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Title: Millimeter-wave molecular line observations of the Tornado nebula

We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15' × 15' area was mapped in the J = 1-0 lines of CO, {sup 13}CO, and HCO{sup +} with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V{sub LSR} = –14 km s{sup –1} and +5 km s{sup –1}. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado 'head' in the –14 km s{sup –1} cloud, also suggesting the interaction. Virial analysis shows that the +5 km s{sup –1} cloud is more tightly bound by self-gravity than the –14 km s{sup –1} cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s{sup –1} cloud collided into the –14 km s{sup –1} cloud, generating a high-density layer behind the shock front,more » which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.« less
Authors:
 [1] ; ; ; ; ;  [2]
  1. Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
  2. Department of Physics, Institute of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522 (Japan)
Publication Date:
OSTI Identifier:
22365371
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 791; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CARBON 13; CARBON MONOXIDE; COMPACTS; CORRELATIONS; DENSITY; EMISSION; GALAXY NUCLEI; GRAVITATION; INTERACTIONS; LAYERS; NEBULAE; TELESCOPES; VELOCITY