Bibcode
Bouquin, A. Y. K.; Gil de Paz, Armando; Muñoz-Mateos, Juan Carlos; Boissier, Samuel; Sheth, Kartik; Zaritsky, Dennis; Peletier, Reynier F.; Knapen, J. H.; Gallego, Jesús
Bibliographical reference
The Astrophysical Journal Supplement Series, Volume 234, Issue 2, article id. 18, 30 pp. (2018).
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2
2018
Citations
33
Refereed citations
30
Description
We present new spatially resolved surface photometry in the
far-ultraviolet (FUV) and near-ultraviolet (NUV) from images obtained by
the Galaxy Evolution Explorer (GALEX) and IRAC1 (3.6 μm) photometry
from the Spitzer Survey of Stellar Structure in Galaxies
(S4G). We analyze the radial surface brightness profiles μ
FUV, μ NUV, and μ [3.6], as well
as the radial profiles of (FUV ‑ NUV), (NUV ‑ [3.6]), and
(FUV ‑ [3.6]) colors in 1931 nearby galaxies (z < 0.01). The
analysis of the 3.6 μm surface brightness profiles also allows us to
separate the bulge and disk components in a quasi-automatic way and to
compare their light and color distribution with those predicted by the
chemo-spectrophotometric models for the evolution of galaxy disks of
Boissier & Prantzos. The exponential disk component is best isolated
by setting an inner radial cutoff and an upper surface brightness limit
in stellar mass surface density. The best-fitting models to the measured
scale length and central surface brightness values yield distributions
of spin and circular velocity within a factor of two of those obtained
via direct kinematic measurements. We find that at a surface brightness
fainter than μ [3.6] = 20.89 mag
arcsec‑2, or below 3 × 108 M
⊙ kpc‑2 in stellar mass surface density,
the average specific star formation rate (sSFR) for star-forming and
quiescent galaxies remains relatively flat with radius. However, a large
fraction of GALEX Green Valley galaxies show a radial decrease in sSFR.
This behavior suggests that an outside-in damping mechanism, possibly
related to environmental effects, could be testimony of an early
evolution of galaxies from the blue sequence of star-forming galaxies
toward the red sequence of quiescent galaxies.
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