A dataset provided by the European Space Agency

Proposal ID 0740026
Obs ID 07400260001
Title Constraining spectral breaks in Galactic black hole transients in the hard state
Download Data Associated to the proposal https://isla.esac.esa.int/tap/download/bundle?format=ascii_curl&product_id=prop_id:0740026
DOI https://doi.org/10.57780/esa-rgazgd0
Author Kalemci
Abstract Even though the spectrum of canonical hard state of Galactic black hole transients (GBHT) is often described by a power law with a cut-off, analysis of the RXTE and the INTEGRAL data show that this description may not be entirely correct. Some sources show a break in the power-law spectrum during the transition to the hard state, but once a compact jet forms, the break disappears at the HEXTE band (15 -- 200 keV). Therefore the shape of the hard X-ray spectrum in the low hard state is still one of the most important open questions of the black hole science. The disappearance of cut-offs may point out yet another relation between the jets and high energy emission. We propose one TOO observation of a GBHT with INTEGRAL at the hard state after the jet turns on (determined by radio or optical/infrared, OIR, observations) to search for breaks beyond 200 keV. By characterizing the gamma-ray domain at the hard state, we will constrain the X- and gamma-ray emission mechanisms, and also investigate the relation between the X-ray emission and jet formation. We will achieve multiwavelength coverage using ATCA in radio and SMARTS in optical/infrared. The current archival data are not enough to carry out this research. We request a single observation of 300 ks for one source.
Publications
Temporal Coverage 2010-04-18T02:37:09Z / 2010-04-21T20:05:11Z
Version 1.0
Mission Description The INTEGRAL (International Gamma-Ray Astrophysics Laboratory) mission, launched by the European Space Agency (ESA) on October 17, 2002, was designed to study high-energy phenomena in the universe. INTEGRAL was operating until february 2025 and it was equipped with three high-energy instruments: the Imager on Board the INTEGRAL Satellite (IBIS), the Spectrometer on INTEGRAL (SPI), and the JEM-X (Joint European Monitor for X-rays). Its Optical Monitoring Camera (OMC) provided optical V-band magnitude measurements, complementing the high-energy observations.
Creator Contact https://www.cosmos.esa.int/web/integral/helpdesk
Date Published 2025-03-25T09:54:36Z
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, Kalemci, 2025, 'Constraining spectral breaks in Galactic black hole transients in the hard state', 1.0, European Space Agency, https://doi.org/10.57780/esa-rgazgd0