Imperial College London


Faculty of Natural SciencesDepartment of Physics

Professor of Astrophysics



+44 (0)20 7594 7554s.j.warren




1115Blackett LaboratorySouth Kensington Campus





Research Interests: I am an observational astronomer. I am primarily interested in discovering what is out there, and so I am interested in surveys, particularly for high-redshift quasars, and cool brown dwarfs. I am also interested in (strong) gravitational lensing, and quasar absorption lines.

Brief bio: I have been at Imperial since 1994. My first degree was in Engineering and I worked as a Civil Engineer for 6 yrs, specialising in Geotechnics. I did my PhD at the Institute of Astronomy, Cambridge, supervised by Paul Hewett, finishing in 1988, and then held a number of post-doc positions before moving to Imperial: a NATO Fellowship at Steward Observatory, Tucson, an ESO Fellowship at ESO Headquarters, Munich, and a Royal Society University Research Fellowship at Oxford. I was the Survey Scientist for the UKIRT Infrared Deep Sky Survey which finished in 2012. I was Head of Astrophysics at Imperial from 2010 to 2015.

Astronomers like the Astrophysics Data System, so I have provided a link to my publications on ADS.



Barnett R, Warren SJ, Becker GD, et al., 2017, Observations of the Lyman series forest towards the redshift 7.1 quasar ULAS J1120+0641, Astronomy & Astrophysics, Vol:601, ISSN:1432-0746

Skrzypek N, Warren SJ, Faherty JK, 2016, Photometric brown-dwarf classification II. A homogeneous sample of 1361 L and T dwarfs brighter than J=17.5 with accurate spectral types, Astronomy & Astrophysics, Vol:589, ISSN:1432-0746

Barnett R, Warren SJ, Banerji M, et al., 2015, The spectral energy distribution of the redshift 7.1 quasar ULAS J1120+0641, Astronomy & Astrophysics, Vol:575, ISSN:1432-0746

Skrzypek N, Warren SJ, Faherty JK, et al., 2015, Photometric brown-dwarf classification I. A method to identify and accurately classify large samples of brown dwarfs without spectroscopy, Astronomy & Astrophysics, Vol:574, ISSN:1432-0746

Simpson C, Mortlock D, Warren S, et al., 2014, No excess of bright galaxies around the redshift 7.1 quasar ULAS J1120+0641, Monthly Notices of the Royal Astronomical Society, Vol:442, ISSN:0035-8711, Pages:3454-3461

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