Relevant bibliographies by topics / Stars – Initial mass function

Academic literature on the topic 'Stars – Initial mass function'

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Published: 10 December 2022
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Journal articles on the topic "Stars – Initial mass function"

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Larson, Richard B. "Fragmentation and the Initial Mass Function." International Astronomical Union Colloquium 120 (1989): 44–55. http://dx.doi.org/10.1017/s0252921100023472.

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A central problem in the theory of star formation is to understand the spectrum of masses, or Initial Mass Function, with which stars are formed. The fundamental role of the IMF in galactic evolution has been described by Tinsley (1980), and an extensive review of evidence concerning the IMF and its possible variability has been presented by Scalo (1986). Although the IMF derived from the observations is subject to many uncertainties, two basic features seem reasonably well established. One is that the typical stellar mass, defined such that equal amounts of matter condense into stars above and below this mass, is within a factor of 3 of one solar mass. A theory of star formation should therefore be able to explain why most stars are formed with masses of order one solar mass. The second apparently universal feature is that the IMF for relatively massive stars can be approximated by a power law with a slope not greatly different from that originally proposed by Salpeter (1955). Thus we also need to understand why the IMF always has a similar power-law tail toward higher masses.
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Leitherer, Claus. "The Stellar Initial Mass Function in Starburst Galaxies." Symposium - International Astronomical Union 186 (1999): 243–50. http://dx.doi.org/10.1017/s0074180900112707.

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Starburst galaxies are currently forming massive stars at prodigious rates. I discuss the star-formation histories and the shape of the initial mass function, with particular emphasis on the high- and on the low-mass end. The classical Salpeter IMF is consistent with constraints from observations of the most massive stars, irrespective of environmental properties. The situation at the low-mass end is less clear: direct star counts in nearby giant H II regions show stars down to ~1 M⊙, whereas dynamical arguments in some starburst galaxies suggest a deficit of such stars.
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Yoshii, Y., and H. Saio. "Initial mass function for zero-metal stars." Astrophysical Journal 301 (February 1986): 587. http://dx.doi.org/10.1086/163925.

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Zorec, J., R. Levenhagen, J. Chauville, Y. Frémat, D. Ballereau, A. M. Hubert, M. Floquet, and N. V. Leister. "The Initial Mass Function of Be Stars." Symposium - International Astronomical Union 215 (2004): 83–84. http://dx.doi.org/10.1017/s0074180900195270.

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Allowing for systematic differences in the counting of Be Stars due to their overluminosity, changes produced by their fast rotation on spectral types and time spent in the main sequence, a difference between the IMF (Be) and IMF(B) appears, which indicates that the appearance of the Be phenomenon may relay on differences in the initial star formation conditions.
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Larson, Richard B. "Some processes influencing the stellar initial mass function." Symposium - International Astronomical Union 147 (1991): 261–73. http://dx.doi.org/10.1017/s0074180900239600.

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Current evidence suggests that the stellar initial mass function has the same basic form everywhere, and that its fundamental features are (1) the existence of a characteristic stellar mass of order one solar mass, and (2) the existence of an apparently universal power-law form for the mass spectrum of the more massive stars. The characteristic stellar mass may be determined in part by the typical mass scale for the fragmentation of star forming clouds, which is predicted to be of the order of one solar mass. The power-law extension of the mass spectrum toward higher masses may result from the continuing accretional growth of some stars to much larger masses; the fact that the most massive stars appear to form preferentially in cluster cores suggests that such continuing accretion may be particularly important at the centers of clusters. Numerical simulations suggest that forming systems of stars may tend to develop a hierarchical structure, possibly self-similar in nature. If most stars form in such hierarchically structured systems, and if the mass of the most massive star that forms in each subcluster increases as a power of the mass of the subcluster, then a mass spectrum of power-law form is predicted. Some possible physical effects that could lead to such a relation are briefly discussed, and some observational tests of the ideas discussed here are proposed.
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Larson, Richard B. "Some processes influencing the stellar initial mass function." Symposium - International Astronomical Union 147 (1991): 261–73. http://dx.doi.org/10.1017/s0074180900198985.

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Current evidence suggests that the stellar initial mass function has the same basic form everywhere, and that its fundamental features are (1) the existence of a characteristic stellar mass of order one solar mass, and (2) the existence of an apparently universal power-law form for the mass spectrum of the more massive stars. The characteristic stellar mass may be determined in part by the typical mass scale for the fragmentation of star forming clouds, which is predicted to be of the order of one solar mass. The power-law extension of the mass spectrum toward higher masses may result from the continuing accretional growth of some stars to much larger masses; the fact that the most massive stars appear to form preferentially in cluster cores suggests that such continuing accretion may be particularly important at the centers of clusters. Numerical simulations suggest that forming systems of stars may tend to develop a hierarchical structure, possibly self-similar in nature. If most stars form in such hierarchically structured systems, and if the mass of the most massive star that forms in each subcluster increases as a power of the mass of the subcluster, then a mass spectrum of power-law form is predicted. Some possible physical effects that could lead to such a relation are briefly discussed, and some observational tests of the ideas discussed here are proposed.
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Federrath, Christoph, Mark Krumholz, and Philip F. Hopkins. "Converging on the Initial Mass Function of Stars." Journal of Physics: Conference Series 837 (May 30, 2017): 012007. http://dx.doi.org/10.1088/1742-6596/837/1/012007.

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Malkov, O., and H. Zinnecker. "Binary stars and the fundamental initial mass function." Monthly Notices of the Royal Astronomical Society 321, no. 1 (February 11, 2001): 149–54. http://dx.doi.org/10.1046/j.1365-8711.2001.04015.x.

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Hopkins, Andrew. "Measuring the stellar initial mass function." Proceedings of the International Astronomical Union 15, S352 (June 2019): 98. http://dx.doi.org/10.1017/s1743921320001155.

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AbstractThe birth of stars and the formation of galaxies are cornerstones of modern astrophysics. While much is known about how galaxies globally and their stars individually form and evolve, one fundamental property that affects both remains elusive. This is problematic because this key property, the stellar initial mass function (IMF), is a key tracer of the physics of star formation that underpins almost all of the unknowns in galaxy and stellar evolution. It is perhaps the greatest source of systematic uncertainty in star and galaxy evolution. The past decade has seen a growing number and variety of methods for measuring or inferring the shape of the IMF, along with progressively more detailed simulations, paralleled by refinements in the way the concept of the IMF is applied or conceptualised on different physical scales. This range of approaches and evolving definitions of the quantity being measured has in turn led to conflicting conclusions regarding whether or not the IMF is universal. Here I summarise the growing wealth of approaches to our understanding of this fundamental property that defines so much of astrophysics, and highlight the importance of considering potential IMF variations, reinforcing the need for measurements to quantify their scope and uncertainties carefully. I present a new framework to aid the discussion of the IMF and promote clarity in the further development of this fundamental field.
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De Marchi, Guido, and Francesco Paresce. "The Initial Mass Function of Low-Mass Stars in Globular Clusters." Astrophysical Journal 476, no. 1 (February 10, 1997): L19—L22. http://dx.doi.org/10.1086/310490.

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Dissertations / Theses on the topic "Stars – Initial mass function"

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Bressert, Eli Walter. "The initial distribution of stars." Thesis, University of Exeter, 2012. http://hdl.handle.net/10036/3890.

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The primary focus of my PhD is to quantify the spatial distribution of star-forming environments from optical to radio wavelengths using data from the Hubble Space Telescope, the Very Large Telescope, the Spitzer Space Telescope, the Herschel Space Observatory, and the Caltech Submillimeter Observatory. Towards the end of my PhD study I have developed theoretical models. With these observational and theoretical avenues I have led a series of research projects to (1) quantify the initial spatial structure of pre-stellar cores and proto-stars, (2) test whether massive stars can form in isolation or not, (3) and develop a theoretical model on how young massive clusters form. These research projects have been fruitful as my collaborators and I have shown that pre-stellar cores and stars form in a smooth continuum of surface densities from a few to thousands of stars per pc^2. These two works have important implications on our understanding of what a young stellar cluster is and how star forming environments can evolve to form field star populations or gravitationally bound clusters. In my second study my collaborators and I found evidence for isolated massive star formation in the active star forming region 30 Doradus, in the Large Magellanic Cloud. The result impacts the field of the initial mass function and star formation models. Massive stars forming in isolation is consistent with a stochastically sampled initial mass function. Additionally, the result would put constraints on theoretical models on massive star formation. Continuing my work on massive star forming environments my collaborators and I have developed a theoretical model on how young massive clusters form. From the models we argue that feedback energies can be contained by the gravitational potential well of the massive progenitors. Furthermore, we predict the physical properties the massive cluster progenitors in terms of initial gas mass, radii and flux brightness to enable a search for these objects in Galactic plane surveys and upcoming telescopes. Using the common thread of spatial distribution analysis of star formation I describe my future research plans, which entails studies on extragalactic scales in the conclusion.
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Thompson, Simon. "Low mass stars, brown dwarfs and the initial mass function in Cepheus OB3b." Thesis, Keele University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288434.

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Luhman, Kevin Lee 1971. "Low-mass star formation and the initial mass function in young clusters." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288884.

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I have used optical and near-infrared spectroscopy and imaging to measure spectral types and luminosities for young (τ < 10 Myr), embedded (Aᵥ = 0-50), low-mass (0.1-1 M(⊙)) stars in three nearby (d < 300 pc) clusters: L1495E, IC 348, and ρ Ophiuchi. In conjunction with theoretical evolutionary tracks, I have derived the star formation history and initial mass function for each stellar population. A large number of brown dwarf candidates have been identified in the photometry, several of which are confirmed through spectroscopy. Finally, I have measured the frequency and survival times of circumstellar disks and investigated the photometric and spectroscopic properties of protostars. In § 2, I apply observational tests to the available sets of evolutionary models for low-mass stars, concluding that the calculations of D'Antona & Mazzitelli are preferred for the range of masses and ages considered here. In § 3 and § 4, I examine in detail the spectroscopic characteristics and substellar nature of two brown dwarf candidates. The study then expands to include the populations within the clusters L1495E (§ 5), IC 348 (§ 6), and ρ Ophiuchi (§ 7). In § 8, I briefly discuss the past, present, and future of scientific research related to this thesis.
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Selman, Fernando Javier Scoville Nicholas Zabriskie. "The initial mass function and star-formation history in the 30 Doradus super-association /." Diss., Pasadena, Calif. : California Institute of Technology, 2004. http://resolver.caltech.edu/CaltechETD:etd-05122004-130955.

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Jones, Michael Oliver. "The role of protostellar heating in star formation." Thesis, University of Exeter, 2018. http://hdl.handle.net/10871/34560.

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Previous studies have shown that thermal feedback from protostars plays a key role in the process of low-mass star formation. In this thesis, we explore the effects of protostellar heating on the formation of stellar clusters. We describe new methods for modelling protostellar accretion luminosities and protostellar evolution in calculations of star formation. We then present results of a series of numerical simulations of stellar cluster formation which include these effects, and examine their impact. We begin by investigating the dependence of stellar properties on the initial density of molecular clouds. We find that the dependence of the median stellar mass on the initial density of the cloud is weaker than the dependence of the thermal Jeans mass when radiative effects are included. We suggest that including protostellar accretion luminosities and protostellar evolution may weaken this dependence further, and may account for the observed invariance of the median stellar mass in Galactic star-forming regions. Next, we investigate the effects of including accretion feedback from sink particles on the formation of small stellar groups. We find that including accretion feedback in calculations suppresses fragmentation even further than calculations that only include radiative transfer within the gas. Including feedback also produces a higher median stellar mass, which is insensitive to the sink particle accretion radius used. Finally, we compare calculations of small stellar clusters which model the evolution of protostars using a live stellar model with those which use a fixed stellar structure. We find that the dynamics of the clusters are primarily determined by the accretion luminosities of protostars, but that the relative effects of protostellar evolution depend on the accretion rate and advection of energy into the protostar. We also demonstrate how such calculations may be used to study the properties of young stellar populations.
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Burgess, 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.

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La détermination de l'extrémité inférieure de la fonction de masse initiale (FMI) prévoit de fortes contraintes sur les théories de la formation des étoiles. IC4665 est un amas d'´étoile jeune (30Myr) et il a situe 356pc de la Terre. L'extinction est Av~ 0.59 ± 0.15 mag. WIRCam Y, J, H et K observations ont été faites par le CFHT et a comprise 10 champs (de 1.1sq.deg totale) et deux zones de contrle de 20'x20' chacun. Diagrammes couleur/magnitude et couleur/couleur ont été utilisées pour comparer les candidats sélectionnées par les modèles BT-SETTL 30 et 50Myr. Les images CH4off et CH4on ont été obtenus avec CFHT/WIRCam plus 0.11 sq.deg. dans IC348. Naines-T ont ensuite été identifiés à partir de leur couleur de 1.69μm d'absorption du méthane et trois candidats nain-T ont été trouvée avec CH4on−CH4 >0.4 mag. Extinction a été estimée à Av~ 5 − 12 mag. Les comparaisons avec les naines-T modèles, et des diagrammes couleur/couleur et magnitude, rejeter 2 entre 3 candidats en raison de leur extrême z′ − J coleur. L'objet reste n'est pas considéré comme un nain avant l'amas en raison d'un argument de densité en nombre ou l'extinction forte Av~ 12 mag, ni d'être un champ de fond nain-T qui serait devrait être beaucoup plus faible. Les modèles et les schémas de donner cet objet un type T6 préliminaires spectrale. Avec un peu de la masse de Jupiter, ce jeune candidat nain-T est potentiellement parmi les plus jeunes, des objets de masse plus faible détectée dans une région de formation d'´étoiles `a ce jour. Sa fréquence est conforme à l'extrapolation du courant lognormal FMI estime `a au domaine de masse planétaire.
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Faimali, Alessandro Daniele. "The history and rate of star formation within the G305 complex." Thesis, University of Hertfordshire, 2013. http://hdl.handle.net/2299/13732.

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Within this thesis, we present an extended multiwavelength analysis of the rich massive Galactic star-forming complex G305. We have focused our attention on studying the both the embedded massive star-forming population within G305, while also identifying the intermediate-, to lowmass content of the region also. Though massive stars play an important role in the shaping and evolution of their host galaxies, the physics of their formation still remains unclear. We have therefore set out to studying the nature of star formation within this complex, and also identify the impact that such a population has on the evolution of G305. We firstly present a Herschel far-infrared study towards G305, utilising PACS 70, 160 μm and SPIRE 250, 350, and 500 μm observations from the Hi-GAL survey of the Galactic plane. The focus of this study is to identify the embedded massive star-forming population within G305, by combining far-infrared data with radio continuum, H2O maser, methanolmaser,MIPS, and Red MSX Source survey data available from previous studies. From this sample we identify some 16 candidate associations are identified as embedded massive star-forming regions, and derive a two-selection colour criterion from this sample of log(F70/F500)! 1 and log(F160/F350)! 1.6 to identify an additional 31 embedded massive star candidates with no associated starformation tracers. Using this result, we are able to derive a star formation rate (SFR) of 0.01 - 0.02 M! yr−1. Comparing this resolved star formation rate, to extragalactic star formation rate tracers (based on the Kennicutt-Schmidt relation), we find the star formation activity is underestimated by a factor of !2 in comparison to the SFR derived from the YSO population. By next combining data available from 2MASS and VVV, Spitzer GLIMPSE and MIPSGAL, MSX, and Herschel Hi-GAL, we are able to identify the low-, to intermediate-mass YSOs present within the complex. Employing a series of stringent colour selection criteria and fitting reddened stellar atmosphere models, we are able remove a significant amount of contaminating sources from our sample, leaving us with a highly reliable sample of some 599 candidate YSOs. From this sample, we derive a present-day SFR of 0.005±0.001M! yr−1, and find the YSOmass function (YMF) of G305 to be significantly steeper than the standard Salpeter-Kroupa IMF. We find evidence of mass segregation towards G305, with a significant variation of the YMF both with the active star-forming region, and the outer region. The spatial distribution, and age gradient, of our 601 candidate YSOs also seem to rule out the scenario of propagating star formation within G305, with a more likely scenario of punctuated star formation over the lifetime of the complex.
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Canameras, R., N. P. H. Nesvadba, R. Kneissl, M. Limousin, R. Gavazzi, D. Scott, H. Dole, et al. "Planck's dusty GEMS III. A massive lensing galaxy with a bottom-heavy stellar initial mass function at z=1.5." EDP SCIENCES S A, 2017. http://hdl.handle.net/10150/624365.

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We study the properties of the foreground galaxy of the Ruby, the brightest gravitationally lensed high-redshift galaxy on the sub-millimeter sky as probed by the Planck satellite, and part of our sample of Planck's dusty GEMS. The Ruby consists of an Einstein ring of 1.4" diameter at z = 3.005 observed with ALMA at 0.1" resolution, centered on a faint, red, massive lensing galaxy seen with HST/WFC3, which itself has an exceptionally high redshift, z = 1.525 +/- 0.001, as confirmed with VLT/X-shooter spectroscopy. Here we focus on the properties of the lens and the lensing model obtained with LENSTOOL. The rest-frame optical morphology of this system is strongly dominated by the lens, while the Ruby itself is highly obscured, and contributes less than 10% to the photometry out to the K band. The foreground galaxy has a lensing mass of (3.70 +/- 0.35) x 10(11) M-Theta Magnification factors are between 7 and 38 for individual clumps forming two image families along the Einstein ring. We present a decomposition of the foreground and background sources in the WFC3 images, and stellar population synthesis modeling with a range of star-formation histories for Chabrier and Salpeter initial mass functions (IMFs). Only the stellar mass range obtained with the latter agrees well with the lensing mass. This is consistent with the bottom-heavy IMFs of massive high-redshift galaxies expected from detailed studies of the stellar masses and mass profiles of their low-redshift descendants, and from models of turbulent gas fragmentation. This may be the first direct constraint on the IMF in a lens at z = 1.5, which is not a cluster central galaxy.
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Lyo, A.-Ran Physical Environmental &amp Mathematical Sciences Australian Defence Force Academy UNSW. "The nearby young [special character] Chamaeleontis cluster as a laboratory for star formation and evolution." Awarded by:University of New South Wales - Australian Defence Force Academy. School of Physical, Environmental and Mathematical Sciences, 2004. http://handle.unsw.edu.au/1959.4/38707.

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[Special characters cannot be displayed. Please see the pdf version of the Abstract for an accurate reproduction.] We studied the circumstellar discs, the initial mass function (IMF), mass distribution, binarity and the fundamental properties of the [special character] 9 Myr-old pre-main sequence (PMS) [special character] Chamaeleontis cluster. Using JHKL colour-colour and colour-excess diagrams, we found the circumstellar disc fraction to be [special character] 0.60 among the late-type members. Four stars with [special character] (K - L) > 0.4 were identified as experiencing ongoing accretion which was later confirmed by high-resolution spectroscopic study. Quantitative analysis of the H[special character] profiles found accretion in these four stars at rates comparable to that of two members of the similarly-aged TW Hydrae Association (TWA); rates 1 - 3 orders of magnitude lower than in younger classical T Tauri stars. Together these results suggest that, while the mass accretion rate decreases with age, PMS stars can retain their inner discs for [special character] 10 Myr. An optical photometric survey spanning 1.3 ?? 1.3 pc added two low-mass stars to the cluster inventory. Together with other recent surveys the population is likely to be significantly complete for primaries with masses M > 0.15M[special character]. The cluster now consists of 18 primaries and 9 confirmed and candidate secondaries, with [special character] 2-4 times higher multiplicity than seen in field dwarfs. The cluster IMF is consistent with that of rich young clusters and field stars. By extending the IMF to lower masses, we predict 20-29 low-mass stars and brown dwarfs may remain undiscovered. From study of the cluster???s spatial and mass distribution, we find the [special character] Cha cluster has significant mass segregation, with > 50 per cent of the stellar mass residing within the central 0.17 pc. Lastly we classified members of the cluster with low-resolution spectra, providing information about the fundamental properties of the PMS stars by comparison to standard dwarfs. Broadband VRI colours and pseudocontinuum indices derived for the cluster stars are indistinguishable from dwarfs at visual and red wavelengths. This suggests the temperature sequence for the PMS [special character] Cha cluster is similar to that of the dwarf sequence. Narrow-band spectral indices for the [special character] Cha cluster possibly indicate higher metallicity and strongly indicate lower surface gravity than the dwarf indices.
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Mor, Crespo Roger. "The star formation history and the stellar initial mass function of the Milky Way disc. The population synthesis Besançon Galaxy Model in the Gaia era." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/667482.

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AIMS: We develop a new theoretical framework to generate Besançon Galaxy Model Fast Approximate Simulations (BGM FASt) to address fundamental questions of the Galactic structure and evolution performing multi-parameter inference. The flexibility of BGM FASt allows the inference of fundamental parameters related to the stellar initial mass function (IMF), the star formation history (SFH), the density distribution, the kinematics and the chemo-dynamics, among others. BGM FASt allows the study of different Milky Way (MW) components. In this thesis we are focused in a first application of our strategy to simultaneously infer the IMF and the SFH of the MW disc. METHOD: BGM FASt is based on a reweighing scheme, that uses a specific pre-sampled simulation. We use BGM FASt together with an approximate Bayesian computation algorithm to obtain the posterior probability distribution function of the inferred parameters, by automatically comparing synthetic versus observed data. Our full strategy is codified to run on Apache Spark and Hadoop, suited to deal with large surveys. BGM FASt is implemented in the big data infrastructure known as Gaia Data Analytics Framework (GDAF) at the University of Barcelona. To evaluate the performance of BGM FASt we execute a set of validation tests comparing density, colour, mass and age distributions of BGM FASt versus BGM standard simulations. We present two scientific cases that compare synthetic versus Tycho-2 colour-magnitude diagrams. We obtain for the first time using BGM an IMF and SFH of the thin disc by exploring a 6-Dimensional parameter space. We use Gaia data-release 2 magnitudes, colours, and parallaxes for stars with G<12 to explore a parameter space with 15 dimensions. This includes simultaneously the IMF and, for the first time, a non-parametric SFH for the Galactic disc. RESULTS: The set of tests applied show a very good agreement between equivalent simulations performed with BGM FASt and standard BGM. It has resulted to be 10000 times faster. We demonstrate it is a very valuable tool to perform multi-parameter inference using large catalogues. The two scientific demonstration cases of our strategy applied to Tyhco-2 data gives us, for the first time using BGM, a full 6D posterior probability distribution function of the parameters involved in the IMF and the SFH of the thin disc component. Using Gaia DR2 we find an imprint of a star formation burst 2-3 Gyr ago in the Galactic thin disc domain. Our results show a decreasing trend followed by a Star Formation Rate (SFR) enhancement starting at about 5 Gyr ago and continuing until about 1 Gyr ago. This enhancement is detected with high statistical significance by discarding the null hypothesis of an exponential SFH. The timescale and the amount of stellar mass generated during this SFR enhancement event lead us to hypothesise that its origin, currently under investigation, is not intrinsic to the disc. When we adopt a non-parametric SFH the resulting IMF for the thin disc has an alpha3 of approximately 2 for masses M larger than 1.53 Msun and alpha2 approximately 1.3 for the mass range between 0.5 and 1.53Msun. CONCLUSIONS: BGM FASt has allowed us to increase our knowledge about the IMF and the SFH of the MW disc. Our results have shown that the evolution of the SFR with time is much more complex than a simple mathematical exponential decreasing shape. We have seen how the imposition of a mathematical shape for the SFH has a clear impact into the derivation of the IMF at high masses. The good performance of our whole strategy opens very promising perspectives, among them, the possibility to study whether the IMF variates with the time or not.
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Books on the topic "Stars – Initial mass function"

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Marie, Treyer, Wyder Ted K, Neill James D, Seibert Mark, Lee Janice C, and Astronomical Society of the Pacific, eds. UP2010: Have observations revealed a variable upper end of the initial mass function? : proceedings of a conference held at Sedona, Arizona, USA, 20-25 June 2010. San Francisco, Calif: Astronomical Society of the Pacific, 2011.

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Hill, Robert James. The initial mass function for massive stars in the Magellanic Clouds. Toronto: Dept. of Astronomy, University of Toronto, 1991.

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Herstmonceux Conference (38th 1998 Cambridge, England). The stellar initial mass function: 38th Herstmonceux Conference : proceedings of the meeting held at Institute of Astronomy and Royal Greenwich Observatory, Cambridge, UK, 14-18 July, 1998. San Francisco, Calif: Astronomical Society of the Pacific, 1998.

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Corbelli, Edvige, Francesco Palla, and Hans Zinnecker, eds. The Initial Mass Function 50 Years Later. Dordrecht: Springer Netherlands, 2005. http://dx.doi.org/10.1007/978-1-4020-3407-7.

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Palla, Francesco, Hans Zinnecker, and Edvige Corbelli. Initial Mass Function 50 Years Later. Springer, 2005.

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Palla, Francesco, Hans Zinnecker, and Edvige Corbelli. The Initial Mass Function 50 Years Later. Springer, 2014.

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Hill, Robert. The initial mass function for massive stars in the magellanic clouds. 1991.

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(Editor), Edvige Corbelli, Francesco Palla (Editor), and Hans Zinnecker (Editor), eds. The Initial Mass Function 50 Years Later (Astrophysics and Space Science Library). Springer, 2005.

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Scalo, John M. The stellar initial mass function. Gordon and Breach Science Publishers, 1986.

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Gilmore, Gerry. The Stellar Initial Mass Function: 38th Herstmonceux Conference: Proceedings of the Meeting Held at Institute of Astronomy and Royal Greenwich Observa ... Society of the Pacific Conference Series). Astronomical Society of the Pacific, 1998.

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Book chapters on the topic "Stars – Initial mass function"

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Larson, Richard B. "The Initial Mass Function." In Galactic and Extragalactic Star Formation, 635–36. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-2973-9_42.

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Schneider, Raffaella. "Cosmic Relevance of the First Stars." In The Initial Mass Function 50 Years Later, 475–76. Dordrecht: Springer Netherlands, 2005. http://dx.doi.org/10.1007/978-1-4020-3407-7_86.

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Petr-Gotzens, M. G., H. R. Ledo, and D. E. A. Nürnberger. "A 2.2 Micron Catalogue of Stars in NGC 3603." In The Initial Mass Function 50 Years Later, 159–60. Dordrecht: Springer Netherlands, 2005. http://dx.doi.org/10.1007/978-1-4020-3407-7_30.

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Haardt, Francesco. "From Population III Stars to (Super)Massive Black Holes." In The Initial Mass Function 50 Years Later, 501–6. Dordrecht: Springer Netherlands, 2005. http://dx.doi.org/10.1007/978-1-4020-3407-7_93.

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Hony, Sacha, and Timo Prusti. "Limitations of the Ir-Excess Method for Identifying Young Stars." In The Initial Mass Function 50 Years Later, 127–30. Dordrecht: Springer Netherlands, 2005. http://dx.doi.org/10.1007/978-1-4020-3407-7_20.

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Rieke, G. H. "Evolution and Initial Mass Function in Starbursts." In Galactic and Extragalactic Star Formation, 561–70. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-2973-9_34.

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Kroupa, Pavel, Carsten Weidner, Jan Pflamm-Altenburg, Ingo Thies, Jörg Dabringhausen, Michael Marks, and Thomas Maschberger. "The Stellar and Sub-Stellar Initial Mass Function of Simple and Composite Populations." In Planets, Stars and Stellar Systems, 115–242. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-5612-0_4.

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Larson, Richard B. "Some Processes Influencing the Stellar Initial Mass Function." In Fragmentation of Molecular Clouds and Star Formation, 261–73. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3384-5_29.

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D’Antona, Francesca. "The Initial Mass Function of Very Low Mass Stars and the Significance of Brown Dwarfs." In Astrophysics and Space Science Library, 367–80. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-0605-1_32.

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Zapatero Osorio, María Rosa, José Caballero, Eduardo L. Martín, Víctor J. S. Béjar, and Rafael Rebolo. "Clues to Substellar Formation: Rotation and the Low-Mass End of the Initial Mass Function." In Magnetic Fields and Star Formation, 499–505. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-94-017-0491-5_51.

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Conference papers on the topic "Stars – Initial mass function"

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FERRARA, A. "FIRST STARS AND THEIR INITIAL MASS FUNCTION." In Proceedings of the XXI Symposium on Relativistic Astrophysics. WORLD SCIENTIFIC, 2003. http://dx.doi.org/10.1142/9789812704009_0005.

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Johnson, Jennifer A., and Thomas Masseron. "Abundance Ratios in Carbon‐Enhanced Metal‐Poor Stars and the Intermediate‐Mass Star Initial Mass Function." In FIRST STARS III: First Stars II Conference. American Institute of Physics, 2008. http://dx.doi.org/10.1063/1.2905540.

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Suda, Takuma, Yutaka Komiya, Shimako Yamada, Yutaka Katsuta, Wako Aoki, Pilar Gil-Pons, Carolyn L. Doherty, Simon W. Campbell, Peter R. Wood, and Masayuki Y. Fujimoto. "Transition of the initial mass function in the galaxy based on binary population synthesis." In FIRST STARS IV – FROM HAYASHI TO THE FUTURE –. AIP, 2012. http://dx.doi.org/10.1063/1.4754407.

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Richer, Harvey B., and Gregory G. Fahlman. "The initial mass function: Now and then." In The seventh astrophysical conference: Star formation, near and far. AIP, 1997. http://dx.doi.org/10.1063/1.52802.

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Heap, Sara R. "Observations of the extragalactic initial mass function and modes of star formation." In The seventh astrophysical conference: Star formation, near and far. AIP, 1997. http://dx.doi.org/10.1063/1.52810.

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Shang, Fu-Min, Shi-Long Fan, and Jian-Hong Liu. "The Start-Up Performance of Pulsating Heat Pipe With Communicating Pipe at Different Inclination Angles." In ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/mnhmt2019-4015.

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Abstract The pulsating heat pipe (PHP) is a passive cooling device, which has the advantages of simple structure, high heat transfer performance and low production cost. The complex vapor-liquid phase change occurs in the in the initial stage of PHP. In this work, we explore the start-up performance of PHP at different inclination angles and the experiment shows that start-up performance is respectively different when the angles are 0°, 45°, 90°, 135° and 180°. Since the gravitational auxiliary function, the working fluid in the communicating pipe which takes longer time to vaporize change phase earlier than that in PHP’s loop when the angles are 0° and 45°. Nevertheless, when the angle is 90°, the phase change of working fluid in communicating pipe and in the loop occurs at the same time. Meanwhile, the oscillating mode affects the stability of the starting and heat transfer performance of the PHP.
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de Pablos, Fernando, and Jordi Cepa. "Star formation rates, efficiencies and initial mass functions in spiral galaxies." In The seventh astrophysical conference: Star formation, near and far. AIP, 1997. http://dx.doi.org/10.1063/1.52812.

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Prado, E., and F. J. Moody. "Transient Waterhammer Force and Pipe Response Using Fluid and Structural Coupling." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-55003.

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The problem presented in this report is intended to be instructive. It is designed to be a step by step approach on how pipe response due to waterhammer can be solved using fundamental engineering principles. When fluid accelerates in a piping system, the pipe experience a reaction force that is equal and opposite to the force exerted by the fluid. The relationship between fluid and structural behaviors in this type of problem can be analyzed by the fluid-structure coupling approach. This methodology takes the decoupled fluid force, predicted for a rigid pipe, and applies it to the dry pipe with an added hydraulic mass to obtain the exact coupled pipe motion response. To demonstrate the application of the fluid-structure coupling approach, an analysis of waterhammer effects due to valve closure is performed on a horizontal pipe with elbows attached to two vertical segments at both ends; both instantaneous and ramp-in-time valve closures are modeled. The analysis starts first by determining whether the fluid response corresponds to bulk flow or propagative flow. Then from conservation of mass and momentum equations, employed with the space-time diagram, the transient forcing function on the stationary, rigid horizontal pipe is determined. By modeling the two vertical piping segments as cantilever beams, and adding the appropriate hydraulic mass to the dry pipe, the piping response can be obtained. As a result, the piping response is a function of pipe geometry, initial fluid velocity, mass of pipe and fluid, and pipe stiffness. Given this fluid-structure coupled function, one can predict the maximum deflection of the pipe and the stresses induced on the pipe restraints.
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Eretnova, O., and A. Dudorov. "The mass function of pre-main sequence stars." In ASTRONOMY AT THE EPOCH OF MULTIMESSENGER STUDIES. Proceedings of the VAK-2021 conference, Aug 23–28, 2021. Crossref, 2022. http://dx.doi.org/10.51194/vak2021.2022.1.1.040.

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The information about 26 pre-man sequence (PMS) binary stars and 34 stars with protoplanetary disks with well determinedmasses from the observations is collected. We constructed the mass distribution of PMS stars and approximated it with apower law dN ∼M −γ dM . The slope is γ = 2.16±0.17 for stars in a mass range of 0.6M ⊙ < M < 6.3M ⊙ , which is close tothe Salpeter mass function. Over the entire mass range, the mass distribution of young stars may be approximated with alognormal law, which the most probable mass M prob = (0.78 ± 0.12)M ⊙ .
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Moore, Toby J. T., Giuliana Giobbi, Amedeo Tornambe, Gabriella Raimondo, Marco Limongi, L. A. Antonelli, Nicola Menci, and Enzo Brocato. "Origins of the Stellar Initial Mass Function." In PROBING STELLAR POPULATIONS OUT TO THE DISTANT UNIVERSE: CEFALU 2008, Proceedings of the International Conference. AIP, 2009. http://dx.doi.org/10.1063/1.3141529.

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Reports on the topic "Stars – Initial mass function"

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Li, J., C. Lam, W. A. Dawson, B. S. Gaudi, N. R. Golovich, M. Medford, F. Abdurrahman, and R. L. Beaton. From Stars to Compact Objects: The Initial-Final Mass Relation. Office of Scientific and Technical Information (OSTI), October 2019. http://dx.doi.org/10.2172/1572254.

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Yaron, Zvi, Abigail Elizur, Martin Schreibman, and Yonathan Zohar. Advancing Puberty in the Black Carp (Mylopharyngodon piceus) and the Striped Bass (Morone saxatilis). United States Department of Agriculture, January 2000. http://dx.doi.org/10.32747/2000.7695841.bard.

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Both the genes and cDNA sequences encoding the b-subunits of black carp LH and FSH were isolated, cloned and sequenced. Sequence analysis of the bcFSHb and LHb5'flanking regions revealed that the promoter region of both genes contains canonical TATA sequences, 30 bp and 17 bp upstream of the transcription start site of FSHb and LHb genes, respectively. In addition, they include several sequences of cis-acting motifs, required for inducible and tissue-specific transcriptional regulation: the gonadotropin-specific element (GSE), GnRH responsive element (GRE), half sites of estrogen and androgen response elements, cAMP response element, and AP1. Several methods have been employed by the Israeli team to purify the recombinant b subunits (EtOH precipitation, gel filtration and lentil lectin). While the final objective to produce pure recombinantGtH subunits has not yet been achieved, we have covered much ground towards this goal. The black carp ovary showed a gradual increase in both mass and oocyte diameter. First postvitellogenic oocytes were found in 5 yr old fish. At this age, the testes already contained spermatozoa. The circulating LH levels increased from 0.5 ng/ml in 4 yr old fish to >5ng/ml in 5 yr old fish. In vivo challenge experiments in black carp showed the initial LH response of the pituitary to GnRH in 4 yr old fish. The response was further augmented in 5 yr old fish. The increase in estradiol level in response to gonadotropic stimulation was first noted in 4 yr old fish but this response was much stronger in the following year. In vivo experiments on the FSHb and LHb mRNA levels in response to GnRH were carried out on common carp as a model for synchronom spawning cyprinids. These experiments showed the prevalence of FSHP in maturing fish while LHP mRNA was prevalent in mature fish, especially in females. The gonadal fat-pad was found to originate from the retroperitoneal mesoderm and not from the genital ridge, thus differing from that reported in certain amphibians This tissue possibly serves as the major source of sex steroids in the immature black carp. However, such a function is taken over by the developing gonads in 4 yr old fish. In the striped bass, we described the ontogeny of the neuro-endocrine parameters along the brain-pituitary-gonadal axis during the first four years of life, throughout gonadal development and the onset of puberty. We also described the responsiveness of the reproductive axis to long-term hormonal manipulations at various stages of gonadal development. Most males reached complete sexual maturity during the first year of life. Puberty was initiated during the third year of life in most females, but this first reproductive cycle did not lead to the acquisition of full sexual maturity. This finding indicates that more than one reproductive cycle may be required before adulthood is reached. Out of the three native GnRHs present in striped bass, only sbGnRH and cGnRH II increased concomitantly with the progress of gonadal development and the onset of puberty. This finding, together with data on GtH synthesis and release, suggests that while sbGnRH and cGnRH II may be involved in the regulation of puberty in striped bass, these neuropeptides are not limiting factors to the onset of puberty. Plasma LH levels remained low in all fish, suggesting that LH plays only a minor role in early gonadal development. This hypothesis was further supported by the finding that experimentally elevated plasma LH levels did not result in the induction of complete ovarian and testicular development. The acquisition of complete puberty in 4 yr old females was associated with a rise in the mRNA levels of all GtH subunit genes, including a 218-fold increase in the mRNA levels of bFSH. mRNA levels of the a and PLH subunits increased only 11- and 8-fold, respectively. Although data on plasma FSH levels are unavailable, the dramatic increase in bFSH mRNA suggests a pivotal role for this hormone in regulating the onset and completion of puberty in striped bass. The hormonal regulation of the onset of puberty and of GtH synthesis and release was studied by chronic administration of testosterone (T) and/or an analog of gonadotropin-releasing hormone (G). Sustained administration of T+G increased the mRNA levels of the PLH subunit to the values characteristic of sexually mature fish, and also increased the plasma levels of LH. However, these changes did not result in the acceleration of sexual maturation. The mRNA levels of the bFSH subunit were slightly stimulated, but remained about 1/10 of the values characteristic of sexually mature fish. It is concluded that the stimulation of FSH gene expression and release does not lead to the acceleration of sexual maturity, and that the failure to sufficiently stimulate the bFSH subunit gene expression may underlie the inability of the treatments to advance sexual maturity. Consequently, FSH is suggested to be the key hormone to the initiation and completion of puberty in striped bass. Future efforts to induce precocious puberty in striped bass should focus on understanding the regulation of FSH synthesis and release and on developing technologies to induce these processes. Definite formulation of hormonal manipulation to advance puberty in the striped bass and the black carp seems to be premature at this stage. However, the project has already yielded a great number of experimental tools of DNA technology, slow-release systems and endocrine information on the process of puberty. These systems and certain protocols have been already utilized successfully to advance maturation in other fish (e.g. grey mullet) and will form a base for further study on fish puberty.
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