J/ApJ/798/58ivo://CDS.VizieR/J/ApJ/798/58doi:10.26093/cds/vizier.17980058CDSKirk J.M.Gear W.K.Fritz J.Smith M.W.L.Ford G.Baes M.Bendo G.J.,De Looze I.Eales S.A.Gentile G.Gomez H.L.Gordon K.O'Halloran B.,Madden S.C.Roman-Duval J.Verstappen J.Viaene S.Boselli A.,Cooray A.Lebouteiller V.Spinoglio L.2017-06-13T11:08:30Z2015-06-18T12:13:22ZCDS support team

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

cds-question@unistra.frgalaxiesmolecular-cloudsinfrared-photometryIn this paper we present a catalog of giant molecular clouds (GMCs) in the Andromeda (M31) galaxy extracted from the Herschel Exploitation of Local Galaxy Andromeda (HELGA) data set. GMCs are identified from the Herschel maps using a hierarchical source extraction algorithm. We present the results of this new catalog and characterize the spatial distribution and spectral energy properties of its clouds based on the radial dust/gas properties found by Smith et al. (Paper II, 2012ApJ...756...40S). A total of 326 GMCs in the mass range 10^4^-10^7^M_{sun}_ are identified; their cumulative mass distribution is found to be proportional to M^-2.34^, in agreement with earlier studies. The GMCs appear to follow the same correlation of cloud mass to L_CO_ observed in the Milky Way. However, comparison between this catalog and interferometry studies also shows that the GMCs are substructured below the Herschel resolution limit, suggesting that we are observing associations of GMCs. Following Gordon et al. (2006ApJ...638L..87G), we study the spatial structure of M31 by splitting the observed structure into a set of spiral arms and offset rings. We fit radii of 10.3 and 15.5kpc to the two most prominent rings. We then fit a logarithmic spiral with a pitch angle of 8.9{deg} to the GMCs not associated with either ring. Last, we comment on the effects of deprojection on our results and investigate the effect different models for M31's inclination will have on the projection of an unperturbed spiral arm system.2015ApJ...798...58Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/798/58CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVI/139 : Herschel Observation Log (Herschel Science Centre, 2013)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)VII/7 : Lynds' Catalogue of Dark Nebulae (LDN) (Lynds 1962)J/ApJ/752/146 : Star forming complexes in Galactic WMAP sources (Lee+, 2012)J/A+A/542/A108 : Giant molecular clouds in M33 (Gratier+, 2012)J/MNRAS/422/1071 : Cores in IR Dark Clouds for 300<=l<=330 (Wilcock+, 2012)J/AJ/142/139 : A new catalog of HII regions in M31 (Azimlu+, 2011)J/ApJ/723/492 : Properties of GRS molecular clouds (Roman-Duval+, 2010)J/ApJ/680/349 : Galactic distribution of IRDCs (Jackson+, 2008)J/ApJ/661/830 : Giant molecular clouds of M33 (Rosolowsky+, 2007)J/ApJ/654/240 : Giant molecular clouds in M31 (Rosolowsky+, 2007)J/AJ/87/1165 : Reddening Maps derived from HI & Galaxy Counts (Burstein+ 1982)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/798/58https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/798/58http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/798/58https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/798/58https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/798/58http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/798/58GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/798/58/gmc (GMCs leaf-node and SED parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/798/58/gmc?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/798/58/gmc?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/798/58/gmc?GETtext/xml+votable180.050000true9.792540.62250.0055555555555555566/2622 2623 2666 2667 2708 2709 27524.62055710559558e-22 2.284409653682218e-21https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/798/58?format=asciiInfrareddefaultJ/ApJ/798/58/gmcGMCs leaf-node and SED parametersTemp[14/33]? TemperatureKphys.temperatureintnullablel_LCOLimit on LCOmeta.code.errorcharl_S100Limit flag on S100meta.code.errorcharSeq[1/326] Running sequence numbermeta.id;meta.mainintprimaryRAJ2000[0] Hour of Right Ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000[40/42] Degree of Declination (J2000) (1)pos.eq.dec;meta.mainXX offset (2)kpcpos;arith.difffloatYY offset (2)kpcpos;arith.difffloatR[0.2/21] Galactocentric distance (3)kpcpos.distance;pos.galactocentricfloatFWHM[78/890] Geometric mean of deconvolved FWHMpcphys.size.radiusintl_S350Limit flag on S350meta.code.errorcharS350[0.025/4.7] Herschel/SPIRE 350 micron filter flux densityJyphot.flux.density;em.mm.750-1500GHzfloate_S350[0.004/0.1]? Uncertainty in S350Jystat.errorfloatnullableS250[0.07/9.6] Herschel/SPIRE 250 micron filter flux densityJyphot.flux.density;em.mm.750-1500GHzfloate_S250[0.004/0.2] Uncertainty in S250Jystat.errorfloatl_S160Limit flag on S160meta.code.errorcharS160[0.05/13] Herschel/PACS 160 micron filter flux densityJyphot.flux.density;em.mm.1500-3000GHzfloate_S160[0.01/1]? Uncertainty in S160Jystat.errorfloatnullableS100[0.03/7] Herschel/PACS 100 micron filter flux densityJyphot.flux.density;em.IR.60-100umfloate_S100[0.008/0.5]? Uncertainty in S100Jystat.errorfloatnullableMass[0.08/140]? Total cloud mass100000solMassphys.massfloatnullableLFIR[0.3/55]? Far-IR (10-1000{mu}m) luminosity;100000solLumphys.luminosity;em.IRfloatnullableLCO[0.2/56]? Integrated CO luminosity10000K.km.s**-1.pc**-2phys.luminosity;em.radiofloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar