HerMES catalogues - Data Release DR2 Contact: hedam@lam.fr L. Wang, A. Smith, V. Buat, C. Clarke 2012-04-03 (updated 2015-04-30) ####################### This is the README file for the catalogues associated with the second Herschel-SPIRE/SAG-1/HerMES public data release (DR2). The HerMES programme is presented in Oliver et al (2012). The HerMES second data release provides three different catalogue types for each field: StarFinder and SUSSEXtractor mono-wavelength catalogues and a band-merged xID one. ####################### FILE NAMES The file names indicate the level, field, catalogue type and version number (here DR2). -__DR2.fits.gz (or .xml.gz for VO-table format) Level: defined in Oliver et al. (table 1). Each level corresponds to an initial nominal depth of the survey, from Level 1 (L1, deep) to Level 6 (L6, shallow). Cluster observations are refered as CD (deep), CS (shallow) and CH (high-z). The type is: - SCAT250, SCAT350 and SCAT500 for 250 µm, 350 µm and 500 µm Starfinder catalogues - SCAT250-SXT, SCAT350-SXT and SCAT500-SXT for 250 µm, 350 µm and 500 µm SUSSEXtractor catalogues - xID250 for band-merged catalogues extracted on Starfinder 250 µm positions ####################### SOURCE NAMING CONVENTION Here is the naming convention used to identify unambiguously each source (IAU name): xHERMES Syyy zz d JHHMMSS.s+DDMMSS x: the version number of the catalogue (here 2) Syyy: the wavelength of the map where the source was identified 'S250', 'S350' or 'S500' for SPIRE catalogues zz: the pipeline used to identify the source 'SX' for SUSSEXtractor, 'SF' for Starfinder d: 'D' to identify a source found on a deep map where a shallow map is also available (nested fields), nothing otherwise JHHMMSS.S+DDMMSS: coordinates, Equinox J2000 ####################### StarFinder CATALOGUES StarFinder is an IDL iterative source finding and fitting program, originally designed for crowded stellar fields analysis (Diolaiti et al. 2000). As such, StarFinder is expected to do better at de-blending sources and finding faint sources around bright sources than SUSSEXtractor (Wang et al. 2014). We use a Gaussian shaped PSF with the FWHM set to 18.15, 25.15 and 36.3 arcsecs at 250, 350 and 500 micron respectively. Single-band StarFinder catalogues are provided at 250, 350 and 500 micron with a photometry based on a cross-identification (XID) method. Positions of the sources are obtained with StarFinder and fluxes are extracted with the HerMES XID code at the positions of StarFinder sources. For details of the HerMES XID pipeline, please refer to Roseboom et al. (2010) (for more details, Wang et al. 2014) Column descriptions (for 250 µm catalogues, adjust for 350 and 500): iau_name - IAU Name ra deg Right Ascension (J2000) dec deg Declination (J2000) f250 mJy Flux density e250 mJy Instrumental error in flux density et250 mJy Total error (instrumental + confusion) in flux density chi250 - Local reduced chi2 statistic of photometry fit in 11x11 pixel window gid - ID of the segment where the source is gsize - Number of sources in the segment gid bkg250 mJy/Beam Background substracted from map ########################## SUSSEXtractor CATALOGUES SUSSEXtractor is a simple peak finder written in IDL and Jython. For more details on the SUSSEXtractor source extraction method, please refer to Savage & Oliver (2007) and Smith et al. (2011). We use a Gaussian shaped PSF with the FWHM set to 18.15, 25.15 and 36.3 arcsec at 250, 350 and 500 micron respectively. Single-band SUSSEXtractor catalogues at 250 (PSW), 350 (PMW) and 500 (PLW) micron are provided for all the fields in the DR1. Column descriptions: iau_name - IAU Name ra deg Right Ascension (J2000) raerr deg Uncertainty on Right Ascension dec deg Declination (J2000) decerr deg Uncertainty on Dec flux mJy Flux density fluxerr mJy Formal uncertainty on flux (instrumental noise) quality - Signal-to-instrumental noise ratio (flux/fluxerr) fluxerrtotal mJy Total uncertainty in the source flux, due to confusion and instrumental noise snr - Signal-to-total noise ratio (flux/fluxerrtotal) centralregion - 1 if source lies within a well defined central region of the map, 0 otherwise fluxhalfdata1 mJy Source flux, as measured using a map based on the first half of the data qualityhalfdata1 - Signal-to-instrumental noise as measured using a map based on the first half of the data fluxhalfdata2 mJy Source flux, as measured using a map based on the second half of the data qualityhalfdata2 - Signal-to-instrumental noise as measured using a map based on the second half of the data The 'halfdata' maps are available for the fields from the 'complementary data' page of HeDaM web site. ####################### xID CATALOGUES Band-merged StarFinder catalogues with xID multi-band (250, 350 and 500 micron) fluxes at the positions of the StarFinder 250 micron sources. We use a Gaussian shaped PSF with the FWHM set to 18.15, 25.15 and 36.3 arcsecs at 250, 350 and 500 micron respectively. Column descriptions: iau_name - IAU Name ra deg Right Ascension (J2000) dec deg Declination (J2000) f250 mJy Flux density at 250 µm e250 mJy Instrumental error in flux 250 µm density et250 mJy Total error (instrumental + confusion) in 250 µm flux density chi250 - Local reduced chi2 statistic of 250 µm photometry fit in 11x11 pixel window f350 mJy Flux density at 350 µm e350 mJy Instrumental error in flux 350 µm density et350 mJy Total error (instrumental + confusion) in 350 µm flux density chi350 - Local reduced chi2 statistic of 350 µm photometry fit in 11x11 pixel window f500 mJy Flux density at 500 µm e500 mJy Instrumental error in flux 500 µm density et500 mJy Total error (instrumental + confusion) in 500 µm flux density chi500 - Local reduced chi2 statistic of 500 µm photometry fit in 11x11 pixel window gid - ID of the segment where the source is gsize - Number of sources in the segment gid bkg250 mJy/Beam Background substracted from 250 µm map bkg350 mJy/Beam Background substracted from 350 µm map bkg500 mJy/Beam Background substracted from 500 µm map Notes In case of nested fields, (cf. the readme for the maps and the HerMES_DR2_nested_fields.pdf document), the image associated with the catalogue is the full nested one, thus much larger than the catalogue coverage. The full description of the fields is given in the readme for the maps. For L1-ECDFS, the catalogues contain an extra column named 'Flag', which contains "goods-s" for the sources extracted in the deepest part of the nested map, corresponding to the GOODS-S field (AOR 13). ####################### REFERENCES Diolaiti et al. 2000, SPIE 4007, 879 Oliver, S. et al. 2012, MNRAS 424, 1614 Roseboom, I.G., et al. 2010, MNRAS, 409, 48 Savage, R.S., & Oliver, S. 2007, ApJ, 661, 1339 Smith, A.J. et al. 2012, MNRAS, 419, 377 Wang, L. et al. 2014, MNRAS, 444, 2870