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Related papers: Simulating a white dwarf dominated halo

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We present an alternative method for the kinematic analysis of high proper motion surveys and discuss its application to the survey of Oppenheimer et al. (2001) for the selection of reliable halo white dwarfs (WDs). The local WD space…

Astrophysics · Physics 2009-11-10 A. Spagna , D. Carollo , M. G. Lattanzi , B. Bucciarelli

Variations in the stellar initial mass function (IMF) have been invoked to explain the spectroscopic and dynamical properties of early-type galaxies. However, no observations have yet been able to disentangle the physical driver. We analyse…

Recent results suggest that the initial mass function (IMF) of globular clusters (GCs) is metallicity and density dependent. Here it is studied how this variation affects the initial masses and the numbers of core collapse supernovae…

Astrophysics of Galaxies · Physics 2022-09-21 Henriette Wirth , Pavel Kroupa , Jaroslav Haas , Tereza Jerabkova , Zhiqiang Yan , Ladislav Šubr

In two previous papers, we presented simulations of the first galaxies in a representative volume of the Universe. The simulations are unique because we model feedback-regulated galaxy formation, using time-dependent,…

Astrophysics · Physics 2008-11-26 Massimo Ricotti , Nickolay Y. Gnedin , J. Michael Shull

We present a combined analysis of the low-mass Initial Mass Function (IMF) for seven star forming regions. We first demonstrate that the ratios of stars to brown dwarfs are consistent with a single underlying IMF. Assuming the underlying…

Astrophysics · Physics 2009-11-13 M. Andersen , M. R. Meyer , J. Greissl , A. Aversa

An analytical model predicting the growth rates, the absolute growth times and the saturation values of the magnetic field strength within galactic haloes is presented. The analytical results are compared to cosmological MHD simulations of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Alexander M. Beck , Harald Lesch , Klaus Dolag , Hanna Kotarba , Annette Geng , Federico A. Stasyszyn

Residual-gas expulsion after cluster formation has recently been shown to leave an imprint in the low-mass present-day stellar mass function (PDMF) which allowed the estimation of birth conditions of some Galactic globular clusters (GCs)…

Astrophysics of Galaxies · Physics 2015-06-04 Michael Marks , Pavel Kroupa , Jörg Dabringhausen , Marcel S. Pawlowski

We use stellar dynamics, strong lensing, stellar population synthesis models, and weak lensing shear measurements to constrain the dark matter (DM) profile and stellar mass in a sample of 53 massive early-type galaxies. We explore three DM…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 M. W. Auger , T. Treu , R. Gavazzi , A. S. Bolton , L. V. E. Koopmans , P. J. Marshall

We present results of cosmological N-body hydrodynamic chemistry simulations of primordial structure growth and evolution in a scenario with warm dark matter (WDM) having a mass of 3 keV (thermal relic) and compare with a model consisting…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Umberto Maio , Matteo Viel

[abridged] We report a series of simulations of the formation of a star cluster similar to the Orion Nebula Cluster (ONC), including both radiative transfer and protostellar outflows, and starting from both smooth and self-consistently…

Solar and Stellar Astrophysics · Physics 2015-06-04 Mark R. Krumholz , Richard I. Klein , Christopher F. McKee

We study properties of dark matter halos at high redshifts z=2-10 for a vast range of masses with the emphasis on dwarf halos with masses 10^7-10^9 Msun/h. We find that the density profiles of relaxed dwarf halos are well fitted by the NFW…

Astrophysics · Physics 2009-11-10 P. Colin , A. Klypin , O. Valenzuela , S. Gottlober

By means of N-body+Hydrodynamic zoom-in simulations we study the evolution of the inner dark matter and stellar mass distributions of central dwarf galaxies formed in halos of virial masses Mv=2-3x10^10 Msun at z=0, both in a WDM and CDM…

Astrophysics of Galaxies · Physics 2016-03-15 Alejandro Gonzalez-Samaniego , Vladimir Avila-Reese , Pedro Colin

The true nature of primordial magnetic fields (PMFs) and their role in the formation of galaxies still remains elusive. To shed light on these unknowns, we investigate their impact by varying two sets of properties: (i) accounting for the…

Astrophysics of Galaxies · Physics 2024-10-02 Mahsa Sanati , Sergio Martin-Alvarez , Jennifer Schober , Yves Revaz , Adrianne Slyz , Julien Devriendt

There is substantial evidence that the initial mass function (IMF) may be a function of the local star formation conditions. In particular, the IMF is predicted to flatten with increasing local luminosity density, with the formation of…

Astrophysics · Physics 2009-10-30 Jason A. Taylor

Intermediate Mass Black Holes (IMBHs; 10^1.3-5 M_sun) are thought to form as relics of Population III stars or from the runaway collapse of stars in young clusters; their number and very existence are uncertain. We ran N-body simulations of…

Astrophysics · Physics 2009-11-11 M. Mapelli , A. Ferrara , N. Rea

Fifty years after Ed Salpeter's seminal paper, tremendous progress both on the observational and theoretical sides allow a fairly accurate determination of the Galactic IMF not only down to the hydrogen-burning limit but into the brown…

Astrophysics · Physics 2015-11-11 Gilles Chabrier

We use a series of magnetohydrodynamic simulations including both radiative and protostellar outflow feedback to study the environmental variation of the initial mass function. The simulations represent a carefully-controlled experiment…

Astrophysics of Galaxies · Physics 2022-09-28 Tabassum S Tanvir , Mark R Krumholz , Christoph Federrath

Approximately $0.2 \pm 0.2$ of white dwarfs (WDs) show signs of pollution by metals, which is likely due to the accretion of tidally disrupted planetary material. Models invoking planet-planet interactions after WD formation generally…

Earth and Planetary Astrophysics · Physics 2016-08-03 Adrian S. Hamers , Simon F. Portegies Zwart

The cold dark matter (CDM) model has two unsolved issues: simulations overpredict the satellite abundance around the Milky Way (MW) and it disagrees with observations of the central densities of dwarf galaxies which prefer constant density…

Astrophysics of Galaxies · Physics 2015-09-10 Victor H. Robles , V. Lora , T. Matos , F. J. Sanchez-Salcedo

Black holes are usually observed to be of stellar-mass or supermassive. By natural extension, there should be a population of Intermediate-Mass Black Holes (IMBHs: with mass between $100$ to $10^6 M_{\odot}$) in the Universe; which has…

Astrophysics of Galaxies · Physics 2020-06-24 Paramita Barai , Elisabete M. de Gouveia Dal Pino
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