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Author Sand, D. J. ♦ Crnojević, D. ♦ Seth, A. C. ♦ Spekkens, K. ♦ Strader, J. ♦ Adams, E. A. K. ♦ Caldwell, N. ♦ Randall, S. ♦ Guhathakurta, P. ♦ Kenney, J. ♦ Simon, J. D. ♦ Toloba, E. ♦ Willman, B.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ CLOUDS ♦ COMPACTS ♦ GALAXIES ♦ GALAXY CLUSTERS ♦ LUMINOSITY ♦ METALLICITY ♦ SPACE ♦ STARS ♦ SUPERNOVA REMNANTS ♦ TELESCOPES ♦ VELOCITY ♦ VISIBLE RADIATION
Abstract We analyze the optical counterpart to the ultra-compact high velocity cloud AGC 226067, utilizing imaging taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope . The color–magnitude diagram of the main body of AGC 226067 reveals an exclusively young stellar population, with an age of ∼7–50 Myr, and is consistent with a metallicity of [Fe/H] ∼ −0.3 as previous work has measured via H ii region spectroscopy. Additionally, the color–magnitude diagram is consistent with a distance of D ≈ 17 Mpc, suggesting an association with the Virgo cluster. A secondary stellar system located ∼1.′6 (∼8 kpc) away in projection has a similar stellar population. The lack of an old red giant branch (≳5 Gyr) is contrasted with a serendipitously discovered Virgo dwarf in the ACS field of view (Dw J122147+132853), and the total diffuse light from AGC 226067 is consistent with the luminosity function of the resolved ∼7–50 Myr stellar population. The main body of AGC 226067 has a M {sub V} = −11.3 ± 0.3, or M {sub stars} = 5.4 ± 1.3 × 10{sup 4} M {sub ⊙} given the stellar population. We searched 20 deg{sup 2} of imaging data adjacent to AGC 226067 in the Virgo Cluster, and found two similar stellar systems dominated by a blue stellar population, far from any massive galaxy counterpart—if this population has star-formation properties that are similar to those of AGC 226067, it implies ∼0.1 M {sub ⊙} yr{sup −1} in Virgo intracluster star formation. Given its unusual stellar population, AGC 226067 is likely a stripped remnant and is plausibly the result of compressed gas from the ram pressure stripped M86 subgroup (∼350 kpc away in projection) as it falls into the Virgo Cluster.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-07-10
Publisher Place United States
Journal Astrophysical Journal
Volume Number 843
Issue Number 2


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