Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· References in the article
· Citations to the Article (8) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (12)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
A 21 cm Spectral and Continuum Study of IC 443 Using the Very Large Array and the Arecibo Telescope
Authors:
Lee, Jae-Joon; Koo, Bon-Chul; Yun, Min S.; Stanimirović, Snežana; Heiles, Carl; Heyer, Mark
Affiliation:
AA( Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Korea, ; Present address: Department of Astronomy and Astrophysics, 525 Davey Lab, University Park, PA 16802, USA.; ), AB( Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Korea, ), AC( Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA ), AD( Department of Astronomy, University of Wisconsin, 475 North Charter Street, Madison, WI 53706, USA ), AE( Radio Astronomy Lab, UC Berkeley, 601 Campbell Hall, Berkeley, CA 94720, USA ), AF( Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA )
Publication:
The Astronomical Journal, Volume 135, Issue 3, pp. 796-808 (2008). (AJ Homepage)
Publication Date:
03/2008
Origin:
IOP
DOI:
10.1088/0004-6256/135/3/796
Bibliographic Code:
2008AJ....135..796L

Abstract

We report 21 cm spectral-line and continuum observations of the Galactic supernova remnant IC 443 using the Very Large Array (VLA) and the Arecibo telescope. By combining the VLA and Arecibo data, both covering the full extent of IC 443, we have achieved an unprecedented combination of sensitivity and angular resolution, over the continuous range of angular scales from ~40'' to ~1°. Our new radio observations not only reveal previously unknown features of IC 443 but also show the details of the remnant more clearly. The radio morphology of IC 443 consists of two nearly concentric shells. Our 21 cm radio continuum data show that the two shells have distinctly different radial intensity distributions. This morphology supports the scenario whereby the western shell is a breakout portion of the remnant into a rarefied medium. We have developed a dynamical model accounting for the breakout, which provides an estimate for the remnant age of ~2 × 104 yr. The southeastern boundary of the remnant shows interesting features, seen in our observations for the first time: a faint radio continuum halo and numerous "spurs." These features are mainly found in the region where IC 443 overlaps with another remnant, G189.6+3.3. These features most likely originate from the interactions of IC 443 with the surrounding medium. The H I emission associated with IC 443 appears over the velocity range between -100 km s-1 and 50 km s-1. The strongest absorption is seen around v LSR ~ -5 km s-1, which corresponds to the systemic velocity of IC 443. We identify a broad, extended lane of H I gas near the systemic velocity as preshock gas in the southern part of the remnant. Most of the shocked H I gas is located along the southern supernova remnant (SNR) boundary and is blueshifted. We derive an accurate mass of the shocked H I gas using template HCO+ (1-0) spectra, which is 493 ± 56 M ☉. Our high-resolution H I data enable us to resolve the shocked H I in the northeastern region into a few filamentary structures, which are well correlated with radiative filaments, in both position and velocity. This represents the first unambiguous detection of the recombined H I in an atomic shock. The characteristics of the filaments are not consistent with a clumpy shock model where the radiative signature is from dense clumps. Instead we propose that the shock has been propagating through a uniform medium of n H~ 10 cm-3.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints