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Title: A survey of satellite galaxies around NGC 4258

Journal Article · · Astrophysical Journal
;  [1];  [2]
  1. Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States)
  2. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States)

We conduct a survey of satellite galaxies around the nearby spiral NGC 4258 by combining spectroscopic observations from the Apache Point Observatory 3.5 m telescope with Sloan Digital Sky Survey (SDSS) spectra. New spectroscopy is obtained for 15 galaxies. Of the 47 observed objects, we categorize 8 of them as probable satellites, 8 as possible satellites, and 17 as unlikely to be satellites. We do not speculate on the membership of the remaining 14 galaxies due to a lack of velocity and distance information. Radially integrating our best-fit NFW profile for NGC 4258 yields a total mass of 1.8 × 10{sup 12} M {sub ☉} within 200 kpc. We find that the angular distribution of the satellites appears to be random, and not preferentially aligned with the disk of NGC 4258. In addition, many of the probable satellite galaxies have blue u–r colors and appear to be star-forming irregulars in SDSS images; this stands in contrast to the low number of blue satellites in the Milky Way and M31 systems at comparable distances.

OSTI ID:
22356574
Journal Information:
Astrophysical Journal, Vol. 788, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English