ORFEUS II echelle spectra: Absorption by H_2 in the LMC
| dc.creator | de Boer, K. S. | |
| dc.creator | Richter, P. | |
| dc.creator | Bomans, D. J. | |
| dc.creator | Heithausen, A. | |
| dc.creator | Koornneef, J. | |
| dc.date | 1998-08-24 | |
| dc.date.accessioned | 2026-07-07T02:27:43Z | |
| dc.date.available | 2026-07-07T02:27:43Z | |
| dc.description | We present the first detection of molecular hydrogen (H_2) UV absorption profiles on the line of sight to the LMC. The star LH 10:3120 in the LMC was measured with the ORFEUS telescope and the Tuebingen echelle spectrograph during the space shuttle mission of Nov./Dec. 1996. 16 absorption lines from the Lyman band are used to derive the column densities of H_2 for the lowest 5 rotational states in the LMC gas. For these states we find a total column density of N(H_2)=6.6 x 10^18$ cm^-2 on this individual line of sight. We obtain equivalent excitation temperatures of T < 50 K for the rotational ground state and T = 470 K for 0 < J < 6 by fitting the population densities of the rotational states to theoretical Boltzmann distributions. We conclude that UV pumping dominates the population of the higher rotational levels, as known from the H_2 gas in the Milky Way. (Research supported in part by the DARA) | |
| dc.description | Astronomy & Astrophysics, Letter, in press | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9808256 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9808256 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/12808 | |
| dc.subject | Astrophysics | |
| dc.title | ORFEUS II echelle spectra: Absorption by H_2 in the LMC | |
| dc.type | text |