J/ApJ/688/1142ivo://CDS.VizieR/J/ApJ/688/1142doi:10.26093/cds/vizier.16881142CDSKoenig X.P.Allen L.E.Gutermuth R.A.Hora J.L.Brunt C.M.,Muzerolle J.2018-02-12T08:45:34Z2011-01-31T15:53:32ZCDS support team

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

cds-question@unistra.frh-ii-regionsinfrared-photometrypre-main-sequence-starsactive-galactic-nucleiWe present images and initial results from our extensive Spitzer Space Telescope imaging survey of the W5 HII region with the Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS). We detect dense clusters of stars, centered on the O stars HD 18326, BD +60 586, HD 17505, and HD 17520. At 24um, substantial extended emission is visible, presumably from heated dust grains that survive in the strongly ionizing environment of the HII region. With photometry of more than 18000 point sources, we analyze the clustering properties of objects classified as young stars by their IR spectral energy distributions (a total of 2064 sources) across the region using a minimal-spanning-tree algorithm. We find ~40%-70% of infrared excess sources belong to clusters with >=10 members. We find that within the evacuated cavities of the HII regions that make up W5, the ratio of Class II to Class I sources is ~7 times higher than for objects coincident with molecular gas as traced by ^12^CO emission and near-IR extinction maps. We attribute this contrast to an age difference between the two locations and postulate that at least two distinct generations of star formation are visible across W5. Our preliminary analysis shows that triggering is a plausible mechanism to explain the multiple generations of star formation in W5 and merits further investigation.2008ApJ...688.1142Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/688/1142CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/503/107 : Spitzer/IRAC view of Sh2-284 (Puga+, 2009)J/ApJ/674/336 : Spitzer observations of NGC 1333 (Gutermuth+, 2008)J/ApJ/678/200 : YSOs in N63 and N180 (Caulet+, 2008)J/ApJ/643/965 : Spitzer photometry of the Trifid nebula (M20) (Rho+, 2006)J/ApJ/639/1069 : Radial velocities in the Cas OB6 association (Hillwig+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/688/1142https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/688/1142http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/688/1142https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/688/1142https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/688/1142http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/688/1142GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/688/1142/table2 (W5 source list)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/688/1142/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/688/1142/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/688/1142/table2?GETtext/xml+votable180.050000true41.0815261160.510606940.005555555555555556Cone search capability for table J/ApJ/688/1142/table4 (Star-forming globules in W5)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/688/1142/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/688/1142/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/688/1142/table4?GETtext/xml+votable180.050000true42.482416760.44012780.005555555555555556Cone search capability for table J/ApJ/688/1142/table6 (W5 extragalactic sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/688/1142/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/688/1142/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/688/1142/table6?GETtext/xml+votable180.050000true41.1766019460.6726050.0055555555555555565/825 6/3278 3279 3290 3297 3312 33146.772611666688002e-21 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/688/1142?format=asciiInfrareddefaultJ/ApJ/688/1142/table2W5 source listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource identification (<[KAG2008] NNNNN> in Simbad)meta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainJmag? 2MASS J band magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag? Error in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag? 2MASS H band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag? Error in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKsmag? 2MASS Ks band magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag? Error in Kmagmagstat.error;phot.mag;em.IR.Kfloatnullable[3.6]Spitzer/IRAC 3.6 micron band magnitudemagphot.mag;em.IR.3-4umfloate_[3.6]Error in [3.6]magstat.errorfloat[4.5]Spitzer/IRAC 4.5 micron band magnitudemagphot.mag;em.IR.4-8umfloate_[4.5]Error in [4.5]magstat.errorfloat[5.8]? Spitzer/IRAC 5.8 micron band magnitudemagphot.flux.density;em.IR.4-8umfloatnullablee_[5.8]? Error in [5.8]magstat.errorfloatnullable[8.0]? Spitzer/IRAC 8.0 micron band magnitudemagphot.flux.density;em.IR.8-15umfloatnullablee_[8.0]? Error in [8.0]magstat.errorfloatnullable[24]? Spitzer/MIPS 24 micron band magnitudemagphot.flux.density;em.IR.15-30umfloatnullablee_[24]? Error in [24]magstat.errorfloatnullableTypeSource type as defined in text (1)src.classcharf_Type[v?-] Source flag (2)meta.codechar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharJ/ApJ/688/1142/table4Star-forming globules in W5recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource identification (<[KAG2008] globule NN> in Simbad)meta.id;meta.mainintRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainTypeComet (for cometary) or Trunk (1)src.classcharJ/ApJ/688/1142/table6W5 extragalactic sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource identification (<[KAG2008] gNNN> in Simbad)meta.id;meta.maincharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainJmag? 2MASS J band magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag? Error in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag? 2MASS H band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag? Error in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKsmag? 2MASS Ks band magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag? Error in Kmagmagstat.error;phot.mag;em.IR.Kfloatnullable[3.6]Spitzer/IRAC 3.6 micron band magnitudemagphot.mag;em.IR.3-4umfloate_[3.6]Error in [3.6]magstat.errorfloat[4.5]Spitzer/IRAC 4.5 micron band magnitudemagphot.mag;em.IR.4-8umfloate_[4.5]Error in [4.5]magstat.errorfloat[5.8]Spitzer/IRAC 5.8 micron band magnitudemagphot.flux.density;em.IR.4-8umfloate_[5.8]Error in [5.8]magstat.errorfloat[8.0]Spitzer/IRAC 8.0 micron band magnitudemagphot.flux.density;em.IR.8-15umfloate_[8.0]Error in [8.0]magstat.errorfloat[24]? Spitzer/MIPS 24 micron band magnitudemagphot.flux.density;em.IR.15-30umfloatnullablee_[24]? Error in [24]magstat.errorfloatnullableTypeGalaxy type (1)src.classcharProbProbability that the object is a YSO (2)stat.probabilityfloat2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar