We discuss constraints that the observed brightness temperatures impose on coherent processes in pulsars and Fast Radio Bursts (FRBs), particular hypothesis of curvature emission by bunches. estimate peak temperature a bunch charge $Ze$ can produce via synchrotron and/or as $k_B T \sim (Z e)^2/\lambda$, where $\lambda$ is typical emitted wavelength. demonstrate bunch's electrostatic energy requ...

The peculiar velocity of the intergalactic gas responsible for the cosmic 21-cm background from the epoch of reionization and beyond introduces an anisotropy in the three-dimensional power spectrum of brightness temperature fluctuations. Measurement of this anisotropy by future 21-cm surveys is a promising tool for separating cosmology from 21-cm astrophysics. However, previous attempts to mode...

We present results from 86 GHz VLBI1 observations of 28 compact radio sources made in April 1993. All but two of the observed objects are active galactic nuclei. The remaining two objects are the galactic center Sgr A∗ and the X-ray binary star Cygnus X-3. Of the observed sources, 26 have yielded fringe detections. We present correlated flux densities, estimate the maximum observed brightness t...

To better constrain models of cool core galaxy cluster formation, we have used X-ray observations taken from the Chandra and ROSAT archives to examine the properties of cool core and non-cool core clusters, especially beyond the cluster cores. Using an optimized reduction process, we produced X-ray images, surface brightness profiles, and hardness ratio maps of 30 nearby rich Abell clusters (17...