An Empirical Connection between the UV Color of Early Type Galaxies and the Stellar Initial Mass Function

Abstract

Using new UV magnitudes for a sample of early-type galaxies, ETGs, with published stellar mass-to-light ratios, Upsilon_*, we find a correlation between UV color and Upsilon_* that is tighter than those previously identified between Upsilon_* and either the central stellar velocity dispersion, metallicity, or alpha enhancement. The sense of the correlation is that galaxies with larger Upsilon_* are bluer in the UV. We conjecture that differences in the lower mass end of the stellar initial mass function, IMF, are related to the nature of the extreme horizontal branch populations that are generally responsible for the UV flux in ETGs. If so, then UV color can be used to identify ETGs with particular IMF properties and to estimate Upsilon_*.

Submitted for publication in ApJ Letters

References in corpus (8)

• The GALEX Ultraviolet Atlas of Nearby Galaxies
• A systematic variation of the stellar initial mass function in early-type galaxies
• A binary model for the UV-upturn of elliptical galaxies (MNRAS version)
• The Detailed Evolution of E+A Galaxies into Early Types
• Bottom-heavy initial mass function in a nearby compact L*-galaxy
• Kinematic modeling of disk galaxies III. The warped "Spindle" NGC 2685
• Stellar age versus mass of early-type galaxies in the Virgo Cluster
• AGB Connection and Ultraviolet Luminosity Excess in Elliptical Galaxies

Cited by in corpus (10)

• Color--Mass-to-Light Ratio Relations for Disk Galaxies
• The Dawes Review 8: Measuring the Stellar Initial Mass Function
• Depleted cores, multi-component fits, and structural parameter relations for luminous early-type galaxies
• The GALEX/S4G Surface Brightness and Color Profiles Catalog - I. Surface Photometry and Color Gradients of Galaxies
• Determining the Halo Mass Scale where Galaxies Lose Their Gas
• Ionized gas disks in elliptical and S0 galaxies at $z<1$
• The GALEX/S4G UV-IR color-color diagram: Catching spiral galaxies away from the Blue Sequence
• The ALHAMBRA survey: tight dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5
• Revealing the formation mechanism of the shell galaxy NGC474 with MUSE
• The connection between the UV colour of early type galaxies and the stellar initial mass function revisited