and its redward neighbour, we study the colour-magnitude distributions of cluster galaxies to similar to m(*) + 2, finding that: (1) The intrinsic rest frame g - r colour width of the red sequence (RS) population is similar to 0.03 out to z similar to 0.85 with a preference for an increase to similar to 0.07 at z = 1, and (2) the prominence of the RS declines beyond z similar to 0.6. The spatial distribution of cluster galaxies is well described by the NFW profile out to 4R(200) with a concentration of c(g) = 3.59(-0.18)(+0.20), 5.37(-0.24)(+0.27) and 1.38(-0.19)(+0.21) for the full, the RS and the blue non-RS populations, respectively, but with similar to 40 per cent to 55 per cent cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region N-200 exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The RS fraction within R-200 is (68 +/- 3) per cent at z = 0.46, varies from similar to 55 per cent at z = 1 to similar to 80 per cent at z = 0.1 and exhibits intrinsic variation among

This masters thesis has a few objectives. One of them is to acquaint with the problems of genome engineering, especially with fragmentation of DNA, the macromolecule DNA, the methods for purification and separation of the nucleic acids, the enzymes used for modification of these acids, amplification and get to know with cluster and gradient analysis as well. The next aim is to peruse the existed application and compare it to the layout of the proposed application, that is the third aim. The last one from the objectives is the implementation and the report how was the application tested by the real data. The results will be discussed as well as the possibilities of the further extension.

Briser la frontière observationnelle de l’Univers lointain suscite de nombreux axes de recherches dans la cosmologie moderne. Exigeantes par la sensibilité demandée, ces observations constituent aussi bien un défi technologique pour les prochaines générations d’instruments qu’une étape nécessaire à la compréhension des différentes étapes d’évolution de l’Univers. Une des étapes importantes est la réionisation du milieu intergalactique, époque charnière marquant la fin des “Âges Sombres”. Déterminer quand et comment ce processus s’est déroulé et quelles ont été les sources l’ayant déclenché et entretenu sont les principales questions motivant ces recherches. Les travaux présentés dans cette thèse participent à l’effort de la communauté scientifique internationale dans la caractérisation de l’histoire de l’époque de la réionisation en recherchant des galaxies à grand décalage spectral vers le rouge (redshift). Après un panorama complet des contraintes observationnelles actuelles sur l’époque de la réionisation, sont ensuite présentés les deux projets ayant fournis les données constituant la matière première de cette analyse. En utilisant une même technique d’imagerie en bande étroite dans le domaine de longueurs d’onde proche-infrarouge, des observations avec l’instrument WIRCAM (CFHT) et d’autres avec l’instrument HAWK-I (VLT) ont permis d’établir des contraintes robustes sur la fonction deluminosité des Emetteurs Lyman-α au redshift z = 7.7. A l’occasion de la présentation du second projet, la problématique de la stratégie observationnelle est abordée, notamment via l’utilisation des amas de galaxies comme lentilles gravitationnelles amplifiant le flux des sources d’arrière-plan. L’absence de confirmation spectroscopique des Emetteurs Lyman-– sélectionnés durant l’analyse des données WIRCAM et l’absence de candidats dans le sondage HAWK-I suggèrent une évolution de la fonction de luminosité des Emetteurs Lyman-– entre les redshifts z = 6.5, telle quedéterminée dans d’autres études, et z = 7.7. La tendance de cette évolution, en luminosité ou en densité de galaxies, ne peut pas encore être déterminée compte tenu de la variabilité des résultats obtenus à plus bas redshift. Si cette évolutions’effectuait en luminosité, ce pourrait être le signe d’une augmentation de l’opacité du milieu intergalactique au rayonnement Lyman-α causée par une plus importante fraction d’hydrogène neutre, ce qui est une signature attendue de la réionisation
Breaking through the observational frontier of the distant universe motivates numerous scientific cases in modern cosmology. Demanding by the required sensitivity, high-redshift observations provide both a technological challenge for next generation instruments and a necessary step toward the understanding of cosmic evolution. One critical epoch is the reionization of the intergalactic medium bringing to light the end of the so-called “Dark Ages”. Determine when and how this process took place and what were the sources that started and maintained the reionization are the mainquestions motivating this research. The work presented in this thesis contributes to the effort of the internationalscientific community in characterizing the reionization epoch history by searching for galaxies at high redshift. First, I describe the current observational constraints in a comprehensive chapter. Then the two datasets used in that work are presented. From narrow-band observations in the near-infrared with WIRCAM at the CFHT and HAWK-I at the VLT, I put strong constraints on the luminosity function of Lyman-α Emitters at z = 7.7. The best strategy for this type of survey is discussed, in particular with the use of massive galaxy clusters acting as gravitational lenses that amplify the flux from background sources. The lack of spectroscopic confirmation of candidates found with WIRCAM and the lack of candidates found with HAWK-I suggest an evolution of the luminosity function from z = 6.5. This evolution could be either in luminosity or in number density but somewhat discrepant results at lower redshift prevent any definitive answer to this question. If the evolution was mostly in luminosity, it could be interpreted as an increase in the opacity of the intergalactic medium caused by an increased fraction of neutral hydrogen, which is an expected signature of reionization

The main task of this thesis was a statistical study of lion roar wave emissions in the Earth's magnetosheath. Large data set obtained from the Cluster spacecraft has been used. We have studied a frequency distribution, a wave power distribution and a spatial distribution. We have investigated propagation characteristics using advanced methods applied on multi-components measurement. We have confirmed the narrow-band structure of lion roars. We have compared observed and estimated (from the cold plasma theory) time lags between spacecraft during short separations.

Este estudo pretende contribuir para avaliação dos hábitos alimentares das crianças e jovens através do comportamento alimentar diário utilizando métodos estatísticos. No âmbito de um projeto promovido pela a Associação Portuguesa Promotora de Saúde e Higiene Oral (APPSHO) foi analisada uma amostra de 152 indivíduos com idades compreendidas entre os 5 e os 19 anos de idade do Agrupamento de escolas do concelho do Seixal. Neste trabalho propôs-se analisar o estado nutricional, utilizando a informação disponível sobre o Z-score ajustado às idades das crianças e jovens em estudo e investigar associações e fatores determinantes deste índice. Ao longo do estudo foram procuradas e aplicadas metodologias de Estatística Univariada e Bivariada mais usuais para comparação de grupos e estudo de associações, e utilizaram-se também, modelos multivariados essencialmente descritivos e exploratórios. Neste âmbito, recorreu-se à Análise de Escalonamento Multidimensional (MDS) de forma a caraterizar o consumo alimentar das crianças e jovens em determinadas refeições. A Análise de Clusters (AC) foi aplicada com o intuito de verificar a existência de agrupamentos dos diversos tipos de alimentos consumidos. Aprofundou-se o estudo com a Análise Fatorial (AF) pelo método das Componentes Principais (CP), com o objetivo de identificar, com base na frequência do consumo, padrões alimentares no grupo de indivíduos. Consequentemente, foram encontrados dois padrões alimentares, denominados por “padrão misto” e “padrão ocidental”. Apontam-se algumas limitações relacionadas com a amostra e as variáveis em estudo e algumas recomendações para estudos futuros, no que respeita ao tipo de dados a solicitar no questionário e às variáveis a incluir na investigação.
This study aims to contribute to the evaluation of the eating habits of children and youngsters through daily dietary behavior using statistical methods. In the context of a project promoted by the Portuguese Association for the Promotion of Oral Health and Hygiene (APPSHO), a sample of 152 individuals aged between 5 and 19 years of age from the School Group of the municipality of Seixal was analyzed. The objective of this study was to analyze the nutritional status using the information available on the Z-score adjusted to the ages of the children and youngsters in the study and to investigate associations and determinants of this index. Throughout the study, most common Univariate and Bivariate Statistics methodologies were used to compare groups and study associations, and multivariate, essentially descriptive and exploratory models were also used. In this context, Multidimensional Scaling Analysis (MDS) was used in order to characterize the food consumption of children and young people in certain meals. The Cluster Analysis (CA) was applied in order to verify the existence of clusters of the different types of food consumed. The study with the Factorial Analysis (PA) was deepened by the Principal Components (CP) method, aiming to identify, based on the frequency of consumption, food patterns in the group of individuals. Consequently, two dietary patterns, called "mixed pattern" and "western standard", were found. Some limitations related to the sample and variables under study and some recommendations for future studies are pointed out, regarding the type of data to be requested in the questionnaire and the variables to be included in the research.

This thesis focuses on the topic of VAT in EU member states. The aim is to specify groups of member states in accordance to the significance of VAT in national tax systems and to identify factors, which may affect the grouping process. The hierarchical method of cluster analysis based on the 1995, 2002, 2009 and 2017 data is used for sorting states into similarity-based groups. Macroeconomic indicators characterizing VAT are chosen for cluster analysis: VAT per capita, VAT share of GDP, VAT share of total tax revenues, Standard rate and Average reduced rate. Development of cluster structure during the period discovers an increasing number of states separated into one-member clusters for their remarkable dissimilarity. It also indicates, that member states classification as OMS or NMS still remains a significant factor of the clustering process. So-called old and new member states seem to appear together in one cluster rarely. Testing of hypothesis of VAT convergence concerning 28 EU member states during 1995-2017 (in the field of chosen variables) is another sub-target of this paper. Via application of basic statistics on timeline data, and especially evaluation of coefficient of variation development, the hypothesis of VAT convergence in the EU during years 1995-2017 is proven.

This thesis is concerned with a comparison of excise duty on tobacco products in the Czech Republic and the member countries of the European Union. Its aim is to find groups of countries with similar indicators, to explore the similarities between these countries and to try to identify the possible effects that may cause differences. The thesis is divided into two parts. The theoretical part is focused on the characteristics of excise duties and primarily on excise duty on tobacco products. It deals with European Commission directives and minimum excise rates. The practical part deals with selected indicators related to excise duty on tobacco products. These indicators are excise duty on tobacco products as percentage of GDP and percentage of total taxation, specific excise per 1 000 cigarettes as percentage of WAP and excise yield in EUR per 1 000 cigarettes of the WAP. The last indicator is cigarettes consumption per capita, which is not included in the analysis. Data is processed by cluster analysis for the years 2003 and 2014 in computer software STATISTICA 12. The task of cluster analysis is to find groups of countries which are similar. The results of cluster analysis are described in the next chapters. The differences of the individual clusters and the possible influences that these differences may have caused are also described in the last chapters.

This thesis deals with the consumption taxes changes in the Member States of EU in relation with the harmonization process. Its goal is to find out via chosen indicators, whether the influence of the harmonization processes in an area of value added taxes and excise duty, brings Member States of EU closer in an area of consumption taxation. As the main method of data processing is used the cluster analysis for which three indicators of tax burden are selected. Via analysis the cluster processes are used in selected years 2000 and 2017. All Member States are included with the exception of Croatia and that is because absence of the data. The data that are used in the cluster analysis are extracted from the Eurostat and from the database of European Commission. The states are divided according to the similarity of taxation into particular clusters. The results are presented in a form of graphical outputs the so called dendrograms. The conclusion is comparison of researched years according to the harmonization process. According to the cluster analysis results gained via selected consumption tax indicators, there is no converge occurring in 2000 to 2017 between original EU-15 states and the new Member States which have joined EU in 2004 or later.

The study is concerned with corporate income taxes in the European Union and comparison these taxation systems. The theoretical part includes development of the harmonisation of the direct tax in the EU and a common consolidated corporate tax base. The study proceeds with the description of the corporate taxation system of the member states. The practical part is mainly dedicated to analysis of these taxation systems of the member countries. It describes elements of corporate income tax legislative and implicit tax rate and share corporate income tax on taxation mix. The analysis is processed in the computer program STATISTICA. The classify is made by cluster analysis that should find the similar taxation system. In conclusion, there are pointed out differences between member countries and an identification of the effects that cause differences.

Within the degree of master, follows a consulting project, made for the multinational Teixeira Duarte, S.A, which has been struggling along with every company in the sector, with the lack of vocational manpower. Therefore, it is working together with other multinationals in the sector, under the project of PTPC of rebranding the construction sector. With the aim of bringing attractiveness into construction, in order to attract Generation Z and its advisors, the main goals are to collect target’s knowledge and perceptions towards construction, to identify the most valuable factors at work among the target, to determine which variables need to be enhanced to the target and to identify the most suitable communication strategy and educational practices among the target. For that purpose, a focus group and an online survey, whose results were analyzed by a factor analysis and a cluster analysis, were conducted, offering as main recommendations: the implementation of specialized courses with internships and well-known sponsorships; the communication of a sector where it is possible to build a career and to get a higher salary to the younger generations; the communication of some assurances to the older generation, concerned about stability; the use of communication techniques to improve constructions’ image.

The present dissertation has for subject "The importance of creative clusters in Music Industry", but also takes in consideration the Microclimatic music scene case of Leiria, a city in the centre of Portugal. Music always have defined and influenced societies. Nowadays, it still plays a major role in modern society, but also has a profound and meaningful position in the world’s economy. Following this idea, it is purposed to consider the definition and context of Music Industry, to better understand how it influences the all market behind and how it interacts with companies and organizations that can be related to music. It was of interest to understand how Music scenes arise in certain geographic areas, once they have been one of the steps to have a greater understanding of the importance of clustering geographically, and its influences in the development of regional economic growth, where some scenarios were taken in account. The following chapter refers to creative industries and creative clusters, where it is searched the importance of creative industries to cluster and its influences in communities around. The last chapter takes in account the music scene in Leiria, how it aroused and the influences on the community. Finally, it was conducted a survey for music bands/music artists, creatives, producers, agents and promoters, to understand, what are, in fact, the importance's of creative collectives in producing and collaborating with music bands/music artists on their works.
A presente dissertação tem como título "A importância das aglomerações de criativos na Indústria da Música", mas considera, também, o caso do Microclima do cenário musical de Leiria, uma cidade no centro de Portugal. A música sempre definiu e influenciou sociedades. Nos dias de hoje, ainda tem um papel bastante importante na Sociedade moderna, mas tem, também, uma profunda e significante posição na economia mundial. Através desta ideia, é proposto a consideração da definição e contexto da Indústria da Música, para melhor perceber como influencia todo o mercado envolvente, e como interage com empresas e organizações que podem estar relacionadas com música. Revelou ser de interesse, perceber de que forma crescem alguns cenários musicais, em certas áreas geográficas, uma vez que estes foram dos principais passos para ter uma maior compreensão da importância de aglomerações geográficas, assim como das suas influências no desenvolvimento do crescimento económico regional. Alguns cenários, são tidos em consideração. O seguinte capítulo refere-se às Indústrias criativas e às aglomerações criativas, onde se procura perceber a importância de aglomerações entre Indústrias criativas, assim como das suas influências nas comunidades adjacentes. Por último, é conduzido um questionário para bandas musicais/artistas musicais, criativos, produtores, agentes e promotores, para melhor perceber, qual é de fato, a importância dos coletivos de criativos na produção e colaboração em trabalhos para bandas musicais/artistas musicais.

Clusters of galaxies represent the largest laboratories in the universe for testing the incredibly chaotic physics governing the collapse of baryons into the stars, galaxies, groups, and diffuse clouds that we see today. Within the cluster environment, there are a wide variety of physical processes that may be acting to transform galaxies.

In this thesis, we combine extensive Keck spectroscopy with wide-field HST imaging to perform a detailed case study of two intermediate redshift galaxy clusters, Cl 0024+1654 (z=0.395) and MS 0451-03 (z=0.540). Leveraging a comprehensive multiwavelength data set that spans the X-ray to infrared, and with spectral-line measurements serving as the key to revealing both the recent star-formation histories and kinematics of infalling galaxies, we aim to shed light on the environmental processes that could be acting to transform galaxies in clusters.

We adopt a strategy to make maximal use of our HST-based morphologies by splitting our sample of cluster galaxies according to morphological type, characterizing signs of recent evolution in spirals and early types separately. This approach proves to be powerful in identifying galaxies that are currently being altered by an environmental interaction: early-type galaxies that have either been newly transformed or prodded back into an active phase, and spiral galaxies where star formation is being suppressed or enhanced all stand out in our sample.

We begin by using variations in the early-type galaxy population as indicators of recent activity. Because ellipticals and S0s form such a homogeneous class in the local universe, we are sensitive to even very subtle signatures of recent and current environmental interactions. This study has yielded two key results: By constructing the Fundamental Plane (FP) of Cl 0024, we observe that elliptical and S0 galaxies exhibit a high scatter in their FP residuals, which occurs only among galaxies in the cluster core, suggesting a turbulent assembly history for Cl 0024 early types. Near the Virial radius of Cl 0024, we observe a number of compact, intermediate-mass ellipticals undergoing a burst of star formation or weak AGN activity, indicated by strong [O II] emission; their locations may mark the minimum radius at which merging is effective in each cluster.

While E+S0 galaxies do prove to be sensitive indicators of environmental interaction, it is the spiral galaxies that, of course, host the bulk of star formation within and around these clusters. We therefore probe for kinematic disturbances in spiral disks by measuring resolved rotation curves from optical emission lines, and constructing the Tully-Fisher relation for spirals across Cl 0024 and MS 0451. We find that the cluster Tully-Fisher relation exhibits significantly higher scatter than the field relation. In probing for the origin of this difference, we find that the central mass densities of star-forming spirals exhibit a sharp break near the cluster Virial radius, with spirals in the cluster outskirts exhibiting significantly lower densities. We argue that these results considered together demonstrate that cluster spirals are kinematically disturbed by their environment, likely due to galaxy-galaxy interactions (harassment).

We then discuss our most powerful method of tracking galaxy evolution across Cl 0024 and MS 0451: identifying and studying "transition galaxies"-galaxies whose stellar populations or dynamical states indicate a recent or ongoing change in morphology or star formation rate. Such galaxies are often revealed by star formation histories that seem to be at odds with the galaxy morphologies: for example, spiral galaxies with no signs of star formation, or elliptical galaxies that do show signs of star formation.

We identify and study one such class of objects, the "passive spirals" in Cl 0024. These objects exhibit no emission lines in their spectra, suggesting a lack of star formation, yet are surprisingly detected in the UV, revealing the presence of young stars. By modeling the different temporal sensitivities of UV and spectroscopic data to recent activity, we show that star formation in Cl 0024 passive spirals has decayed on timescales of less than 1 Gyr, consistent with the action of "gas starvation".

We then build on and link together our previous indications of galaxy evolution at work, aiming to piece together a more comprehensive picture of how cluster galaxies are affected by their environment at intermediate redshift. To accomplish this, we document what we believe to be the first direct evidence for the transformation of spirals into S0s: through an analysis of their stellar populations and recent star formation rates, we link the passive spiral galaxies in both clusters to their eventual end states as newly generated cluster S0 galaxies. Differences between the two clusters in both the timescales and spatial location of this conversion process allow us to evaluate the relative importance of several proposed physical mechanisms that could be responsible for the transformation. Combined with other diagnostics that are sensitive to either ICM-driven galaxy evolution or galaxy-galaxy interactions, we describe a self-consistent picture of galaxy evolution in clusters.

We find that spiral galaxies within infalling groups have already begun a slow process of conversion into S0s primarily via gentle galaxy-galaxy interactions that act to quench star formation. The fates of spirals upon reaching the core of the cluster depend heavily on the cluster ICM, with rapid conversion of all remaining spirals into S0s via ram-pressure stripping in clusters where the ICM is dense. In the presence of a less-dense ICM, the conversion continues at a slower pace, with galaxy-galaxy interactions continuing to play a role along with "starvation" by the ICM. We conclude that the buildup of the local S0 population through the transformation of spiral galaxies is a heterogeneous process that nevertheless proceeds robustly across a variety of different environments from cluster outskirts to cores.

Trichomonas vaginalis is flagelated microaerophilic protozoan parasite from Excavata group, which causes trichomoniasis, the most common nonviral sexually transmitted disease in the world. It causes vaginitis in women and uretritis in man and it can also cause problems for example during pregnancy. This thesis is aimed on the characterisation of hydrogenosomal iron-sulfur flavoproteins (ISF) from Trichomonas vaginalis, proteins, which were only recently discovered in the proteome of hydrogenosome of T. vaginalis. Specifically, we have focused on characterisation of ISF3 which is, according to our data, active homodimer and binds flavin mononucleotide (FMN) and iron-sulphur centre in its active site. The iron- sulphur centre is not characterised yet. ISF3 is able to reduce oxygen, hydrogen peroxide, sodium nitrate and metronidazole also in the enzymatic system with PFO and ferredoxin. Next, I tried to reduce ammonium sulphate with ISF3, but unsuccessfully. These results correspond with the activities obtained for ISF from Methanosarcina thermophila, where ISF reduces oxygen and hydrogen peroxide to water. In addition, ISF3 is able to reduce nitrogen compounds. It is important according to the fact, that metronidazole is a drug from the group of 5−nitroimidazoles. The other results show the decrease...

In five thematic sections was realized the cluster analysis which is one of more-dimensional statistical methods. In the base of monitored indexes in thematic sections were identified the general, significant attributes and differences chosen regions. In the base of results of quantitative analyses was made the SWOT analysis and elaborated the recommendations to increase their attractivity.

We conduct a deep mid-infrared census of nine massive galaxy clusters at (0 < z < 1.3) with a total of ~ 1500 spectroscopically confirmed member galaxies using Spitzer /IRAC photometry and established mid-infrared color selection techniques. Of the 949 cluster galaxies that are detected in at least three of the four IRAC channels at the >= 3 sigma level, we identify 12 that host mid-infrared selected active galactic nuclei (IR-AGN). To compare the IR-AGN across our redshift range, we define two complete samples of cluster galaxies: (1) optically-selected members with rest-frame VAB magnitude < -21.5 and (2) mid-IR selected members brighter than (M*_3.6 +0.5), i.e. essentially a stellar mass cut. In both samples, we measure f_IR-AGN ~ 1% with a strong upper limit of ~3% at z < 1. This uniformly low IR-AGN fraction at z < 1 is surprising given the fraction of 24 micrometer sources in the same galaxy clusters is observed to increase by about a factor of four from z ~ 0 to z ~ 1; this indicates that most of the detected 24 micrometer flux is due to star formation. Only in our single galaxy cluster at z = 1.24 is the IR-AGN fraction measurably higher at ~15% (all members; ~70% for late-types only). In agreement with recent studies, we find the cluster IR-AGN are predominantly hosted by late-type galaxies with blue optical colors, i.e. members with recent/ongoing star formation. The four brightest IR-AGN are also X-ray sources; these IR+X-ray AGN all lie outside the cluster core (R_proj > 0.5 Mpc) and are hosted by highly morphologically disturbed members. Although our sample is limited, our results suggest that f_IR-AGN in massive galaxy clusters is not strongly correlated with star formation at z < 1, and that IR-AGN have a more prominent role at z > 1.