H I ZEEMAN EXPERIMENTS OF SHOCKED ATOMIC GAS IN TWO SUPERNOVA REMNANTS INTERACTING WITH MOLECULAR CLOUDS

Journal Article · Thu Jul 15 04:00:00 EDT 2010 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/140/1/262· OSTI ID:21443287

Koo, Bon-Chul ^[1]; Heiles, Carl ^[2]; Stanimirovic, Snezana ^[3]; Troland, Tom ^[4]

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1. Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
2. Astronomy Department, University of California, Berkeley, CA 94720-3411 (United States)
3. Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States)
4. Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States)

We have carried out observations of Zeeman splitting of the H I 21 cm emission line from shocked atomic gas in the supernova remnants (SNRs) IC 443 and W51C using the Arecibo telescope. The observed shocked atomic gas is expanding at {approx}100 km s{sup -1} and this is the first Zeeman experiment of such fast-moving, shocked atomic gas. The emission lines, however, are very broad and the systematic error due to baseline curvature hampers an accurate measurement of field strengths. We derive an upper limit of 100-150 {mu}G on the strength of the line-of-sight field component. These two SNRs are interacting with molecular clouds, but the derived upper limits are considerably smaller than the field strengths expected from a strongly shocked dense cloud. We discuss the implications and conclude that either the magnetic field within the telescope beam is mostly randomly oriented or the high-velocity H I emission is from a shocked interclump medium of relatively low density.

• OSTI ID: 21443287
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 1 Vol. 140; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CLOUDS
COSMIC RADIO SOURCES
EMISSION
MAGNETIC FIELDS
SUPERNOVA REMNANTS
TELESCOPES
ZEEMAN EFFECT