S-COSMOS MIPS-Ge GO2 Delivery 27May2007 14Aug2008 Added notice H. Aussel + S-COSMOS team 0. IMPORTANT NOTICE While working on the GO-3 SCOSMOS data, we have discovered a problem with the fluxes of the distributed GO-2 deep and main catalogs. A correction factor has been applied twice to all flux columns of both catalogs. The affected columns are "fitflux", "fitbkg", "fluxaper", "mesaper" and "corraper" in both catalogs. In order to retrieve the correct values, the following correction should be applied: correct_flux = 1.32 * catalog_flux The distributed images are not suffering from this problem. Also please note that there is still some asteroid contamination in the Main catalog were the small number of repeat observations did not allow us to filter out the slow moving objects. Asteroid have been filtered out from the Deep catalog were numerous epochs were available. I. Basic Information Telescope: Spitzer PI: David B. Sanders Program Title: SCOSMOS Program ID: 20070 MIPS Band : 24um SSC Software Version: S 13.2.0 See SSC website for S 13.2.0 data issues and Calibration. These are the MIPS 24 maps and catalog resulting from the General Observer Cycle 2 observations of the S-COSMOS program. Please refer to Sanders et al. (astro-ph/0701318) for a discussion of the observations. The current data product version is 1.1. The directory contains: mips_24_g02_cat.tbl Main area catalog mips_24_g02_sci_11.fits Main area image mips_24_g02_cov_11.fits Main area coverage map mips_24_g02_unc_11.fits Main area uncertainty map mips_24_g02_deep_cat.tbl Deep area catalog mips_24_g02_deep_sci_11.fits Deep area image mips_24_g02_deep_cov_11.fits Deep area coverage map mips_24_g02_deep_unc_11.fits Deep area uncertainty map Images and uncertainty images are in units of MJy/sr. To convert the images in mJ, multiply them for the factor 0.141085553. Note that the coverage map is somewhat unusual due to the large number of asteroids that have been removed from these data. Notes on Catalogs: ----------------- The catalogs were produced in two passes. First, a detection pass was performed using the IDL implementation of DAOPHOT. Then aperture photometry and PSF-fitting photometry were performed on the detections in a 7x7 pixels subimage centered on the detection. The signal over noise on the peak pixel is given by the "pksn" catalog column. Neighboring sources were masked out, using a 3 pixel radius aperture. If no other sources were detected nearby, the number of pixels fitted is therefore 49. If other sources fall within this box, their corresponding pixels will be masked and the number of pixels used for the fit will be lower than 49. The catalog column "np" holds the number of pixels used. The PSF fit photometry is determined by fitting a set of PSF build from the MIPS 24 PRF ("Pixel Response Function") with the source position at different sub-pixel locations within the peak pixel, plus a constant background to the subimage. The "fitflux" and "fitbkg" catalog columns hold the values of the fitted source flux and background respectively. The "chi2" column contains the reduced chi-squared of the fit. Since the fit is done on background subtracted images, the "fitbkg" value should be close to zero. Aperture photometry is performed on the same sub-image as the PSF- fitting photometry, so the aperture used is a square 7x7 aperture, with neighboring sources masked out, assuming a zero background. The raw measurement if given by the "mesaper" column of the catalog. The aperture photometry was then corrected to total fluxes using the MIPS 24 PSF model. The correction factor is given by the "corrape" column. The total flux after aperture correction is given by the "fluxaper" column. The error on the flux aperture measurment is given by the "erraper" column. For isolated point sources, fitflux and fluxaper should be equal. The catalogs have been cut at 0.06 mJy for the Deep, and 0.300 mJy for the Main. Users are invited to exercise caution with all sources but especially with low S/N ones (as tested by fluxaper/erraper). The number of pixels (np) is a good indication of blending. np = 49 for almost isolated sources. The lower, the most confused it is. Also, sources with fitflux very different from fluxaper should be treated with caution, as they may be extended, blended or spurious. Catalogs columns are: id : Identification number of the source ra : Right Ascension, degree J2000 dec : Declination, degree J2000 pksn : peak signal/noise ratio np : number of pixels used for PSF fitting and aperture photometry fitflux : PSF fitted flux, mJy fitbkg : Derived background during PSF fitting (mJy) Should be close to zero chi2 : Reduced chi square of the fit solution mesaper : Raw aperture measurment (mJy) fluxaper : Aperture photometry flux, including aperture correction (mJy) given by the corraper column err aper : Error on the flux aper (mJy) corraper : Aperture correction factor idmain : ID of the counterpart in the Main (resp Deep) catalog. 0 if no counterparts distm : distance in arcsec to the counterpart, 99.99 if too far.