Investigating the transport of angular momentum from young stellar objects: do H2 jets from Class I YSOs rotate?

Details Investigating the transport of angular momentum from young stellar objects: do H2 jets from Class I YSOs rotate? Investigating the transport of angular momentum from young stellar objects: do H2 jets from Class I YSOs rotate?

2008-02-13

arxiv.org/abs/0802.1881v2

Astronomy and Astrophysics

Astrophysics

11 pages, 5 figures, accepted for publication in Astronomy & Astrophysics

Scientific paper

10.1051/0004-6361:20078494

In this pilot study, we examine molecular jets from the embedded Class I sources, HH 26 and HH 72, to search, for the first time, for kinematic signatures of jet rotation from young embedded sources.High resolution long-slit spectroscopy of the H2 1-0 S(1) transition was obtained using VLT/ISAAC, position-velocity (PV) diagrams constructed and intensity-weighted radial velocities transverse to the jet flow measured. Mean intensity-weighted velocities vary between vLSR ~ -90 and -65 km/s for HH 26, and -60 and -10 km/s for HH 72; maxima occur close to the intensity peak and decrease toward the jet borders. Velocity dispersions are ~ 45 and ~ 80 km/s for HH 26 and HH 72, respectively, with gas motions as fast as -100 km/s present. Asymmetric PV diagrams are seen for both objects which a simple empirical model of a cylindrical jet section shows could in principle be reproduced by jet rotation alone. Assuming magneto-centrifugal launching, the observed HH 26 flow may originate at a disk radius of 2-4 AU from the star with the toroidal component of the magnetic field dominant at the observed location, in agreement with magnetic collimation models. We estimate that the kinetic angular momentum transported by the HH 26 jet is ~ 2E5 M_sun/yr AU km/s. This value (a lower limit to the total angular momentum transported by the flow) already amounts to 70% of the angular momentum that has to be extracted from the disk for the accretion to proceed at the observed rate. The results of this pilot study suggest that jet rotation may also be present at early evolutionary phases and supports the hypothesis that they carry away excess angular momentum, thus allowing the central protostar to increase its mass.

Affiliated with

Also associated with

No associations

Rating

Investigating the transport of angular momentum from young stellar objects: do H2 jets from Class I YSOs rotate? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Investigating the transport of angular momentum from young stellar objects: do H2 jets from Class I YSOs rotate?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Investigating the transport of angular momentum from young stellar objects: do H2 jets from Class I YSOs rotate? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-676948