The Combined XSC and PSC Allsky Images

The Extended Source Catalog allsky images are presented in XSC Allsky. The PSC allsky image is showcased in the 2MASS image gallery. In order to directly compare the PSC with the XSC allsky images, we have transformed the PSC allsky images into the equatorial system used for galaxies.

2MASS Local Universe: As seen in the 2MASS Near-Infrared bands: J (1.2 microns), H (1.6 microns) and Ks (2.2 microns). The All Sky image is composed of sources with integrated fluxes brighter than Ks=14th mag, comprising the 2MASS Extended Source Catalog (XSC) -- more than 1.6 million galaxies, and the Point Source Catalog (PSC) -- nearly 0.5 billion Milky Way stars (here tinted in blue to show contrast with the background galaxies.) The map is projected with an equal area aitoff in the Geo-equatorial system (centered at 6 hr Right Ascension). The plane of the Milky Way runs diagonally across the image, with the Galactic anti-center facing you. The image was created by Thomas Jarrett, John Carpenter & Robert Hurt (IPAC/Caltech).

Note: Known Milky Way sources (e.g., HII regions) have been removed from the XSC ALLSKY image, and thus the remaining XSC image is nearly 100% extragalactic in nature. Galactic (Milky Way) sources are primarily confined to the Plane of the Galaxy, as is easily seen in the XSC vs. PSC movie shown below.

  • SuperGalactic View of the Local Universe

    As demonstrated below, the XSC is completely decoupled (for |glat| > 3 degrees) from the PSC since it is dominated by galaxies. Note the very red sources spanning the Galactic plane (|glat| < 3 deg) -- these are predominantly Milky Way in origin (and have been removed from the combined XSC+PSC allsky image, shown above).

    2MASS Integrated Flux Allsky Movie
    Aitoff equal-area projection of the integrated PSC and XSC flux for cummulative mag bins. See the LSS chart for image orientation and Large Scale Structure map. The PSC FITS images are courtesy of John Carpenter.

    [Last Updated: 2002 Nov 20 ; by Tom Jarrett]