Proposal Details - 0820030
Hard X-ray spectroscopy of two ultraluminous X-ray sources and a low-luminosity AGN (Sazonov)

Proposal Summary (based on proposal abstract)

The nature of ultraluminous X-ray sources (ULXs) remains controversial. We do not know whether they host stellar- or intermediate-mass black holes, nor do we have a clear understanding of the accretion process. Similarly poorly studied is the accretion onto supermassive black holes in low-luminosity active galactic nuclei (LLAGN). To address these problems, sensitive observations at energies above 10 keV are needed. A total INTEGRAL exposure of 4 Msec (2 Msec in AO7 + 2 Msec in AO8) is proposed for a unique sky region where two of the brightest ULXs, M82 X-1 and Holmberg IX X-1, and one of the brightest LLAGN, M81, are located. One will measure the spectra of these sources from 3 keV up to 50-100 keV and possibly study their spectral variability. A preliminary analysis of the AO-7 data confirms the feasibility of achieving the scientific goals upon completion of the entire observational campaign.

Observation Strategy (Recommended by TAC)

Total of 2 Ms in the standard 5x5 dithering mode centered on RA, Dec = 148.958, 69.679 (l, b = 141.412, 40.564). The INTEGRAL observations will be accompanied by two XMM-Newton pointings with 60 ks centered on M82 X-1, and another 60 ks centered halfway between M81 and Ho IX X-1.

Proposal grade: A

Data Rights (Recommended by TAC)

The TAC has allocated the following specific data rights to this proposal: M81, M82 X1, and Ho IX X-1.

Consult the Data Rights policy for more information on Russian Federation proposals.

Exposure Map

Exposure maps are in units of s and shown using Galactic coordinates. The intensity scale is given by the colourbar, and there are contour levels at 100, 300 and 500 ks.