A1644 and A1795 GBT Observation

I have completed observation on A1644 and completed two out of three observation sessions on A1795.

Observation on A1664 is completely useless due to strong RFI signal from a not so nearby Air Surveillance Radar, the Bedford radar.

Bedford radar operates at 1255, 1260,1302 and 1307 MHz, which coincide with HI line of A1664 which is redshifted to 1259MHz.

The figure below shows the typical spectra extracted using GBT

For A1795, There are several RFI within out region of interest, the two RFI at 680km/s and 1150km/s are rather strong.

After subtracting the baseline, results are:

first session: 56 mins on source

second session: 74 mins on source

We have the third session on 27 May 11am HKT. (1 hour long)

Before subtracting baseline: