The AllWISE Source Catalog and Reject Table contain detections of both point-like and extended sources such as galaxies and nebulae. The ext_flg is used to flag AllWISE sources that are either identified with or superimposed on known galaxies, or have large PSF-fit measurement goodness of fit reduced chi-squared values, a signature of resolved or confused sources. The values of the ext_flg and their descriptions are given in Table 1.
|0||The source has w?rchi2<3.0 in all bands and is not associated with a 2MASS XSC source.|
|1||The source has w?rchi2≥3.0 in any band - suspected to be resolved or confused.|
|2||The source is located within the isophotal extent of a 2MASS XSC source.|
|3||The source is located within the isophotal extent of a 2MASS XSC source and has w?rchi2≥3.0 in any band.|
|4||The source is identically associated with a 2MASS XSC source (xscprox<2 arcsec)|
|5||The source is identically associated with a 2MASS XSC source (xscprox<2 arcsec) and has w?rchi2≥3.0 in any band.|
The procedure used to set the ext_flg in AllWISE source extraction is based on that used for the WISE All-Sky Release Catalog, described in section IV.4.c.vi of the WISE All-Sky Release Explanatory Supplement.
Two updates have been implemented for AllWISE:
|Figure 1 - r_W1 vs. r_Ks||Figure 2 - r_W2 vs. r_Ks|
|Isophotal radii for Galaxies measured on WISE Atlas Images plotted as a function of the Ks isophotal radii from the 2MASS XSC. The red lines show the best-fit linear scaling relationships between the WISE and 2MASS sizes (Cluver et al. 2014).|