THE SPITZER SURVEY OF INTERSTELLAR CLOUDS IN THE GOULD BELT. V. OPHIUCHUS NORTH OBSERVED WITH IRAC AND MIPS

Journal Article · Wed Aug 01 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/754/2/104· OSTI ID:22039243

Hatchell, J ^[1]; Terebey, S ^[2]; Huard, T ^[3]; others, and

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1. Astrophysics Group, Physics, University of Exeter, Exeter EX4 4QL (United Kingdom)
2. Department of Physics and Astronomy PS315, 5151 State University Drive, California State University at Los Angeles, Los Angeles, CA 90032 (United States)
3. Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)

We present Spitzer IRAC (2.1 deg{sup 2}) and MIPS (6.5 deg{sup 2}) observations of star formation in the Ophiuchus North (Oph N) molecular clouds. This fragmentary cloud complex lies on the edge of the Sco-Cen OB association, several degrees to the north of the well-known {rho} Oph star-forming region, at an approximate distance of 130 pc. The Oph N clouds were mapped as part of the Spitzer Gould Belt project under the working name 'Scorpius'. In the regions mapped, selected to encompass all the cloud with visual extinction A{sub V} > 3, 11 young stellar object (YSO) candidates are identified, 8 from IRAC/MIPS color-based selection and 3 from Two Micron All Sky Survey (2MASS) K{sub S} /MIPS colors. Adding to one source previously identified in L43, this increases the number of YSOcs identified in Oph N to 12. During the selection process, four color-based YSOcs were rejected as probable asymptotic giant branch stars and one as a known galaxy. The sources span the full range of YSOc classifications from Class 0/1 to Class III, and starless cores are also present. Twelve high extinction (A{sub V} > 10) cores are identified with a total mass of {approx}100 M{sub Sun }. These results confirm that there is little ongoing star formation in this region (instantaneous star formation efficiency <0.34%) and that the bottleneck lies in the formation of dense cores. The influence of the nearby Upper Sco OB association, including the 09V star {zeta} Oph, is seen in dynamical interactions and raised dust temperatures but has not enhanced levels of star formation in Oph N.

• OSTI ID: 22039243
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 754; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
APPROXIMATIONS
ASTRONOMY
ASTROPHYSICS
COLOR
COSMIC GASES
DISTANCE
EFFICIENCY
GALAXIES
GIANT STARS
MASS
PROTOSTARS
STAR EVOLUTION
STARS