We propose precision spectroscopy for four quiescent neutron stars (NSs). The quiescent luminosities are due at least in part and perhaps entirely to thermal emission, powered by reactions in the deep crust, from the NS surface. Fits to previous observations with realistic H atmosphere spectralmodels find emission area radii consistent with that of a NS (10 km). We will use the unparalleled spectral capabilities of XMM to measure the radius/distance of these sources to 10 percent. Only if accretion occurs in quiescence can metals be present in the photosphere; for metalicities down to as low as Z=0.03 Zsun, we will then measure the surface gravitational redshift, and constrain the NS equation of state.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2001-08-20T10:38:19Z/2004-04-19T21:14:01Z
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.
European Space Agency, Dr Robert Rutledge, 2005, 'Quiescent Emission From Transient Type I X-Ray Bursters', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-ui8rnx4
