Brexit’s Effect on Citizens, Human Rights & Immigration

This report records the roundtable on “Brexit’s Effect on Citizens, Human Rights and Immigration” organised by Dr Adrienne Yong on 11 June 2019 at City, University of London funded by the Higher Education Innovation Fund (HEIF) 2018/19. Speakers included: • Hannah Wilkins (House of Commons Library) • Blanca Grey (Home Office)1 • Paul Erdunast (Immigration Law Practitioner’s Association - ILPA) • Christopher Desira (Seraphus Solicitors) • Nicole Masri (Rights of Women) • Ollie Persey (Public Law Project) • Katarzyna Zagrodniczek (East European Resource Centre) • Mihai Calin Bica (Roma Support Group) • Dr Adrienne Yong (City, University of London) • Dr Michaela Benson (Goldsmiths, University of London) • Madeleine Sumption (Migration Observatory) • Sheona York (Kent Law Clinic) A host of unique legal questions were raised in the aftermath of the UK’s referendum result where the electorate voted in favour of leaving the EU on the 23 June 2016. Opinion has been split as to whether the UK and EU have indeed struck a fair deal for citizens, with arguments that citizens have been used as bargaining chips throughout the process to achieve a deal. As negotiations progressed towards the original mandated date of withdrawal, 29 March 2019, various schemes emerged to handle post-Brexit immigration of EU citizens in the UK and reciprocal arrangements for British citizens in the EU. This is now reflected in the EU Settlement Scheme, the Immigration and Social Security Co-ordination Bill, and the reciprocity agreed with EU Member States as to British citizens in the EU. These issues and more were discussed at the roundtable

Automating Searches for Gravitationally Lensed AGN in Wide-Field Surveys

Gravitational lensing is a rare phenomenon which requires the exact alignment between a distant source and a massive foreground galaxy. The light from the source is bent around the galaxy forming spectacular rings, arcs and multiple images which have captured the public imagination since their discovery in 1979. This thesis focuses on searches for lensed systems where the background source is an active galactic nucleus (AGN) - a galaxy powered by their central supermassive black hole (SMBH). Gravitational lensing of the most distant and luminous subclass of AGN, known as quasars, provide a unique way to study the universe. They have been used to constrain the Hubble constant (H0), probe the dark matter content of galaxies and uncover the proposed co-evolution between SMBHs and their hosts. Until recently, these studies have been hindered by low sample sizes. However, increased research into automated approaches such as machine learning, combined with a wealth of data from new wide-field surveys, will enable us to dramatically increase the lensed quasar population. In this thesis we develop a number of searches leveraging classic colour selection as well as supervised machine learning techniques. We target quadruply imaged and high-redshift lensed quasars using photometric data from DES, WISE and Pan-STARRS, together with Gaia astrometry. Candidates were confirmed with follow-up spectroscopy, resulting in the discovery of several new systems. A search for radio-loud AGN was conducted using newly released VLASS data and candidates were prepared for high spatial resolution radio confirmation. We discuss the serendipitous discovery of an exciting lensed radio-loud galaxy with extreme high ionisation UV line emission and damped Lyα absorption. We finally outline a deep learning approach to automate the visual inspection stage of our lens searches in preparation for the release of new surveys such as LSST and Euclid.STFC (CDT Data Intensive Science

A candidate optically quiescent quasar lacking narrow emission lines

Many active galactic nuclei (AGN) surveys rely on optical emission line signatures for robust source classification. There are, however, examples of luminous AGN candidates lacking such signatures, including those from the narrow-line region, which are expected to be less susceptible to classical nuclear (torus) obscuration. Here, we seek to formalize this subpopulation of AGN with a prototypical candidate, SDSS J075139.06+402810.9. This shows infrared (IR) colours typical for AGN, an optical spectrum dominated by an early type galaxy continuum, an [O III] λ5007Å limiting flux about two dex below Type 2 quasars at similar IR power, and a k-corrected 12 μm quasar-like luminosity of ∼ 1045 erg s−1. These characteristics are not consistent with jet and host galaxy dilution. A potential scenario to explain this AGN quiescence in the optical is a sky-covering ‘cocoon’ of obscuring material, such that the AGN ionizing radiation is unable to escape and excite gas on kpc scales. Alternatively, we may be witnessing the short phase between recent triggering of obscured AGN activity and the subsequent narrow-line excitation. This prototype could define the base properties of an emerging candidate AGN subtype – an intriguing transitional phase in AGN and galaxy evolution