Magnetic Reconnection as the Origin of Galactic-Ridge X-Ray Emission

Publications of the Astronomical Society of Japan

Matsumoto, Ryoji⁵  Shibata, Kazunari³  Tanuma, Syuniti⁴  Kudoh, Takahiro³  Yokoyama, Takaaki¹  Makishima, Kazuo² 

[1] Nobeyama Radio Observatory, Minamimaki, Minamisaku, Nagano 384-1305;Department of Physics, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033;National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588;Department of Astronomy, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 E-mail (TANU): National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588;Department of Physics, Faculty of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Chiba 263-8522

关键词: "Galaxies: Milky Way";    "Galaxies: X-rays";    "Interstellar: magnetic fields";    Magnetohydrodynamics;    Plasmas;   

DOI  :  10.1093/pasj/51.1.161

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

WepresentascenariofortheoriginofthehotplasmainourGalaxyasamodelofstrongX-rayemission[∼3–10keV;LX(2–10keV)∼1038ergs−1],calledGalacticRidgeX-rayEmission(GRXE),whichhasbeenobservedneartothegalacticplane.GRXEisthermalemissionfromahotcomponent(∼7keV)andacoolcomponent(∼0.8keV).Observationssuggestthatthehotcomponentisdiffuse,andthatitisnotescapingawayfreely.Bothwhatheatsthehotcomponentandwhatconfinesitinthegalacticridgestillremainpuzzling,whilethecoolcomponentisbelievedtobecreatedbysupernovae.Weproposeanewscenario:thehotcomponentisheatedbymagneticreconnection,andconfinedbyahelicalmagneticfieldproducedbymagneticreconnection.Wesolvedtwo-dimensionalmagnetohydrodynamicequationsnumericallytostudyhowmagneticreconnection,triggeredbyasupernovaexplosion,createshotplasmasandmagneticislands(helicaltubes),andhowthemagneticislandsconfinethehotplasmasintheGalaxy.ThisisoneofthepossiblemechanismstotriggerreconnectionintheGalaxy.WeconcludethatmagneticreconnectionisabletoheattheGRXEplasmaifthemagneticfieldislocalizedinanintensefluxtubewithBlocal∼30μG.

【 授权许可】

Unknown