Discovery of radiatively excited molecular hydrogen in the giant extragalactic HII region complex NGC 604

Author(s):
Israel, F.P.; Hawarden, T.G.; Wade, R.S.; Geballe, T.R.; Dishoeck, E.F. van
Published
1989
Publication type
Article / Letter to editor

Abstract

The 1-0S(1), 2-1S(1), 1-0S(0) and 1-0Q branch transitions of molecular hydrogen (H2) towards the giant emission nebula (HII region) NGC 604 in M33 have been detected. The line ratios are incompatible with shock-excited H2, but indicate the widespread presence of fluorescent H2 at a mean temperature T = 70 + or - 15 K. This is the first detection of fluorescent H2 emission associated with a giant (extragalactic) HII region complex.

H II regionshydrogenmolecular excitationnebulaeline spectraultraviolet radiation
Date issued
1989
Language
English
Publisher
Royal Astronomical Society
hdl
1887/1989