The scientific potential of the ISOPHOT serendipity sky survey

Manfred Stickel, Dietrich Lemke, Ulrich Klaas, Oliver Krause, L. Victor Toth, Roland Vavrek, Stefan Hotzel

Research output: Contribution to journalConference article


The telescope movement of the Infrared Space Observatory (ISO) was utilized for scientific observations in the far-infrared (FIR) using the ISOPHOT C200 stressed Ge:Ga array detector. While slewing from one target to the next, strip scanning measurements of the sky at 170 μm were collected, comprising the ISOPHOT 170 μm Serendipity Sky Survey. It is the first slew survey designed as an integral part of a space observatory mission, and the only survey to date covering a large area of the sky at a wavelength region beyond the IRAS 100 μm limit. During more than 12000 slews, FIR measurements with a total slew length of more than 150000 degrees within nearly 550 hours were collected, corresponding to a sky coverage of about 15%. The slew data cover a wide variety of source types from unresolved compact sources to extended structures of the galactic cirrus and the large scale diffuse galactic FIR emission. The slew data analysis has been focused on the detection of compact sources, particularly galaxies. The selection of known galaxies from the Serendipity Survey data requires a cross-correlation with galaxy entries in the NED and Simbad databases and a subsequent cross-check of optical images from the Digital Sky Survey. A large catalogue with 170 μm fluxes for ≈ 2000 galaxies is currently being compiled. The particularly interesting rare galaxies with very cold dust and very large dust masses further require additional FIR data from the IRAS survey as well as measured redshifts. A large fraction of the compact galactic structures are pre-stellar cores inside cold star forming regions. Early stages of medium and high mass star forming regions are identified by combining compact bright and cold Serendipity Survey sources with the near-infrared 2M ASS and MSX surveys. This combination indicates large dust masses in conjunction with embedded young stars of early spectral types. In all the studied samples of different object classes the 170 μm flux provides the crucial data point for a complete characterization of the FIR spectral energy distributions and the derivation of total dust masses. Follow-up observations are underway to study selected objects in more detail.

Original languageEnglish
Pages (from-to)169-173
Number of pages5
JournalEuropean Space Agency, (Special Publication) ESA SP
Issue number511
Publication statusPublished - Feb 1 2003
EventExploiting the ISO Data Archive: Infrared Astronomy in the Internet Age - Siguenza, Spain
Duration: Jun 24 2002Jun 27 2002



  • Data Analysis
  • Far Infrared Surveys
  • Observatory Operations

ASJC Scopus subject areas

  • Aerospace Engineering
  • Space and Planetary Science

Cite this

Stickel, M., Lemke, D., Klaas, U., Krause, O., Victor Toth, L., Vavrek, R., & Hotzel, S. (2003). The scientific potential of the ISOPHOT serendipity sky survey. European Space Agency, (Special Publication) ESA SP, (511), 169-173.