TY - JOUR

T1 - Dynamical and chemical properties of the "starless" core L1014

AU - Crapsi, A.

AU - DeVries, C. H.

AU - Huard, Tracy L.

AU - Lee, J. E.

AU - Myers, P. C.

AU - Ridge, N. A.

AU - Bourke, T. L.

AU - Evans, N. J.

AU - Jørgensen, J. K.

AU - Kauffmann, J.

AU - Lee, C. W.

AU - Shirley, Y. L.

AU - Young, C. H.

PY - 2005/9/1

Y1 - 2005/9/1

N2 - Spitzer Space Telescope observations of a point-like source, L1014-IRS, close to the dust peak of the low-mass dense core L1014, have raised questions about its starless nature. These show the presence of an object with colors expected for an embedded protostar with the implication that L1014-IRS would be the lowest luminosity isolated protostar known, and an ideal target with which to test star formation theories at the low mass end. In order to study its molecular content and to search for the presence of a molecular outflow, we mapped L1014 in at least one transition of 12CO, N2H +, HCO+, CS, and of their isotopologues 13CO, C18O, C17O, N2D+, and H 13CO+, using the Five College Radio Astronomy Observatory (FCRAO), the IRAM 30 m antenna, and the Caltech Submillimeter Observatory (CSO). The data show physical and chemical properties in L1014 typical of moderately evolved dense cores: i.e. H2 central density of a few 105 molecules cm-3, estimated mass of ∼2 M⊙, CO integrated depletion factor less than 10, N(N2H+) ≃ 6 × 1012 cm-2, N(N2D+)/N(N 2H+) equal to 10%, and relatively broad N 2H+ and N2D+ lines (0.35 km s -1). Infall signatures and significant velocity shifts between optically thick and optically thin tracers are not observed in the line profiles. No classical signatures of molecular outflow are found in the 12CO and 13CO FCRAO observations. In particular, no high velocity wings are found, and no well-defined blue-red lobes of 12CO emission are seen in the channel maps. Sensitive, higher resolution observations will clarify the presence of a molecular outflow on a smaller scale than that probed by our observations.

AB - Spitzer Space Telescope observations of a point-like source, L1014-IRS, close to the dust peak of the low-mass dense core L1014, have raised questions about its starless nature. These show the presence of an object with colors expected for an embedded protostar with the implication that L1014-IRS would be the lowest luminosity isolated protostar known, and an ideal target with which to test star formation theories at the low mass end. In order to study its molecular content and to search for the presence of a molecular outflow, we mapped L1014 in at least one transition of 12CO, N2H +, HCO+, CS, and of their isotopologues 13CO, C18O, C17O, N2D+, and H 13CO+, using the Five College Radio Astronomy Observatory (FCRAO), the IRAM 30 m antenna, and the Caltech Submillimeter Observatory (CSO). The data show physical and chemical properties in L1014 typical of moderately evolved dense cores: i.e. H2 central density of a few 105 molecules cm-3, estimated mass of ∼2 M⊙, CO integrated depletion factor less than 10, N(N2H+) ≃ 6 × 1012 cm-2, N(N2D+)/N(N 2H+) equal to 10%, and relatively broad N 2H+ and N2D+ lines (0.35 km s -1). Infall signatures and significant velocity shifts between optically thick and optically thin tracers are not observed in the line profiles. No classical signatures of molecular outflow are found in the 12CO and 13CO FCRAO observations. In particular, no high velocity wings are found, and no well-defined blue-red lobes of 12CO emission are seen in the channel maps. Sensitive, higher resolution observations will clarify the presence of a molecular outflow on a smaller scale than that probed by our observations.

KW - ISM: clouds

KW - ISM: evolution

KW - ISM: individual objects: L1014

KW - ISM: jets and outflows

KW - ISM: molecules

KW - Stars: formation

UR - http://www.scopus.com/inward/record.url?scp=24944445190&partnerID=8YFLogxK

U2 - 10.1051/0004-6361:20042411

DO - 10.1051/0004-6361:20042411

M3 - Journal article

AN - SCOPUS:24944445190

VL - 439

SP - 1023

EP - 1032

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

IS - 3

ER -