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The Nature of the Emission-line Nebulae in Powerful Far-infrared Galaxies

Published online by Cambridge University Press:  12 April 2016

Lee Armus
Affiliation:
The Johns Hopkins University
Timothy M. Heckman
Affiliation:
The Johns Hopkins University
George K. Miley
Affiliation:
Sterrewacht Leiden

Abstract

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We discuss our program of narrow-band (Hα + [Nil]) imaging of a sample of 30 powerful far-infrared galaxies (FIRG’s) chosen to have far-infrared spectral energy distributions similar to the prototype FIRG’s Arp 220, NGC 3690, NGC 6240, and M82. The emission-line nebulae of these IR color-selected sample (ICSS) galaxies as a class are both impressively large (mean half light radius, r ~1.3 Kpc, and mean diameter, D ~16 Kpc) and luminous (LTOT ~108 Lo; uncorrected for internal extinction). The mean total Hα + [Nil] luminosity of the FIRG’s is comparable to that found for pairs of optically selected interacting galaxies (Bushouse, Lamb, and Werner 1988), but is a factor of ~5 greater than that of isolated spirals (Kennicutt and Kent 1983). Only ~25% of the nearby (z ≤ 0.10) FIRG’s have morphologies suggesting that large HII~regions contribuí significantly to their emission-line appearance. The broad-band morphologies of our IR color-selected galaxies fall into three major categories. Nearly 75% are single galaxy systems, with the remaining FIRG’s being either multiple nuclei systems, or members of interacting pairs. Since we see few (10%) currently interacting FIRG’s, yet many (80%) with highly distorted continuum morphologies, our IR color criteria may be preferentially selecting galaxies that have undergone highly inelastic, rapidly merging interactions.

Type
V. Observations of Nuclear and Near-Nuclear Activity
Copyright
Copyright © NASA 1990

References

Armus, L., Heckman, T.M., and Miley, G.K. 1989, Ap.J., 347 747.Google Scholar
Bushouse, H.A., Lamb, S.A., and Werner, M.W. 1988, Ap.J., 335 74.Google Scholar
Heckman, T.M., Armus, L., and Miley, G.K., 1987, A.J., 93 276.Google Scholar
Kennicutt, R.C. 1983, Ap.J., 272 54.Google Scholar
Kennicutt, R.C., and Kent, S.M. 1983, A.J., 88, 1094.CrossRefGoogle Scholar
McCarthy, P.J., Heckman, T.M., and vanBruegel, W. 1987, A.J., 93 264.Google Scholar