INTEGRAL and ATCA observations of the black hole transient GRS 1716-249
ATel #10069; Melania Del Santo (INAF/IASF-Palermo, Italy), Lorenzo Ducci (IAAT, Germany; ISDC, Switzerland), James Miller-Jones (ICRAR-Curtin, Australia), Carlo Ferrigno (ISDC, Switzerland), Antonino D'Ai' (INAF/IASF-Palermo, Italy), Tiziana Bassi (INAF/IASF-Palermo, Universita' di Palermo, Italy), Simone Migliari (ESA Madrid, Spain), John Tomsick (SSL/UCB, USA), Piergiorgio Casella (INAF/OAR, Italy), Tomaso Belloni (INAF/OAB, Italy), Greg Sivakoff (University of Alberta, Canada)
on 11 Feb 2017; 13:41 UT
Credential Certification: Melania Del Santo (email@example.com)
Subjects: Black Hole, Transient
INTEGRAL performed a target of opportunity observation of the black-hole X-ray transient
GRS 1716-249 during the on-going outburst (ATel #9876, #9895).
The 90 ks observation started on 2017 February 8th at 22:37:54
and ended on February 10th at 00:52:56 (UTC).
The source flux was more than 0.5 Crab in the 20-80 keV band covered by the
IBIS/ISGRI detector and 0.3 Crab in the 3-20 keV, as determined using JEM-X.
The source emission extends significantly up to 300 keV.
Preliminary spectral analysis shows a hard spectrum
well modelled with a cutoff power-law (CUTOFFPL in XSPEC)
with gamma=1.66+/-0.05 and a roll-over at very high energy, i.e. about 240 keV.
We also fit the broad-band spectrum with NTHCOMP obtaining a power-law slope of 1.73+/-0.03
and the Comptonising electron temperature kTe=165+124/-48 keV.
The 0.1-500 keV flux, which is 2.8E-8 erg/cm^2/s is consistent with
the Swift flux observed at the end of January (ATel #10036).
A combined radio observation was performed on 2017 February 9th
from 19:00 to 21:00 UT with the Australia Telescope Compact Array
under NAPA program C2538, for a total of 80 min of on-source exposure time.
A radio source is clearly detected at the target position.
Preliminary analysis shows that an elliptical Gaussian fit to the source
in the image plane gives a 5.5-GHz flux density of 3.28+/-0.05 mJy/beam.
We note that the X-ray spectral slope and radio detection are consistent with a hard
spectral state, although the high-energy cutoff, as well as the electron temperature, are quite high.
Further simultaneous observations with REM and Swift have been
performed and the analysis is on-going.
We would like to thank the INTEGRAL Project Scientist and
the science planners and the ATCA schedulers for making these observations possible.