Quasar shines through phone calls

SKCorrelator

An important aspect of Molonglo’s operations in the last decade is the increasing use of mobile phones.

The image above shows a phone call (nearly vertically slanted lines the lower right hand panels) occurring in our operating band.

Phone calls can be recognised as they distort the signal in the telescope receivers — and can be removed by a measuring in real time whether even quite weak distortion is present. This challenge has been met at UTMOST, where we are taking data at a very high rate — 22 GB/sec in the final design. Our GPU processors (otherwise known as games console graphics cards) have sufficient power to process the astronomical data but also monitor live for the presence of phone calls — which can then be masked out or excised from the data.

After taking out phone call activity, a quasar can be easily seen despite the fact it is far fainter than the phone call (seen as the spike in the right hand panels in the top figure).

Well done to Andrew Jameson at UTMOST for this significant achievement.