Molecular jet emission and a spectroscopic survey of S235AB

¹ Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Kôrimoto, 890-0065, Kagoshima, Japan
e-mail: RossBurns88@Googlemail.com
² Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, 181-8588 Tokyo, Japan
³ Department of Astronomical Sciences, SOKENDAI (Graduate University for Advanced Studies), Osawa 2-21-1, Mitaka, 181-8588 Tokyo, Japan
⁴ Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, 2-12 Hoshi-ga-oka, Mizusawa-ku, Oshu-shi, 023-0861 Iwate, Japan

Received: 24 August 2015
Accepted: 12 December 2015

Abstract

Context. The S235AB star forming region houses a massive young stellar object which has recently been reported to exhibit possible evidence of jet rotation – an illusive yet crucial component of disk aided star formation theories.

Aims. We confirm the presence of a molecular counterpart to the jet and we also study the molecular environment in S235AB.

Methods. We search for velocity wings in the line emission of thermal SiO (J = 2–1, v = 0), a tracer of shocked gas, which would indicate the presence of jet activity. Utilising other lines detected in our survey we use the relative intensities of intra species transitions, isotopes, and hyperfine transitions to derive opacities, temperatures, column densities, and abundances of various molecular species in S235AB.

Results. The SiO (J = 2–1, v = 0) emission exhibits velocity wings of up to 75 km s^-1 above and below the velocity of the star, indicating the presence of a jet. The molecular environment describes an evolutionary stage resembling a hot molecular core.