J/A+A/671/A55ivo://CDS.VizieR/J/A+A/671/A55doi:10.26093/cds/vizier.36710055CDSAnastasopoulou K.Ponti G.Sormani M.C.Locatelli N.Haberl F.,Morris M.R.Churazov E.M.Schoedel R.Maitra C.Campana S.,Di Teodoro E.M.Jin C.Khabibullin I.Mondal S.Sasaki M.Zhang Y.,Zheng X.2024-11-06T20:03:13Z2023-03-08T08:34:57ZCDS support team

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

cds-question@unistra.frmilky-way-galaxygalactic-centerx-ray-sourcesThe diffuse Fe XXV (6.7keV) line emission observed in the Galactic ridge is widely accepted to be produced by a superposition of a large number of unresolved X-ray point sources. In the very central degrees of our Galaxy, however, the existence of an extremely hot ~7keV diffuse plasma is still under debate. In this work we measure the Fe~XXV line emission using all available XMM-Newton observations of the Galactic centre (GC) and inner disc (-10deg<l<10deg, -2deg<b<2deg). We use recent stellar mass distribution models to estimate the amount of X-ray emission originating from unresolved point sources, and find that within a region of l=+/-1deg and b=+/-0.25deg the 6.7keV emission is 1.3 to 1.5 times in excess of what is expected from unresolved point sources. The excess emission is enhanced towards regions where known supernova remnants are located, suggesting that at least a part of this emission is due to genuine diffuse very hot plasma. If the entire excess is due to very hot plasma, an energy injection rate of at least 6*10^40^erg/s is required, which cannot be provided by the measured supernova explosion rate or past Sgr A* activity alone. However, we find that almost the entire excess we observe can be explained by assuming GC stellar populations with iron abundances ~1.9 times higher than those in the bar/bulge, a value that can be reproduced by fitting diffuse X-ray spectra from the corresponding regions. Even in this case, a leftover X-ray excess is concentrated within l=+/-0.3deg and b=+/-0.15deg, corresponding to a thermal energy of ~2*10^52^erg, which can be reproduced by the estimated supernova explosion rate in the GC. Finally we discuss a possible connection to the observed GC Fermi-LAT excess.2023A&A...671A..55Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/671/A55CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/xmm : XMM-Newton Observation Log (XMM-Newton Science Operation Center, 201IX/65 : XMM-Newton Serendipitous Source Catalogue 4XMM-DR11 (Webb+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/671/A55https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/671/A55http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/671/A55https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/671/A55https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/671/A55http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/671/A55GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/671/A55/tableb1 (XMM-Newton observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/671/A55/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/671/A55/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/671/A55/tableb1?GETtext/xml+votable180.050000true263.67495-32.581670.0055555555555555564/1801 5/7203 6/28803 28805-28806 28809 28811 28833 28837 28848-28849 28852-28853 28857 28860 28866 28872 28875 28896 28912-28913 28915 28918-28921 28924 29088 29090 29097 42439 42445 42450-42451 42454-42455 42457 42460-42461 42463https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/671/A55?format=asciiX-raydefaultJ/A+A/671/A55/tableb1XMM-Newton observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsIDObservation IDmeta.id;obscharExp-pnEPIC-pn exposure timestime.duration;obs.exposureintExp-MOS1EPIC-MOS1 exposure timestime.duration;obs.exposureintExp-MOS2EPIC-MOS2 exposure timestime.duration;obs.exposureintExp-pn-cleanEPIC-pn clean exposure timestime.duration;obs.exposureintExp-MOS1-cleanEPIC-MOS1 clean exposure timestime.duration;obs.exposureintExp-MOS2-cleanEPIC-MOS2 clean exposure timestime.duration;obs.exposureintthreshold-pn? EPIC-pn background thresholdct/sphot.count;em.X-rayfloatnullablethreshold-MOS1? EPIC-MOS1 background thresholdct/sphot.count;em.X-rayfloatnullablethreshold-MOS2? EPIC-MOS2 background thresholdct/sphot.count;em.X-rayfloatnullable_RAPosition from XMM-Newton Observation Log (Cat. B/xmm) (right ascension part)degpos.eq.ra;meta.main_DEPosition from XMM-Newton Observation Log (Cat. B/xmm) (declination part)degpos.eq.dec;meta.main