Gravitational lensing and galaxy evolution with e-MERLIN

Principle Investigators:
Neal Jackson (JBCA, University of Manchester, UK) and Stephen Serjeant (The Open University, UK)

Time Allocation: 228 hours*

Co-Investigators include:-
David Bacon (University of Portsmouth, UK), Andrew Biggs (ESO), Andrew Blain (Caltech, USA), Mark Birkinshaw (Bristol, UK), Ian Browne (Manchester, UK), Nieves Castro-Rodriguez, (IAC Tenerife, Spain), Scott Chapman (Cambridge, UK), David Clements (Imperial, UK) Kristen Coppin (Durham, UK), Simon Dye (Cardiff, UK), Steve Eales (Cardiff, UK), Ian Heywood (Oxford,UK), Rosalind Hopwood (OU, UK), David Hughes 9INAOE Mexico), John McKean (MPIfR Bonn, Germany), Angela Mortier (ROE, UK), Mattia Negrello (OU, UK), Chris Pearson (RAL, UK), Ismael Perez-Fournon (IAC, Spain), Steve Rawlings (Oxford, UK), Douglas Scott (U. British Columbia, Canada), Mark Thompson (U. Hertfordshire, UK), Mattia Vaccari (Padua, Italy), Ludovic van Waerbeke (U. British Columbia, Canada), Steve Warren (Imperial, UK), Glenn White (OU/RAL, UK) Olaf Wucknitz (Argelander-Institut, Bonn, Germany), Ming Zhang (Manchester, UK), Gianfranco de Zotti (Padua, Italy)


The UK gravitational lensing community have agreed a co-ordinated strategy for the next generation radio facility, e-MERLIN, which will make ground-breaking progress in strong (multiple-image) lensing research. Our proposed Legacy Survey is two-pronged: a high-z lens discovery programme, using the approved Herschel ATLAS Key Programme and SCUBA-2 SASSy surveys, and a deep mapping programme of known lenses. The heavily magnification-biased submm surveys will have ~50- 100% lens selection efficiency out to z=~5, generating the largest and most distant sample of lenses to date. The z_lens > 1 objects can be efficiently selected using K-band cross-identifications (e.g. with UKIDSS LAS). The project will play the role for e-MERLIN that the pioneering CLASS survey had for MERLIN. We will map the brightest radio sources in the z_lens > 1 catalogue, identified in FIRST. The lens sample will allow evolution of galaxy mass profiles to be studied out to unprecedented redshifts. Using well-proven techniques, we will separate the dark halo and baryonic component of each lens galaxy to directly observe the build-up of stellar mass and its interplay with dark matter over this period.

Deep mapping of existing radio lenses, together with selected sources from the Herschel and SASSy surveys, will allow discovery of many central images. These are crucial for investigating mass distributions in the central regions of galaxies over a wide range of redshift, and hence probing changes in the central mass as a result of changing black hole mass and baryon distribution over a significant fraction of cosmic time. e-MERLIN gives the required factor of 10 extra sensitivity needed to do this. Mapping the extended radio emission in the images will also provide us with the ability to make detailed investigations of CDM substructure in lenses at a frequency where microlensing is not a serious problem.

Full proposals (pdf)

*Additional time may be allocated subject to interim reviews throughout the course of this project.