A dataset provided by the European Space Agency

Proposal ID 0120102
Obs ID 01201020004
Title Cygnus X-1 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:0120102
DOI https://doi.org/10.57780/esa-1y1fguw
Author Malzac
Abstract We propose 4 observations (75 ks each) of Cygnus X-1 in the hard state.For each individual observation, the broadband coverage of INTEGRAL will enable us to study for the first time the spectral and timing characteristics of the emission above 200 keV together with the lower energy and down to 3 keV.In particular, thanks to the timing capabilities of INTEGRAL, we will learn the characteristics the rapid aperiodic variability above 200 keV (power spectra, time-lags with othe renergy bands...).We will perform simultaneous radio, IR and optical observations and search for timing correlations between these wavelengths and the high energy emission. We will focus on the expected (but not detected yet) timing correlations on short time-scales (minutes, hours).The comparisons between the different observations will allow the first comprehensive study of the broad-band spectral evolution: in particular we will search for correlated changes in the spectral parameters (spectral slope,reflection amplitude, cut-off energy and shape) on time-scales > 2 days. The multi-wavelength coverage will reveal how the radio/IR/optical spectrum changes (or not) when the high energy spectrum change. The long term fluctuations of the timing properties will be studied in parallel to the spectral evolutions, with the aim of searching for spectro/timing correlations. These observations will address the following points:what is the nature of the emitting plasma e+-e- or e--p? What is the geometry of the inner accretion flow (central spherical hot corona surrounded by a cold disk, or a patchy corona atop the a cold disc)? How does the ejection process take place, and in particular what is the nature of the link between the Comptonising corona and the jet ?What is the nature of the excess above 200 keV (non-thermal processes, multi-temperature Comptonisation...) ? What is the mechanism of short term variability ?
Publications
Temporal Coverage 2003-06-07T05:47:03Z / 2003-06-11T09:03:01Z
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 2026-03-05T13:05:51Z
Keywords INTEGRAL gamma-ray data, ESA INTEGRAL mission dataset, gamma-ray astronomy observations, high-energy astrophysics data, IBIS imaging data, SPI spectrometer data, JEM-X X-ray monitoring data, OMC optical monitoring data, coded mask telescope observations, gamma-ray spectroscopy dataset, MeV astrophysics data, keV–MeV photon observations, gamma-ray burst observations dataset, black hole gamma-ray data, neutron star high-energy observations, positron annihilation 511 keV line data, Galactic Center gamma-ray emission dataset, supernova nucleosynthesis gamma-ray lines, active galactic nuclei high-energy data, transient astrophysical source monitoring, calibrated photon event lists, gamma-ray light curves, high-energy spectra data, sky maps gamma-ray, time-series astrophysical observations, long-term gamma-ray monitoring dataset
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, Malzac, 2026, 'Cygnus X-1 in the hard state', 1.0, European Space Agency, https://doi.org/10.57780/esa-1y1fguw