Southern Galaxies. I. Luminosity, Rotation, and Mass of the Magellanic System NGC 55.
Abstract
NGC 55 is one of the largest and brightest galaxies in the southern sky and a member of the Sculptoi group of late-type spirals whose distance modulus is about 27.0. Photographic isophotes and the total magnitude, mr = 7 9 (IPg), were determined with the Mount Stromlo 30-inch reflector Spectra of a few emission objects secured with the 74-inch reflector are used for a preliminary estimate of the mass of the system. This estimate is 1.6 + 0.3 (p e.) times the mass of the Large Magellanic Cloud, or 2- 4 X 1010 solar masses; the mass-luminosity ratio is / 3-6 Comparison with the Large Magellanic Cloud indicates a close similarity of structure and other characteristics
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1961
- DOI:
- 10.1086/147043
- Bibcode:
- 1961ApJ...133..405D