SPATIALLY CORRELATED CLUSTER POPULATIONS IN THE OUTER DISK OF NGC 3184
- University of Arizona/Steward Observatory, 933 N Cherry Avenue, Tucson, AZ 85721 (United States)
- Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)
- Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany)
- Department of Astronomy, University of Wisconsin-Madison, 475 N. Charter St., Madison, WI 53706 (United States)
- INAF, Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, I-35122 Padova (Italy)
- INAF, Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio (Italy)
- Department of Astronomy, The Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210-1173 (United States)
- INAF, Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-34131 Trieste (Italy)
We use deep ({approx}27.5 mag V-band point-source limiting magnitude) V- and U-band Large Binocular Telescope imaging to study the outer disk (beyond the optical radius R {sub 25}) of the non-interacting, face-on spiral galaxy NGC 3184 (D = 11.1 Mpc; R {sub 25} = 11.1 kpc) and find that this outer disk contains >1000 objects (or marginally resolved 'knots') resembling star clusters with masses {approx}10{sup 2}-10{sup 4} M {sub sun} and ages up to {approx}1 Gyr. We find statistically significant numbers of these cluster-like knots extending to {approx}1.4 R {sub 25}, with the redder knots outnumbering bluer at the largest radii. We measure clustering among knots and find significant correlation to galactocentric radii of 1.5 R {sub 25} for knot separations <1 kpc. The effective integrated surface brightness of this outer disk cluster population ranges from 30-32 mag arcsec{sup -2} in V. We compare the H I extent to that of the correlated knots and find that the clusters extend at least to the damped Lyman-{alpha} threshold of H I column density (2 x 10{sup 20} cm{sup -2}; {approx}1.62 R {sub 25}). The blue knots are correlated with H I spiral structure to {approx}1.5 R {sub 25}, while the red knots may be correlated with the outer fringes of the H I disk to {approx}1.7 R {sub 25}. These results suggest that outer disks are well populated, common, and long-lasting features of many nearby disk galaxies.
- OSTI ID:
- 21313733
- Journal Information:
- Astrophysical Journal, Vol. 700, Issue 2; Other Information: DOI: 10.1088/0004-637X/700/2/1977; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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