Observations of B335 in the Millimeter Continuum and the 226 GHz H2CO Line

TL;DR

This study observes the protostar B335 in millimeter continuum and H2CO line, revealing infall motion, possible outflow influence, and complex radiative transfer effects in the inner envelope.

Contribution

First detailed millimeter observations of B335 combining continuum and line data to analyze envelope kinematics and outflow interactions.

Findings

Inner envelope mass ~0.02 Msun

Blue-skewed double peak profile indicating infall

Evidence of outflow influence on H2CO emission

Abstract

The protostar B335 was observed in the 1.3 mm continuum and in the H2CO 312 - 211 line with an angular resolution of about 8 arcsec. The mass of the inner envelope detected by the dust continuum emission is about 0.02 Msun. The H2CO spectrum at the protostellar position shows a blue-skewed double peak profile, suggesting that the kinematics of the inner envelope is dominated by infall motion. When the blueshifted and the redshifted peaks were imaged separately, however, there is a small east-west displacement between the maximum positions. This displacement suggests that some part of the H2CO emission might come from the outflowing gas. A combined effect of the infalling envelope and the outflow on the radiative transfer is discussed. This effect can make the line profile asymmetry severer than what is expected from infall-only models.