SDWFS Variability Catalog Definitions

SDWFS Overview

The Spitzer Deep, Wide-Field Survey (SDWFS) is a four-epoch infrared survey of 10 square degrees in the Boötes field of the NOAO Deep Wide-Field Survey using the IRAC instrument on the Spitzer Space Telescope. SDWFS, a Spitzer Cycle 4 Legacy project, occupies a unique position in the area-depth survey space defined by other Spitzer surveys. The four epochs that make up SDWFS permit - for the first time - the selection of infrared-variable and high proper motion objects over a wide field on timescales of years. Because of its large survey volume, SDWFS is sensitive to galaxies out to z ~ 3 with relatively little impact from cosmic variance for all but the richest systems. The SDWFS data sets will thus be especially useful for characterizing galaxy evolution beyond z ~ 1.5.

The SDWFS Variability Catalog presents variability information for all SDWFS sources with a 5-sigma detection at 3.6 microns. For more details, see Kozlowski et al. (2010).

SDWFS Variability Catalog Column Descriptions

Gator serves the SDWFS Variability Catalog (24 columns, 515055 data rows).

Name	Intype	Units	Description
objectname	char		object name
ra	real	deg	Right Ascension (J2000)
dec	real	deg	Declination (J2000)
ch1	real	mag	4 arcsec diameter aperture-corrected magnitude in ch1
err1	real	mag	error for 4 arcsec diameter aperture-corrected magnitude in ch1
ch2	real	mag	4 arcsec diameter aperture-corrected magnitude in ch2
err2	real	mag	error for 4 arcsec diameter aperture-corrected magnitude in ch2
ch3	real	mag	4 arcsec diameter aperture-corrected magnitude in ch3
err3	real	mag	error for 4 arcsec diameter aperture-corrected magnitude in ch3
ch4	real	mag	4 arcsec diameter aperture-corrected magnitude in ch4
err4	real	mag	error for 4 arcsec diameter aperture-corrected magnitude in ch4
nch1	int		number of epochs used for variability in ch1
sig1	real	mag	standard deviation for the light curve in ch1, based only on epochs in ch1
vs1	real		variability significance in ch1
nch2	int		number of epochs used for variability in ch2
sig2	real	mag	standard deviation for the light curve in ch2, based only on epochs in ch2
vs2	real		variability significance in ch2
nch12	int		common number of epochs used for variability in ch1 and ch2
csig1	real	mag	standard deviation for the light curve in ch1, based on epochs in ch1 for which there are corresponding epochs in ch2
csig2	real	mag	standard deviation for the light curve in ch2, based on epochs in ch2 for which there are corresponding epochs in ch1
cov12	real	mag^2	covariance between ch1 and ch2
r12	real		correlation between ch1 and ch2
sig12	real		joint ch1 and ch2 variability significance
flag	int		flag (1=reliable object, 0=object close to bright star)