IGR J18284-0345: a new hard X-ray transient detected by INTEGRAL

Research output: Contribution to journalJournal article – Annual report year: 2009Research

  • Author: Blanchard, T.

  • Author: Beckmann, V.

  • Author: Chenevez, Jérôme

    Astrophysics, National Space Institute, Technical University of Denmark, Elektrovej, 2800, Kgs. Lyngby, Denmark

  • Author: Corbel, S.

  • Author: Del Santo, M.

  • Author: Ferrigno, C.

  • Author: Gehrels, N.

  • Author: Gotz, D.

  • Author: Kennea, J. A.

  • Author: Mattana, F.

  • Author: Mereghetti, S.

  • Author: Paizis, A.

  • Author: Sidoli, L.

  • Author: Watanabe, K.

  • Author: Weidenspointner, G.

  • Author: Zurita, J. A.

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The IBIS/ISGRI and the JEM-X1 instrument aboard INTEGRAL discovered a new X-ray source during an observation of the inner Galactic disk conducted from 2009 March 18 at 18:37 UT to March 19, 6:22 UT. The new source, IGR J18284-0345 was detected at RA=277.114, DEC=-3.764 (J2000) in the 20-40 keV energy band by ISGRI with 6.3 sigma detection significance for 27 ksec on-source exposure time and about 3 sigma in JEM-X1 (3-10 keV; 8 ksec). The flux of the source was about 10 mCrab at 3-10 keV and 6 mCrab in the 10-25 keV and in the 20-40 keV energy band, respectively. No source had been reported in the X-rays at this position previous to this finding within the error circle of 4 arcmin. Analysis of 4.8 Msec of IBIS/ISGRI data on the source position gives a marginal detection of 3.9 sigma, indicating strong source variability. Swift has performed a follow-up observation of the source, starting at 2009 March 20 at 15:58 UT for an effective on source time of 1.9 ksec. Swift/XRT detected one source within the INTEGRAL error circle at RA=277.125, DEC=-3.762 with an uncertainty of 4 arcsec. The spectrum can be fit together with the INTEGRAL data by a black body model with kT = 4.0±0.2 keV. The intrinsic absorption is not well constrained and has been fixed to the Galactic value of NH = 5.6e21 1/cm**2. The model flux of IGR J18284-0345 is 3.5e-11 erg/cm**2/sec and 1.4e-10 erg/cm**2/sec in the 2-10 keV and 2-30 keV band, respectively. No source has been reported within the Swift/XRT error circle and no source is visible in the Swift U, V, and B filter image or on plates of the Second Palomar Observatory Sky Survey (POSS-II).
Original languageEnglish
JournalThe Astronomer´s Telegram
Publication statusPublished - 2009

    Research areas

  • Transients, X-ray, Request for Observations
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ID: 3506919