STScI Preprint #1211

A Bipolar Outflow in the M1-67 Nebula around the Wolf-Rayet Star WR124

Based on observations obtained at the European Southern Observatory, La Silla

Ground based high resolution coronographic images of the inner M1-67 nebula ( 40" × 60") around the Wolf Rayet WR124 have been obtained with the Johns Hopkins Adaptive Optic Coronograph at the Swope 40" telescope, Las Campanas, in the light of H + [NII]. The inner M1-67 nebula appears very clumpy and remarkably axisymmetric. In addition, we present new high signal-to-noise long slit spectroscopic data, with full spatial coverage of the nebula ( 90" × 75"), which have been used to derive its radial velocity map (from the [NII] 6583 Å line profile). The radial velocity data reveal the presence of two different motions in the environment of WR124: a spherical hollow shell, 46" in radius expanding with a velocity of 46 km s^-1, and a newly discovered bipolar outflow, with a velocity of 88 km s^-1. Their dynamical ages are estimated to be 2 × 10⁴ yrs and 1.2 × 10⁴ yrs respectively, and their overall N enriched composition seem to indicate that they formed during the post-main sequence evolution of WR124. This scenario is consistent with two subsequent outbursts, possibly occured during a previous LBV phase.

Status:

Appeared in: Astronomy & Astrophysics, 335:1029-1039, 1998

Affiliations:

¹) Space Telescope Science Institute 3700 San Martin Drive Baltimore, MD 21218 USA

²) Center of Studies and Activities for Space "G. Colombo" University of Padova, Italy

³) Affiliated with the Astrophysics Division, Space Science Department of the European Space Agency