Search

Magnetized radio filaments are found in abundance in the inner few hundred pc of our Galaxy. Progress in understanding this population of filaments has been slow, in part due to a lack of detection elsewhere in the Galaxy or in external galaxies. Recent highly sensitive radio continuum observations of radio galaxies in galaxy clusters have revealed remarkable isolated filamentary structures in the ICM that are linked to radio jets, tails and lobes. The origin of this class of filaments is not understood either. Here, we argue that the underlying physical mechanisms responsible for the creation of the two populations are the same because of their similarity in morphology, spacing between the filaments, aspect ratio, magnetic energy densities to thermal pressure of the medium, and that both populations have undergone synchrotron aging. These similarities provide an opportunity to investigate the physical processes in the ISM and ICM for the first time. We consider that the origin of the filaments in both the GC and ICM is a result of the interaction of a large-scale wind with clouds, or the filaments arise through the stretching and collection of field lines by turbulence in weakly magnetized medium. We examine these ideas toward four radio galaxy filaments associated with four radio galaxies IC 40B, IC 4496, J1333-3141, ESO137-006 and argue that much can be understood in the future by comparing these two populations of filaments., Comment: 14 pages, 4 figures, ApJL (in press)

In October 2008, for the second time we demonstrated a monolithic Backshort Under Grid (BUG) 8×16 TES array in the field using our 2 mm wavelength imager GISMO (Goddard IRAM Superconducting 2 Millimeter Observer) at the IRAM 30 m telescope in Spain. We present astronomical results from this observing run together with a discussion of the instrument performance.

We present high resolution 11.7 and 18.3 um mid-IR images of SN 1987A obtained on day 6526 since the explosion with the Thermal-Region Camera and Spectrograph (T-ReCS) attached to the Gemini South 8m telescope. The images show that the emission arises from the equatorial ring (ER). Near contemporaneous spectraobtained on day 6184 with the MIPS, IRAC and IRS instruments on board the Spitzer Space Telescope show that the emission consists of thermal emission from silicate dust. The dust temperature is 166( 18,-12) K, and the emitting dust mass is 2.6( 2.0,-1.4) 10-6 Solar Mass. These data together with X-ray images obtained by Chandra, UV-Optical images obtained by HST, and radio synchrotron images obtained by the ATCA, suggest that the dust giving rise to the emission could be eithercollisionally heated by the X-ray emitting plasma, or it could be radiatively heated in the dense UV-optical knots that are overrun by the advancing supernova blast wave. In either case the dust-to-gas mass ratio in the circumstellar medium around the supernova is significantly lower than that in the general interstellar medium of the LMC, suggesting either a low condensation efficiency in the wind of the progenitor star, or the efficient destruction of the dust by the SN blast wave. Overall, we are witnessing the interaction of the SN blast wave with its surrounding medium, creating an environment that is rapidly evolving at all wavelengths. Continuous multi wavelengths observations of SN 1987A such as these provide unique snapshots of the very early evolution of supernova remnant, and shed some light on the role of supernovae in the dust production in the universe.