| Proposal ID | 050350 |
| Title | A Study of the Discontinuous Drop in X-ray Emission at Spectral Type B1 |
| Download Data Associated to the proposal | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0503500101 |
| DOI | https://doi.org/10.5270/esa-or3081d |
| Principal Investigator, PI | Dr Wayne Waldron |
| Abstract | B supergiants display a discontinuous drop in X-ray emission along a dividingline in the H-R diagram (analogous to the one for K giants) which is referred toas the bistability jump at spectral type B1. Our XMM study of the X-rayproperties on both sides of the jump have revealed several interesting results,but some uncertainties have arisen since B supergiant winds are thick to softX-rays, and these winds are thought to be clumpy. We now have observationalevidence that the bistabilty jump extends to the lower luminosity B giants whichhave lower wind densities. Hence, they do not have the problems that areassociated with B supergiants. Therefore we are requesting XMM EPIC observationsof 5 B giants to broaden our understanding of the B star dividing line. |
| Publications |
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| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2008-03-06T15:51:03Z/2008-03-12T22:06:49Z |
| 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 | 2009-04-03T00:00:00Z |
| Last Update | 2025-01-27 |
| Keywords | "bistabilty jump extends", "lower luminosity", "discontinuous drop", "diagram analogous", "EPIC", "lower wind densities", "star dividing line", "requesting xmm epic", "xray properties", "xray emission", "soft xray", "bistability jump", "XMM", "spectral type b1", "dividing line", "supergiant winds", "supergiants display" |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Dr Wayne Waldron, 2009, 'A Study of the Discontinuous Drop in X-ray Emission at Spectral Type B1', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-or3081d |