Kinematics and Chemistry of the Hot Molecular Core in G34.26+0.15 at High Resolution

Abstract

(abridged) We present high angular resolution (~ 1") multi-tracer spectral line observations toward the hot core associated with G34.26+0.15 between 87--109 GHz. We have mapped emission from (i) complex nitrogen- and oxygen-rich molecules like CH3OH, HC3N, C2H5CN, NH2CHO, CH3OCH3, HCOOCH3; (ii) sulfur-bearing molecules like OCS, SO and SO2; and (iii) the recombination line H53 beta. The high angular resolution enables us to directly probe the hot molecular core associated with G34.26+0.15 at spatial scales of 0.018 pc. At this resolution we find no evidence for the hot core being internally heated. The continuum peak detected at lambda=2.8 mm is consistent with the free-free emission from component C of the ultracompact H II region. Velocity structure and morphology outlined by the different tracers suggest that the hot core is primarily energized by component C. Emission from the N- and O-bearing molecules peak at different positions within the innermost regions of the core; none is coincident with the continuum peak. Based on the brightness temperatures of optically thick lines in our sample, we estimate the kinetic temperature of the inner regions of the HMC to be 160+-30 K. Comparison of the observed abundances of the different species in G34.26+0.15 with existing models does not produce a consistent picture.

arXiv commentAccepted for publication in ApJ

References in corpus (11)

• Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores
• Resetting chemical clocks of hot cores based on S-bearing molecules
• The Physical and Chemical Structure of Hot Molecular Cores
• A detailed study of the rotating toroids in G31.41+0.31 and G24.78+0.08
• Hot gas and dust in a protostellar cluster near W3(OH
• Rotating disks in high-mass young stellar objects
• Methanol in W3(H2O) and Surrounding Regions
• Mid-Infrared Detection of a Hot Molecular Core in G29.96-0.02
• A Search for Mid-Infrared Emission from Hot Molecular Core Candidates
• Astrochemical confirmation of the rapid evolution of massive YSOs and explanation for the inferred ages of hot cores
• The chemistry of high-mass star formation

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