J/A+A/581/A48ivo://CDS.VizieR/J/A+A/581/A48doi:10.26093/cds/vizier.35810048CDSGong Y.Henkel C.Thorwirth S.Spezzano S.Menten K.M.Walmsley C.M.Wyrowski F.Mao R.Q.Klein B.2021-11-18T11:23:37Z2015-09-02T09:20:09ZCDS support team

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

cds-question@unistra.frinterstellar-mediumspectroscopyyoung-stellar-objectssurveysradio-astronomyOrion KL has served as a benchmark for spectral line searches throughout the (sub)millimeter regime. The main goal is to systematically study spectral characteristics of Orion KL in the 1.3cm band. We carried out a spectral line survey (17.9GHz to 26.2GHz) with the Effelsberg-100m telescope towards Orion KL. We find 261 spectral lines, yielding an average line density of about 32 spectral features per GHz above 3 sigma. The identified lines include 164 radio recombination lines (RRLs) and 97 molecular lines. A total of 23 molecular transitions from species known to exist in Orion KL are detected for the first time in the interstellar medium. Non-metastable ^15^NH_3_ transitions are detected in Orion KL for the first time. Based on the velocity information of detected lines and the ALMA images, the spatial origins of molecular emission are constrained and discussed. A narrow feature is found in SO_2_ (8_1,7_-7_2,6_), possibly suggesting the presence of a maser line. Column densities and fractional abundances relative to H_2_ are estimated for 12 molecules with LTE methods. Rotational diagrams of non-metastable ^14^NH_3_ transitions with J=K+1 to J=K+4 yield different results; metastable ^15^NH_3_ is found to have a higher excitation temperature than non-metastable ^15^NH_3_, indicating that they may trace different regions. Elemental and isotopic abundance ratios are estimated: ^12^C/^13^C=63+/-17, ^14^N/^15^N=100+/-51, D/H=0.0083+/-0.0045. The dispersion of the He/H ratios derived from H_alpha/He_alpha_ pairs to H_delta_/He_delta_ pairs is very small, which is consistent with theoretical predictions that the departure coefficients bn factors for hydrogen and helium are nearly identical. Based on a non-LTE code neglecting excitation by the infrared radiation field and a likelihood analysis, we find that the denser regions have lower kinetic temperature, which favors an external heating of the Hot Core.2015A&A...581A..48Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/581/A48CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/532/A32 : HCOOCH3 map of Orion-KL (Favre+, 2011)J/A+A/559/A51 : HC_3_N in Orion KL (Esplugues+, 2013)J/A+A/572/A44 : Vibrationally excited vinyl cyanide in Orion-KL (Lopez+, 2014)J/AJ/149/162 : GBT 67-93.6GHz spectral line survey of Orion-KL (Frayer+ 2015)J/ApJ/769/48 : Water maser in Orion-KL with Herschel (Neufeld+, 2013)J/ApJ/777/120 : cm to submm spectra of H_2_C=CH-CH_2_NC (Haykal+, 2013)J/ApJ/779/119 : HCOOCH_2_D detection in Orion KL (Coudert+, 2013)J/ApJS/156/127 : 350{mu}m molecular line survey of Orion KL (Comito+, 2005)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/A+A/581/A48https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/581/A48http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/581/A48https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/581/A48https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/581/A48http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/581/A48GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/581/A48/list (Information of fits spectrum)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/581/A48/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/581/A48/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/581/A48/list?GETtext/xml+votable180.050000true83.19458-5.411130.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/581/A486/22804https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/581/A48?format=asciiRadiodefaultJ/A+A/581/A48/listInformation of fits spectrumrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainNxNumber of wavelengthsmeta.number;em.wlintObs.DateObservation date (YYYY-MM-DDThh:mm:ss.sss)stime.epoch;obsnullablenu.min[16.27] Lower value of frequency intervalGHzinstr.bandwidthfloatnu.max[26.27] Upper value of frequency intervalGHzinstr.bandwidthfloatdnuSpectral resolutionkHzspect.resolutionfloatSizeSize of the fits fileKibytephys.size;meta.fitsintspShow the spectrummeta.ref.urlcharfitsDownload the FITS filemeta.ref.urlcharFileNameName of the fits filemeta.id;meta.fitscharTitleTitle of the filemeta.title;meta.filecharAssocDataAssociated Data web pagemeta.ref.urlchar