SDWFS Catalog August 2009 v1.1 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 delivery consists of four band-matched catalogs for each of the four epochs and for the total SDWFS coadd data, a total of 20 catalogs. Vega magnitudes are reported for each IRAC band: 3.6, 4.5, 5.8, and 8 microns. Each source was measured three ways: 4 arcsec diameter aperture, 6 arcsec diameter aperture, and Kron radius aperture (MAG_AUTO in SExtractor). Source coordinates correspond to 2MASS catalog positions to within 0.2 arcsec. The tabulated uncertainties are twice the SExtractor (statistical only) uncertainties as an attempt to account for systematic uncertainties.

The SDWFS data delivery documentation can be found here.

SDWFS Catalog August 2009 v1.1 Column Descriptions

Gator serves the 20 SDWFS August 2009 v1.1 catalogs (27 columns, 38314 data rows in the smallest catalog to 677522 data rows in the largest). SDWFS provides the following information for the catalog:

Column Name Intype Units Description
ra real deg RA (decimal degrees, J2000.0)
dec real deg Dec (decimal degrees, J2000.0)
ch1_4 real mag 3.6um Vega mag: 4 arcsec diameter aperture
ch2_4 real mag 4.5um Vega mag: 4 arcsec diameter aperture
ch3_4 real mag 5.8um Vega mag: 4 arcsec diameter aperture
ch4_4 real mag 8.0um Vega mag: 4 arcsec diameter aperture
err1_4 real mag 3.6um uncertainty: 4 arcsec aperture
err2_4 real mag 4.5um uncertainty: 4 arcsec aperture
err3_4 real mag 5.8um uncertainty: 4 arcsec aperture
err4_4 real mag 8.0um uncertainty: 4 arcsec aperture
ch1_6 real mag 3.6um Vega mag: 6 arcsec diameter aperture
ch2_6 real mag 4.5um Vega mag: 6 arcsec diameter aperture
ch3_6 real mag 5.8um Vega mag: 6 arcsec diameter aperture
ch4_6 real mag 8.0um Vega mag: 6 arcsec diameter aperture
err1_6 real mag 3.6um uncertainty: 6 arcsec aperture
err2_6 real mag 4.5um uncertainty: 6 arcsec aperture
err3_6 real mag 5.8um uncertainty: 6 arcsec aperture
err4_6 real mag 8.0um uncertainty: 6 arcsec aperture
ch1_ma real mag 3.6um Vega mag: Kron (MAG_AUTO) radius aperture
ch2_ma real mag 4.5um Vega mag: Kron (MAG_AUTO) radius aperture
ch3_ma real mag 5.8um Vega mag: Kron (MAG_AUTO) radius aperture
ch4_ma real mag 8.0um Vega mag: Kron (MAG_AUTO) radius aperture
err1_ma real mag 3.6um uncertainty: Kron (MAG_AUTO) radius aperture
err2_ma real mag 4.5um uncertainty: Kron (MAG_AUTO) radius aperture
err3_ma real mag 5.8um uncertainty: Kron (MAG_AUTO) radius aperture
err4_ma real mag 8.0um uncertainty: Kron (MAG_AUTO) radius aperture
flag int SExtractor flag