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ATEL # 2969; Kazutaka Yamaoka (Aoyama Gakuin U.), Philip Kaaret (U. Iowa), Satoshi Nakahira, Ichiro Takakashi, Atsumasa Yoshida (Aoyama Gakuin U.), Mikio Morii, Nobuyuki Kawai (Tokyo Tech.), Hitoshi Negoro, Motoki Nakajima (Nihon Univ.), Yoshihiro Ueda (Kyoto Univ.), Motoko Suzuki, and Takayuki Yamamoto (RIKEN)
on 25 Oct 2010; 9:55 UT
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Subjects: X-ray, Binaries, Transients
Referred to by ATEL #: 3060, 3067, 3070
Following the MAXI/GSC detection (ATel #2959) and the Swift/XRT confirmation (ATel #2962) of a new transient MAXI J1409-619, we carried out three RXTE Target of Opportunity (ToO) observations on Oct 22-23, 2010 with a net exposure of 7.5 kseconds.
The averaged PCA flux was 1.12E-10, 1.18E-10, and 1.28E-10 ergs cm^-2 s^-1 in the 2-10 keV band, respectively, corresponding to about 5 mCrab. The X-ray flux is very highly variable on time scales of hundreds of seconds, but shows no clear coherent periodicity in the current data. The PCA X-ray spectrum can be fitted by a cutoff power-law with a reflection model, in which reflection dominates over direct emission, or a partially covered power-law plus emission line model, in which the partially covering absorption column density is near 1E24 cm^-2 and the iron line at 6.5+/-0.2 keV has an equivalent width near 200 eV. Both spectral fits suggest that the central object is (at least partially) strongly absorbed and there is significant reflection. This behavior is similar to that seen from supergiant fast X-ray transients as suggested by ATel #2962 and #2965, but we cannot rule out a possibility that it is a long-period pulsar. Further RXTE observations will be requested for solving the nature of this source.
We thank the RXTE operation team for their rapid scheduling of this observation.