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Properties of infrared-luminous galaxies, or, how I spent seven summer vacations

Citation

Carico, David Paul (1991) Properties of infrared-luminous galaxies, or, how I spent seven summer vacations. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-05162007-161518

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Galaxies selected from the IRAS database having unusually high 60 - 100µm luminosities are studied at wavelengths ranging from ~1 - 1000µm. It is found that these galaxies differ significantly from normal, optically-selected galaxies, not only in their far-infrared luminosities, but in their near-infrared properties as well. A substantial excess emission at near-infrared wavelengths is attributed to emission from hot dust, with temperatures ~500 - 1000 K. Furthermore, this hot dust emission is confined to the central nuclear regions, within characteristic scale sizes ~1 - 3 kpc. This suggests that the bulk of the infrared luminosity, and hence the processes responsible for the extreme activity in infrared-luminous galaxies, is highly localized about galaxy nuclei. High resolution images of a number of these nuclei reveals a high percentage of double-nucleus sources amongst the most luminous galaxies, giving evidence that galaxy-galaxy interactions play a significant role in the generation of high infrared luminosities. The distribution of the mass of, and luminosity from, dust in infrared-luminous galaxies is analyzed as a function of the temperature of the dust. It is found that, in galaxies for which the entire energy distribution is dominated by emission from dust heated to a steady-state, the mass of dust scales with steady-state temperature as [...], where [...] is typically in the range 6 - 6.5. Dust continues to contribute substantially to the total luminosity up to temperatures in excess of 300 K above the temperatures responsible for the peak in the infrared luminosity. At the lowest temperatures, however, it is very difficult to constrain the contribution to the observed emission: For the galaxies studied, the observations are consistent with models in which the amount of very cold dust ranges from essentially non-existent, to the dominant component of the total dust mass.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Cowan, Eugene W. (advisor)
  • Porter, Frank C. (advisor)
  • Thorne, Kip S. (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:9 August 1990
Record Number:CaltechETD:etd-05162007-161518
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-05162007-161518
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1840
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:16 May 2007
Last Modified:07 Mar 2013 21:17

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