| Name | 076191 |
| Title | Unifying X-ray Weak Quasars: Is there a Highly Absorbed Component in PHL 1811? |
| URL | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0761910201 |
| 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 |