The Effect of Porosity on X-ray Emission Line Profiles from Hot-Star Winds
| dc.creator | Owocki, Stanley P. | |
| dc.creator | Cohen, David H. | |
| dc.date | 2006-02-02 | |
| dc.date.accessioned | 2026-07-07T10:43:35Z | |
| dc.date.available | 2026-07-07T10:43:35Z | |
| dc.description | We investigate the degree to which the nearly symmetric form of X-ray emission lines seen in Chandra spectra of early-type supergiant stars could be explained by a possibly porous nature of their spatially structured stellar winds. Such porosity could effectively reduce the bound-free absorption of X-rays emitted by embedded wind shocks, and thus allow a more similar transmission of red- vs. blue-shifted emission from the back vs. front hemispheres. For a medium consisting of clumps of size l and volume filling factor f, in which the `porosity length' h=l/f increases with local radius as h = h' r, we find that a substantial reduction in wind absorption requires a quite large porosity scale factor h' > 1, implying large porosity lengths h > r. The associated wind structure must thus have either a relatively large scale l~ r, or a small volume filling factor f ~ l/r << 1, or some combination of these. The relatively small-scale, moderate compressions generated by intrinsic instabilities in line-driving seem unlikely to give such large porosity lengths, leaving again the prospect of instead having to invoke a substantial (ca. factor 5) downward revision in assumed mass-loss rates. | |
| dc.description | 6 pages in apj-emulate; 3 figures; submitted to ApJ | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0602054 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0602054 | |
| dc.identifier | Astrophys.J.648:565-571,2006 | |
| dc.identifier | doi:10.1086/505698 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/182295 | |
| dc.subject | Astrophysics | |
| dc.title | The Effect of Porosity on X-ray Emission Line Profiles from Hot-Star Winds | |
| dc.type | text |