Molecular Hydrogen in High-Velocity Clouds

Details Molecular Hydrogen in High-Velocity Clouds Molecular Hydrogen in High-Velocity Clouds

2001-10-11

arxiv.org/abs/astro-ph/0110279v1

Astronomy and Astrophysics

Astrophysics

12 pages, 3 figures; Accepted for publication in ApJ Letters

Scientific paper

10.1086/338050

We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of interstellar molecular hydrogen (H_2) in two Galactic high-velocity clouds (HVCs). Molecular hydrogen absorption is detected in the Magellanic Stream (abundance ~0.3 solar) toward the Seyfert galaxy Fairall 9 in the lowest three rotational states (J=0-2) at v(LSR)=+190 km/s, yielding a total H_2 column density of log N(H_2)=16.40(+0.26)(-0.53). In contrast, no H_2 absorption is seen in the high-velocity cloud Complex C (abundance ~0.1 solar) toward the quasar PG 1259+593 (log N(H_2)<13.96 at v(LSR)=-130 km/s) although both HVCs have similar HI column densities on the order of log N(HI)~20. Weak H_2 absorption is detected in the Intermediate-Velocity Arch (IV Arch; abundance \~1.0 solar) toward PG 1259+593 (log N(H_2)=14.10(+0.21)(-0.44) at v(LSR)=-55 km/s and log N(HI)=19.5). It thus appears that metal- and dust-poor halo clouds like Complex C are not able to form and maintain widely distributed H_2, whereas metal and dust-rich halo clouds like the IV Arch can maintain H_2 even at low HI column densities.

Affiliated with

Also associated with

No associations

Rating

Molecular Hydrogen in High-Velocity Clouds 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 Molecular Hydrogen in High-Velocity Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Molecular Hydrogen in High-Velocity Clouds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-327347