Anthony C. S. Readhead

  • Citations Per Year
Learn More
In this paper we discuss the design of low-noise amplifiers (LNAs) for both cryogenic and room-temperature operation in general and take the stability and linearity of the amplifiers into special consideration. Oscillations that can occur within a multi-finger transistor are studied and verified with simulations and measurements. To overcome the stability(More)
We present a determination of the Hubble constant, H0, from measurements of the Sunyaev-Zeldovich effect in an orientation-unbiased sample of seven galaxy clusters. With improved X-ray models and a more z ! 0.1 accurate 32 GHz calibration, we obtain km s 1 Mpc 1 for a standard cold dark matter (CDM) 14 H p 64 14 0 11 sys cosmology, or km s 1 Mpc 1 for a(More)
We have developed a new Bayesian Markov Chain Monte Carlo method to deconvolve light curves of blazars into individual flares, including proper estimation of the fit errors. We use the method to fit 15 GHz light curves obtained within the OVRO 40-m blazar monitoring program where a large number of AGN have been monitored since 2008 in support of the Fermi(More)
We present coincident observations of the cosmic microwave background (CMB) from the Very Small Array (VSA) and Cosmic Background Imager (CBI) telescopes. The consistency of the full data sets is tested in the map plane and the Fourier plane, prior to the usual compression of CMB data into flat bandpowers. Of the three mosaics observed by each group, two(More)
We describe a uniform all-sky survey of bright blazars, selected primarily by their flat radio spectra, that is designed to provide a large catalog of likely γray AGN. The defined sample has 1625 targets with radio and X-ray properties similar to those of the EGRET blazars, spread uniformly across the |b| > 10 sky. We also report progress toward optical(More)
We report on HET and Palomar 5 m spectroscopy of recently identified γ-ray blazars in the Fermi LAT Bright Source List. These data provide identifications for 10 newly discovered γ-ray flat spectrum radio quasars (FSRQ) and six new BL Lacs plus improved spectroscopy for six additional BL Lacs. We substantially improve the identification completeness of the(More)
We describe a 4.85 GHz survey of bright, flat-spectrum radio sources conducted with the Effelsberg 100 m telescope in an attempt to improve the completeness of existing surveys, such as CRATES. We report the results of these observations and of follow-up 8.4 GHz observations with the VLA of a subset of the sample. We comment on the connection to the WMAP(More)