J/ApJ/806/74ivo://CDS.VizieR/J/ApJ/806/74doi:10.26093/cds/vizier.18060074CDSCamarata M.A.Jackson J.M.Chambers E.2017-01-23T22:00:00Z2015-11-04T15:25:51ZCDS support team

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

cds-question@unistra.frh-ii-regionsmolecular-cloudsradio-astronomyspectroscopyinterstellar-mediumAnomalous ammonia (NH_3_) spectra, exhibiting asymmetric hyperfine satellite intensity profiles in the (J,K)=(1,1) inversion transition, have been observed in star-forming regions for over 35 years. We present a systematic study of this "hyperfine intensity anomaly" (HIA) toward a sample of 334 high-mass star forming regions: 310 high-mass (>~100M_{sun}_) clumps and 24 infrared dark clouds. The HIA is ubiquitous in high-mass star forming regions. Although LTE excitation predicts that the intensity ratios of the outer satellites and inner satellites are exactly unity, for this sample the ensemble average ratios are 0.812+/-0.004 and 1.125+/-0.005, respectively. We have quantified the HIA and find no significant relationships between the HIA and temperature, line width, optical depth, and the stage of stellar evolution. The fact that HIAs are common in high-mass star-forming regions suggests that the conditions that lead to HIAs are ubiquitous in these regions. A possible link between HIAs and the predictions of the competitive accretion model of high-mass star formation is suggested; however, the expected trends of HIA strength with clump evolutionary stage, rotational temperature, and line width for evolving cores in competitive accretion models are not found. Thus, the exact gas structures that produce HIAs remain unknown. Turbulent gas structures are a possible explanation, but the details need to be explored.2015ApJ...806...74Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/806/74CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/443/1555 : ATLASGAL massive star forming clumps (Urquhart+, 2014)J/ApJ/777/157 : 90GHz obs. of high-mass star-forming regions (Hoq+, 2013)J/A+A/544/A146 : ATLASGAL cold high-mass clumps with NH_3_ (Wienen+, 2012)J/A+A/540/A113 : Starless clumps in ATLASGAL (Tackenberg+, 2012)J/ApJ/715/310 : Early stages of star formation in IRDCs (Rathborne+, 2010)J/ApJ/653/1325 : Galactic distribution of infrared dark clouds (Simon+, 2006)J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/806/74https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/806/74http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/806/74https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/806/74https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/806/74http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/806/74GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/806/74/table1 (Source properties and hyperfine intensity anomaly (HIA) results)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/806/74/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/806/74/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/806/74/table1?GETtext/xml+votable180.050000true269.30428-24.207570.0055555555555555565/7376 7377 7383 7564 7579 6/12974 14337 14352 14353 28901 28912 28913 28915 28916 28918 28919 29090 29091 29097 29101 29113 29114 29115 29118 29119 29162 29457 29462 29463 29522 29528 29529 30218 30219 30222 30223 30240 30241 30244 30245 30260 30262 30263 30268 30269 30312 30313 30315 30330 30416 30417 30418 30420 30421 30422 30592 30595 30622 30623 30692 30694 30707 30710 30712 30713 30717 30718 30719 41772 41802 41804 42171 42206 42224 42225 42228 42392 42456 42457 42461 42462 42496 42497https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/806/74?format=asciiRadiodefaultJ/ApJ/806/74/table1Source properties and hyperfine intensity anomaly (HIA) resultsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource Name (GL.ll+B.bb)meta.id;meta.maincharn_Name[*] Flag on Source Name (1)meta.notecharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latTrot[11/25]? NH3 Rotational Temperature (2)Kphys.temperaturefloatnullablee_Trot[0.3/2]? Uncertainty in TrotKstat.errorfloatnullableHIAa[0.4/1.4] Ratio of NH3 outer satellite intensities (3)spect.line.intensity;arith.ratiofloate_HIAa[0.02/0.2] Uncertainty in HIAastat.errorfloatHIAb[0.6/3.1] Ratio of NH3 inner satellite intensities (4)spect.line.intensity;arith.ratiofloate_HIAb[0.02/0.4] Uncertainty in HIAbstat.errorfloatClassClassification (HII, Protostellar, Quiescent or Unclassified) (5)src.classchartau[0.3/3.9]? Optical Depth, {tau} (2)phys.absorption.opticalDepthdoublenullablee_tau[0.04/0.3]? Uncertainty in taustat.errordoublenullable_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed