| Proposal ID | 005914 |
| Title | Multi-Epoch XMM-EPIC Observations of the Active Nucleus in NGC4258 |
| Download Data Associated to the proposal | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0059140101 |
| DOI | https://doi.org/10.5270/esa-hw7zthc |
| Principal Investigator, PI | Dr Lincoln J. Greenhill |
| Abstract | We will search for hard (>2 keV) X-ray spectral variability in the NGC4258active nucleus with eight, 10-ksec XMM-EPIC observations spaced over the twoyears covered by AO-1. NGC4258 is noteworthy for its remarkable nuclearmegamaser. VLBI imaging of the maser has provided the first direct images of anAGN on sub-parsec scales and has yielded uniquely precise estimates for a numberof important and normally inaccessible quantities, such as the AGN central mass and the accretion disk orientation. We will use variability in the X-rayspectrum to explore the three-dimensional geometry of the NGC4258 accretiondisk, to determine whether the central engine is obscured by a thin, warped diskas opposed to a thick torus, and to provide tighter constraints on the Fe k line |
| Publications |
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| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2001-05-06T18:50:18Z/2002-05-23T02:04:01Z |
| 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. |
| Creator Contact | https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk |
| Date Published | 2003-06-15T00:00:00Z |
| Last Update | 2025-08-04 |
| Keywords | "central engine", "ngc4258 accretion disk", "XMM", "inaccessible quantities", "warped disk", "active nucleus", "tighter constraints", "accretion disk orientation", "ngc4258 active nucleus", "sub parsec scales", "nuclear megamaser", "NGC4258", "dimensional geometry", "xmm epic", "thick torus", "xray spectrum", "EPIC", "agn central mass", "vlbi imaging" |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Dr Lincoln J. Greenhill, 2003, 'Multi-Epoch XMM-EPIC Observations of the Active Nucleus in NGC4258', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-hw7zthc |