@inproceedings{90ae5e74193d4312b3286672d5c54a1c,
title = "The ultraluminous X-ray source ic 342 X-1 and its environment",
abstract = "We present optical observations of a ULX in the nearby spiral galaxy IC 342. This variable source has an average X-ray luminosity of some 1040 erg/s. At the position of the source there is an ionized nebula (the {"}Tooth{"}) having huge dimensions (280 × 130 pc), much larger than normal supernova remnants. Our optical spectra reveal highly supersonic expansion velocities and emission line ratios typical of SNRs. It has been claimed that two [OIII] λ5007 bright regions in the nebula might be indicative of excitation by non-isotropic emission from the ULX. However, our continuum subtracted [OIII] A5007 image reveals that O++ ions are rather smoothly distributed in the nebula, fully consistent with shock excitation. Within the nebula we find two candidate stars (V=24.0 & 24.6) in the Chandra X-ray error circle. Both are substantially reddened being consistent with the patchy interstellar absorption. We will discuss the nature of this source in the framework of what is currently known about optical counterparts of ULXs.",
author = "F. Gris{\'e} and M. Pakull and C. Motch",
year = "2006",
language = "English (US)",
isbn = "9290929154",
series = "European Space Agency, (Special Publication) ESA SP",
number = "604",
pages = "451--452",
booktitle = "X-ray Universe 2005",
edition = "604",
note = "X-ray Universe 2005 ; Conference date: 26-09-2005 Through 30-09-2005",
}