The Galactic Disk Mass Function: Reconciliation of the Hubble Space Telescope and Nearby Determinations

By G. Chabrier. 2003

521 citations recorded by the source corpus.

We derive and parameterize the Galactic mass function (MF) below 1 M☉ characteristic of both single objects and binary systems. We resolve the long-standing discrepancy between the MFs derived from the Hubble Space Telescope (HST) and from the nearby luminosity functions, respectively. We show that this discrepancy stemmed from two cumulative effects, namely, (1) incorrect color-magnitude-determined distances, due to a substantial fraction of M dwarfs in the HST sample belonging to the metal-depleted thick-disk population, as corrected recently by Zheng et al., and (2) unresolved binaries. We show that both the nearby and HST MF for unresolved systems are consistent with a fraction ~50% of M dwarf binaries, with the mass of both the primaries and the companions originating from the same underlying single MF. This implies that ~30% of M dwarfs should have an M dwarf companion and ~20% should have a brown dwarf companion, in agreement with recent determinations. The present calculations show that the so-called "brown dwarf desert" should be reinterpreted as a lack of high mass ratio (m2/m1 ≲ 0.1) systems and does not preclude a substantial fraction of brown dwarfs as companions of M dwarfs or for other brown dwarfs.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/f98137940d1b58d9b5506f2ab09f165b5c919dd2

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

Deriving model-based Te-consistent chemical abundances in ionized gaseous nebulae (2014, methodology): “…(Mollá et al. 2009) synthesis evolutionary models as cluster ionising SED assuming an instantaneous burst with an age of 1 Myr with an initial mass function of Chabrier (2003) and using in each model the metallicity assumed for the gas, as scaled to the solar value with the oxygen abundance.”
FORMING REALISTIC LATE-TYPE SPIRALS IN A ΛCDM UNIVERSE: THE ERIS SIMULATION (2011, background): “…stellar mass of Eris can now be weighted selfconsistently against the Behroozi et al. (2010) average stellar mass-halo relation (which uses a Chabrier 2003 IMF), free of IMF systematics, after offsetting all Behroozi et al. (2010) stellar masses by 0.06 dex (to correct from Chabrier to…”
ON THE DEARTH OF COMPACT, MASSIVE, RED SEQUENCE GALAXIES IN THE LOCAL UNIVERSE (2009, methodology): “…by the MPIA Garching group.3 JB has fit the ugriz photometry of all galaxies using the synthetic stellar population library described by Gallazzi et al. (2005), based on Bruzual & Charlot (2003) models and assuming a Chabrier (2003) stellar initial mass function (IMF) in the range 0.1—100 M⊙.”
x-cigale: fitting AGN/galaxy SEDs from X-ray to infrared (2020, methodology): “We adopt a Chabrier (2003) IMF with metallicity (Z) fixed to the solar value of 0.02.”
MOST SUBMILLIMETER GALAXIES ARE MAJOR MERGERS (2010, methodology): “We conclude that the Hainline (2008) stellar masses, adjusted to a Chabrier (2003) IMF, are consistent with our independent mass measurements (Fig.”
COLOR–MASS-TO-LIGHT-RATIO RELATIONS FOR DISK GALAXIES (2014, methodology): “Whether this can be reconciled with measurements on the IMF and other known dynamical constraints (e.g., Sellwood 1999) is beyond the scope of this work.”
OGLE 2003-BLG-235/MOA 2003-BLG-53: A Planetary Microlensing Event (2004, unknown): “There are few systems known with (Halbwachs et al.0.01 q 0.1 2000; Chabrier 2003; Mazeh & Zucker 2002).”
Star formation and mass assembly in high-redshift galaxies (2009, methodology): “To be able to compare our findings with the Millennium Simulation predictions, we converted 〈 SSFR [Gyr−1] 〉 ∆z IR+UV SED fitting Mlim[M⊙] our masses and SFR to the Chabrier (2003) IMF used by the Millennium Simulation.”
The Field Substellar Mass Function Based on the Full-sky 20 pc Census of 525 L, T, and Y Dwarfs (2020, methodology): “…laws (dN/dM ∝ M−α) with α values ranging from −1.0 to 1.5, the log-normal distribution (dN/dM ∝ e−(ln(M)−µ)2/2σ2 ) with values of the mean (µ) and standard deviation (σ) taken from Chabrier (2001), Chabrier (2003a), and Chabrier (2003b), and a bi-partite power law favored by Kroupa et al. (2013).”
Production of dust by massive stars at high redshift (2011, background): “Later studies have shown thatthe IMF flattens for stars below 0.5 M⊙ and significantly declines in the mass regime< 0.1 M⊙ (e.g., Kroupa, 2002; Chabrier, 2003a,b).”
DIFFERENT STAR FORMATION LAWS FOR DISKS VERSUS STARBURSTS AT LOW AND HIGH REDSHIFTS (2010, methodology): “While the general consensus is that the appropriate IMF for local spirals is bottom-light as in Chabrier (2003) or Kroupa (2002), very little is known observationally for the case of local (U)LIRGs and even less for high redshift galaxies.”
AN ALMA SURVEY OF SUB-MILLIMETER GALAXIES IN THE EXTENDED CHANDRA DEEP FIELD SOUTH: PHYSICAL PROPERTIES DERIVED FROM ULTRAVIOLET-TO-RADIO MODELING (2015, methodology): “We compute the emission by SSPs using the spectral population synthesis models of Bruzual & Charlot (2003; using a Chabrier 2003 IMF); we adopt a uniform prior in metallicity from 0.2 to 2 times solar.”
The mass function of dense molecular cores and the origin of the IMF (2006, methodology): “Also plotted are the field star IMFs of Kroupa (2001) (solid grey) and Chabrier (2003) (dotted grey), and the Muench et al. (2002) (dashed grey) IMF all scaled up by a factor of∼ 3 in mass. therefore the stellar and core mass functions should be of similar overall functional form.”
The stellar masses of 25 000 galaxies at 0.2 ≤ z ≤ 1.0 estimated by the COMBO-17 survey (2006, methodology): “The stellar M/L values and colors from such an IMF are very similar to those of a Kroupa (2001) IMF or a Chabrier (2003) IMF.”
Galaxy luminosities, stellar masses, sizes, velocity dispersions as a function of morphological type (2009, methodology): “This is based on a likelihood analysis of the spectra, assumes the Chabrier (2003) IMF, and returns M∗/Lz.”
Physical Processes in the Interstellar Medium (2014, background): “More information on the stellar IMF can be found in the seminal papers by Scalo (1986), Kroupa (2002), and Chabrier (2003a), as well as in the reviews by Kroupa et al. (2013) and Offner et al. (2014).”
Resolved stellar mass maps of galaxies. I: method and implications for global mass estimates (2009, background): “In the following, we will work under the assumption that the IMF is universal and well described by Chabrier (2003).”
Stellar population synthesis at the resolution of 2003 (2003, methodology): “Here we adopt the Chabrier (2003b) IMF because it is physically motivated and provides a better fit to counts of low-mass stars and brown dwarfs in the Galactic disc (Chabrier 2001, 2002, 2003a).”