J/ApJ/803/97ivo://CDS.VizieR/J/ApJ/803/97doi:10.26093/cds/vizier.18030097CDSSakai Y.Kobayashi K.Hirota T.2017-10-09T08:34:49Z2017-09-18T13:11:39ZCDS support team

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

cds-question@unistra.fratomic-physicsinterstellar-mediumWe recently reported the first identification of rotational transitions of methyl formate (HCOOCH_3_) in the second torsionally excited state toward Orion Kleinmann-Low (KL), observed with the Nobeyama 45 m telescope. In combination with the identified transitions of methyl formate in the ground state and the first torsional excited state, it was found that there is a difference in rotational temperature and vibrational temperature, where the latter is higher. In this study, high spatial resolution analysis by using Atacama Large Millimeter/Submillimeter Array (ALMA) science verification data was carried out to verify and understand this difference. Toward the Compact Ridge, two different velocity components at 7.3 and 9.1 km/s were confirmed, while a single component at 7.3 km/s was identified toward the Hot Core. The intensity maps in the ground, first, and second torsional excited states have quite similar distributions. Using extensive ALMA data, we determined the rotational and vibrational temperatures for the Compact Ridge and Hot Core by the conventional rotation diagram method. The rotational temperature and vibrational temperatures agree for the Hot Core and for one component of the Compact Ridge. At the 7.3 km/s velocity component for the Compact Ridge, the rotational temperature was found to be higher than the vibrational temperature. This is different from what we obtained from the results by using the single-dish observation. The difference might be explained by the beam dilution effect of the single-dish data and/or the smaller number of observed transitions within the limited range of energy levels (<=30 K) of E_u_ in the previous study.2015ApJ...803...97Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/803/97CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/532/A32 : HCOOCH3 map of Orion-KL (Favre+, 2011)J/ApJS/205/9 : Rotational transition frequencies of HCOOCH_3_J/ApJS/215/25 : Methyl formate (HCOOCH_3_) observations (Favre+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/803/97https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/803/97http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/803/97https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/803/97https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/803/97http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/803/97GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/803/97/table1Transition List for the Compact RidgerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFreqThe rest frequency of methyl formateMHzem.freqdoublevt[0/2] Quantum number of the torsional statephys.mol.qnintJ'[6/39] Rotational quantum number of the lower statephys.atmol.qnintKa'[0/17] Lower Ka quantum numberphys.atmol.qn;stat.minintKc'[0/32] Lower Kc quantum numberphys.atmol.qn;stat.minintJ"[5/39] Rotational quantum number of the upper statephys.atmol.qnintKa"[0/17] Upper Ka quantum numberphys.atmol.qn;stat.maxintKc"[0/33] Upper Kc quantum numberphys.atmol.qn;stat.maxintSym[AE] Symmetry sublevelphys.atmol.paritycharSmu2Line strength, S{mu}^2^D**2spect.line.intensityfloatEuUpper level energyKphys.energy;phys.atmol.levelfloatT7.3? Temperature (1)Kphys.temperaturefloatnullableFWHM7.3? FWHM (1)km/sspect.line.widthfloatnullableVLSR7.3? Local Standard of Rest velocity (1)km/sphys.veloc;pos.lsrfloatnullableW7.3? W component of the velocity (1)km/sphys.veloc;pos.cartesian.zfloatnullableT9.1? Temperature (2)Kphys.temperaturefloatnullableFWHM9.1? FWHM (2)km/sspect.line.widthfloatnullableVLSR9.1? Local Standard of Rest velocity (2)km/sphys.veloc;pos.lsrfloatnullableW9.1? W component of the velocity (2)km/sphys.veloc;pos.cartesian.zfloatnullableComComment (4)meta.notecharDiag[*-] Diagram (5)meta.codecharJ/ApJ/803/97/table2Transition List for the Hot CorerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFreqThe rest frequency of methyl formateMHzem.freqdoublevt[0/2] Quantum number of the torsional statephys.mol.qnintJ'[6/39] Rotational quantum number of the lower statephys.atmol.qnintKa'[0/17] Lower Ka quantum numberphys.atmol.qn;stat.minintKc'[0/32] Lower Kc quantum numberphys.atmol.qn;stat.minintJ"[5/39] Rotational quantum number of the upper statephys.atmol.qnintKa"[0/17] Upper Ka quantum numberphys.atmol.qn;stat.maxintKc"[0/33] Upper Kc quantum numberphys.atmol.qn;stat.maxintSym[AE] Symmetry sublevelphys.atmol.paritycharSmu2Line strength, S{mu}^2^D**2spect.line.intensityfloatEuUpper level energyKphys.energy;phys.atmol.levelfloatT? Temperature (3)Kphys.temperaturefloatnullableFWHM? FWHM (3)km/sspect.line.widthfloatnullableVLSR? Local Standard of Rest velocity (3)km/sphys.veloc;pos.lsrfloatnullableW? W component of the velocity (3)km/sphys.veloc;pos.cartesian.zfloatnullableComComment (4)meta.notecharDiag[*-] Diagram (5)meta.codechar