We present wide-field near-infrared images of the DR21/W75 high-mass star forming region, obtained with the Wide Field Camera, WFCAM, on the United Kingdom Infrared Telescope. Broad-band JHK and narrow-band H 2 1-0S(1) images are compared to archival mid-IR images from the Spitzer Space Telescope, and 850µm dust-continuum maps obtained with the Submillimeter Common User Bolometer Array (SCUBA)....

We calculate the time evolution of the flux, apparent size, and image centroid motion of gamma-ray burst (GRB) radio jets and show that they can be resolved by the Very Long Baseline Array (VLBA) at distances of hundreds of megaparsecs. We find that GRB 030329, which showed spectroscopic evidence for an associated Type Ic supernova (SN) at a distance of ≈800 Mpc, might just be resolvable by VLB...

Using CARMA, we imaged the 87 GHz SiO v=0 J=2-1 line toward Orion-KL with 0.45 angular resolution. The maps indicate that radio source I drives a bipolar outflow into the surrounding molecular cloud along a NE–SW axis, in agreement with the model of Greenhill et al. (2004). The extended high velocity outflow from Orion-KL appears to be a continuation of this compact outflow. High velocity gas e...

We present 2.5-dimensional time-dependent simulations of nonrelativistic and nonradiative outflows from sinusoidally perturbed Keplerian accretion disks. A sinusoidal perturbation is introduced in the velocity of the gas ejected from the surface of the disk into a cold corona. In the simulations, the disk is a fixed boundary from which the gas is ejected with a pulsed velocity. The maximum valu...

We calculate the time evolution of the flux, apparent size, and image centroid motion of gamma-ray burst (GRB) jets in the radio, and show that they can be resolved by the VLBA at distances of hundreds of Mpc. We find that GRB 030329 which showed spectroscopic evidence for an associated supernova (SN) Type Ib/c at a distance of ≈ 800 Mpc might just be resolvable by VLBA after several months. Th...

We present simulations of the propagation of magnetized jets. This work differs from previous studies in that the cross-sectional distributions of the jets’s state variables are derived from analytical models for magneto-centrifugal launching. The source is a magnetized rotator whose properties are specfied as boundary conditions. The jets in these simulations are considerably more complex than...

We have made continuum and spectral line observations of several outflow sources in the Mon OB1 dark cloud (NGC 2264) using the Heinrich Hertz Telescope (HHT) and ARO 12m millimeter-wave telescope. This study explores the kinematics and outflow energetics of the young stellar systems observed and assesses the impact star formation is having on the surrounding cloud environment. Our data set inc...

We have investigated steady, radial gas outflows (or winds) from galaxies and the development of thermal instability in the hot gas. In order to see the maximum influence of the instability on the global structure of the galactic outflows, we study inhomogeneous comoving flows and the non-linear fate of the fluctuations in the flows. We compare the results with solutions for homogeneous flows. ...

We present a 5–37 μm infrared spectrum obtained with the Spitzer Space Telescope toward the southeastern lobe of the young protostellar outflow HH211. The spectrum shows an extraordinary sequence of OH emission lines arising in highly excited rotational levels up to an energy E/ k ≈ 28200K above the ground level. This is, to our knowledge, by far the highest rotational excitation of OH observed...

Received ; accepted – 2 – ABSTRACT We report high resolution (2.5 ′′) CO J=1−0 line imaging which confirms the presence of a molecular disk around the origin of the spectacular, 14 ′ × 4 ′ , episodic jets in the planetary nebula KjPn 8. The disk is 30 ′′ in diameter with an expansion velocity of ≈ 7 km s −1. The axis of the disk is aligned with the youngest and fastest (≈ 300 km s −1) of the bi...