Are Spiral Disks Really Opaque ?
| dc.creator | Xu, C. | |
| dc.creator | Buat, V. | |
| dc.date | 1994-11-24 | |
| dc.date.accessioned | 2026-07-07T02:19:36Z | |
| dc.date.available | 2026-07-07T02:19:36Z | |
| dc.description | We compare the ultra-violet, optical, and far-infrared emission for a sample of 135 spiral galaxies in order to address the widely debated problem concerning the opacity of spiral disks. We find that the re-radiation of the dust, estimated from the far-infrared emission, is on average only 31$\pm 1$ percent of the bolometric luminosity of a spiral galaxy, indicating that less than one third of the stellar radiation is absorbed and then re-radiated by dust in a spiral disk. Applying a radiation transfer model which assumes a `Sandwich' configuration for the spiral disk, and fully takes into account the effect of scattering, we find for our sample a median of the face-on blue (4400Å) optical depth $\rm τ_B=0.49$ and the mean $\rm <τ_B> =0.60\pm 0.04$, indicating that most spiral galaxies in our sample are {\it not} opaque for blue light ($\rm τ_B <1$). | |
| dc.description | 4 pages of uuencoded postscript file, accepted as a Letter to Astronomy and Astrophysics. 3 of 4 figures (Figures 1, 2, 4) are in a separate file. Figure 3 is available on request | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9411101 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9411101 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/9926 | |
| dc.subject | Astrophysics | |
| dc.title | Are Spiral Disks Really Opaque ? | |
| dc.type | text |