Telescope back in action!
After over a month of downtime due a problem with one of the wheel girders, the Lovell telescope was finally cleared for elevation movement again yesterday afternoon. The telescope has two semi-circular girders which run under the bowl, down to the main diametrical girder underneath. A while ago one of the girders developed a crack which needed some serious work to fix so, for the last few weeks, the telescope has been parked pointing roughtly northwards while engineers from a company who normally repair bridges took out and replaced the damaged section. This is not as daft as it might sound, the telescope was originally designed by an engineer who's speciality was bridges after all. All is well now and the telescope is back in action again.
Today's "crazy paper title of the day" on astro-ph is The Extragalactic Lens VLBI Imaging Survey. I. A Search for the Central Image in the Gravitational Lens PMN J1838-3427 by Edward Boyce (MIT) and colleagues. ELVIS, get it? Seriously, gravitational lensing is pretty cool, and something I find quite interesting having spent some time working on them while I was an undergraduate. One of the things you can do with lens systems (where a nearby galaxy "lenses" the light from a distant quasar by causing the light path to distort as it passes through the gravitational field of the galaxy) is investigate the mass profile of the lensing galaxy, how much mass is contained within a certain radius and how this varies as you move out from the centre, by searching for a central image. The theory of lensing says that you should get an odd number of images of the quasar, with the odd one being nearest to the line of sight through the galaxy. Usually, this central image is demagnified so much that it is undetectable. The detection of this central image can help with modelling the mass profile of the galaxy, but even a non-detection can rule out some models, as in this case.
Meantime, I've been busy with more data analysis than you can shake a stick at. Oh, and playing with my new toy. I aquired a second-hand electric guitar at the weekend a Korean-made telecaster copy. It's pretty old and rather ropey (basically, it's a plank of plywood) but it was going down to the charity shop anyway, and it does work. The sound isn't great and it needs tuning even more often than my old classical, but hey - it works!