| Name | 065384 |
| Title | Monitoring of the extreme alpha_ox variations in the luminous NL QSO PHL 1092 |
| URL | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0653840301 |
| DOI | https://doi.org/10.5270/esa-870fx7v |
| Author | European Space Agency |
| Description | During a 2008 XMM-Newton observation the luminous Narrow-Line quasar PHL 1092 showed a dramatic X-ray flux drop by a factor virgul200 with respect to previous X-ray observations, becoming one of the most extreme X-ray weak QSO (alpha_ox = -2.44), after being X-ray normal (alpha_ox = -1.56) only 4.5 years earlier. The aim of this proposal is to continue our UV and X-ray monitoring of this extreme source with two 25 ks exposures (one for each visibility window, hence separated by about 6 months) to unveil the timescale over which transitions from X-ray weak to normal QSO states take place in this most extraordinary AGN. |
| Publication | No observations found associated with the current proposal |
| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2010-07-07T21:51:15Z/2010-12-30T14:33:40Z |
| 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 | 2012-01-26T00:00:00Z |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, 2012, Monitoring Of The Extreme Alpha_Ox Variations In The Luminous Nl Qso Phl 1092, 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-870fx7v |