S4G Early Type Galaxy Catalog Definitions

Overview

The Spitzer Survey of Stellar Structure in Galaxies (S4G) is a volume-, magnitude-, and size-limited survey of over 2300 nearby galaxies at 3.6 and 4.5 microns. This is an extremely deep survey reaching an unprecedented 1 sigma surface brightness limit of μ3.6(AB) = 27 mag arcsec-2. This translates to a stellar surface density of << 1 Msun pc-2.

The S4G Early Type Galaxy Catalog extends S4G to include 465 early type galaxies not observed during the original S4G. If you use this catalog, please cite Watkins et al. (2022).

Name Intype Units Description
object char Galaxy name
mag1 double mag Asymptotic AB magnitude at 3.6 microns
emag1 double mag Growth-curve fitting error in mag1
semag1 double mag Local sky-subtraction error on mag1
Mabs1 double mag Absolute AB magnitude at 3.6 microns
mag2 double mag Asymptotic AB magnitude at 4.5 microns
emag2 double mag Growth-curve fitting error in mag2
semag2 double mag Local sky-subtraction error on mag2
Mabs2 double mag Absolute AB magnitude at 4.5 microns
c31_1 double r75/r25 concentration index at 3.6 microns
c42_1 double 5*log10(r80/r20) concentration index at 3.6 microns
c31_2 double r75/r25 concentration index at 4.5 microns
c42_2 double 5*log10(r80/r20) concentration index at 4.5 microns
Mstar double solMass log10(stellar mass)
dmean double Mpc Mean redshift-independent distance
re1 double arcsec Effective (half-light) radius at 3.6 microns
re2 double arcsec Effective (half-light) radius at 4.5 microns
sky1 double MJy/sr Sky level at 3.6 microns
ssky1 double MJy/sr Local, pixel-to-pixel noise at 3.6 microns
esky1 double MJy/sr Large scale sky noise at 3.6 microns
sky2 double MJy/sr Sky level at 4.5 microns
ssky2 double MJy/sr Local, pixel-to-pixel noise at 4.5 microns
esky2 double MJy/sr Large scale sky noise at 4.5 microns
sma1_25p5 double arcsec Semi-major axis at mu_3.6 = 25.5 AB mag/arcsec2
sma2_25p5 double arcsec Semi-major axis at mu_4.5 = 25.5 AB mag/arcsec2
PA1_25p5 double deg Position angle at mu_3.6 = 25.5 AB mag/arcsec2
PA2_25p5 double deg Position angle at mu_4.5 = 25.5 AB mag/arcsec2
ellip1_25p5 double Ellipticity (1-b/a) at mu_3.6 = 25.5 AB mag/arcsec2
ellip2_25p5 double Ellipticity (1-b/a) at mu_4.5 = 25.5 AB mag/arcsec2
sma1_26p5 double arcsec Semi-major axis at mu_3.6 = 26.5 AB mag/arcsec2
sma2_26p5 double arcsec Semi-major axis at mu_4.5 = 26.5 AB mag/arcsec2
PA1_26p5 double deg Position angle at mu_3.6 = 26.5 AB mag/arcsec2
PA2_26p5 double deg Position angle at mu_4.5 = 26.5 AB mag/arcsec2
ellip1_26p5 double Ellipticity (1-b/a) at mu_3.6 = 26.5 AB mag/arcsec2
ellip2_26p5 double Ellipticity (1-b/a) at mu_4.5 = 26.5 AB mag/arcsec2
ra double deg Right ascension (J2000)
dec double deg Declination (J2000)
type char Optical Hubble type
bar char Bar presence
ring char Ring presence
multiple char Multiple system
compactness char C=Compact. D=Difusse. NULL just means not classified!
t double Morphological type code
e_t double Error on t
logd25 double log(0.1arcmin) log10 of apparent diameter (d25 in 0.1')
e_logd25 double Error on logd25
pa double deg Major axis position angle at mu_B = 25 mag/arcsec2
brief double mag/arcsec**2 Mean effective surface brightness in the B band
e_brief double mag/arcsec**2 Error on brief
bt double mag Total B-magnitude
e_bt double mag Error on bt
it double mag Total I-magnitude
e_it double mag Error on it
ube double mag Effective U-B color
bve double mag Effective B-V color
vmaxg double km/s Apparent maximum rotation velocity of gas
e_vmaxg double km/s Error on vmaxg
vdis double km/s Central velocity dispersion
e_vdis double km/s Error on vdis
mg2 double mag Central Mg2 Lick index
e_mg2 double mag Error on mg2
m21 double mag 21-cm line flux in magnitude (see definition in text)
e_m21 double mag Error on m21
mfir double mag Far infrared magnitude (see definition in text)
vrad double km/s Heliocentric radial velocity from radio measurement
e_vrad double km/s Error on vrad
vopt double km/s Heliocentric radial velocity from optical measurement
e_vopt double km/s Error on vopt
v double km/s Mean heliocentric radial velocity
e_v double km/s Error on v
ag double mag Galactic extinction in B magnitude
ai double mag Extinction due to inclination in B magnitude
incl double deg Inclination between line of sight and polar axis
a21 double mag 21-cm self absorption in magnitude
logdc double log(0.1arcmin) log10 of apparent corrected diameter (dc in 0.1')
btc double mag Total apparent corrected B-magnitude
ubtc double mag Total apparent corrected U-B color
bvtc double mag Total apparent corrected B-V color
bri25 double mag/arcsec**2 Mean surface brightness within isophote 25
vrot double km/s Maximum velocity rotation
e_vrot double km/s Error on vrot
m21c double mag Corrected 21-cm line flux in magnitude (see text)
hic double mag 21-cm index bt-m21c in magnitude
vlg double km/s Radial velocity with respect to the Local Group
vgsr double km/s Radial velocity with respect to the GSR
vvir double km/s Radial velocity corrected for Virgocentric infall
v3k double km/s Radial velocity with respect to the CMB radiation
modz double mag Redshift distance modulus
e_modz double mag Error on modz
mod0 double mag True distance modulus (from parameters)
e_mod0 double mag Error on mod0
mabs double mag Absolute B-magnitude
e_mabs double mag Error on mabs
lim1_1 double mag/arcsec Inner linear fitting limit on growth-curve extrapolation at 3.6 microns, dMag/d
lim2_1 double mag/arcsec Outer linear fitting limit on growth-curve extrapolation at 3.6 microns, dMag/d
lim1_2 double mag/arcsec Inner linear fitting limit on growth-curve extrapolation at 4.5 microns, dMag/d
lim2_2 double mag/arcsec Outer linear fitting limit on growth-curve extrapolation at 4.5 microns, dMag/d
cvrhs_class char CVRHS morphological classification (see Buta et al. 2015)
outer char CVRHS outer structures (see Buta et al. 2015)
family long CVRHS family (see Buta et al. 2015)
inner char CVRHS inner structures (see Buta et al. 2015)
cvrhs_t long CVRHS numerical T-type (see Buta et al. 2015)
dstd double Mpc Standard deviation of all redshift-indenpendent distances
dmin double Mpc Minimum redshift-independent distance
dmax double Mpc Maximum redshift-independent distance