The 2MASS Extended Source Catalog

The files released by IPAC must be processed before WCSTools can access them. Although IPAC suggests that they be ingested into a relational database manager, WCSTools can access the catalog after it is processed by the simple process described here.

2MASS used two highly-automated 1.3-m telescopes, one at Mt. Hopkins, AZ, and one at CTIO, Chile. Each telescope is equipped with a three-channel camera, each channel consisting of a 256W256 array of HgCdTe detectors, capable of observing the sky simultaneously at J (1.25 5m), H (1.65 5m), and Ks (2.17 5m).

The northern 2MASS facility began routine operations in 1997 June, and the southern facility in 1998 March. The 2MASS Second Incremental Data Release contains Image and Catalog data covering 19,681 square degrees of sky, derived from Survey observations made at the northern 2MASS facility on Mt. Hopkins, AZ, and the southern facility on Cerro Tololo, Chile. The observations in this release were obtained between 1997 June 7 and 1999 May 21 UT at Mt. Hopkins and 1998 March 19 and 1999 February 20 UT at Cerro Tololo.

To enable rapid access of specific stars in the catalog, WCSTools software numbers each star using an RA region number (0000-2330) and a seven-digit star number within each region, separated by a decimal point. stmx lists 2MASS extended sources by number or sky region. imtmx lists the 2MASS extended sources within an IRAF or FITS image with a world coordinate system defined in its header.