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arXiv · 0909.0771

An Isolated HII Region near ESO 481-G017

N. Santiago-Figueroa·M. Putman·J. Werk·E. Ryan-Weber·G. Meurer
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Abstract

We obtained VLA 21-cm observations of the galaxy ESO 481-G017 to determine the environment and trigger of remote star formation traced by a HII region found 43 kpc from the galaxy (in projection). ESO 481-G017 is an early type spiral galaxy with a HI mass of 1.1*10^9 Msun and a distance of 55 Mpc. The isolated HII region has a H-alpha luminosity of 10^38.1 erg s^-1 and minimal continuum emission suggesting that new stars have formed where little or no stars previously existed. The difference in velocity between the HI disk of ESO 481-G017 (3840-4000 km s^-1) and the isolated HII region (4701 +/- 80 km s^-1) indicates the origin of the HII region may be stars forming in a tidal feature or newly triggered star formation in a very low luminosity companion galaxy. The VLA observations shed light on the nature of this young object.

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N. Santiago-Figueroa, M. Putman, J. Werk, E. Ryan-Weber, G. Meurer. 2009-09-03. An Isolated HII Region near ESO 481-G017. https://arxiv.org/abs/0909.0771

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