An X-Ray Face-On View of the Sagittarius B Molecular Clouds Observed with Suzaku

Publications of the Astronomical Society of Japan

Fukuoka, Ryosuke¹  Nobukawa, Masayoshi¹  Koyama, Katsuji¹  Tsuru, Takeshi Go¹  Ryu, Syukyo G.¹ 

[1] Department of Physics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502

关键词: "Galaxy: center";    "ISM: molecules";    clouds;    structure;    "X-rays: spectra";   

DOI  :  10.1093/pasj/61.4.751

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

WepresentanewmethodologytoderivethepositionsoftheSagittarius(Sgr)Bmolecularclouds(MCs)alongthelineofsight,asanapplicationstudyoftheGalacticcenterdiffuseX-rays(GCDX).TheGCDXarecomposedofhotplasmaemissionofabout7keVand1keVtemperatures,andnon-thermalcontinuumemissionincludingthe6.4keVlinefromneutralirons.Theformer,theGalacticcenterplasmaemission(GCPE),isuniformlydistributedover1$$^circ$$inlongitude,whilethelatterisclumpyemissionproducedbyThomsonscatteringandfluorescencefromMCsirradiatedbyexternalX-rays(theX-rayreflectionnebulaemission:XRNE).WeexaminedtheSuzakuX-rayspectraoftheGCPEandXRNEneartotheSgrBMCcomplex,andfoundthatthespectrasufferfromtwodifferentabsorptionsof$$N_{mH}$$(Abs1)$$geq$$10$$^{23}$$Hcm$$^{-2}$$and$$N_{mH}$$(Abs2)$$simeq$$6$$imes$$10$$^{22}$$Hcm$$^{-2}$$.Abs1isproportionaltothe6.4keV-lineflux,andhenceisduetotheMCs,whileAbs2istypicalofinterstellarabsorptiontowardtheGalacticcenter.AssumingthattheGCPEplasmaisspherically-extendedaroundSgrA$$^ast$$withauniformdensityandthesameangulardistributionofthetwotemperaturecomponents,wequantitativelyestimatedtheline-of-sightpositionsoftheMCsfromthefluxratiotheGCPEspectrumsufferedbyAbs1andthatwithnoAbs1.TheresultssuggestthattheSgrBMCsarelocatedatthenearsideofSgrA$$^ast$$intheGCPE.

【 授权许可】

Unknown