Document Type

Article

Publication Date

10-1-2007

Publication Title

The Astrophyical Journal

Volume

670

Publisher

The American Astronomical Society

Abstract

We present new observations of the fundamental rovibrational CO spectrum of V1647 Ori, the young star whose recent outburst illuminated McNeil's Nebula. Previous spectra, acquired during outburst in 2004 February and July, had shown the CO emission lines to be broad and centrally peaked, similar to the CO spectrum of a typical classical T Tauri star. In this Letter, we present CO spectra acquired shortly after the luminosity of the source returned to its pre-outburst level (2006 February) and roughly 1 year later (2006 December and 2007 February). The spectrum taken in 2006 February revealed blueshifted CO absorption lines superimposed on the previously observed CO emission lines. The projected velocity, column density, and temperature of this outflowing gas were 30 km s-1, 3+2-1×1018 cm-2, and 700+300-100 K, respectively. The absorption lines were not observed in the 2006 December and 2007 February data, and so their strengths must have decreased in the interim by a factor of 9 or more. We discuss three mechanisms that could give rise to this unusual outflow.

Comments

This article has been published in the Astrophysical Journal. Please find the published version here (note that a subscription may be necessary to access this version):

http://iopscience.iop.org/1538-4357/670/1/L29/fulltext/21635.text.html

The American Astronomical Society holds the copyright in this article.

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