Refined position and hard X-ray spectrum of the new X-ray transient MAXI J1619-383

ATel #6767; M. Morii (RIKEN), H. Negoro (Nihon U.), S. Ueno, H. Tomida, S. Nakahira, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, M. Serino, J. Sugimoto, T. Takagi, A. Yoshikawa, M. Matsuoka (RIKEN), N. Kawai, T. Yoshii, Y. Tachibana (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), H. Tsunemi, D. Uchida (Osaka U.), M. Nakajima, K. Fukushima, T. Onodera, K. Suzuki, T. Namba, M. Fujita, F. Honda (Nihon U.), Y. Ueda, M. Shidatsu, T. Kawamuro, T. Hori (Kyoto U.), Y. Tsuboi, A. Kawagoe (Chuo U.), M. Yamauchi, Y. Morooka, D. Itoh (Miyazaki U.), K. Yamaoka (Nagoya U.)
on 28 Nov 2014; 17:13 UT
Credential Certification: Mikio Morii (mikio.morii@riken.jp)

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MAXI J1619-383 discovered on 2014 November 14 (Serino et al. ATel #6708) showed roughly constant X-ray flux of about 15 mCrab till November 27. After that, MAXI could not observed the source due to the Sun angle constraint. Using available GSC data, we refined the source position at
(R.A., Dec) = (244.767 deg, -38.226 deg) = (16 19 04, -38 13 34) (J2000)
with a statistical 90% C.L. elliptical error region with long and short radii of 0.18 deg and 0.14 deg respectively. The roll angle of the long axis from the north direction is 11 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
We also obtained an average 2-20 keV energy spectrum from November 13 to 26. The spectrum can be represented by an absorbed power-law model with the hydrogen column density (N_H) of < 2.2e22 (90 % confidence level) and the power-law index of 1.43 (-0.21, +0.43).
The relatively long duration of the outburst and the hard energy spectrum suggest the source to be a black hole or neutron star X-ray binary in the hard state. Followup observations are encouraged to reveal the nature of the source though the source is currently close to Sun (~ 17 deg).