High-velocity HCO/sup +/ in cepheus A: Ionization levels in high-density clumps within a molecular flow

Journal Article · Sat Dec 15 04:00:00 EST 1984 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/162729· OSTI ID:6026017

Loren, R B; Wootten, A; Sandqvist, A A; Friberg, P; Hjalmarson, A

High-velocity (FWZP approx.44 km s/sup -1/) HCO/sup +/ wings have been detected in both the J = 1-0 and J = 3-2 lines toward Cep A. Modeling the intensity ratio in the wings of these two lines indicates that this emission arises in high-density (10/sup 6/ cm/sup -3/) clumps within a high-velocity outflow. The highest velocity HCO/sup +/ emission is confined to an unresolved region at the location of the IR cluster and H/sub 2/O masers. At intermediate velocities the HCO/sup +/ emission is spatially extended, with redshifted and blueshifted lobes on opposite sides of the dense core, a bipolar pattern similar to that seen in CO emission wings. Both the HCO/sup +/ abundance (3-6 x 10/sup -9/) and the electron abundance (<10/sup -8/) in the high-velocity flow are similar to more quiescent cold molecular clouds. Such low ionization levels with the molecular flow are a condition needed for the magnetic precursor model of shock structure (Draine 1980).

• Research Organization: Millimeter Wave Observatory, Electrical Engineering Research Laboratory, The University of Texas at Austin and McDonald Observatory
• OSTI ID: 6026017
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 287:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics &amp; Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACYL RADICALS
CHARGED PARTICLES
DISTRIBUTION
EMISSION
ENERGY-LEVEL TRANSITIONS
FORMYL RADICALS
INTERSTELLAR GRAINS
IONS
MAPS
NEBULAE
PARTICLES
RADIAL VELOCITY
RADICALS
SPATIAL DISTRIBUTION
SPECTRA
SPECTRAL SHIFT
STELLAR ACTIVITY
STELLAR WINDS
VELOCITY