INTEGRAL observations of MAXI J1820+070
ATel #11478; E. Bozzo, V. Savchenko, C. Ferrigno, L. Ducci (ISDC, Switzerland), E. Kuulkers (ESA/ESTEC, Netherlands), P. Ubertini (IASF-IAPS, Italy), P. Laurent (CEA, France)
on 26 Mar 2018; 22:00 UT
Credential Certification: E. Bozzo (enrico.bozzo@unige.ch)
INTEGRAL observed the newly discovered blackhole candidate MAXI J1820+070 (ATel #11400, #11403, #11418, #11421, #11423, #11424, #11425, #11426, #11427, #11432, #11437, #11439, #11440, #11445, #11451, #11458) during a dedicated ToO campaign from 16 March 2018 at 11:07 to 18 March at 12:52 (UTC; satellite revolution 1931).
In the near real time (NRT) INTEGRAL data, the source was detected at a 3-20 keV flux of 2.2E-8 ergs/cm^2/s by the two JEM-X units and a 20-500 keV flux of 1.2E-7 ergs/cm^2/s by IBIS/ISGRI. A preliminarily spectral analysis was carried out using only the IBIS/ISGRI data, due to the limited accuracy of the JEM-X calibrations in this NRT version of the data. The ISGRI spectrum (effective exposure time 66 ks) could be well fit (chi^2_reduced/dof = 0.8/11; 3% systematics included) by using a cutoff power-law with a photon index of 1.1+/-0.1 and a cutoff energy of 100+/-10 keV.
Further INTEGRAL observations of the source are already on-going.
