Title: Commissioning of FLAG: A phased array feed for the GBT,
Abstract: Phased Array Feed (PAF) technology is the next major advancement in radio
astronomy in terms of combining high sensitivity and large field of view. The
Focal L-band Array for the Green Bank Telescope (FLAG) is one of the most
sensitive PAFs developed so far. It consists of 19 dual-polarization elements
mounted on a prime focus dewar resulting in seven beams on the sky. Its
unprecedented system temperature of$\sim$17 K will lead to a 3 fold increase in
pulsar survey speeds as compared to contemporary single pixel feeds. Early
science observations were conducted in a recently concluded commissioning phase
of the FLAG where we clearly demonstrated its science capabilities. We observed
a selection of normal and millisecond pulsars and detected giant pulses from
PSR B1937+21.