TY - JOUR
T1 - Bolocam survey for 1.1 mm dust continuum emission in the c2d legacy clouds. II. Ophiuchus
AU - Young, Kaisa E.
AU - Enoch, Melissa L.
AU - Evans, Neal J.
AU - Glenn, Jason
AU - Sargent, Anneila
AU - Huard, Tracy L.
AU - Aguirre, James
AU - Golwala, Sunil
AU - Haig, Douglas
AU - Harvey, Paul
AU - Laurent, Glenn
AU - Mauskopf, Philip
AU - Sayers, Jack
PY - 2006/6/10
Y1 - 2006/6/10
N2 - We present a large-scale millimeter continuum map of the Ophiuchus molecular cloud. Nearly 11 deg2, including all of the area in the cloud with AV ≥ 3 mag, was mapped at 1.1 mm with Bolocam on the Caltech Submillimeter Observatory (CSO). By design, the map also covers the region mapped in the infrared with the Spitzer Space Telescope. We detect 44 definite sources, and a few likely sources are also seen along a filament in the eastern streamer. The map indicates that dense cores in Ophiuchus are very clustered and often found in filaments within the cloud. Most sources are round, as measured at the half-power point, but elongated when measured at lower contour levels, suggesting spherical sources lying within filaments. The masses, for an assumed dust temperature of 10 K, range from 0.24 to 3.9 M ⊙, with a mean value of 0.96 M⊙. The total mass in distinct cores is 42 M⊙, 0.5%-2% of the total cloud mass, and the total mass above 4 σ is about 80 M⊙. The mean densities in the cores are quite high, with an average of 1.6 × 10 6 cm-3, suggesting short free-fall times. The core mass distribution can be fitted with a power law with slope α = 2.1 ± 0.3 for M > 0.5 M⊙, similar to that found in other regions, but slightly shallower than that of some determinations of the local IMF. In agreement with previous studies, our survey shows mat dense cores account for a very small fraction of the cloud volume and total mass. They are nearly all confined to regions with AV ≥ 9 mag, a lower threshold than found previously.
AB - We present a large-scale millimeter continuum map of the Ophiuchus molecular cloud. Nearly 11 deg2, including all of the area in the cloud with AV ≥ 3 mag, was mapped at 1.1 mm with Bolocam on the Caltech Submillimeter Observatory (CSO). By design, the map also covers the region mapped in the infrared with the Spitzer Space Telescope. We detect 44 definite sources, and a few likely sources are also seen along a filament in the eastern streamer. The map indicates that dense cores in Ophiuchus are very clustered and often found in filaments within the cloud. Most sources are round, as measured at the half-power point, but elongated when measured at lower contour levels, suggesting spherical sources lying within filaments. The masses, for an assumed dust temperature of 10 K, range from 0.24 to 3.9 M ⊙, with a mean value of 0.96 M⊙. The total mass in distinct cores is 42 M⊙, 0.5%-2% of the total cloud mass, and the total mass above 4 σ is about 80 M⊙. The mean densities in the cores are quite high, with an average of 1.6 × 10 6 cm-3, suggesting short free-fall times. The core mass distribution can be fitted with a power law with slope α = 2.1 ± 0.3 for M > 0.5 M⊙, similar to that found in other regions, but slightly shallower than that of some determinations of the local IMF. In agreement with previous studies, our survey shows mat dense cores account for a very small fraction of the cloud volume and total mass. They are nearly all confined to regions with AV ≥ 9 mag, a lower threshold than found previously.
KW - Dust, extinction
KW - ISM: individual (Ophiuchus molecular cloud)
KW - Submillimeter
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U2 - 10.1086/503327
DO - 10.1086/503327
M3 - Article
AN - SCOPUS:33747070475
SN - 0004-637X
VL - 644
SP - 326
EP - 343
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
ER -