- ID:
- ivo://CDS.VizieR/II/312
- Title:
- GALEX-DR5 (GR5) sources from AIS and MIS
- Short Name:
- II/312
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galaxy Evolution Explorer (GALEX) is an ultraviolet space telescope launched in 2003. It observes in 2 ultraviolet bands, FUV (far-UV) and NEV (near-UV), which characteristics are: -------------------------------------------------------------------- FUV NUV -------------------------------------------------------------------- Bandwidth 1344-1786 1771-2831 ({AA}) Effective wavelength 1538.6 2315.7 ({AA}) Astrometry (R<0.6deg) 0.59 0.49 (arcsec) Photometry 0.05 0.03 (ABmag) Zero point 18.82 20.08 (ABmag) Image resolution 4.2 5.3 (arcsec/pix) Spectral resolution 200 118 ({delta}{lambda}/{lambda}) -------------------------------------------------------------------- Two catalogs of UV sources from GALEX surveys are provided: * the All-sky Imaging Survey (AIS), containing 65.3million sources over 21435 square degrees, has a 5{sigma} depth in FUV/NUV of 19.9/20.8 (AB magnitudes); * the Medium-depth Imaging Survey (MIS), with 12.6million sources, covers 1579 square degrees and has a 5{sigma} depth in FUV/NUV of 22.6/22.7 (AB magnitudes). See also the description by Bianchi et al. (2011MNRAS.411.2770B)
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- ID:
- ivo://CDS.VizieR/J/ApJ/724/1389
- Title:
- Mapping the diffuse UV sky with GALEX
- Short Name:
- J/ApJ/724/1389
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a map of the diffuse ultraviolet cosmic background in two wavelength bands (FUV: 1530{AA} and NUV: 2310{AA}) over almost 75% of the sky using archival data from the Galaxy Evolution Explorer (GALEX) mission. Most of the diffuse flux is due to dust-scattered starlight and follows a cosecant law with slopes of 545 photons/cm^2^/s/sr/{AA} and 433 photons/cm^2^/s/sr/{AA} in the FUV and NUV bands, respectively. There is a strong correlation with the 100um Infrared Astronomy Satellite (IRAS) flux with an average UV/IR ratio of 300 photons/cm^2^/s/sr/{AA}/(MJy/sr) in the FUV band and that of 220 photons/cm^2^/s/sr/{AA}/(MJy/sr) in the NUV band but with significant variations over the sky. In addition to the large-scale distribution of the diffuse light, we note a number of individual features including bright spots around the hot stars Spica and Achernar.
- ID:
- ivo://CDS.VizieR/II/335
- Title:
- Revised catalog of GALEX UV sources (GUVcat_AIS GR6+7)
- Short Name:
- II/335
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galaxy Evolution Explorer (GALEX) imaged the sky in two ultraviolet (UV) bands, far-UV (FUV, {lambda}_eff_~1528{AA}), and near-UV (NUV, {lambda}_eff_~2310{AA}), delivering the first comprehensive sky surveys at these wavelengths. The GALEX database contains FUV and NUV images, ~500 million source measurements and over 100000 low-resolution UV spectra. The UV surveys are a unique resource for statistical studies of hot stellar objects, z<~2 QSOs, star-forming galaxies, nebulae and the interstellar medium, and provide a roadmap for planning future UV instrumentation and follow-up observing programs. We present science-enhanced, "clean" catalogs of GALEX UV sources, with useful tags to facilitate scientific investigations. The catalogs are an improved and expanded version of our previous catalogs of UV sources (BCScat; Bianchi+, 2011, J/MNRAS/411/2770 ; II/312 and 2014AdSpR..53..900B). With respect to BCScat, we have patched 640 fields for which the pipeline had improperly coadded non-overlapping observations, and we provide a version with a larger sky coverage (about 10%) by relaxing the restriction to the central area of the GALEX field to 1.1{deg} diameter (GUVcat_AIS_fov055: GUVcat_AIS FOV_radius <0.55{deg}), as well as the cleaner, more restrictive version using only the 1{deg} central portion of each field as in BCScat (GUVcat_AIS_fov050: GUVcat_AIS FOV_radius <0.50{deg}). We added new tags to facilitate selection and cleaning of statistical samples for science applications: we flag sources within the footprint of extended objects (nearby galaxies, stellar clusters) so that these regions can be excluded for estimating source density. As in our previous catalogs, in GUVcat duplicate measurements of the same source are removed, so that each astrophysical object has only one entry. Such a unique-source catalog is needed to study the density and distributions of sources, and to match UV sources with catalogs at other wavelengths. The catalog includes all observations from the All-Sky Imaging Survey (AIS), the survey with the largest area coverage, with both FUV and NUV detectors exposed: over 28700 fields, made up of a total of 57000 observations ("visits"). The total area covered, when overlaps are removed and gaps are accounted for, is 24790 square degrees for GUVcat_AIS_fov055 (GUVcat_AIS_fov055) and 22125 square degrees for (GUVcat_AIS_fov050). The total numbers of "unique" AIS sources (eliminating duplicate measurements) are 82,992,086 (GUVcat_AIS_fov055) and 69,772,677 (GUVcat_AIS_fov050). The typical depth of the GUVcat_AIS catalog is FUV=19.9, NUV=20.8 AB mag.
