Extragalactic FLS Overview

The Extragalactic First Look Survey is composed of 4 square degrees of imaging with MIPS and IRAC centered at J1718+5930, with extensive ancillary data from ground-based optical and radio telescopes. As one of the first observations made with Spitzer after the completion of Science Verification at the end of 2003 November, the aim of this 67 hr survey was to characterize the extragalactic source populations observed with Spitzer down to sub-millijansky levels in the mid-infrared.

Details about the IRAC observations can be found in Lacy et al. (2005).

XFLS IRAC Single Channel Catalog Column Descriptions

IRSA serves XFLS IRAC Single Channel Catalogs for each of the four IRAC channels, covering both the Main and Verification fields of the XFLS (24 columns, 2,517 data rows in the smallest catalog to 93,689 data rows in the largest).

Name	Intype	Units	Description
srcID	int		Source identification
pix_x	double		x pixel coordinate
pix_y	double		y pixel coordinate
ra	double	deg	Right Ascension (J2000)
dec	double	deg	Declination (J2000)
bestflux	double	microjy	Most reliable estimate of the flux density
bestaper	double	pixel	Aperture of bestflux
errbestfl	double	microjy	Uncertainty of bestflux
SN	double		Signal to noise ratio
ap1	double	microjy	Aperture corrected flux density in a 6" diameter aperture
ap2	double	microjy	Aperture corrected flux density in a 9.26" diameter aperture
ap3	double	microjy	Aperture corrected flux density in a 14.86" diameter aperture
ap4	double	microjy	Aperture corrected flux density in a 24.4" diameter aperture
errap1	double	microjy	Uncertainty in ap1
errap2	double	microjy	Uncertainty in ap2
errap3	double	microjy	Uncertainty in ap3
errap4	double	microjy	Uncertainty in ap4
area	int	pixel	Area of isophotal aperture
Ixx	double		Second moment of the flux distribution
Iyy	double		Second moment of the flux distribution
Ixy	double		Second moment of the flux distribution
flag	int		Sum of flag bits: 0 = More than 10\% area affected by bad pixels 1 = Object originally blended with another one 2 = At least one object pixel is saturated 3 = Object is truncated at image boundary 4 = Object's aperture data are incomplete or corrupted 5 = Object's isophotal data are incomplete or corrupted 6 = A memory overflow occurred during deblending 7 = A memory overflow occurred during extraction 8 = Region affected by muxbleed, pulldown, or banding 9 = Object in halo of bright star 10 = Object contaminated by latent image
class	double		Stellarity index. Between 0 and 1, low values correspond to probable extended sources and high values to point-like sources.
Coverage	double		Number of unit frames contributing to mosaic at source position