INTEGRAL detection of hard X-ray emission from MAXI J1828-249
ATel #5476; E. Filippova (ISDC, Switzerland), E. Kuulkers, C. Sanchez-Fernandez (ESAC, Spain), J. Wilms, V. Grinberg (ECAP, Germany), M. Cadolle-Bel (TUM, Germany), J. Chenevez (DTU, Denmark), R. Wijnands (UVA, Netherlands), M. Del Santo, A. Tarana, F. Capitanio (INAF/IAPS, Italy), E. Bozzo, C. Ferrigno (ISDC, Switzerland), J. Rodriguez (CEA, France), A. Paizis (INAF/IASF, Italy), V. Beckmann (APC, France), K. Pottschmidt (CRESST-UMBC/NASA-GSFC, USA), K. Watanabe (FGCU, USA)
on 16 Oct 2013; 16:27 UT
Distributed as an Instant Email Notice Transients
Credential Certification: E. Bozzo (email@example.com)
Subjects: X-ray, Binary, Black Hole, Neutron Star, Transient
The new transient source MAXI J1828-249 (Atel #5474) was detected by the
IBIS/ISGRI on-board INTEGRAL during the observations performed in the
direction of the Galactic Center (from 2013 October 15 at 18:03
to 2013 October 16 at 09:10 UTC).
The improved source position determined by ISGRI is at:
RA= 277.23 deg, Dec=-25.03 deg (J2000)
with a 90% confinement radius of 1.3 arcmin.
In the ISGRI mosaic the source is detected at a significance level of 22.4 sigma in the
20-40 keV energy band and 18.4 sigma in the 40-80 keV energy band
(effective exposure time 33.6 ks).
The corresponding fluxes were of 45+/-2 mCrab and 48+/-2 mCrab.
The preliminary analysis of the ISGRI data revealed that the source
spectrum is well described by a power-law model
with photon index of ~1.7.
From the spectral fit we estimated a flux of 3.3E-10 (4.0E-10) ergs/cm^2/s
in the 20-40 keV (40-80 keV) energy band.
The spectrum measured by ISGRI does not favour the
hypothesis of MAXI J1828-249 being a black-hole candidate
in the soft state as reported in Atel #5474.
The source was outside the JEM-X field of view during the entire
Further observations with INTEGRAL in the direction of MAXI J1828-249 are
already planned for the next days.