The distribution of dark matter in the dwarf galaxy DDO 170

This paper reports the results of observations on the dwarf galaxy DDO 170 (absolute magnitude -15.15) and examines the implications of these observations on the distribution of dark matter. Using H I images and new photometry, three component models of the DDO-170 mass distribution are developed: (...

Full description

Saved in:
Bibliographic Details
Published in:The Astronomical journal 1990-02, Vol.99, p.547
Main Authors: Lake, George, Schommer, R. A., van Gorkom, J. H.
Format: Article
Language:English
Subjects:
640105 - Astrophysics & Cosmology- Galaxies
CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
CONFIGURATION
DISTRIBUTION
GALAXIES
LUMINOSITY
MASS DISTRIBUTION
MATHEMATICAL MODELS
MOTION
NONLUMINOUS MATTER
OPTICAL PROPERTIES
PHOTOMETRY
PHYSICAL PROPERTIES
ROTATION
SPATIAL DISTRIBUTION
SPIRAL CONFIGURATION
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper reports the results of observations on the dwarf galaxy DDO 170 (absolute magnitude -15.15) and examines the implications of these observations on the distribution of dark matter. Using H I images and new photometry, three component models of the DDO-170 mass distribution are developed: (1) a luminous disk with a constant mass/luminosity ratio, (2) a gas disk whose mass is determined by H I flux, and (3) a dark halo. It is found that the mass-to-luminosity ratio derived from the last point of the rotation curve (12.5 kpc) 56, the ratio of gas mass (derived from the 21 cm flux) to blue luminosity is about 3.7 in solar units, and that the DDO 170 is the smallest galaxy where the basic halo parameters (core radius and asymptotic velocity) are determined by fitting detailed mass models. It was also found that the DDO 170 has a companion with a projected separation of 62 kpc and a line-of-sight velocity difference of 85 km/sec. (I.S.)
ISSN:0004-6256
1538-3881
DOI:10.1086/115349