Prof Richard McMahon
The main focus of my current research is in the study of galaxy formation and evolution in the Epoch of Reionization ; focusing on the discovery and characterisation of high redshift primeval active galaxies and quasars powered by the accretion of matter onto supermassive black holes. My research work includes the discovery of quasars and active galaxies that host supermassive black holes, the determination of the space densities, star formation rates and how and when massive galaxies and quasars form.
This research is centered around the building and use of large scale data intensive techniques using optical and infra-red imaging and spectroscopic sensors on telescopes around the world (primarily in Chile) and in space using Gigapixel cameras and Petsacale multiwavelength datasets.
I worked on the experimental determination of the total mass of the Universe and the measurement of the rate of gravitational deceleration of the Universe. This work via the discovery of distant Supernova resulted in the unexpected discovery that the expansion of the Universe is accelerating. I am a member of the team that discovered the accelerating expansion of the Universe through observations of distant supernovae. The team leader Saul Perlmutter was awarded the 2011 Nobel Prize in Physics for this discovery.
I am interesting in the use of quasar light curve time delay measurements for gravitationally lensed quasars and the detection of Baryon Acoustic Oscillations in quasar absorption lines caused by Hydrogen in order to determine whether the acceleration requires a new form Dark Energy or modifications to General Relativity on large (Giga light year) scales.
My current research focuses on the discovery and study of high redshift galaxies and quasars that contain supermassive (100-1000 million Solar mass) black holes; determining how their space density, star formation and accretion properties evolve with redshift; and using the quasars to probe the baryonic content of the Universe via intervening absorption lines from H, C, N, O. My group has pioneered the use of high redshift quasars to determine the mass of neutral hydrogen in the high redshift Universe via intervening absorption lines imprinted on the spectra of background high redshift quasars. I have also pioneered the use of mm and submm microwave radiation to determine the star formation rate in quasar host galaxies.
I am the Principal Investigator (PI) of the VISTA Hemisphere Survey(VHS) which is an ambitious new near Infra-Red sky survey project which started in April, 2010. VHS has been been awarded around 300 clear nights over a 5 year period on the new 4.2m ESO VISTA telescope in Chile. I lead the quasar science working group in the Dark Energy Survey (DES) project which has built the largest CCD camera in existence and has been awarded 500 nights on the CTIO 4m telescope in Chile to use this camera to observe at optical wavelengths part of the sky that will be surveyed in the near Infra-Red with the VISTA Hemisphere Survey. I am also working on the 4MOST project which is designing a wide field spectroscopic instrument for the VISTA telescope. Other projects that I am involved in, are the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) project and the ESA satellite mission EUCLID
The exploitation of the extremely large datasets from these new surveys requires the use and development of scalable 'Big Data' data-mining techniques that are robust to the effects of 'bad data'; distributed databases; machine-learning techniques such as decision trees, supervised learning and multi-dimensional data visualisation techniques.
Prizes and awards
Current Departmental and University responsibilities
IOA Instrumentation Group Homepage | CIRSI(Sackler) Camera Homepage
Published by Richard G. McMahon <email@example.com>
Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 OHA
FAX: +44-(0)-1223-337523 Last modified: Wed Aug 2 17:25:46 BST 2017