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Related papers: Simulating a white dwarf dominated halo

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The stellar initial-mass function (IMF) represents a fundamental quantity in astrophysics and cosmology, describing the mass distribution of stars from low to very-high masses. It is intimately linked to a wide variety of topics, including…

High Energy Astrophysical Phenomena · Physics 2024-09-17 Francesco Gabrielli , Lumen Boco , Giancarlo Ghirlanda , Om Sharan Salafia , Ruben Salvaterra , Mario Spera , Andrea Lapi

According to the now strongly supported concordance $\Lambda$CDM model, galaxies may be grossly described as a luminous component embedded in a dark matter halo. The density profile of these mass dominating haloes may be determined by N -…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 A. Del Popolo , V. F. Cardone

A longstanding puzzle of fundamental importance in modern cosmology has been the origin of the nearly universal density profiles of dark matter halos found in N-body simulations -- the so-called NFW profile. We show how this behavior may be…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-25 Neal Dalal , Yoram Lithwick , Michael Kuhlen

Previous studies indicate that assembly bias effects are stronger for lower mass dark matter haloes. Here we make use of high resolution re-simulations of rich clusters and their surroundings from the Phoenix Project and a large volume…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Ran Li , Liang Gao , Lizhi Xie , Qi Guo

We present a suite of FIRE-2 cosmological zoom-in simulations of isolated field dwarf galaxies, all with masses of $M_\mathrm{halo} \approx 10^{10}\,$M$_\odot$ at $z=0$, across a range of dark matter models. For the first time, we compare…

Deep optical/near-IR surface photometry of galaxies outside the Local Group have revealed faint and very red halos around objects as diverse as disk galaxies and starbursting dwarf galaxies. The colours of these structures are too extreme…

Astrophysics · Physics 2009-11-13 E. Zackrisson , N. Bergvall , C. Flynn , G. Ostlin , G. Micheva , B. Caldwell

Supernova and multiple supernova events regulate several structural properties of dwarf galaxies. In particular, they govern the metal enrichment and the energy budget of the ISM; they might induce partial (blowout) or total (blowaway) gas…

Astrophysics · Physics 2009-10-31 A. Ferrara , E. Tolstoy

When star clusters are formed at low star-formation rates (SFRs), their stellar initial mass function (IMF) can hardly be filled continuously with stars at each mass. This lack holds for massive stars and is observationally verified by the…

Astrophysics of Galaxies · Physics 2023-09-12 Patrick Steyrleithner , Gerhard Hensler

We present constraints on the stellar initial mass function (IMF) in two ultra-faint dwarf (UFD) galaxies, Hercules and Leo IV, based on deep HST/ACS imaging. The Hercules and Leo IV galaxies are extremely low luminosity (M_V = -6.2, -5.5),…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 M. Geha , T. M. Brown , J. Tumlinson , J. Kalirai , J. D. Simon , E. Kirby , D. VandenBerg , R. M. Munoz , R. Avila , P. Guhathakurta , H. Ferguson

The recently inferred variations in the stellar initial mass function (IMF) among local high-mass early-type galaxies may require a reinterpretation of observations of galaxy populations and may have important consequences for the…

Astrophysics of Galaxies · Physics 2018-07-17 Christopher Barber , Robert A. Crain , Joop Schaye

Given a flurry of recent claims for systematic variations in the stellar initial mass function (IMF), we carry out the first inventory of the observational evidence using different approaches. This includes literature results, as well as…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Crescenzo Tortora , Aaron J. Romanowsky , Nicola R. Napolitano

We use the ZFIRE survey (http://zfire.swinburne.edu.au) to investigate the high mass slope of the initial mass function (IMF) for a mass-complete (log10(M$_*$/M$_\odot$)~9.3) sample of 102 star-forming galaxies at z~2 using their H$\alpha$…

We investigate the origin of a bottom-heavy stellar initial mass function (IMF) recently observed in elliptical galaxies by using chemical evolution models with a non-universal IMF. We adopt the Kroupa IMF with the three slopes (alpha_1,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Kenji Bekki

Observations of normal galactic star-forming regions suggest there is widespread near-uniformity in the initial stellar mass function (IMF) in spite of diverse physical conditions. Fluctuations may come largely from statistical effects and…

Astrophysics · Physics 2007-05-23 B. G. Elmegreen

The white dwarf luminosity function has proven to be an excellent tool to study some properties of the galactic disk such as its age and the past history of the local star formation rate. The existence of an observational luminosity…

Astrophysics · Physics 2009-10-30 Santiago Torres , Enrique Garcia-Berro , Jordi Isern

The high metallicity of the intra-cluster medium (ICM) is generally interpreted on the base of the galactic wind scenario for elliptical galaxies. In this framework, we develop a toy-model to follow the chemical evolution of the ICM,…

Astrophysics · Physics 2009-11-10 A. Moretti , L. Portinari , C. Chiosi

We investigate the effect of a metallicity-dependent stellar initial mass function (IMF), as deduced observationally by Martin-Navarro et al. (2015c), on the inferred stellar masses and star formation rates (SFRs) of a representative sample…

Astrophysics of Galaxies · Physics 2016-08-31 Bart Clauwens , Joop Schaye , Marijn Franx

The stellar initial mass function (IMF) of early-type galaxies is the combination of the IMF of the stellar population formed in-situ and that of accreted stellar populations. Using as an observable the effective IMF $\alpha_{IMF}$, defined…

Astrophysics of Galaxies · Physics 2017-01-18 Alessandro Sonnenfeld , Carlo Nipoti , Tommaso Treu

Given the importance of white dwarfs (WDs) in many fields of modern astrophysics, the precise knowledge of the actual degree of accuracy of the associated theoretical predictions is a primary task. In the first paper of a series dedicated…

Astrophysics · Physics 2009-11-13 P. G. Prada Moroni , O. Straniero

We present detailed evolutionary calculations for carbon - oxygen - and helium - core white dwarf (WD) models with masses ranging from M= 0.1 to M= 1.2 solar masses and for metallicities Z= 0.001 and Z= 0. The sequences cover a wide range…

Astrophysics · Physics 2016-08-30 O. G. Benvenuto , L. G. Althaus