J/ApJ/826/24ivo://CDS.VizieR/J/ApJ/826/24doi:10.26093/cds/vizier.18260024CDSDarling J.Gerard B.Amiri N.Lawrence K.2018-01-30T07:18:24Z2016-10-27T08:10:40ZCDS support team

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

cds-question@unistra.frastrophysical-masersradio-astronomyinterstellar-mediuminfrared-sourcesWe report the results of a Green Bank Telescope survey for water masers, ammonia (1,1) and (2,2), and the H66{alpha} recombination line toward 506 luminous compact 24{mu}m emitting regions in the Andromeda Galaxy (M31). We include the 206 sources observed in the Darling water maser survey for completeness. The survey was sensitive enough to detect any maser useful for ~10{mu}as/yr astrometry. No new water masers, ammonia lines, or H66{alpha} recombination lines were detected individually or in spectral stacks reaching rms noise levels of ~3mJy and ~0.2mJy, respectively, in 3.1-3.3km/s channels. The lack of detections in individual spectra and in the spectral stacks is consistent with Galactic extrapolations. Contrary to previous assertions, there do not seem to be any additional bright water masers to be found in M31. The strong variability of water masers may enable new maser detections in the future, but variability may also limit the astrometric utility of known (or future) masers because flaring masers must also fade.2016ApJ...826...24Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/826/24CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/826/136 : Water masers in M31. II. Multiwavelength data (Amiri+, 2016)J/MNRAS/418/1689 : Red MSX water maser and ammonia emissions (Urquhart+, 2011)J/ApJ/741/110 : The BGPS. VII. Massive star-forming regions (Dunham+, 2011)J/ApJ/687/230 : Survey of M31 with Spitzer (Mould+, 2008)J/A+A/476/1161 : Spitzer photometry of M33 (Verley+, 2007)J/MNRAS/369/120 : Kinematic survey of PNe in M31 (Merrett+, 2006)J/A+AS/101/153 : Galactic H2O masers (Palagi+ 1993)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/826/24https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/826/24http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/826/24https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/826/24https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/826/24http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/826/24GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/826/24/table1 (M31 line survey results)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/826/24/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/826/24/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/826/24/table1?GETtext/xml+votable180.050000true9.6612540.4370830.0055555555555555566/2622 2623 2666 2705 2708 2709 2752https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/826/24?format=asciiInfraredRadiodefaultJ/ApJ/826/24/table1M31 line survey resultsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject name (HHMMSS.s+DDMMSS.s; J2000)meta.id;meta.maincharf_Name[abm] Flag on Name (1)meta.codecharH2O[0.7/4.8] H_2_O rm noise value (2)mJystat.snr;instr.det.noisefloatNH3-1[0.6/5.1] NH_3_ (1,1) rms noise value (2)mJystat.stdev;instr.det.noisefloatNH3-2[0.6/4.8] NH_3_ (2,2) rms noise value (2)mJystat.stdev;instr.det.noisefloatH66a[0.5/4.5] H66{alpha} rms noise value (2)mJystat.stdev;instr.det.noisefloatVobs[-500/-100] The observed central velocity tuning of the 632-674km/s (50MHz) bandwidth (3)km/sphys.veloc;instr.bandwidthintVCO[-582/-31]? CO velocity (3)(4)km/sspect.dopplerVelocintnullable_RAPositions from names (right ascension part)degpos.eq.ra;meta.main_DEPositions from names (declination part)degpos.eq.dec;meta.main