TY - JOUR

T1 - The rotating molecular core and precessing outflow of the young stellar object Barnard 1c

AU - Matthews, Brenda C.

AU - Hogerheijde, Michiel R.

AU - Jørgensen, Jes K.

AU - Bergin, Edwin A.

PY - 2006/12/1

Y1 - 2006/12/1

N2 - We investigate the structure of the core surrounding the recently identified deeply embedded young stellar object Barnard 1c. B1c lies within the Perseus molecular cloud at a distance of 250 pc. It is a deeply embedded core of 2.4 M⊙ (Kirk et al.) and a luminosity of 4 ± 2 L ⊙. Observations (and resolutions) of 12CO J - 1-0 (9″.2 × 5″9), 13CO J = 1-0, C18O J = 1 - 0 (14″.3 × 6″.7), HCO+ J = 1-0 (7″.6 × 5″.8), and N2H+ J = 1-0 (5″.9 × 4″.6) were obtained with the BIMA array, together with the continuum at 3.3 mm (6″.4 × 4″. 9) and 2.7 mm (9″.5 × 6″.3). Single-dish measurements of N2H+ J = 1-0 and HCO+ J = 1-0 with FCRAO reveal the larger scale emission in these lines with ∼ 60 resolution. The 12CO and HCO+ emission traces the outflow extending over the full field of view (2′.1), which coincides in detail with the S-shaped jet recently found in Spitzer IRAC imaging. The N2H+ emission, which anti-correlates spatially with the C18O emission, originates from a rotating envelope with effective radius ∼2400 AU and mass 2.1-2.9 M⊙, as derived from the 3.3 mm continuum emission. N2H+ emission is absent from a 600 AU diameter region around the young star, offset from the continuum peak. The remaining N2H+ emission may lie in a coherent torus of dense material. With its outflow and rotating envelope, B1c closely resembles the previously studied object L483 mm, and we conclude that it is a protostar in an early stage of evolution, i.e., Class 0 or in transition between Class 0 and Class I. We hypothesize that heating by the outflow and star has desorbed CO from grains, which has destroyed N2H+ in the inner region, and surmise that the presence of grains without ice mantles in this warm inner region can explain the unusual polarization signature observed from B1c.

AB - We investigate the structure of the core surrounding the recently identified deeply embedded young stellar object Barnard 1c. B1c lies within the Perseus molecular cloud at a distance of 250 pc. It is a deeply embedded core of 2.4 M⊙ (Kirk et al.) and a luminosity of 4 ± 2 L ⊙. Observations (and resolutions) of 12CO J - 1-0 (9″.2 × 5″9), 13CO J = 1-0, C18O J = 1 - 0 (14″.3 × 6″.7), HCO+ J = 1-0 (7″.6 × 5″.8), and N2H+ J = 1-0 (5″.9 × 4″.6) were obtained with the BIMA array, together with the continuum at 3.3 mm (6″.4 × 4″. 9) and 2.7 mm (9″.5 × 6″.3). Single-dish measurements of N2H+ J = 1-0 and HCO+ J = 1-0 with FCRAO reveal the larger scale emission in these lines with ∼ 60 resolution. The 12CO and HCO+ emission traces the outflow extending over the full field of view (2′.1), which coincides in detail with the S-shaped jet recently found in Spitzer IRAC imaging. The N2H+ emission, which anti-correlates spatially with the C18O emission, originates from a rotating envelope with effective radius ∼2400 AU and mass 2.1-2.9 M⊙, as derived from the 3.3 mm continuum emission. N2H+ emission is absent from a 600 AU diameter region around the young star, offset from the continuum peak. The remaining N2H+ emission may lie in a coherent torus of dense material. With its outflow and rotating envelope, B1c closely resembles the previously studied object L483 mm, and we conclude that it is a protostar in an early stage of evolution, i.e., Class 0 or in transition between Class 0 and Class I. We hypothesize that heating by the outflow and star has desorbed CO from grains, which has destroyed N2H+ in the inner region, and surmise that the presence of grains without ice mantles in this warm inner region can explain the unusual polarization signature observed from B1c.

KW - ISM: clouds

KW - ISM: individual (Barnard 1)

KW - ISM: molecules

KW - Radio lines: ISM

KW - Stars: formation

UR - http://www.scopus.com/inward/record.url?scp=33845888298&partnerID=8YFLogxK

U2 - 10.1086/508645

DO - 10.1086/508645

M3 - Journal article

AN - SCOPUS:33845888298

VL - 652

SP - 1374

EP - 1389

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2 I

ER -