Previous | Session 63 | Next
K. Coppin, M. Halpern, D. Scott (UBC), C. Borys, S. Chapman (Caltech)
We present an 850-micron map and list of candidate sources in a sub-area of the Groth Strip obtained using SCUBA. The map consists of a long strip of adjoining jiggle-maps covering the southwestern 70 arcmin2 of the original WFPC2 Groth Strip to an average 1-sigma rms noise level of ~3.5 mJy. We initially detect 7 candidate sources with signal-to-noise ratios (SNRs) between 3.0 and 3.5-sigma and 4 candidate sources with SNR>3.5. Simulations suggest that on average in a map this size one expects 1.6 false positive sources >3.5-sigma and 4.5 between 3 and 3.5-sigma. Flux boosting in maps is a well known effect and we have developed a simple Bayesian prescription for estimating the unboosted flux distribution and used this method to determine the best flux estimates of our sources. This method is easily adapted for any other modest signal-to-noise survey in which there is prior knowledge of the source counts. We performed follow-up photometry to test our flux boosting model on 5 of our candidate sources. We failed to significantly re-detect 3 of the sources, however, we did confirm the reality of 2 of the SCUBA sources, although at lower flux levels than suggested in the map. Not surprisingly, we find that the photometry results are consistent with and confirm the de-boosted map fluxes. Our final candidate source list contains 3 sources, including the 2 confirmed detections and 1 further candidate source with SNR>3.5-sigma which has a reasonable chance of being real.
This work was supported by the Natural Sciences and Engineering Research Council of Canada. The James Clerk Maxwell Telescope is operated on behalf of the Particle Physics and Astronomy Research Council of the United Kingdom, the Netherlands Organisation for Scientific Research, and the National Research Council of Canada.
If you would like more information about this abstract, please follow the link to http://cmbr.physics.ubc.ca/groth. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.
The author(s) of this abstract have provided an email address for comments about the abstract: coppin@physics.ubc.ca
Previous | Session 63 | Next
Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.