THE OUTER LIMITS OF THE M31 SYSTEM: KINEMATICS OF THE DWARF GALAXY SATELLITES AND XXVIII and AND XXIX

Journal Article · Wed May 01 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/768/1/50· OSTI ID:22126807

Tollerud, Erik J.; Geha, Marla C.; Vargas, Luis C. ^[1]

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1. Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06510 (United States)

We present Keck/DEIMOS spectroscopy of resolved stars in the M31 satellites And XXVIII and And XXIX. We show that these are likely self-bound galaxies based on 18 and 24 members in And XXVIII and And XXIX, respectively. And XXVIII has a systemic velocity of -331.1 {+-} 1.8 km s{sup -1} and a velocity dispersion of 4.9 {+-} 1.6 km s{sup -1}, implying a mass-to-light ratio (within r{sub 1/2}) of {approx}44 {+-} 41. And XXIX has a systemic velocity of -194.4 {+-} 1.5 km s{sup -1} and velocity dispersion of 5.7 {+-} 1.2 km s{sup -1}, implying a mass-to-light ratio (within r{sub 1/2}) of {approx}124 {+-} 72. The internal kinematics and implied masses of And XXVIII and And XXIX are similar to those of dwarf spheroidals (dSphs) of comparable luminosities, implying that these objects are dark-matter-dominated dwarf galaxies. Despite the large projected distances from their host (380 and 188 kpc), the kinematics of these dSph suggest that they are bound M31 satellites.

• OSTI ID: 22126807
• Journal Information: Astrophysical Journal, Vol. 768, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
DISPERSIONS
DISTANCE
GALAXIES
LUMINOSITY
MASS
NONLUMINOUS MATTER
SATELLITES
SPECTROSCOPY
STARS
VELOCITY