Active Galactic Nuclei and Quasars
The study of Active Galactic Nuclei (AGN), and their powerful cousins, the Quasars, is what has dominated most of my scientific life. Right now, my main focus is on Extreme Variability in AGN, and the clues this gives to how AGN work. I have also worked extensively on AGN obscuration, and the Spectral Energy Distributions of AGN. You can read a little more on the AGN page.
This began as an outreach activity (see the Losing The Sky pages), trying to raise awareness about the increasing problems caused for astronomy by satellite megaconstellations. Increasingly however, I am seeing this as scientific/technical/policy work. I would like to understand how we can, for example, simplify our calculation of collision risks, quantify orbital carrying capacity, and produce useful sustainability ratings for space missions.
I have been involved in many Sky Survey projects, including X-rays with Ariel V, redshift surveys of IRAS galaxies, the UKIDSS infrared survey, VISTA, and submm galaxies with SCUBA. On arrival in Edinburgh, I formed the Wide Field Astronomy Unit, which curates and makes available a variety of databases – for example, the WFCAM Science Archive.
Right now I am working as part of the LSST:UK consortium. This links up to my AGN work, as I am part of the team building the Lasair event broker. At the moment, Lasair processes the ZTF alert stream, but it will evolve into an Rubin Observatory / LSST event broker.
I was part of the QDOT Redshift Survey team, working with IRAS galaxies to measure the Large Scale Structure of the Local Universe. I also worked on Ultraluminous IR galaxies (ULIRGs), discovering what was for a while the most luminous object in the Universe (IRAS F10214+4734) which then led me into collaborating on the study of submm galaxies, and the star formation history of the Universe.
The Virtual Observatory
When you surf the web, and click from link to link all over the world, it just feels as if all those documents are right there in your PC. The aim of the VO is to get the same transparent feel for astronomical data. This is easier said than done, and involves not just technical work, but also much international negotiation on standards, which takes place through an organisation I co-founded, the International Virtual Observatory Alliance. Since 2001, I have been involved in a sequence of VO projects, starting with the UK AstroGrid project, and most recently with the large multi-disciplinary data infrastructure Euro-project, ESCAPE.
Dim and Distant Past
For anybody interested, back about 2014, I wrote slightly longer accounts of the work I have done in the past. These live on my old ROE-hosted site. There is a page on Active Galaxies; one on Survey Astronomy; another on Observational Cosmology; and one on The Virtual Observatory.