title: The L1457 molecular/atomic cloud complex: H I and CO maps.
abstract: L1457 is the closest known molecular cloud (65 pc), and it lies near the edge of the local hot bubble and well out of the Galactic plane (b approximately -34 degrees). We have mapped an 8 degrees x 8 degrees region at 35' resolution and a 3 degrees x 5 degrees region at approximately 2' resolution in H I 21 cm emission. We have also mapped a 2 degrees x 4 degrees region at 2' resolution in 12CO J =  1-0. We find that there is an extended component of atomic gas, clearly associated with the molecular complex and comparable to it in total mass. The H I structure at small scales in the vicinity of the molecular clouds is remarkable, consisting largely of long, narrow filaments less than 20' (0.2 pc) in width and 1 degree-4 degrees in length. A thin (<10') limb-brightened atomic halo is seen to surround the CO at some velocities, but it is ill-defined at other velocities. The halo may be disturbed by external pressure, perhaps from the hot gas in the local bubble.  The molecular clouds are part of a large structure approximately 5 degrees x 3 degrees in extent with a small "funnel-shaped" extension to the south. The structure, which we call the L1457 atomic/molecular complex, is dominated by H I in the north and H2 in the south extension. Roughly one-half the mass of the complex is molecular. The structure of this complex at both large- and small-scale suggests that the south end has been recently compressed.
authors.affiliation: Dominion Radio Astrophysical Observatory, National Research Council, Penticton, Canada.  gms@jach.hawaii.edu
authors.forename: G H
authors.initials: GH
authors.lastname: Moriarty-Schieven
authors.forename: B G
authors.initials: BG
authors.lastname: Andersson
authors.forename: P G
authors.initials: PG
authors.lastname: Wannier
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D002248:Carbon Monoxide / Q000032:analysis* / Q000737:chemistry; D019443:Cosmic Dust / Q000032:analysis*; D005118:Extraterrestrial Environment; D005740:Gases / Q000032:analysis* / Q000737:chemistry; D006859:Hydrogen / Q000032:analysis* / Q000737:chemistry
chemical_list: D019443:Cosmic Dust; D005740:Gases; D002248:Carbon Monoxide; D006859:Hydrogen