J/MNRAS/494/1276ivo://CDS.VizieR/J/MNRAS/494/1276doi:10.26093/cds/vizier.74941276CDSJiang X.-J.Greve T.R.Gao Y.Zhang Z.-Y.Tan Q.de Grijs R.Ho L.C.,Michalowski M.J.Currie M.J.Wilson C.D.Brinks E.Ao Y.Zhao Y.,He J.Harada N.Yang C.Jiao Q.Chung A.Lee B.Smith M.W.L.Liu D.,Matsushita S.Shi Y.Imanishi M.Rawlings M.G.Zhu M.Eden D.,Davis T.A.Li X.2024-08-20T20:17:05Z2020-07-13T16:51:57ZCDS support team

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

cds-question@unistra.frsurveysgalaxiesinterstellar-mediumIn order to study the high-transition dense-gas tracers and their relationships to the star formation of the inner ~2kpc circumnuclear region of NGC 253, we present HCN J=4-3 and HCO^+^ J=4-3 maps obtained with the James Clerk Maxwell Telescope(JCMT). With the spatially resolved data, we compute the concentration indices r90/r50 for the different tracers. HCN and HCO^+^ 4-3 emission features tend to be centrally concentrated, which is in contrast to the shallower distribution of CO 1-0 and the stellar component. The dense-gas fraction (fdense, traced by the velocity-integrated-intensity ratios of HCN/CO and HCO^+^/CO) and the ratio R31 (CO 3-2/1-0) decline towards larger galactocentric distances, but increase with higher SFR surface density. The radial variation and the large scatter of fdense and R31 imply distinct physical conditions in different regions of the galactic disc. The relationships of fdense versus Sigma_stellar, and SFE_dense versus Sigma_stellar are explored. SFE_dense increases with higher Sigma_stellar in this galaxy, which is inconsistent with previous work that used HCN 1-0 data. This implies that existing stellar components might have different effects on the high-J HCN and HCO+ than their low-J emission. We also find that SFE_dense seems to be decreasing with higher f_dense which is consistent with previous works, and it suggests that the ability of the dense gas to form stars diminishes when the average density of the gas increases. This is expected in a scenario where only the regions with high-density contrast collapse and form stars.2020MNRAS.494.1276Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/494/1276CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/MNRAS/388/849 : NGC253 XMM observations (Barnard+, 2008)J/A+A/550/A12 : NGC253 near-infrared H_2_ emission (Rosenberg+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/494/1276https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/494/1276http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/494/1276https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/494/1276https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/494/1276http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/494/1276GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/MNRAS/494/1276/table1Integrated intensities and line ratiosAllDisplay all data for this positionmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintoffsetxOffset along the major axis of NGC253arcsecpos;arith.diffintoffsetyOffset along the major axis of NGC253arcsecpos;arith.diffintl_IHCN43Upper limit flag on IHCN43meta.code.errorcharIHCN43? Integrated intensity of HCN(4-3)K.km/sphot.flux.density;em.radiofloatnullablee_IHCN43? Error of IHCN43 (1)K.km/sstat.errorfloatnullablel_IHCO+43Upper limit flag on IHCO+43meta.code.errorcharIHCO+43? Integrated intensity of HCO+(4-3)K.km/sphot.flux.density;em.radiofloatnullablee_IHCO+43? Error on IHCO+43 (1)K.km/sstat.errorfloatnullableIHCO10? Integrated intensity of CO(1-0)K.km/sphot.flux.density;em.radiointnullablee_IHCO10? Error on ICO10 (1)K.km/sstat.errorintnullableICO32? Integrated intensity of CO(3-2)K.km/sphot.flux.density;em.radiofloatnullablee_ICO32? Error on ICO32 (1)K.km/sstat.errorfloatnullableICO32/ICO10? Ratio between ICO32 and ICO10phot.flux;arith.ratiofloatnullablee_ICO32/ICO10? Error on CO32/CO10 (1)stat.errorfloatnullableIHCN43/ICO10? Ratio between IHCN43 and ICO10phot.flux;arith.ratiofloatnullablee_IHCN43/ICO10? Error on HCN43/CO10 (1)stat.errorfloatnullableIHCO+43/ICO10? Ratio between IHCO+43 and ICO10phot.flux;arith.ratiofloatnullablee_IHCO+43/ICO10? Error on HCO+43/CO10 (1)stat.errorfloatnullablel_IHCN43/IHCO+43Limit flag on HCN43/HCO+43 ("<" and ">" means upper limit and lower limit)meta.code.errorcharIHCN43/IHCO+43? Ratio between IHCN43 and IHCO+43phot.flux;arith.ratiofloatnullablee_IHCN43/IHCO+43? Error on IHCN43 and IHCO+43 (1)stat.errorfloatnullableJ/MNRAS/494/1276/table2Luminosities and dense gas masses calculated based on Table 1recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAllDisplay all data for this positionmeta.ref.urlcharoffsetxOffset along the major axis of NGC253arcsecpos;arith.diffintoffsetyOffset along the major axis of NGC253arcsecpos;arith.diffintl_LHCN43Upper limit flag on LHCN43meta.code.errorcharLHCN43? Line luminosity of HCN(4-3)10000K.km.s**-1phys.luminosity;spect.linefloatnullablee_LHCN43? Error on LHCN43 (1)10000K.km.s**-1stat.errorfloatnullablel_LHCO+43Upper limit flag on LHCO+43meta.code.errorcharLHCO+43? Line luminosity of HCO+(4-3)h10000K.km.s**-1phys.luminosity;spect.linefloatnullablee_LHCO+43? Error on LHCO+43 (1)10000K.km.s**-1stat.errorcharLIR? Total infrared luminosity1e+07solLumphys.luminosity;em.IRfloatnullablee_LIR? Error on LIR (1)1e+07solLumstat.errorfloatnullableSFR? Star formation rate0.001solMass.yr**-1phys.SFRintnullablee_SFR? Error on SFR (1)(2)0.001solMass.yr**-1stat.error;phys.SFRfloatnullablel_MHCN43Upper limit flag on MHCN43meta.code.errorcharMHCN43? HCN mass from a constant conversion factor1e+06solMassphys.massfloatnullablee_MHCN43? Error on MHCN43 (1)1e+06solMassstat.errorfloatnullablel_MHCO+43Upper limit flag on MHCO+43meta.code.errorcharMHCO+43? HCO+ mass from a constant conversion factor1e+06solMassphys.massfloatnullablee_MHCO+43? Error on MHCO+43 (1)1e+06solMassstat.errorfloatnullablel_MHCN43G0Upper limit flag on MHCN43G0meta.code.errorcharMHCN43G0? HCN mass from G0 dependent conversion factor1e+06solMassphys.massfloatnullablee_MHCN43G0? Error on MHCN43 (1)1e+06solMassstat.errorfloatnullablel_MHCO+43G0Upper limit flag on MassHCO+43G0meta.code.errorcharMHCO+43G0? HCO+ mass from G0 dependent conversion factor1e+06solMassphys.massfloatnullablee_MHCO+43G0? Error on MHCO+43G0 (1)1e+06solMassstat.errorfloatnullable