J/AJ/161/71ivo://CDS.VizieR/J/AJ/161/71doi:10.26093/cds/vizier.51610071CDSHunter D.A.Elmegreen B.G.Goldberger E.Taylor H.Ermakov A.I.,Herrmann K.A.Oh S.-H.Malko B.Barandi B.Jundt R.2023-12-20T08:22:52Z2021-04-16T09:58:49ZCDS support team

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

cds-question@unistra.frgalaxiesh-i-line-emissionstar-forming-regionsspectroscopyultraviolet-astronomyThe stellar, gaseous and young stellar disks in the LITTLE THINGS sample of nearby dwarf irregular galaxies are fitted with functions to search for correlations between the parameters. We find that the HI radial profiles are generally flatter in the center and fall faster in the outer regions than the V-band profiles, while young stars are more centrally concentrated, especially if the HI is more centrally flat. This pattern suggests that the HI is turning into molecules in the center, and the molecular clouds are forming stars and FUV. A model that assumes the molecular surface density is proportional to the total gas surface density to a power of 1.5 or 2, in analogy with the Kennicutt-Schmidt relation, reproduces the relationship between the ratio of the visible to the HI scale length and the HI Sersic index. The molecular fraction is estimated as a function of radius for each galaxy by converting the FUV to a molecular surface density using conventional calibrations. The average molecular fraction inside 3RD is 23%{+/-}17%. However, the break in the stellar surface brightness profile has no unified tracer related to star formation.2021AJ....161...71Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/161/71CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/114/2402 : Rotation curves of early-type galaxies (Courteau+, 1997)J/AJ/128/2170 : H{alpha} imaging of irregular galaxies (Hunter+, 2004)J/ApJS/162/49 : UBV imaging of irregular galaxies (Hunter+, 2006)J/ApJS/173/185 : GALEX UV atlas of nearby galaxies (Gil de Paz+, 2007)J/A+A/465/71 : 21cm observations of 452 galaxies (Theureau+, 2007)J/AJ/136/2782 : Star formation efficiency in nearby galaxies (Leroy+, 2008)J/AJ/140/1194 : FUV/HI relations in nearby galaxies (Bigiel+, 2010)J/AJ/144/134 : LITTLE THINGS survey of nearby dwarf galaxies (Hunter+,2012)J/MNRAS/433/2240 : SALT2 parameters and distances for SNe (Ganeshalingam+,2013)J/AJ/146/104 : Dwarf galaxies surface bright. profiles. I. (Herrmann+,2013)J/A+A/566/A44 : gr photometry of Sextans A and Sextans B (Bellazzini+, 2014)J/AJ/151/145 : Dwarf galaxies surface bright. profiles II. (Herrmann+,2016)J/AJ/151/136 : LITTLE THINGS dwarf irregular galax. FUV reg. (Hunter+,2016)J/AJ/157/241 : HI clouds LITTLE THINGS dwarf irregular galax (Hunter+,2019)J/A+A/625/A36 : Breaks in surf. bright. prof. galaxy disks (Watkins+, 2019)J/ApJ/882/5 : ALMA data for 5 luminous IR gal. (Wilson+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/161/71https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/161/71http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/161/71https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/161/71https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/161/71http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/161/71GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/161/71/table1 (The galaxy sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/161/71/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/161/71/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/161/71/table1?GETtext/xml+votable180.050000true189.6669132.766810.0055555555555555566/3042 3389 4522 5287 5607 5978 6399 6502 6560 7523 7769 7799 7878 7956 7970 8028 8908 10762 10881 10970 11019 11041 11120 11143 11933 17165 18041 19833 19990 22495 26858 27351 27926 28149 28510 28610 28631 28636 29699 48942https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/161/71?format=asciiUVRadiodefaultJ/AJ/161/71/table1The galaxy sampleSimbadNameSimbad column added by the CDSmeta.idcharnullableNEDnameNED column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGalaxyGalaxy identificationmeta.id;meta.maincharprimaryNEDNED preferred identifiermeta.id.crosscharDist[0.7/10.3] Distance to galaxy (1)Mpcpos.distancefloate_Dist[0.04/0.8] Uncertainty in Dist (2)Mpcstat.errorfloatMVmag[-18.3/-9.7] Absolute V band magnitudemagphys.magAbsfloate_MVmag[0.03/0.4] Uncertainty in MVmag (2)magstat.error;phot.magfloatRHa[0.3/5.58]? Radius of furthest out detected HII region (3)kpcphys.size.radius;obs.fieldfloatnullableRFUV[0.29/6.79]? Radius of furthest out detected FUV knot (4)kpcphys.size.radiusfloatnullablee_RFUV[0.01/0.1]? Uncertainty in RFUVkpcstat.errorfloatnullableRD[0.15/2.24] Disk scale length (5)kpcphys.angSize;srcfloate_RD[0/0.25] Uncertainty in RDkpcstat.errorfloatRBr[0.13/2.8]? Break radius (6)kpcphys.size.radiusfloatnullablee_RBr[0/1.35]? Uncertainty in RBrkpcstat.errorfloatnullablelogSFR[-3.75/-0.32]? Area normalized, FUV based star formation rate (7)log(solMass.yr**-1.kpc**-2)phys.SFR;arith.ratiofloatnullablee_logSFR[0.04]? Uncertainty in logSFRlog(solMass.yr**-1.kpc**-2)stat.error;phys.SFRfloatnullableC31[2.02/5.29]? Central concentration (8)em.wl.centralfloatnullablelogFUV[-0.14/1.76]? Ratio of the FUV emission interior/exterior to RD (9)stat.fit.omcfloatnullablee_logFUV[0.06]? Uncertainty in logFUVstat.errorfloatnullable_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.mainJ/AJ/161/71/table2Sersic fit parameters and radii for HIGalaxyGalaxy identificationmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlogS0[-0.21/2.39] Extrapolated central surface mass densitylog(solMass.pc**-2)phot.flux.density.sbfloate_logS0[0.01/0.17] Uncertainty in logS0log(solMass.pc**-2)stat.errorfloatR0[0.25/7.71] Characteristic radiuskpcphys.size.radiusfloate_R0[0.02/0.29] Uncertainty in R0kpcstat.errorfloatnHI[0.2/1.65] Curvature of profilemeta.notefloate_nHI[0.0/0.12] Uncertainty in nHIstat.errorfloatR50[0.29/5.03] Radius containing 50% HI gaskpcphys.size.radiusfloate_R50[0.01/0.14] Uncertainty in R50kpcstat.errorfloatR50/R90[0.3/0.67] Central concentration of HIstat.fit.paramfloate_R50/R90[0.04/0.06] Uncertainty in R50/R90stat.errorfloatJ/AJ/161/71/table3FUV interior and exterior to RBrlogFUV1[0.39/2.19]? log, ratio interior/exterior FUV flux ratio, normalized by area (2)phot.flux;arith.ratiofloatnullablee_logFUV1[0.01/0.92]? Uncertainty in logFUVie1stat.errorfloatnullablelogFUV2[-0.27/0.87]? log, ratio interior/exterior FUV flux ratio, normalized by V band flux (2)phot.flux;arith.ratiofloatnullablee_logFUV2[0/0.92]? Uncertainty in logFUVie2stat.errorfloatnullableGalaxyGalaxy identificationmeta.id;meta.maincharTypeBreak Type (1)meta.id;stat.fitcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ/AJ/161/71/table4Sersic fit parameters for FUV profilesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlogFUV[14.22/28.84] Extrapolated central surface brightnesslog(mag.arcsec**-2)phot.flux;arith.ratiofloate_logFUV[0.01/0.64] Uncertainty in logmu0FUVlog(mag.arcsec**-2)stat.errorfloatR0FUV[0.0/2.91] Characteristic radiuskpcphys.size.radiusfloate_R0FUV[0.0/0.12] Uncertainty in R0-FUVkpcstat.errorfloatnFUV[0.21/4.17] Curvature of profilestat.fit.paramfloate_nFUV[0.01/0.27] Uncertainty in nFUVstat.errorfloatGalaxyGalaxy identificationmeta.id;meta.maincharJ/AJ/161/71/table5Rotation curve fit parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRt[0.32/4.18] Transition radius (1)kpcphys.size.radius;phys.atmol.transitionfloate_Rt[0.02/0.34] Uncertainty in Rtkpcstat.errorfloatVc[13.1/160.9] Asymptotic velocity at large radiikm/sphys.velocfloate_Vc[0.3/37.3] Uncertainty in Vckm/sstat.error;phys.velocfloatgamma[0.89/20.88] Sharpness of transition (2)stat.fit.paramfloate_gamma[0.12/15.38] Uncertainty in gammastat.errorfloatGalaxyGalaxy identificationmeta.id;meta.mainchar