Ultraviolet observations of Sirius A and Sirius B with HST-GHRS; An interstellar cloud with a possible low deuterium abundance

Details Ultraviolet observations of Sirius A and Sirius B with HST-GHRS; An interstellar cloud with a possible low deuterium abundance Ultraviolet observations of Sirius A and Sirius B with HST-GHRS; An interstellar cloud with a possible low deuterium abundance

1999-09-03

arxiv.org/abs/astro-ph/9909061v1

Astron.Astrophys. 350 (1999) 643-658

Astronomy and Astrophysics

Astrophysics

17 pages, latex, 14 figures, 5 tables, accepted for publication in Astronomy & Astrophysics

Scientific paper

We present new observations of the binary Sirius A / Sirius B performed with HST-GHRS. Two interstellar clouds are detected on this sightline, one of them being identified as the Local Interstellar Cloud (LIC). The interstellar structure of this sightline is constrained by high spectral resolution data of the species OI, NI, SiII, CII, FeII and MgII. Lyman alpha interstellar lines are also observed toward the two stars. But whereas the deuterium Lyman alpha line is well detected in the LIC with an abundance in agreement with that obtained by Linsky et al. (1993 & 1995), no significant DI line is detected in the other cloud. However, the Lyman alpha lines toward Sirius A and Sirius B are not trivial. An excess of absorption is seen in the blue wing of the Sirius A Lyman alpha line and interpreted as the wind from Sirius A. In its white dwarf companion, an excess in absorption is seen in the red wing and interpreted as the core of the Sirius B photospheric Lyman alpha line. A composite Lyman alpha profile can nonetheless be constructed, and allows one to measure the deuterium abundance in the second cloud 0 < D/H_ISM < 1.6 10^-5, which is marginally in agreement with the Linsky et al. (1993 & 1995) value. This sightline appears consequently as a good candidate for a low D/H_ISM.

Affiliated with

Also associated with

No associations

Rating

Ultraviolet observations of Sirius A and Sirius B with HST-GHRS; An interstellar cloud with a possible low deuterium abundance does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Ultraviolet observations of Sirius A and Sirius B with HST-GHRS; An interstellar cloud with a possible low deuterium abundance, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ultraviolet observations of Sirius A and Sirius B with HST-GHRS; An interstellar cloud with a possible low deuterium abundance will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-542897