The Spitzer Survey of interstellar clouds in the Gould Belt. V. Ophiuchus North Observed with IRAC and MIPS

TY - JOUR

T1 - The Spitzer Survey of interstellar clouds in the Gould Belt. V. Ophiuchus North Observed with IRAC and MIPS

AU - Hatchell, J.

AU - Terebey, S.

AU - Huard, T.

AU - Mamajek, E. E.

AU - Allen, L.

AU - Bourke, T. L.

AU - Dunham, M.M.

AU - Gutermuth, R,

AU - Harvey, P. M.

AU - Jørgensen, Jes Kristian

AU - Merin, M.

PY - 2012/8/1

Y1 - 2012/8/1

N2 - We present Spitzer IRAC (2.1deg2) and MIPS (6.5deg2) 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 ρ Oph star-forming region, at an approximate distance of 130pc. 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 AV > 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) KS /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 (AV > 10) cores are identified with a total mass of 100 M. 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 ζ Oph, is seen in dynamical interactions and raised dust temperatures but has not enhanced levels of star formation in Oph N.

AB - We present Spitzer IRAC (2.1deg2) and MIPS (6.5deg2) 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 ρ Oph star-forming region, at an approximate distance of 130pc. 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 AV > 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) KS /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 (AV > 10) cores are identified with a total mass of 100 M. 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 ζ Oph, is seen in dynamical interactions and raised dust temperatures but has not enhanced levels of star formation in Oph N.

U2 - 10.1088/0004-637X/754/2/104

DO - 10.1088/0004-637X/754/2/104

M3 - Journal article

SN - 0004-637X

VL - 754

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

M1 - 104

ER -