S-




What is the S-COSMOS survey ?

S-COSMOS is a deep infrared imaging survey carried out with the SPITZER space telescope. The survey covers the entire 2 square degrees of the COSMOS field. The infrared images are obtained with the IRAC and MIPS cameras in seven broad band filters 3.6 µm, 4.5 µm, 5.8 µm, 8.0 µm and 24 µm, 70 µm , 160 µm, respectively. This project PI is D.B. Sanders, and the S-COSMOS team consists of approximately forty scientists from institutions in the US, Europe and Japan.



Current status

The cycle 2 IRAC data and cycle 2 MIPS data were acquired during Dec'05-Jan'06.
These data are now public.

Additional Spitzer observing time has been obtained for Cycle 3 to expand the MIPS-deep "test" coverage - currently 0.16 sq.deg. - to cover the full 2 sq.deg. field.
Cycle 3 MIPS data data were acquired during Jan'07-May'07. The data reduction is on going.



Our scientific goals

S-COSMOS is currently the deepest IRAC survey for such a large field. The primary science justification for the survey has been to study the coupled evolution of stellar mass and star formation rates in galaxies, AGN activity, and large scale structures in enormous samples of galaxies out to z~3.

The S-COSMOS survey couples the strengths of the COSMOS project, i.e.:

  • ACS/HST imaging to determine morphological classifications
  • 2 sq.deg. coverage to study the galactic environment on large scales
  • 2 sq.deg. coverage to limit cosmic variance
  • multi-color wavelength coverage from the X-ray to radio
with the specific interest of a deep IR survey, i.e.:
  • tracing the stellar mass from z~0.5 to z~3 using the IRAC data
  • tracing the star formation rates from the light reemitted by dust using the MIPS data
  • identifying particular galaxy populations like obscured AGN, tough to be responsible of the X-ray cosmic background
  • increasing the robustness of photometric redshifts at 1 < z < 5



As an example of the type of science allowed by the S-COSMOS data, the following image shows the region containing a massive structure at z=0.73. The blue, green, red colors show the GALEX data, the IRAC/3.6 micron and MIPS/24 micron data, respectively. The contours represent the XMM soft X-ray emmission (0.5-2 keV). We can simultaneously investigate the distribution of stellar mass (3.6 micron), the location of star formation (24 micron), as well as AGN activity (X-ray). At the same time, the morphology of individual galaxies can be studied with the HST/ACS images.
Last modified: Wed Nov 28 15:32:18 HST 2007