Multicolor Optical Imaging of Powerful Far-Infrared Galaxies: More Evidence for a Link Between Galaxy Mergers and Far-Infrared Emission
Abstract
Broadband optical (B and R) imaging results are presented for a sample of 39 powerful far-infrared galaxies detected by IRAS. These objects, which typically have LIR ≡ 1011L_sun; - 1012L_sun; and LIR/LB ≡ 10 - 100, were chosen to exhibit far-IR spectra similar in shape to the prototypical very luminous infrared galaxies Arp 220 and NGC 6240, and to be faint optically (in apparent magnitude). The imaging program has revealed that: (1) At least 70% of the galaxies have very distorted optical morphologies. (2) There is an unusually low occurrence of apparently flattened members. (3) The galaxies are moderately luminous in the optical. (4) The galaxy colors most closely resemble Sb or Sbc galaxies seen at the appropriate redshift. These results demonstrate that the optical properties of NGC 6240 and Arp 220 are typical of powerful far-infrared galaxies, and add to the impressive body of evidence linking the collision/merger of disk galaxies to the production of intense infrared emission.
- Publication:
-
The Astronomical Journal
- Pub Date:
- October 1987
- DOI:
- 10.1086/114517
- Bibcode:
- 1987AJ.....94..831A
- Keywords:
-
- Disk Galaxies;
- Far Infrared Radiation;
- Hertzsprung-Russell Diagram;
- Infrared Astronomy Satellite;
- Astronomical Maps;
- Data Reduction;
- Histograms;
- Astrophysics;
- INFRARED: SOURCES;
- RADIO SOURCES: GENERAL;
- GALAXIES: SEYFERT