The Metagalactic Ionizing Field in the Local Group
| dc.creator | Bland-Hawthorn, J. | |
| dc.date | 1998-06-23 | |
| dc.date.accessioned | 2026-07-07T02:27:16Z | |
| dc.date.available | 2026-07-07T02:27:16Z | |
| dc.description | We discuss the sources which are likely to dominate the ionizing field throughout the Local Group. In terms of the limiting flux to produce detectable H-alpha emission (4-10 x 10**3 phot/cm**2/s), the four dominant galaxies (M31, Galaxy, M33, LMC) have spheres of influence which occupy a small fraction (<10%) of the Local Volume. There are at least two possible sources of ionization whose influence could be far more pervasive: (i) a cosmic background of ionizing photons; (ii) a pervasive warm plasma throughout the Local Group. The COBE FIRAS sky temperature measurements permit a wide variety of plasmas with detectable ionizing fields. It has been suggested (Blitz et al. 1996; Spergel et al. 1996; Sembach et al. 1995, 1998) that a substantial fraction of high velocity clouds are external to the Galaxy but within the Local Group. Deep H-alpha detections are the crucial test of these claims and, indeed, provide a test bed for the putative Local Group corona. | |
| dc.description | 10 pages; Latex; 1 encapsulated PS figure. Invited talk, ESO/ATNF International Workshop "Looking Deep in the Southern Sky", Dec. 10-12, 1997. Eds. R. Morganti & W. Couch | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9806316 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9806316 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/12620 | |
| dc.subject | Astrophysics | |
| dc.title | The Metagalactic Ionizing Field in the Local Group | |
| dc.type | text |