Multi-epoch broadband spectroscopy of the ultraluminous X-ray source (ULX)NGC1313 X-1 has revealed unusual spectral variability. When fit with accretiondisk models, the data show two distinct groups in the L-T plane, each of whichexhibits its own positive L-T correlation. Understanding this behaviour islikely key to understanding the structure of super-Eddington accretion flows. Holmberg IX X-1 also shows some evidence for this behaviour, but there iscurrently only one broadband observation in the high-flux regime, meaning thiscannot yet be firmly established. This proposal aims to take a series of 4XMM+NuSTAR observations (each 25+50ks) of Holmberg IX X-1 in its high-flux statein order to determine whether it does show the same unusual behaviour as NGC1313 X-1.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2020-10-17T09:28:08Z/2020-11-24T15:45:05Z
Version
18.02_20200221_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Dr Dominic Walton, 2021, 'TESTING THE CONNECTION BETWEEN THE ULTRALUMINOUS X-RAY SOURCES HOLMBERG IX X-1 A', 18.02_20200221_1200, European Space Agency, https://doi.org/10.57780/esa-7gz9cju
