Research

The main focus is in the area of galaxy formation and evolution at the highest redshifts possible, especially in the Epoch of Reionization, focusing on the discovery of new high redshift galaxies and quasars that host supermassive black holes, determination of their space densities, star formation rates and how and when they form.

This research also includes developing experimental survey techniques for discovering new high redshift galaxies and quasars; determining how their space density and properties evolve with cosmic time as the Universe evolves; using the quasars to probe the baryonic content of the Universe. 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 Principal Investigator (PI) of the ambitious VISTA Hemisphere Survey(VHS) which is a new near Infra-Red sky survey project which started in April, 2010.  The has been been awarded 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 is building a very large CCD camera (DECAM) and has been awarded 500 nights on US CTIO 4m telescope in Chile to use this camera  to observe in the optical the VHS region of the sky.

The exploitation of the extremely large datasets from these new surveys requires the use and development of robust data-mining techniques for distributed databases; machine-learning techniques such as decision trees, supervised learning and multi-dimensional data visualisation techniques.

• Dawn after the dark age; Nature News and Views)
• Microsoft Technology, Researchers to Harness Galaxies of Data

Selected papers

Google Scholar page

• The discovery of the first luminous z ~ 6 quasar in the UKIDSS Large Area Survey; Venemans, B., McMahon R.G. et al, 2007, MNRAS, 376L, 76; 
• DAzLE: the dark ages z (redshift) Lyman-α Explorer; Horton et al., 2004, SPIE,5492, 1022.
• The evolution of Ω_HI and the epoch of formation of damped Lyman α absorbers, Peroux, C. McMahon R.G. et al, 2003, MNRAS, 346L, 1103.
• Lyman break galaxies and the star formation rate of the Universe at z~ 6; Stanway, Elizabeth R.; Bunker, Andrew J.; McMahon, Richard G., 2003, MNRAS, 342, 439: 
• The far-infrared-submillimetre spectral energy distribution of high-redshift quasars, Priddey, R. and McMahon, R.G., 2001, MNRAS, 324P, 17.
• Optical Counterparts for 70,000 Radio Sources: APM Identifications for the FIRST Radio Survey; McMahon, Richard G.; White, Richard L.; Helfand, David J.; Becker, Robert H., 2002, ApJS, 143, 1.
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae, Perlmutter S. et al, 1999, ApJ, 517, 565.
• Discovery of radio-loud quasars with z = 4.72 and z = 4.01; Hook, Isobel M.; McMahon, Richard G., 1998, MNRAS, 294, 7.
• Detection of Lyman-α emitting galaxies at redshift z = 4.55; Hu, Esther; McMahon Richard G., 1996, Nature, 382, 231.
• APM z >=4 QSO Survey: Spectra and Intervening Absorption Systems; Storrie-Lombardi, L. J.; McMahon, R. G.; Irwin, M. J.; Hazard, C., 1996, ApJ, 468, 121.
• 1.25-mm continuum observations of very high-redshift QSOs: Is there dust at z = 4.69?, McMahon, R.G. et al, 1994, MNRAS, 267L, 9.

Career

Qualifications

• PhD (Cantab), Institute of Astronomy, University of Cambridge; Supervisor: Cyril Hazard
• Postgraduate Certification in Secondary Education (Physics), University of Cambridge
• BSc (Hons) Physics, Queens University Belfast 

Awards and Prizes

• Gruber Prize 2007