Publications of the Astronomical Society of Australia

Research Article

Large Scale Structure in the Local Universe — The 2MASS Galaxy Catalog

Thomas Jarrett

Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125, USA. Email:


Using twin ground-based telescopes, the Two-Micron All Sky Survey (2MASS) scanned both equatorial hemispheres, detecting more than 500 million stars and resolving more than 1.5 million galaxies in the near-infrared (1–2.2 μm) bands. The Extended Source Catalog (XSC) embodies both photometric and astrometric whole sky uniformity, revealing large scale structures in the local Universe and extending our view into the Milky Way's dust-obscured ‘Zone of Avoidance’. The XSC represents a uniquely unbiased sample of nearby galaxies, particularly sensitive to the underlying, dominant, stellar mass component of galaxies. The basic properties of the XSC, including photometric sensitivity, source counts, and spatial distribution, are presented here. Finally, we employ a photometric redshift technique to add depth to the spatial maps, reconstructing the cosmic web of superclusters spanning the sky.

(Received May 03 2004)

(Accepted October 12 2004)


  • general: galaxies;
  • fundamental parameters: infrared;
  • galaxies: clusters;
  • surveys: astronomical