J/ApJS/277/20ivo://CDS.VizieR/J/ApJS/277/20doi:10.26093/cds/vizier/bb-8n-mCDSLeahy D.Ranasinghe S.Mitra S.Rawal K.2026-08-03T07:26:16Z2026-02-16T10:35:54ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesultraviolet-photometryapparent-magnitudeAn ultraviolet survey of M31 was carried out during 2017-2023 with the UltraViolet Imaging Telescope (UVIT) instrument on board the AstroSat Observatory. Here we present far- and near-ultraviolet (FUV and NUV) observations from the M31 UVIT survey, which covers a sky area of ~3.5x1.3{deg} with a spatial resolution of ~1". The observations included six filter bands in the wavelength range of 120-280nm. Including the six bands, ~115,000 sources with signal-to-noise ratio (S/N)>=3 (~95,000 sources with S/N>=5) were detected at FUV or NUV wavelengths, with the largest set of detections (~54,000 sources) in the FUV 150nm band (F148W filter). This is considerably more than for the first version of the M31 source catalog (published in 2020), in part due to additional observations of M31 by UVIT and in part due to improved data processing. The magnitude (mAB) at which incompleteness sets in is ~23.0 in the F148W band, with the other bands somewhat less sensitive, with least sensitive band (in mAB units) N279N with incompleteness for sources fainter than ~20.3). The faintest sources detectable in F148W have mAB~25.4, with other bands having higher minimum detectable brightness, and with N279N having a minimum detectable limit of mAB~22.1. The product of this work is the new M31 UVIT compact-source catalog, containing positions, fluxes, magnitudes, and S/N for the sources.2025ApJS..277...20Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/277/20CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)J/ApJS/173/185 : GALEX ultraviolet atlas of nearby galaxies (Gil de Paz+, 2007)J/ApJ/703/614 : UV star-forming regions in M31 (Kang+, 2009)J/AJ/144/142 : HST phot. of young stellar populations in M31 (Bianchi+, 2012)J/ApJS/199/37 : GALEX catalog of star clusters in M31 (Kang+, 2012)J/ApJS/215/9 : PHAT X. UV-IR photometry of M31 stars (Williams+, 2014)J/ApJS/247/47 : Ultraviolet survey of M31 with UVIT on AstroSat (Leahy+, 2020)J/AJ/161/215 : Far-ultraviolet variable sources in M31 (Leahy+, 2021)J/AJ/162/199 : UV photometry of 548 variables stars in M31 (Leahy+, 2021)J/AJ/164/183 : UVIT photometry of M31 PHAT stellar clusters (Leahy+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/277/20https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/277/20http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/277/20https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/277/20https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/277/20http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/277/20GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/277/20/table5 (Combined M31 source catalog for the six UVIT filters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/277/20/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/277/20/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/277/20/table5?GETtext/xml+votable180.050000true10.4107030641.2890050.0055555555555555566/2619 2622-2623 2666-2667 2705 2708-2709 2752-2753https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/277/20?format=asciiUVdefaultJ/ApJS/277/20/table5Combined M31 source catalog for the six UVIT filtersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFiltFilter used (1)instr.setup;instr.filtercharFieldObserved fieldmeta.id;obs.fieldcharRAJ2000[9.16/12.6] Right ascension (J2000)degpos.eq.ra;meta.mainindexedDEJ2000[39.8/42.8] Declination (J2000)degpos.eq.dec;meta.mainindexedFlux[2.2e-18/2e-13] Flux; erg/cm2/s/angstromcW.m**-2.nm**-1phot.flux;em.UVdoubleS/N[3/650] Signal-to-noise ratiostat.snrfloatmag[12.58/25.9] Apparent AB magnitude in Filtmagphot.mag;em.UVfloat