J/ApJ/908/61ivo://CDS.VizieR/J/ApJ/908/61doi:10.26093/cds/vizier.19080061CDSKennicutt R.C.De Los Reyes M.A.C.2023-06-06T08:54:31Z2022-07-28T12:14:18ZCDS support team

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

cds-question@unistra.frstar-forming-regionsinterstellar-mediumgalaxiesinfrared-sourcesWe compile observations of molecular gas contents and infrared-based star formation rates (SFRs) for 112 circumnuclear star-forming regions, in order to reinvestigate the form of the disk-averaged Schmidt surface density star-formation law in starbursts. We then combine these results with total gas and SFR surface densities for 153 nearby nonstarbursting disk galaxies from de los Reyes & Kennicutt (Paper I), to investigate the properties of the combined star formation law, following Kennicutt (1998ApJ...498..541K). We confirm that the combined Schmidt law can be fitted with a single power law with slope n=1.5{+/-}0.05 (including fitting method uncertainties), somewhat steeper than the value n=1.4{+/-}0.15 found by Kennicutt. Fitting separate power laws to the nonstarbursting and starburst galaxies, however, produces very different slopes (n=1.34{+/-}0.07 and 0.98{+/-}0.07, respectively), with a pronounced offset in the zero-point (~0.6dex) of the starburst relation to higher SFR surface densities. This offset is seen even when a common conversion factor between CO intensity and molecular hydrogen surface density is applied, and it is confirmed when disk surface densities of interstellar dust are used as proxies for gas measurements. Tests for possible systematic biases in the starburst data fail to uncover any spurious sources for such a large offset. We tentatively conclude that the global Schmidt law in galaxies, at least as it is conventionally measured, is bimodal or possibly multimodal. Possible causes may include changes in the small-scale structure of the molecular interstellar medium or the stellar initial mass function. A single n ~1.5 power law still remains as a credible approximation or "recipe" for analytical or numerical models of galaxy formation and evolution.2021ApJ...908...61Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/908/61CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+AS/126/3 : CO and HI in interacting galaxies (Horellou+ 1997)J/AJ/136/2782 : Star formation efficiency in nearby galaxies (Leroy+, 2008)J/ApJ/674/172 : Oxygen abundances of LIRGs and ULIRGs (Rupke+, 2008)J/ApJ/723/993 : Spatial extent of (U)LIRGs in the MIR. I. (Diaz-Santos+, 2010)J/ApJ/715/572 : GOALS UV and FIR properties (Howell+, 2010)J/ApJ/733/87 : Star formation efficiency in galaxies (Shi+, 2011)J/ApJ/777/156 : Spitzer/IRS spectra GOALS luminous IR galaxies (Inami+, 2013)J/ApJ/805/31 : IR-radio luminosities & surface densities galaxies (Liu+, 2015)J/A+A/591/A136 : Galaxies and QSOs FIR size & surface brightness (Lutz+, 2016)J/ApJS/229/25 : GOALS sample PACS and SPIRE fluxes (Chu+, 2017)J/A+A/609/A37 : 875 nearby galaxies multiwavelength photometry (Clark+, 2018)J/ApJ/872/16 : Integrated star formation law revisited I (de los Reyes+, 2019)J/ApJ/870/104 : 1-500um obs. of nearby luminous IR galaxies (Shangguan+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/908/61https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/908/61http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/908/61https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/908/61https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/908/61http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/908/61GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/908/61/table1 (Basic properties of starburst sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/908/61/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/908/61/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/908/61/table1?GETtext/xml+votable180.050000true11.888-25.288222220.005555555555555556Cone search capability for table J/ApJ/908/61/table3 (*Dust surface densities for spiral galaxies)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/908/61/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/908/61/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/908/61/table3?GETtext/xml+votable180.050000true24.173938115.78364110.0055555555555555566/231 286 627 629 650 700 1276 1521 1918 2320 2363 2397 2433 2518 2722 3364 3506 3824 3910 3934 4447 4511 4993 5200 5492 5523 5617 5715 5751 5793 5816 5865 5966 5976 6098 6348 7132 7241 7424 7552 7606 7659 7743 8106 8266 8482 8673 9133 9310 9770 10081 10144 10281 10465 10475 10637 10716 10841 10847 10856 10900-10901 10911 10925 10927 10941 10977 10990 11006 11029 11127 11180 11434 12537 13184 13522-13523 13632 15323 15592 15955 16441 16655 16755 16758 17183 17506 18209 18398 18406 18432 18932 20060-20061 20230 20254 21416 22468 22721 22792 24144 24293 24855 25136 25462 26198 26271 26298 26303 26323 26338 26351 26365 26472 26932 27030 27514 27537 27603 27617 27728 27731 27738 27757 27763 27766 27773 27857 27861-27862 27914 27917-27918 27937 27942 27945 27947 27955 28015 28035 28123 28167 28188 28393 28496 29439 29795 29937 30383 31081 31158 32740 33958 34010 34273 34471 34531 34641 35993 38139 38786 40801 43881 43994 44671 46079 46130 46296 46399 47078 47235 47854https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/908/61?format=asciiInfrareddefaultJ/ApJ/908/61/table1Basic properties of starburst sampleSimbadNameSimbad column added by the CDSmeta.idcharnullableDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/112] Running index number (1)meta.id;meta.numberintNameGalaxy ID preferred by NEDmeta.id;meta.maincharprimaryRAJ2000[0/23] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDist[3/395] DistanceMpcpos.distancefloatDiam[1.8/66] Diameterarcsecphys.angSizefloatDiamRad[0.13/22]? Diameter measured from radio continuumarcsecphys.angSizefloatnullableIRLum[9.97/12.5]? Log total IR luminositylog(solLum)phys.luminosity;em.IRfloatnullableSFR[-0.49/2.64] Log star formation ratelog(solMass.yr**-1)meta.idfloatfExt[0/0.58] Fraction of IR emission outside diameterphys.emissMeasure;arith.ratio;phys.size.diameterfloatMassH2[7.78/10.7] Log H2 masslog(solMass)phys.massfloatr_MassH2Reference logMassH2meta.ref;pos.framecharMassDust[7.34/8.67]? Log dust masslog(solMass)phys.massfloatnullableMapFlag[0/1] Flag denoting availability of interferometric maps; 1=yes, 0=nometa.code.errorintDerDerives properties (table2)meta.ref.urlcharJ/ApJ/908/61/table2Derived properties of starburst sampleNameGalaxy ID preferred by NEDmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/112] Running index number (1)meta.id;meta.numberintlogSigmaH2[1.96/4.49] Log{Sigma} H2 surface densitylog(solMass.pc**-2)phot.flux.density.sbfloatlogSigmaSFR[-0.57/2.48] Log{Sigma} SFR surface densitylog(solMass.yr**-1.kpc**-2)phys.densityfloatlogSigmaDust[-0.16/2.88]? Log{Sigma} dust mass surface densitylog(solMass.pc**-2)phys.densityfloatnullablevRot[60/350]? Rotational velocitykm/sphys.veloc.rotatintnullabletDyn[0.082/1.2]? Dynamical time1e+08yrtime.epochfloatnullableJ/ApJ/908/61/table3*Dust surface densities for spiral galaxiesSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/76] Running index number (1)meta.id;meta.numberintNameGalaxy ID preferred by NEDmeta.id;meta.maincharlogSigmaDust[-2.1/0.18] Log{Sigma} dust mass surface densitylog(solMass.pc**-2)phys.densityfloat_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.mainJ/ApJ/908/61/refsReferences used for table1recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRef[1/37] Reference codemeta.noteintAutorMain autorobs.observercharBIBBIBcodemeta.bib.bibcodecharCat.Catalog in Viziermeta.notechar