Дисертації з теми "Open cluster and associations"
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Balog, Zoltan, Nick Siegler, G. H. Rieke, L. L. Kiss, James Muzerolle, R. A. Gutermuth, Cameron P. M. Bell, et al. "PROTOPLANETARY AND TRANSITIONAL DISKS IN THE OPEN STELLAR CLUSTER IC 2395." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/622451.
Повний текст джерелаLim, Beomdu, Hwankyung Sung, Jinyoung S. Kim, Michael S. Bessell, Narae Hwang, and Byeong-Gon Park. "A CONSTRAINT ON THE FORMATION TIMESCALE OF THE YOUNG OPEN CLUSTER NGC 2264: LITHIUM ABUNDANCE OF PRE-MAIN SEQUENCE STARS." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/622162.
Повний текст джерелаMessina, Angela Elisa. "Chromospheric activity and lithium abundance in the NGC2516 and NGC3766 open clusters." Thesis, Università degli Studi di Catania, 2011. http://hdl.handle.net/10761/212.
Повний текст джерелаDa, Rio Nicola, Jonathan C. Tan, Kevin R. Covey, Michiel Cottaar, Jonathan B. Foster, Nicholas C. Cullen, John Tobin, et al. "IN-SYNC. V. Stellar Kinematics and Dynamics in the Orion A Molecular Cloud." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/625776.
Повний текст джерелаJoner, Michael Deloss. "High-Quality Broadband BVRI Photometry of Benchmark Open Clusters." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2495.
Повний текст джерелаAn, Deokkeun. "Improving the Local Distance Scale from Empirically Calibrated Stellar Isochrones." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1218593380.
Повний текст джерелаEisner, J. A., J. M. Bally, A. Ginsburg, and P. D. Sheehan. "PROTOPLANETARY DISKS IN THE ORION OMC1 REGION IMAGED WITH ALMA." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621374.
Повний текст джерелаSpitoni, Emanuele. "The effects of galactic fountains on the chemical evolution of galaxies." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3435.
Повний текст джерелаIn this thesis we study the effect of galactic fountains, namely gas and flows from the disk of galaxies produced by multiple supernova explosions, on the chemical evolution of galaxies. Sequential supernova explosions create a superbubble, whereas the swept up interstellar medium is concentrated in a supershell which can break out a stratified medium, producing bipolar outflows. The gas of the supershells can fragment into clouds which eventually fall toward the disk producing so-called galactic fountains. Many works in literature have dealt with superbubble expansion in stratified media. However, very few papers in the past have taken into account the chemical evolution of the superbubble and how the supershell get polluted from the metals produced by supernova explosions. With this thesis for the first time the effect of galactic fountains we consider in a detailed chemical evolution model for the Milky Way. In the first part of our work we study the expansion law and chemical enrichment of a supershell powered by the energetic feedback of a typical Galactic OB association at various galactocentric radii. We follow the orbits of the fragments created when the supershell breaks out and we compare their kinetic and chemical properties with the available observations of high - and intermediate - velocity clouds. We use the Kompaneets (1960) approximation for the evolution of the superbubble driven by sequential supernova explosions and we compute the abundances of oxygen and iron residing in the thin cold supershell. Due to Rayleigh-Taylor instabilities we assume that supershells are fragmented and we follow the orbit of the clouds either ballistically or by means of a hybrid model considering viscous interaction between the clouds and the extra-planar gas. We find that if the initial metallicity is solar, the pollution from the dying stars of the OB association has a negligible effect on the chemical composition of the clouds. The maximum height reached by the clouds above the plane seldom exceeds 2 kpc and when averaging over different throwing angles, the landing coordinate differs from the throwing coordinate by only 1 kpc. Therefore, it is unlikely that galactic fountains can affect abundance gradients on large scales. The range of heights and [O/Fe] ratios spanned by our clouds suggest that the high velocity clouds cannot have a Galactic origin, whereas intermediate velocity clouds have kinematic properties similar to our predicted clouds but have observed overabundances of the [O/Fe] ratios that can be reproduced only with initial metallicities which are too low compared to those of the Galaxy disk. Even if it is unlikely that galactic fountains can affect abundance gradients on large scales, they can still affect the chemical enrichment of the interstellar medium (ISM) because of the time-delay due to the non-negligible time taken by fountains to orbit around and fall back into the Galaxy. This implies a delay in the mixing of metals in ISM which conflicts with the instantaneous mixing approximation usually assumed in all models in literature. We test whether relaxing this approximation in a detailed chemical evolution model can improve or worsen the agreement with observations. To do that, we investigate two possible causes for relaxing of the instantaneous mixing: i) the ``galactic fountain time delay effect'' and ii) the ``metal cooling time delay effect''. We find that the effect of galactic fountains is negligible if an average time delay of 0.1 Gyr, as suggested by our model, is assumed. Longer time delays produce differences in the results but they are not realistic. The metal cooling time delays produce strong effects on the evolution of the chemical abundances only if we adopt stellar yields depending on metallicity. If, instead, the yields computed for the solar chemical composition are adopted, negligible effects are produced, as in the case of the galactic fountain delay. The relaxation of the IMA by means of the galactic fountain model, where the delay is considered only for massive stars and only in the disk, does not affect the chemical evolution results. The combination of metal dependent yields and time delay in the chemical enrichment from all stars starting from the halo phase, instead, produces results at variance with observations.
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Kiminki, Megan M., Nathan Smith, Megan Reiter, and John Bally. "Proper motions of five OB stars with candidate dusty bow shocks in the Carina Nebula." OXFORD UNIV PRESS, 2017. http://hdl.handle.net/10150/624060.
Повний текст джерелаBell, Cameron Pearce MacDonald. "A critical assessment of ages derived using pre-main-sequence isochrones in colour-magnitude diagrams." Thesis, University of Exeter, 2012. http://hdl.handle.net/10036/4017.
Повний текст джерелаOlivares, Romero Javier. "Modélisation hiérarchique bayésienne des amas stellaires jeunes." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY071/document.
Повний текст джерелаThe origin and evolution of stellar populations is one of the greatest challenges in modern astrophysics. It is known that the majority of the stars has its origin in stellar clusters (Carpenter 2000; Porras et al. 2003; Lada & Lada 2003). However, only less than one tenth of these clusters remains bounded after the first few hundred million years (Lada & Lada 2003). Ergo, the understanding of the origin and evolution of stars demands meticulous analyses of stellar clusters in these crucial ages.The project Dynamical Analysis of Nearby Clusters (DANCe, Bouy et al. 2013), from which the present work is part of, provides the scientific framework for the analysis of Nearby Young Clusters (NYC) in the solar neighbourhood (< 500 pc). The DANCe carefully designed observations of the well known Pleiades cluster provide the perfect case study for the development and testing of statistical tools aiming at the analysis of the early phases of cluster evolution.The statistical tool developed here is a probabilistic intelligent system that performs Bayesian inference for the parameters governing the probability density functions (PDFs) of the cluster population (PDFCP). It has been benchmarked with the Pleiades photometric and astrometric data of the DANCe survey. As any Bayesian framework, it requires the setting up of priors. To avoid the subjectivity of these, the intelligent system establish them using the Bayesian Hierarchical Model (BHM) approach. In it, the parameters of prior distributions, which are also inferred from the data, are drawn from other distributions in a hierarchical way.In this BHM intelligent system, the true values of the PDFCP are specified by stochastic and deterministic relations representing the state of knowledge of the NYC. To perform the parametric inference, the likelihood of the data, given these true values, accounts for the properties of the data set, especially its heteroscedasticity and missing value objects. By properly accounting for these properties, the intelligent system: i) Increases the size of the data set, with respect to previous studies working exclusively on fully observed objects, and ii) Avoids biases associated to fully observed data sets, and restrictions to low-uncertainty objects (sigma-clipping procedures).The BHM returns the posterior PDFs of the parameters in the PDFCPs, particularly of the spatial, proper motions and luminosity distributions. In the BHM each object in the data set contributes to the PDFs of the parameters proportionally to its likelihood. Thus, the PDFCPs are free of biases resulting from typical high membership probability selections (sampling bias).As a by-product, the BHM also gives the PDFs of the cluster membership probability for each object in the data set. These PDFs together with an optimal probability classification threshold, which is obtained from synthetic data sets, allow the classification of objects into cluster and field populations. This by-product classifier shows excellent results when applied on synthetic data sets (with an area under the ROC curve of 0.99). From the analysis of synthetic data sets, the expected value of the contamination rate for the PDFCPs is 5.8 ± 0.2%.The following are the most important astrophysical results of the BHM applied tothe Pleiades cluster. First, used as a classifier, it finds ∼ 200 new candidate members, representing 10% new discoveries. Nevertheless, it shows outstanding agreement (99.6% of the 105 objects in the data set) with previous results from the literature. Second, the derived present day system mass distribution (PDSMD) is in general agreement with the previous results of Bouy et al. (2015).Thus, by better modelling the data set and eliminating unnecessary restrictions to it, the new intelligent system, developed and tested in the present work, represents the state of the art for the statistical analysis of NYC populations
Manara, C. F., L. Testi, G. J. Herczeg, I. Pascucci, J. M. Alcalá, A. Natta, S. Antoniucci, et al. "X-shooter study of accretion in Chamaeleon I." EDP SCIENCES S A, 2017. http://hdl.handle.net/10150/625828.
Повний текст джерелаBurgess, Andrew. "Exploration de la fonction de faible masse initiale dans les amas jeunes et les r ´egions de formation stellaire." Phd thesis, Université de Grenoble, 2010. http://tel.archives-ouvertes.fr/tel-00576460.
Повний текст джерелаMiret, Roig Núria. "COSMIC-DANCE : A comprehensive census of nearby star forming regions." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0327.
Повний текст джерелаUnderstanding how stars form is one of the fundamental questions which astronomy aims to answer. Currently, it is well accepted that the majority of stars form in groups and that their predominant mechanism of formation is the core-collapse. However, several mechanisms have been suggested to explain the formation of substellar objects, and their contribution is still under debate. The main goal of this thesis is to determine the initial mass function, the mass distribution of stars at birth time, in different associations and star-forming regions. The mass function constitutes a fundamental observational parameter to constrain stellar and substellar formation theories since different formation mechanisms predict different fraction of stellar and substellar objects. We used the Gaia Data Release 2 catalogue together with ground-based observations from the COSMIC-DANCe project to look for high probability members via a probabilistic model of the distribution of the observable quantities in both the cluster and background populations. We applied this method to the 30 Myr open cluster IC 4665 and the 1 - 10 Myr star-forming region Upper Scorpius (USC) and r Ophiuchi (r Oph). We found very rich populations of substellar objects which largely exceed the numbers predicted by core-collapse models. In USC, where our sensitivity is best, we found a large number of free-floating planets and we suggest that ejection from planetary systems must have a similar contribution than core-collapse in their formation. The age is a fundamental parameter to study the formation and evolution of stars and is essential to accurately convert luminosities to masses. For that, we also presented a strategy to study the dynamical traceback age of young local associations through an orbital traceback analysis. We applied this method to determine the age of the b Pictoris moving group and in the future, we plan to apply it to other regions such as USC. The members we identified with the membership analysis are excellent targets for follow-up studies such as a search for discs, exoplanets, characterisation of brown dwarfs and free-floating planets. I this thesis, we presented a search for discs hosted by members of IC 4665 and we found six excellent candidates to be imaged with ALMA or the JWST. The tools we developed, are ready to be used in other regions such as USC and r Oph, where we expect to find a larger number of disc-host stars
Chappelle, R. J. "Brown dwarfs in the Praesepe open cluster." Thesis, Liverpool John Moores University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431263.
Повний текст джерелаAlbers, Cory David. "Hydraulics of a three obstacle cluster in open channels." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq21149.pdf.
Повний текст джерелаChristensen, Kirsten Elvira. "Open-Framework Germanates : Crystallography, structures and cluster building units." Doctoral thesis, Stockholm : Department of Physical, Inorganic and Structural Chemistry, Stockholm university, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7501.
Повний текст джерелаAfonso, Mário João da Costa. "Clopencl (opencl para ambiente cluster)." Master's thesis, Instituto Politécnico de Bragança, Escola Superior de Tecnologia e Gestão, 2012. http://hdl.handle.net/10198/8066.
Повний текст джерелаPaolucci, Cristian. "Prototyping a scalable Aggregate Computing cluster with open-source solutions." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15716/.
Повний текст джерелаvan, den Brink Nemo. "Chemical abundances in main-sequence stars in open cluster M67." Thesis, Uppsala universitet, Teoretisk astrofysik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-169017.
Повний текст джерелаSimbi, Nadia, and Koukouvinou Panagiota. "Managing Open Digital Technology in the Cluster Environment : A case study of the Cluster of Forest Technology." Thesis, Umeå universitet, Institutionen för informatik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-160771.
Повний текст джерелаYau, Anthony. "A parallel direct open-shell Coupled-Cluster Singles and Doubles algorithm." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0006633.
Повний текст джерелаConrad, Claudia [Verfasser], and Ralf-Dieter [Akademischer Betreuer] Scholz. "Open cluster groups and complexes / Claudia Conrad ; Betreuer: Ralf-Dieter Scholz." Potsdam : Universität Potsdam, 2015. http://d-nb.info/1218399260/34.
Повний текст джерелаBramich, Daniel Martyn. "Transiting extra-solar planets in the field of open cluster NGC 7789." Thesis, University of St Andrews, 2005. http://hdl.handle.net/10023/12944.
Повний текст джерелаTobin, Ryan Wesley. "Photometric variability of Sun-like stars in the old open cluster M67." [Ames, Iowa : Iowa State University], 2008.
Знайти повний текст джерелаThurston, Mark Robert. "X-ray and optical observations of the young open cluster NGC 2516." Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366165.
Повний текст джерелаAhlvind, Julia. "Isochrone and chemical ages of stars in the old open cluster M67." Thesis, Uppsala universitet, Observationell astrofysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-434634.
Повний текст джерелаChristie, Morgan B. "EXAMINING THE ASSOCIATIONS BETWEEN RACIAL IDENTITY AND RACIAL ATTITUDES FOR WHITE AMERICANS USING CLUSTER ANALYSIS." OpenSIUC, 2021. https://opensiuc.lib.siu.edu/dissertations/1954.
Повний текст джерелаWare, Jennifer J. "Exploring associations between the nicotinic acetylcholine receptor gene cluster CHRNA5-A3-B4 and smoking-related behaviours." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/46871/.
Повний текст джерелаSlack, Rebecca A. "Open space preservation in rural residential development." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-12172008-063233/.
Повний текст джерелаSzigeti, László, Szabolcs Mészáros, Verne V. Smith, Katia Cunha, Nadège Lagarde, Corinne Charbonnel, D. A. García-Hernández, et al. "12C/13C isotopic ratios in red-giant stars of the open cluster NGC 6791." OXFORD UNIV PRESS, 2018. http://hdl.handle.net/10150/627135.
Повний текст джерелаFernández, Ortega Carlos. "A differential spectroscopic study of a faint solar twin in the open cluster M67." Thesis, Uppsala universitet, Observationell astrofysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-302601.
Повний текст джерелаEn soltvilling är en stjärna som liknar solen väldigt mycket. Tidigare studier visar att M67-1194 är en av de bästa upptäckta soltvillingarna hittills. Men stjärnan är inte exakt som solen. Det finns skillnader mellan dem angående deras kemiska sammansättningar vilket har också visats i tidigare studier. Den här studiens syfte är att tillämpa en ny metod för att granska likheterna mellan den nämnda stjärnan och solen. En metod som förhoppningsvis ger noggrannare resultat. Metoden använder differensspektra som erhålls genom att subtrahera stjärnans spektrum från solens spektrum, i stället för att använda de vanliga spektra. Frågan är om den här nya metoden kan ge noggrannare resultat än dem som Önehag et al. fick 2011. Svaret är ja. Den tidigare studien visade en osäkerhet på ±0,02 dex medan vår gav osäkerheter mellan ±0,01 dex och ±0,02 dex. Icke desto mindre måste våra slutsatser tas försiktigt ty vår studie är inte lika säker som Önehags et al..
Wynn, James Joshi. "Open Space Cluster Developments to Conservation Subdivisions: Standards and Management Plans Influencing Conservation Goals." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1219345472.
Повний текст джерелаWynn, James Joshi. "Open space cluster developments to conservation subdivisions standards and managment plans influencing conservation goals /." Ohio : Ohio University, 2008. http://www.ohiolink.edu/etd/view.cgi?ohiou1219345472.
Повний текст джерелаLuque, N. E. "Cluster dynamics in the Basque region of Spain." Thesis, Coventry University, 2011. http://curve.coventry.ac.uk/open/items/4f4161ca-11db-4d70-9954-aea64f4fbaa4/1.
Повний текст джерелаStreet, Rachel. "A search for extra-solar planetary transits in the field of open cluster NGC 6819." Thesis, University of St Andrews, 2002. http://hdl.handle.net/10023/12939.
Повний текст джерелаElçi, E. "Algorithmic and geometric aspects of the random-cluster model." Thesis, Coventry University, 2015. http://curve.coventry.ac.uk/open/items/b59dab0c-fef8-4c06-b251-2f5416727431/1.
Повний текст джерелаMorrison, Heather. "Professional library & information associations should rise to the challenge of promoting open access and lead by example." Emerald, 2004. http://hdl.handle.net/2429/956.
Повний текст джерелаReinhardt, Mirko. "Optimizing Point-to-Point Ethernet Cluster Communication." Master's thesis, Universitätsbibliothek Chemnitz, 2006. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200600257.
Повний текст джерелаIrwin, J. M. "Observational constraints on pre-main sequence stellar evolution from time-series analysis of open cluster stars." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604961.
Повний текст джерелаBubnick, Benjamin Frank. "Massive Stellar Clusters in the Disk of the Milky Way Galaxy." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1288378106.
Повний текст джерелаWilking, B. A., C. J. Lada, and E. R. Young. "IRAS Observations of the Rho Ophiuchi Infrared Cluster: Spectral Energy Distributions and Luminosity Function." Steward Observatory, The University of Arizona (Tucson, Arizona), 1988. http://hdl.handle.net/10150/623919.
Повний текст джерелаBurke, Christopher J. "Survey for transiting extrasolar planets in stellar systems stellar and planetary content of the Open Cluster NGC 1245 /." Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1132168623.
Повний текст джерелаEffelsberg, Martin [Verfasser]. "Innovation durch Kooperation in einem Cluster : Eine empirische Analyse von Open Innovation in der deutschen Biotechnologie / Martin Effelsberg." Aachen : Shaker, 2013. http://d-nb.info/1051573378/34.
Повний текст джерелаDavid, David [Verfasser], and Bernhard [Akademischer Betreuer] Dick. "Development of local Coupled Cluster response methods for high-spin open-shell molecules / David David ; Betreuer: Bernhard Dick." Regensburg : Universitätsbibliothek Regensburg, 2020. http://d-nb.info/1204635846/34.
Повний текст джерелаAnacker, Tony. "Incremental Scheme for Open-Shell Systems." Doctoral thesis, Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-197726.
Повний текст джерелаWalk, Rachel Suzanne. "Associations Involving Open Court Reading in Kindergarten and Student Performance on Standardized Assessments in Reading in a Tennessee School System." Digital Commons @ East Tennessee State University, 2005. https://dc.etsu.edu/etd/1036.
Повний текст джерелаShoop, Stephen Scott. "The Texas Bandmasters Association a historical study of activities, contributions, and leadership (1920-1997) /." Thesis, view full-text document, 2000. http://www.library.unt.edu/theses/open/20012/shoop%5Fstephen/index.htm.
Повний текст джерелаChristlmaier, Evelin Martine. "CC2 response method using local correlation and density fitting approximations for the calculation of the electronic g-tensor of extended open-shell molecules." Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22835.
Повний текст джерелаThis work presents an unrestricted coupled-cluster CC2 response method using local correlation and density fitting approximations for the calculation of first and second order properties with particular focus on the electronic g-tensor. The fundamental concepts related to coupled-cluster theory, density fitting, local correlation, general coupled-cluster properties and the electronic g-tensor are discussed. The calculated g-tensors are benchmarked against those obtained from coupled-cluster singles and doubles, density functional theory and experiment. Efficiency and accuracy of the approximations is investigated. A detailed appendix covers the fundamentals of diagrammatic coupled-cluster and its application to the derivation of the working equations. The method presented in this thesis enables the quantitative prediction of the electronic g-tensor of extended systems with a method other than density functional theory. It represents an important step towards the development of low-scaling higher order coupled-cluster methods for this type of problem.
Bertelli, Motta Clio [Verfasser], and Eva K. [Akademischer Betreuer] Grebel. "The footprints of stellar evolution on the chemical composition of the Galactic old open cluster M67 / Clio Bertelli Motta ; Betreuer: Eva K. Grebel." Heidelberg : Universitätsbibliothek Heidelberg, 2018. http://d-nb.info/1177384574/34.
Повний текст джерела