J/ApJ/752/148ivo://CDS.VizieR/J/ApJ/752/148doi:10.26093/cds/vizier.17520148CDSNicholls D.C.Dopita M.A.Sutherland R.S.2014-03-24T15:16:42Z2014-03-04T12:54:28ZCDS support team

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

cds-question@unistra.fratomic-physicsh-ii-regionsinterstellar-mediumplanetary-nebulaeThe measurement of electron temperatures and metallicities in H II regions and planetary nebulae (PNe) has--for several decades--presented a problem: results obtained using different techniques disagree. What is worse, they disagree consistently. There have been numerous attempts to explain these discrepancies, but none has provided a satisfactory solution to the problem. In this paper, we explore the possibility that electrons in H II regions and PNe depart from a Maxwell-Boltzmann equilibrium energy distribution. We adopt a "{kappa}-distribution" for the electron energies. Such distributions are widely found in solar system plasmas, where they can be directly measured. This simple assumption is able to explain the temperature and metallicity discrepancies in H II regions and PNe arising from the different measurement techniques. We find that the energy distribution does not need to depart dramatically from an equilibrium distribution. From an examination of data from H II regions and PNe, it appears that {kappa}>~10 is sufficient to encompass nearly all objects. We argue that the kappa-distribution offers an important new insight into the physics of gaseous nebulae, both in the Milky Way and elsewhere, and one that promises significantly more accurate estimates of temperature and metallicity in these regions.2012ApJ...752..148Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/752/148CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/208/10 : {kappa}-distribution effects in HII regions (Dopita+, 2013)J/MNRAS/415/181 : Deep spectroscopy of NGC 7009 (Fang+, 2011)J/ApJ/700/654 : Keck spectro. of extragalactic HII regions (Esteban+ 2009)J/ApJ/656/168 : Spectrophotometry in NGC 5253 (Lopez-Sanchez+, 2007)J/MNRAS/368/253 : Faint emission lines in M16, M20, N3603 (Garcia-Rojas+, 2006)J/A+A/448/955 : Abundances of emission galaxies in SDSS-DR3 (Izotov+, 2006)J/MNRAS/362/301 : Spectrophot. of the HII region S311 (Garcia-Rojas+, 2005)J/ApJS/123/311 : Excitation rate coefficients for O III (Aggarwal+, 1999)J/A+AS/103/273 : IRON Project II. C-like ions (Lennon+ 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/752/148https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/752/148http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/752/148https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/752/148https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/752/148http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/752/148GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/752/148/table1Collisional excitation rate ratiosrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTex/TU[0/20] Excitation threshold energy (expressed as an equivalent temperature) over the kinetic temperature T_U_ (Equation (16))phys.atmol.excitationfloatRate(2)Collisional excitation rate at {kappa}=2arith.rate;phys.atmol.excitationdoubleRate(3)Collisional excitation rate at {kappa}=3arith.rate;phys.atmol.excitationdoubleRate(4)Collisional excitation rate at {kappa}=4arith.rate;phys.atmol.excitationdoubleRate(6)Collisional excitation rate at {kappa}=6arith.rate;phys.atmol.excitationdoubleRate(10)Collisional excitation rate at {kappa}=10arith.rate;phys.atmol.excitationdoubleRate(20)Collisional excitation rate at {kappa}=20arith.rate;phys.atmol.excitationdoubleRate(50)Collisional excitation rate at {kappa}=50arith.rate;phys.atmol.excitationdoubleRate(100)Collisional excitation rate at {kappa}=100arith.rate;phys.atmol.excitationdoubleJ/ApJ/752/148/table2[OIII] Line flux ratios versus kinetic temperaturerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTU[5000/20000] Kinetic temperature T_U_Kphys.temperatureintOIII(2)OIII line flux ratio at {kappa}=2 (1)phot.flux;arith.ratiofloatOIII(3)OIII line flux ratio at {kappa}=3 (1)phot.flux;arith.ratiofloatOIII(4)OIII line flux ratio at {kappa}=4 (1)phot.flux;arith.ratiofloatOIII(6)OIII line flux ratio at {kappa}=6 (1)phot.flux;arith.ratiodoubleOIII(10)OIII line flux ratio at {kappa}=10 (1)phot.flux;arith.ratiodoubleOIII(20)OIII line flux ratio at {kappa}=20 (1)phot.flux;arith.ratiodoubleOIII(50)OIII line flux ratio at {kappa}=50 (1)phot.flux;arith.ratiodoubleOIII(100)OIII line flux ratio at {kappa}=100 (1)phot.flux;arith.ratiodoubleOIII(M)OIII line flux ratio (Maxwell) (1)phot.flux;arith.ratiodouble