INTEGRAL hard X-ray detection of a new outburst from GX339-4
ATel #14354; V. Sguera (INAF-OAS Bologna, Italy), A. Bazzano, M. Fiocchi, L. Natalucci, P. Ubertini (INAF-IAPS Roma, Italy), A. J. Bird, V. Lepingwell (Univ. of Southampton, UK), A. Bodaghee (Georgia College & State University, USA), P. Charles (Univ. of Southampton), J. Chenevez (DTU Space, Denmark), E. Kuulkers (ESA/ESTEC, Noordwijk, The Netherlands), N. Masetti (INAF-OAS Bolonga, Italy)
on 27 Jan 2021; 09:32 UT
Credential Certification: Vito Sguera (sguera@iasfbo.inaf.it)
Subjects: X-ray, Binary, Black Hole, Transient
Referred to by ATel #: 14367, 14384, 14400, 14419, 14440, 14455, 14484, 14490, 14493, 14494, 14504
Recent MeerKAT observations, from 4 January to 16 January, detected increased radio activity from the recurrent black hole X-ray transient GX339-4, suggesting that the source is likely entering into a new outburst phase (ATel #14336).
We report the INTEGRAL detection of increased hard X-ray activity from GX339-4 which confirms a new outburst. The source sky region has been covered during recent INTEGRAL Galactic plane observations carried out from 17 January 13:41 UTC to 18 January 16:46 UTC (revolution 2321) and from 21 January 18:32 UTC to 22 January 14:35 UTC (revolution 2323).
During revolution 2321, GX339-4 is detected at 6.2sigma level (22-60 keV) with a flux of 15.4+/-2.5 mCrab (1.6 x 10
-10 erg cm
-2 s
-1). No detection is achieved in the energy band 60-100 keV, the 2sigma upper limit is about 13 mCrab (6.5 x 10
-11 erg cm
-2 s
-1).
During revolution 2323 the source is detected with an increased hard X-ray flux in both energy bands 22-60 keV (51.5+/-4.3 mCrab or 5.5 x 10
-10 erg cm
-2 s
-1, 12 sigma) and 60-100 keV (74.6+/-11.7 mCrab, or 3.7 x 10
-10 erg cm
-2 s
-1, 6.4sigma).
The source was not in the JEM-X field of view during these revolutions.
The last outburst activity from GX339-4, as detected by INTEGRAL, dates back to January 2019 (ATel #
12420). Further INTEGRAL Galactic plane observations in the direction of GX339-4 are planned for the next days. Results from the Galactic Plane Scanning are publicly available at:
http://gps.iaps.inaf.it