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相关论文: The SWELLS survey. III. Disfavouring "heavy" initi…

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We use a sample of 53 massive early-type strong gravitational lens galaxies with well-measured redshifts (ranging from z=0.06 to 0.36) and stellar velocity dispersions (between 175 and 400 km/s) from the Sloan Lens ACS (SLACS) Survey to…

Stars and dark matter account for most of the mass of early-type galaxies, but uncertainties in the stellar population and the dark matter profile make it challenging to distinguish between the two components. Nevertheless, precise…

We perform a direct comparison of two state-of-the art single stellar population (SSP) models that have been used to demonstrate the non-universality of the low-mass end of the Initial Mass Function (IMF) slope. The two public versions of…

星系天体物理 · 物理学 2015-06-18 Chiara Spiniello , Scott C. Trager , Léon V. E. Koopmans

Recent studies of early-type galaxies have suggested that the initial mass function (IMF) slope is bottom-heavy, i.e. they contain a larger fraction of low-mass stars than the Milky Way. However, measurements of the IMF remain challenging…

星系天体物理 · 物理学 2020-10-14 A. Feldmeier-Krause , I. Lonoce , W. L. Freedman

The presence (and nature) of variations in the stellar initial mass function (IMF) at substantially sub-solar masses and metallicities ($m$$<$0.5M$_{\odot}$, [M/H]$\lesssim$$-$1) remains poorly constrained. Predictions from simulations vary…

星系天体物理 · 物理学 2026-03-17 Roger E. Cohen , Mario Gennaro , Matteo Correnti , Kristen B. W. McQuinn , Vedant Chandra

Using samples drawn from the Sloan Digital Sky Survey, we study for the first time the relation between large-scale environments (Clusters, Groups and Voids) and the stellar Initial Mass Function (IMF). We perform an observational approach…

星系天体物理 · 物理学 2019-04-29 Elham Eftekhari , Moein Mosleh , Alexandre Vazdekis , Saeed Tavasoli

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),…

宇宙学与河外天体物理 · 物理学 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 high-mass slope of the stellar initial mass function (IMF), first measured by E. Salpeter in 1955, appears universal across star-forming environments. Its origin remains a central unsolved problem in astrophysics. Using $getsf$, we…

星系天体物理 · 物理学 2026-05-22 Guo-Yin Zhang , Alexander Men'shchikov , Jin-Zeng Li

The Sloan Lens ACS (SLACS) Survey is an efficient Hubble Space Telescope Snapshot imaging survey for new galaxy-scale strong gravitational lenses. The targeted lens candidates are selected spectroscopically from within the Sloan Digital Sky…

天体物理学 · 物理学 2010-11-11 Adam S. Bolton , Scott Burles , Leon V. E. Koopmans , Tommaso Treu , Leonidas A. Moustakas

A single-slope "Salpeter" IMF overpredicts the stellar M/L ratio of local elliptical galaxies by about a factor of 2, which requires the IMF to be flatter below about one solar mass. On the other hand a Salpeter IMF for stars more massive…

天体物理学 · 物理学 2015-11-11 Alvio Renzini

In the last decade, growing evidence has emerged supporting a non-universal stellar Initial Mass Function (IMF) in massive galaxies, with a larger number of dwarf stars with respect to the Milky-Way (bottom-heavy IMF). However, a consensus…

The local stellar mass density is observed to be significantly lower than the value obtained from integrating the cosmic star formation history (SFH), assuming that all the stars formed with a Salpeter initial mass function (IMF). Even…

天体物理学 · 物理学 2009-11-13 Stephen M. Wilkins , Andrew M. Hopkins , Neil Trentham , Rita Tojeiro

We combine in a self-consistent way the constraints from both gravitational lensing and stellar kinematics to perform a detailed investigation of the internal mass distribution, amount of dark matter, and dynamical structure of the 16…

宇宙学与河外天体物理 · 物理学 2015-05-27 Matteo Barnabe , Oliver Czoske , Leon V. E. Koopmans , Tommaso Treu , Adam S. Bolton

We present a spatially resolved comparison of the stellar-mass and total-mass surface distributions of nine early-type galaxies. The galaxies are a subset of the Sloan Lens ACS survey (or SLACS; Bolton et al. 2006). The total-mass…

天体物理学 · 物理学 2009-11-13 Ignacio Ferreras , Prasenjit Saha , Scott Burles

We present the current photometric dataset for the Sloan Lens ACS (SLACS) Survey, including HST photometry from ACS, WFPC2, and NICMOS. These data have enabled the confirmation of an additional 15 grade `A' (certain) lens systems, bringing…

宇宙学与河外天体物理 · 物理学 2014-11-20 M. W. Auger , T. Treu , A. S. Bolton , R. Gavazzi , L. V. E. Koopmans , P. J. Marshall , K. Bundy , L. A. Moustakas

This paper revisits the classical Kennicutt method for inferring the stellar initial mass function (IMF) from the integrated light properties of galaxies. The large size, uniform high quality data set from the Sloan Digital Sky Survey DR4…

天体物理学 · 物理学 2011-04-20 Erik A. Hoversten , Karl Glazebrook

Evidence from different probes of the stellar initial mass function (IMF) of massive early-type galaxies (ETGs) has repeatedly converged on IMFs more bottom-heavy than in the Milky Way (MW). This consensus has come under scrutiny due to…

星系天体物理 · 物理学 2023-09-29 Kianusch Mehrgan , Jens Thomas , Roberto Saglia , Taniya Parikh , Bianca Neureiter , Peter Erwin , Ralf Bender

One of the most robust observations of the stellar initial mass function (IMF) is its near-universality in the Milky Way and neighboring galaxies. But recent observations of early-type galaxies can be interpreted to imply a bottom-heavy…

星系天体物理 · 物理学 2019-03-26 David Guszejnov , Philip F. Hopkins , Andrew S. Graus

Spectral absorption features can be used to constrain the stellar initial mass function (IMF) in the integrated light of galaxies. Spectral indices used at low redshift are in the far red, and therefore increasingly hard to detect at higher…

星系天体物理 · 物理学 2017-01-25 Baitian Tang , Guy Worthey

We present a strong and weak gravitational lens model of the galaxy cluster MACSJ0416.1-2403, constrained using spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) and Hubble Frontier Fields (HFF) imaging data. We search…