Search for Remnant Clouds Associated with the TW Hya Association
Kengo Tachihara, Ralph Neuhaeuser, Yasuo Fukui

TL;DR
This study searches for the parental molecular clouds of the TW Hya association using CO emission and Na I absorption, finding minimal remnant gas likely dissipated within the last million years.
Contribution
It provides the first detailed search for remnant molecular clouds associated with TWA, combining CO emission data with Na I absorption lines to constrain cloud distances.
Findings
No significant natal molecular gas detected near TWA.
Only small-scale or faint CO emission observed in candidate clouds.
Most remnant clouds have dissipated within ~1 million years.
Abstract
We report on a search for the parental molecular clouds of the TW Hya association (TWA), using CO emission and Na I absorption lines. TWA is the nearest young (~ 50 pc; ~ 10 Myr) stellar association, yet in spite of its youth, there are no detection of any associated natal molecular gas, as is the case for other typical young clusters. Using infrared maps as a guide, we conducted a CO cloud survey toward a region with a dust extinction of E(B-V) > 0.2 mag, or AV > 0.6 mag. CO emission is detected toward three IR dust clouds, and we reject one cloud from the TWA, as no interstellar Na absorption was detected from the nearby Hipparcos stars, implying that it is too distant to be related. The other two clouds exhibit only faint and small-scale CO emission. Interstellar Na I absorptions of Hipparcos targets, HIP 57809, HIP 64837, and HIP 64925 (at distances of 133, 81, and 101 pc,…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
