The molecular environment of the HH 34 system

Publication date: 
Main author: 
Anglada G.
IAA authors: 
Torrelles J.M.
Anglada G., Estalella R., Mauersberger R., Torrelles J.M., Rodríguez L.F., Cantó J., Ho P.T.P., D'Alessio P.
Astrophysical Journal
Publication type: 
We present single-dish (angular resolution ∼40″) and VLA (angular resolution ∼4″) ammonia observations toward the HH 34 region. Two main condensations are distinguished in both our single-dish and our VLA maps. The northern ammonia condensation is resolved by the VLA as an arclike structure that surrounds the east side of the star HH 34 IRS (the exciting source of the jet) and coincides in projection with Re 24, the reflection nebula associated with the infrared source IRS 5. We suggest that this ammonia structure is tracing the wall of a cavity around HH 34 IRS. Our results are in good agreement with the hypothesis that this cavity was created by the stellar wind from HH 34 IRS, indicating that along the life of the star two kinds of stellar wind might have been present: a low-collimation wind that created the cavity, and a highly collimated wind that is at the origin of the jet. A second VLA ammonia condensation coincides with Re 23, the brightest part of the arc of optical nebulosity previously proposed to be tracing the western wall of a cavity that contains the jet. The inner edges of these two ammonia condensations coincide with zones of a high level of polarization of the optical emission. With the angular resolution of our VLA observations, no ammonia (1, 1) emission is detected directly associated with the star HH 34 IRS, setting an upper limit of 0.1[X(NH3)10-8]-1 M⊙ for the mass of a possible circumstellar disk. From our single-dish observations, we find that there is extended emission (∼3′) of high-density gas, not seen with the VLA. For this gas we estimate a total mass of ∼15 M⊙ and a kinetic temperature of 15 K.
ISM: jets and outflows; ISM: molecules; Radio lines: ISM; Stars: individual (HH 34); Stars: pre-main-sequence