Hunting for radio-loud gravitational lenses

© Minju Lee, John McKean, Adam Deller, Javier Molden

A new pilot project called "'Hunting for radio-loud gravitational lenses' was the one of the summer student projects this year, and as you would expect from the title, is aimed at finding new radio-loud gravitational lens systems. There are only ~35 radio-loud lens systems known so far, and we hoped to find a few more.

By using data from mJIVE-20, the largest VLBA snapshot survey at 1.4 GHz that is still ongoing, we (Summer student : Minju Lee/ Supervisors : John McKean, Adam Deller, Javier Molden) were able to blindly rediscover 2 already known lens systems, and found 12 new candidate systems out of 17700 sources targeted by mJIVE-20. The candidates are to be followed up with multifrequency observations at 4.1 and 7.1 GHz, as well as with deeper 1.4 GHz observations, to compare the spectral indices and to see if there are other fainter counter images around the detected images.

The image shows one of the deeper observations of MJV06997 at 1.4 GHz, which is one of our strongest candidates, but is not yet confirmed. During the summer student project, we had a VLBA DDT proposal approved to carryout multifrequency observations at 4.1 and 7.1 GHz for this target and two others, we are now waiting for them to be observed. We think we are quite close to finding a new lens system, and expect find our new daily image of this one in the near future!