J/MNRAS/446/2030 FUV and NUV magnitudes of ETG (Zaritsky+, 2015)
The connection between the UV colour of early-type galaxies and the stellar
initial mass function revisited.
Zaritsky D., Gil de Paz A., Bouquin A.Y.K.
<Mon. Not. R. Astron. Soc., 446, 2030-2037 (2015)>
=2015MNRAS.446.2030Z 2015MNRAS.446.2030Z (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Photometry, ultraviolet
Keywords: stars: luminosity function, mass function - galaxies: stellar content
Abstract:
We extend our initial study of the connection between the UV colour of
galaxies and both the inferred stellar mass-to-light ratio,
Υ*, and a mass-to-light ratio referenced to Salpeter initial
mass function (IMF) models of the same age and metallicity,
Υ*/ΥSal, using new UV magnitude measurements for a
much larger sample of early-type galaxies, ETGs, with dynamically
determined mass-to-light ratios. We confirm the principal empirical
finding of our first study, a strong correlation between the
GALEX FUV-NUV colour and Υ*. We show that this finding is not
the result of spectral distortions limited to a single passband (e.g.
metallicity-dependent line-blanketing in the NUV band), or of the
analysis methodology used to measure Υ*, or of the inclusion
or exclusion of the correction for stellar population effects as
accounted for using Υ*/ΥSal. The sense of the
correlation is that galaxies with larger Υ*, or larger
Υ*/ΥSal, are bluer in the UV. We conjecture that
differences in the low-mass end of the stellar IMF are related to the
nature of the extreme horizontal branch stars generally responsible
for the UV flux in ETGs. If so, then UV colour can be used to identify
ETGs with particular IMF properties and to estimate Υ*. We
also demonstrate that UV colour can be used to decrease the scatter
about the Fundamental Plane and Manifold, and to select peculiar
galaxies for follow-up with which to further explore the cause of
variations in Υ* and UV colour.
Description:
The parent sample for this study is the set of ATLAS3D galaxies with
published Υ* (Cappellari et al. 2013MNRAS.432.1709C 2013MNRAS.432.1709C,
2013MNRAS.432.1862C 2013MNRAS.432.1862C).
Our addition to the existing data for this sample is the set of
homogeneous measurements of the FUV (1350-1750Å) and NUV
(1750-2750Å) photometry made possible by the Galaxy Evolution
Explorer (GALEX) satellite. We undertake a photometric analysis of
galaxies in the ATLAS3D sample with available pipeline-processed
(GR6/7 release) GALEX data from the Mikulski Archive for Space
Telescopes (MAST) archive maintained by the Space Telescope Science
Institute.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 37 192 Galaxy sample and properties
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See also:
J/MNRAS/413/813 : ATLAS3D project. I. (Cappellari+, 2011)
J/MNRAS/414/888 : ATLAS3D project. III. (Emsellem+, 2011)
J/MNRAS/414/940 : ATLAS3D project. IV. (Young+, 2011)
J/MNRAS/416/1680 : ATLAS3D project. VII. (Cappellari+, 2011)
J/MNRAS/433/2812 : ATLAS3D project. XXIII. (Krajnovic+, 2013)
J/MNRAS/446/120 : ATLAS3D project. XXIX (Duc+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Galaxy name
10- 14 F5.2 mag FUV GALEX FUV asymptotic magnitude
17- 20 F4.2 mag e_FUV 1 sigma uncertainty in FUV magnitude
22- 26 F5.2 mag NUV GALEX NUV asymptotic magnitude
29- 32 F4.2 mag e_NUV 1 sigma uncertainty in NUV magnitude
34- 37 F4.1 Mpc Dist Adopted distance to galaxy
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History:
From electronic version of the journal
References:
Zaritsky et al., Paper I 2014ApJ...780L...1Z 2014ApJ...780L...1Z
(End) Patricia Vannier [CDS] 15-Jun-2015