Discovery of a new X-ray transient source in the scutum region with Suzaku

Yamauchi Shigeo

Ebisawa Ken

Bamba Aya

Ishida Manabu

Iwasawa Kazushi

Tanaka Yasuo

Kokubun Motohide

Koyama Katsuji

Takahashi Hiromitsu

Tsuboi Yohko

Publications of the Astronomical Society of Japan

During an observation of the Galactic plane in the Scutum region with the Suzaku satellite, we discovered a new X-ray transient source, designated Suzaku J1844-0404. Compared with previous Chandra observations of the same field, four Chandra X-ray sources exist within the current positional uncertainty of Suzaku J1844-0404. A firm identification is not possible. From the beginning of the observation, the X-ray intensity was significant at ∼ 5×10-14 erg s-1 cm-2 (2–10 keV), which may be a possible precursor. Later, the source exhibited a flare with a peak flux of ∼ 10-12 erg s-1 cm-2 (2–10 keV). A strong and narrow emission line at ∼ 6.66 keV was observed during the flare, most likely the He-like Fe line. The spectrum in 1–10 keV is consistent with a heavily absorbed (NH ∼3×1022Hcm-2) thin thermal emission with kT as high as ∼7keV. A single short flare, as observed, is rather unlikely for a cataclysmic variable. The source is probably an active binary star or a young stellar object.

stars: flare

stars: individual (Suzaku J1844-0404)

X-rays: spectra

X-rays: stars

X-rays: transients

Astronomy. Space sciences [ 440 ]

eng

日本天文学会

Copyright (c) 2007 Astronomical Society of Japan

[ISSN] 0004-6264

[NCID] AA1082896X

[URI] http://pasj.asj.or.jp/v59/sp1/59s117/59s117a.html