Details

Autor(en) / Beteiligte

• Paladini, R
• DeZotti, G
• Noriega-Crespo, A
• Carey, S. J

Titel

Re-analysis of the Radio Luminosity Function of Galactic H II Regions

Ist Teil von

• The Astrophysical journal, 2009-09, Vol.702 (2), p.1036-1047

Ort / Verlag

IOP Publishing

Erscheinungsjahr

2009

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• We have re-analyzed continuum and recombination lines radio data available in the literature in order to derive the luminosity function (LF) of Galactic H II regions. The study is performed by considering the first and fourth Galactic quadrants independently. We estimate the completeness level of the sample in the fourth quadrant at 5 Jy, and the one in the first quadrant at 2 Jy. We show that the two samples (fourth or first quadrant) include, as well as giant and supergiant H II regions, a significant number of subgiant sources. The LF is obtained, in each Galactic quadrant, with a generalized Schmidt's estimator using an effective volume derived from the observed spatial distribution of the considered H II regions. The re-analysis also takes advantage of recently published ancillary absorption data allowing to solve the distance ambiguity for several objects. A single power-law fit to the LFs retrieves a slope equal to -2.23 +/- 0.07 (fourth quadrant) and to -1.85 +/- 0.11 (first quadrant). We also find marginal evidence of a luminosity break at L knee = 1023.45 erg s-1 Hz-1 for the LF in the fourth quadrant. We convert radio luminosities into equivalent H Delta *a and Lyman continuum luminosities to facilitate comparisons with extragalactic studies. We obtain an average total H II regions Lyman continuum luminosity of 0.89 +/- 0.23 X 1053 s-1, corresponding to 30% of the total ionizing luminosity of the Galaxy.