Discovery of a New X-Ray Transient Source in the Scutum Region with Suzaku

[摘要] DuringanobservationoftheGalacticplaneintheScutumregionwiththeSuzakusatellite,wediscoveredanewX-raytransientsource,designatedSuzakuJ1844$$-$$0404.ComparedwithpreviousChandraobservationsofthesamefield,fourChandraX-raysourcesexistwithinthecurrentpositionaluncertaintyofSuzakuJ1844$$-$$0404.Afirmidentificationisnotpossible.Fromthebeginningoftheobservation,theX-rayintensitywassignificantat$$sim5imes10^{-14},mathrm{erg},mathrm{s}^{-1},mathrm{cm}^{-2}$$(2–10 keV),whichmaybeapossibleprecursor.Later,thesourceexhibitedaflarewithapeakfluxof$$sim10^{-12},mathrm{erg},mathrm{s}^{-1},mathrm{cm}^{-2}$$(2–10 keV).Astrongandnarrowemissionlineat$$sim6.66,mathrm{keV}$$wasobservedduringtheflare,mostlikelytheHe-likeFeline.Thespectrumin1–10 keVisconsistentwithaheavilyabsorbed($$N_{mathrm{H}}sim3imes10^{22},mathrm{H},mathrm{cm}^{-2}$$)thinthermalemissionwith$$kT$$ashighas$$sim7,mathrm{keV}$$.Asingleshortflare,asobserved,isratherunlikelyforacataclysmicvariable.Thesourceisprobablyanactivebinarystarorayoungstellarobject.

[学科分类] 天文学(综合)

[关键词] "stars: flare";"stars: individual (Suzaku J1844–0404)";"X-rays: spectra";"X-rays: stars";"X-rays: transients"