|Title||Unifying X-ray Weak Quasars: Is there a Highly Absorbed Component in PHL 1811?|
|Author||Prof Karen Leighly|
|Description||Quasars exhibit X-ray emission proportional to their UV emission, and most X-ray weak objects are absorbed. The exception may be PHL 1811, a nearby quasar that is 25--100 times X-ray fainter than expected, but has a steep and variable X-ray spectrum suggesting a direct view of the central engine. It also has unusual UV emission line properties that are consistent with its X-ray weak SED. Searches for PHL 1811 analogs, chosen by their UV spectral properties, find objects that are X-ray weak but which have hard X-ray spectra, suggesting absorption. Previous X-ray observations of PHL 1811 extended only to 6 keV, so a highly absorbed component can.t be ruled out. We propose coordinated XMM- Newton and NuSTAR observations to see whether PHL 1811 is intrinsically normal and highly absorbed.|
|Publication||No observations found associated with the current proposal|
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2016-12-12T23:00:00Z, 076191, 17.56_20190403_1200. https://doi.org/10.5270/esa-lggb7q6|