| Proposal ID | 065447 |
| Title | The nature of quiescent emission in the neutron star Cen X-4 |
| Download Data Associated to the proposal | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0654470201 |
| DOI | https://doi.org/10.5270/esa-2m8a4xo |
| Principal Investigator, PI | Dr Edward Cackett |
| Abstract | The neutron star LMXB, Cen X-4, has been in quiescence since 1979. Its quiescentX-ray emission consists of both a thermal and power-law component, withvariability observed on timescales as short as hundreds of seconds and as longas years. Yet, this variability is not understood. We recently found Cen X- 4 ina historically low-state, over 5 times fainter than before. Such a differencerequires the thermal component to vary. This poses a big problem for usingthermal emission to measure neutron star radii and constrain the dense matterequation of state. To investigate the nature of this variability and theemission mechanisms from X-rays through to the optical, we propose four, 12 ksobservations of Cen X-4 to obtain good X-ray spectra and accurate photometry in 5 optical/UV filters. |
| Publications |
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| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2010-08-25T07:49:02Z/2011-01-31T20:56:23Z |
| Version | 17.56_20190403_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. |
| Creator Contact | https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk |
| Date Published | 2012-02-18T00:00:00Z |
| Keywords | "xray spectra", "power law component", "emission mechanisms", "thermal component", "uv filters", "dense matter equation", "quiescent emission", "neutron star radii", "neutron star lmxb", "thermal emission", "cen x", "historically low" |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Dr Edward Cackett, 2012, 'The nature of quiescent emission in the neutron star Cen X-4', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-2m8a4xo |