A DEEP SEARCH FOR FAINT GALAXIES ASSOCIATED WITH VERY LOW-REDSHIFT C IV ABSORBERS: A CASE WITH COLD-ACCRETION CHARACTERISTICS
- Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003-9305 (United States)
- UCO/Lick Observatory, University of California, Santa Cruz, CA 95140 (United States)
- Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)
- Astronomy Department, University of Arizona, Tucson, AZ 85721 (United States)
- University of the Western Cape, Bellville, Cape Town 7535 (South Africa)
Studies of QSO absorber-galaxy connections are often hindered by inadequate information on whether faint/dwarf galaxies are located near the QSO sight lines. To investigate the contribution of faint galaxies to QSO absorber populations, we are conducting a deep galaxy redshift survey near low-z C IV absorbers. Here we report a blindly detected C IV absorption system (z {sub abs} = 0.00348) in the spectrum of PG1148+549 that appears to be associated either with an edge-on dwarf galaxy with an obvious disk (UGC 6894, z {sub gal} = 0.00283) at an impact parameter of ρ = 190 kpc or with a very faint dwarf irregular galaxy at ρ = 23 kpc, which is closer to the sightline but has a larger redshift difference (z {sub gal} = 0.00107, i.e., δv = 724 km s{sup –1}). We consider various gas/galaxy associations, including infall and outflows. Based on current theoretical models, we conclude that the absorber is most likely tracing (1) the remnants of an outflow from a previous epoch, a so-called {sup a}ncient outflow{sup ,} or (2) intergalactic gas accreting onto UGC 6894, ''cold mode'' accretion. The latter scenario is supported by H I synthesis imaging data that shows the rotation curve of the disk being codirectional with the velocity offset between UGC 6894 and the absorber, which is located almost directly along the major axis of the edge-on disk.
- OSTI ID:
- 22364088
- Journal Information:
- Astrophysical Journal Letters, Vol. 779, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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