In The Astrophysical Journal, Volume 647, Issue 2,
pp. L111-L114, 2006.
For a PDF version of the article, click
here.
astro-ph/0604355
Abstract. In this Letter, we announce the discovery of a new satellite of the Milky Way in the constellation of Boötes at a distance of ~ 60 kpc. It was found in a systematic search for stellar overdensities in the North Galactic Cap using Sloan Digital Sky Survey Data Release 5 (SDSS DR5). The color-magnitude diagram shows a well-defined turn-off, red giant branch, and extended horizontal branch. Its absolute magnitude is MV ~ -5m.8, which makes it one of the faintest galaxies known. The half-light radius is ~ 220 pc. The isodensity contours are elongated and have an irregular shape, suggesting that Boo may be a disrupted dwarf spheroidal galaxy.
Keywords galaxies: dwarf -- galaxies: individual (Boötes) --
Local Group
Table of Contents
1 Institute of Astronomy,
University of Cambridge,
Madingley Road, Cambridge CB3 0HA,
UK; vasily,
zucker,
nwe@ast.cam.ac.uk
2 Center for
Cosmology and Particle Physics,
Department
of Physics,
New York University,
4 Washington Place, New York, NY 10003
3 Rensselaer
Polytechnic Institute, Troy, NY 12180
4 The Johns
Hopkins University, 3701 San Martin Drive,
Baltimore, MD 21218
5 Max Planck Institute for Astronomy, Königstuhl
17, 69117 Heidelberg, Germany
6 Department
of Physics and Astronomy,
CSCE: Center
for the Study of Cosmic Evolution, and
JINA: Joint Institute for Nuclear Astrophysics,
Michigan State
University, East Lansing, MI 48824
7 Lick
Observatory,
University of
California, Santa Cruz, CA
95064
8 Fermi
National Accelerator Laboratory, P.O. Box 500,
Batavia, IL 60510
9 Astronomical Institute of the University of Basel,
Department of Physics and Astronomy, Venusstrasse
7,CH-4102 Binningen, Switzerland
10 Department of Astronomy and Astrophysics,
Pennsylvania State
University, 525 Davey Laboratory, University Park, PA 16802
11 Princeton University Observatory,
Peyton Hall, Princeton, NJ 08544
12 Apache
Point Observatory, P.O. Box 59, Sunspot, NM 88349
13 Mt. Suhora Observatory,
Cracow
Pedagogical University, ul. Podchorazych 2, 30-084 Cracow, Poland
14 Los Alamos
National Laboratory, ISR-4, MS D448, Los
Alamos, NM 87545