NOAO >   Observing Info >   Approved Programs >   2009B-0407

# Proposal Information for 2009B-0407

PI: Knox S. Long, STScI, long@stsci.edu
Address: Science Division, 3700 San Martin Drive, Baltimore, MD 21218, USA

CoI: P. Frank Winkler, Middlebury College

Title: UV Lightbulbs behind Young Supernova Remnants

Abstract: Much of the ejecta in young SNRs is normally invisible because it has not been shocked, and is therefore cold, producing no optical or X- ray emission. For a complete inventory of the SN ejecta, one needs to somehow probe this cold material, and we seek to do so through UV \it absorption spectroscopy. The COS spectrograph, soon to be installed on HST, will be an ideal instrument for this purpose, provided suitable UV sources, lightbulbs," can be identified behind SNRs. Here we propose to identify UV lightbulbs behind the Tycho (SN 1572) and 3C58 (SN 1181) remnants by obtaining accurate spectral types, and therefore distances, for stars bright enough to observe in the UV with HST/COS\@. Distance is all that we need to find, because the UV brightness of candidate stars (or other objects) has already been measured by the optical monitor on XMM. Through spectroscopy from the 2.1m we will obtain spectra to identify the best candidate lightbulbs from 60 objects (selected from several hundred) that appear within the (projected) area of Tycho and 3C58. If we are successful, this study will not only lead to a better understanding of two important SNRs, but also to an efficient method for probing ejecta in other Galactic SNRs.

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 NOAO >   Observing Info >   Approved Programs >   2009B-0407