Ian Browne

Professor of Radio Astronomy in the School of Physics and Astronomy of the University of Manchester at Jodrell Bank, Founder member of the CLASS gravitational lens survey.

Designing and getting built a telescope system capable of detecting
baryon acoustic oscillations (BAO) in the distribution of redshifted
neutral hydrogen emission is my current research priority. The project
is called BINGO (Bao from Integrated Neutral Gas Observations). The
plan is to build a fixed offset parabolic telescope equipped with
multiple correlation receivers which will map, with 0.3 degree angular
resolution and 1 MHz frequency resolution, a 10 degree strip of sky at
a frequency centred around 1.05 GHz.

I also have a strong interest in the physics of active galaxies with
particular emphasis on low luminosity radio-loud objects including BL
Lacs. We are currently studying a redshift-limited radio sources
selected by the strength of their compact nuclei. This SENSE sample
(Survey of Extragalactic Nuclear Spectral Energies) contains all
compact nuclei with 5 GHz flux densities greater than 90 mJy and with
redshifts lass than 0.2 in the SDSS DR6 imaging region. Exploiting
data from the Fermi gamma-ray satellite we have also been studying the
"Compton efficiencies" of blazars trying to see if the availability of
external photons from the presence of an optically active affects the
overall energetics of gamma-ray production.

A long-term project is OCRA --the One Centimeter Receiver Array. The
scientific goal is to carry out surveys of the sky at a wavelength
seven times shorter than any previously done. Some of the aims are to
find new types of radio source, to make a blind search for clusters of
galaxies by virtue of the Sunyaev-Ze'ldovich (S-Z) decrement they
produce and to identify extragalactic radio sources which act as a
confusing foreground for cosmic microwave background mapping
experiments. OCRA would consist of an array of about 100 feeds and
receivers and would be installed on the 32m Torun Telescope in
Poland. The full OCRA 100-beam array is not yet funded but a 2-beam
prototype has been constructed with funds from the Royal Society and
testing on the 32m Telescope started in November 2002 and it is now
being used regularly for measuring flux densities. Research into using
MMICS for the low noise amplifiers in OCRA is part of the
project funded by the EU. Construction of an 8-beam 30GHz system is
complete and being commisioned.

Second-year lab tutor
Second-year demonstrating on Tuesdays
Prof I.W.A. Browne,
Jodrell Bank Centre for Astrophysics,
Alan Turing Building,
University of Manchester,
Oxford Road,
M13 9PL,