next up previous
Next: 1 Introduction Up: FIRST Home Page

The Angular Two-Point Correlation Function for the FIRST Radio Survey

Catherine M. Cress, David J. Helfand

Department of Astronomy, Columbia University, 538 West 120th Street, New York, NY 10027

Robert H. Becker

Department of Physics, University of California, Davis, CA 95616 and

Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, CA 94450

Michael D. Gregg

Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, CA 94450

Richard L. White

Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218

--------------------------------------

Abstract:

The FIRST (Faint Images of the Radio Sky at Twenty Centimeters) survey now covers 1550 tex2html_wrap_inline435 of sky where tex2html_wrap_inline437 tex2html_wrap_inline439 tex2html_wrap_inline441 tex2html_wrap_inline439 tex2html_wrap_inline445 and tex2html_wrap_inline447 tex2html_wrap_inline439 tex2html_wrap_inline451 tex2html_wrap_inline439 tex2html_wrap_inline455. This yields a catalog of 138,665 sources above the survey threshold of 1 mJy, about one third of which are in double-lobed and multi-component sources. We have used these data to obtain the first high-significance measurement of the two-point angular correlation for a deep radio sample. We find that the correlation function between tex2html_wrap_inline457 and tex2html_wrap_inline459 is well fitted by a power law of the form tex2html_wrap_inline461 where tex2html_wrap_inline463 and tex2html_wrap_inline465. On small scales (tex2html_wrap_inline467), double and multi-component sources are shown to have a larger clustering amplitude than that of the whole sample. Sources with flux densities below 2 mJy are found to have a shallower slope than that obtained for the whole sample, consistent with there being a significant contribution from starbursting galaxies at these faint fluxes. The cross-correlation of radio sources and Abell clusters is determined. A preliminary approach to inferring spatial information is outlined.





Richard L. White, rlw@stsci.edu
FIRST Home Page
1996 Dec 20