Spitzer Documentation & Tools
First Look Survey

On behalf of the Spitzer user community, the SSC conducted a First-Look Survey (FLS) as one of the first science tasks during nominal operations, which started on day 98 of the mission. The FLS is the inaugural Director's Discretionary Time (DDT) program.

The extragalactic and Galactic components of the Spitzer First Look Survey were executed on the observatory December 1-11, 2003 and the ecliptic component was executed January 21-22, 2004. The raw data are available through the Spitzer Data Archive, and the enhanced data products are available through IRSA's Image and Spectrum Server (Atlas). The FLS programs and AORs are listed with Tom Soifer as PI (because the FLS programs used Director's Discretionary Time), and the PIDs are listed below.

Release notes and README files are provided below and in each FLS component sub-directory with the data.

PidProgram nameDescription
26FLS_EXTRAGAL Extragalactic ComponentREADME (Plain Text, 2 KB)
98FLS_ECLIPTIC_PLANE Ecliptic Plane ComponentREADME (Plain Text, 2 KB)
104FLS_GAL Galactic ComponentREADME (Plain Text, 1 KB)

The Spitzer First-Look Survey was initially motivated by the scientific loss of the Wide-Field Infrared Explorer (WIRE) mission in March 1999. WIRE would have provided small-area imaging surveys at 12 and 25 microns, reaching sensitivities of a few hundred micro-Janskys, and thereby yielding important data on galaxy evolution. The FLS was not intended to scientifically recover the WIRE mission, per se. Rather, it was an attempt to provide the essential characterization of the mid-infrared sky at depths comparable to what WIRE would have probed. Pushing two orders of magnitude deeper in sensitivity than presently known, the FLS provided the science community with invaluable data for planning Spitzer observations.

The primary goals of this ~110-hour survey were (1) to provide a characteristic "first-look" at the mid-infrared sky at sensitivities that are ~100 times deeper than previous systematic large-area surveys; and (2) to rapidly process the data and place it into the public domain in time to impact early Spitzer investigations.


  • Detect enough extragalactic sources at unexplored sensitivity levels in order to generate a representative sample and to reduce the uncertainties in source counts.
  • Characterize the dominant source populations with both MIPS and IRAC data from Spitzer, plus ancillary data at optical, near-infrared and radio wavelengths.
  • Explore the cirrus foreground at moderately high Galactic latitudes, and its effect on point-source detectability.

Galactic/Solar System

  • Characterize the cirrus and background source counts at low Galactic latitudes
  • Characterize internal cirrus and background source counts toward a molecular cloud
  • Characterize the ecliptic plane and zodiacal light for Solar System observations

SIRTF First Look Survey (PDF, 8.26 MB) - Overview talk given by Lisa Storrie-Lombardi in May 2002 for the JPL Infrared Astronomy 001 talk series.