Early Release Compact Source Catalog

Purpose
The ESA Planck mission will survey the entire sky using radiometers at 30, 44, and 70 GHz and bolometers at 100, 143, 217, 353, 545, and 857 GHz. The corresponding wavelengths range from 1 cm to 350 microns. This will be the first all-sky survey at submillmeter wavelengths.

The Early Release Compact Source Catalog (ERCSC) will provide source lists derived from the first sky coverage at the 10-sigma level. The source lists will be available to all scientists approximately 20 months after the joint Herschel/Planck launch, in time for the first post-launch call for Herschel observing proposals.

Sensitivity
To the right is a comparison of the expected flux limits of the Planck ERCSC (black) with existing surveys (in blue: IRAS Faint Source Catalog, NRAO Green Bank 4.85 GHz catalog, and the WMAP 3-year source catalog) and the near-future SASSy survey.

Shown for comparison (in red) are theoretical spectral energy distributions for objects dominated by synchrotron emission, free-free emission, thermal emission from objects warmer than 1000 K in the Rayleigh-Jeans limit, and a 15 K blackbody.

Planck's capabilities are suited to measuring the brightnesses of cold objects as well as those with relatively bright free-free radiation from ionized gas. The compact sources will include extragalactic objects, in particular flat-spectrum radio sources (like blazars) at low frequencies and redshifted galaxies (whose dust emission peaks in the high Planck frequencies for redshifts ~1-2). Galactic sources will include HII regions and cold cores in molecular clouds. Since Planck will perform the first all-sky survey at many of its frequencies, we also anticipate some surprises!

The sensitivity expected for an observation lasting 47 minutes with the Herschel/SPIRE spectrometer (from the Herschel observation planning tool) is shown in cyan; Planck/ERCSC sources can be studied in detail using the spectral and spatial resolving power of the Herschel observatory.