A dataset provided by the European Space Agency

Name 076191
Title Unifying X-ray Weak Quasars: Is there a Highly Absorbed Component in PHL 1811?


DOI https://doi.org/10.5270/esa-lggb7q6
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
Temporal Coverage 2015-11-29T09:38:07Z/2015-11-30T02:08:07Z
Version 17.56_20190403_1200
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.
Creator Contact https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk
Date Published 2016-12-12T23:00:00Z
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, Prof Karen Leighly, 2016, 076191, 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-lggb7q6