| Name | 078474 |
| Title | Testing Accretion Disc Theory: X-ray - UVW1 Lag Measurement in NGC 4593 |
| URL | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0784740101 |
| DOI | https://doi.org/10.5270/esa-m63x5og |
| Author | Prof Ian McHardy |
| Description | Recent Swift UV/optical lag measurements show that UV/optical variability in NGC5548 comes from reprocessing of X-rays by the accretion disc. However the implied disc size is 3x larger than predicted by standard Shakura-Sunyaev theory. Before speculating about the discrepancy we should measure high S/N lags in AGN with different disc parameters. A very large Swift campaign has been proposed for NGC4593, mass 7x lower than NGC5548, with guaranteed continuous Kepler, daily HST and 3x daily griz monitoring. Swift will measure UV-optical lags easily but struggles to measure the estimated 20ks X-ray/UV lag. This timescale is, however, perfectly suited to XMM, as our recent PN/OM fast mode observations of NGC4395 show. Here we propose a 130ks observation to measure the crucial X-ray/UVW1 lag. |
| Publication | No observations found associated with the current proposal |
| Instrument | EPN, RGS1, OM, RGS2, EMOS1, EMOS2 |
| Temporal Coverage | 2016-07-14T19:08:29Z/2016-07-16T10:36:49Z |
| 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 | 2017-08-02T22:00:00Z |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Prof Ian McHardy, 2017, 078474, 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-m63x5og |