Tsys during psr xb obs (vela & B0329+54)



    On 17dec21 the pulsars B0329+54 and B0833-45 (vela) were observed with the 12meter using the xband receiver. These are the two strongest known pulsars (vela 1000 mJy, B0329+54 200mJ at lband). Ben detected Vela but did not detect B0329+54 (although detection was expected). I looked at the Tsys during the observation to see it there was a reason for this.


Standard pulsar processing.

Ben processed both pulsars using the standard psr reduction routines. He detected vela but did not detect B0329+54.
Ben's notes:

I looked at the Vela and B0329 data that you collected on Dec 17.

I first processed Vela data and the pulsar can be clearly seen. I have attached a couple of slides and the first slide shows some plots of Vela. I first combined the fits files and then processed using the pulsar ephemeris. Note that S/N given in the plot is underestimated. I estimated using the pulse profile and it turns out to be S/N~18.

Then I processed B0329 data, but unfortunately the pulsar cannot be seen. I have the same set of plots on the second slide in the attached pdf. I processed the two sequences separately as the sequence 00101 has a lot of stuff after ~16 min (see the bottom-middle plot). 

I calculated the expected S/N using the measured flux densities of the pulsar at low frequencies (fluxes at Lband and 5 GHz are 203 and 10 mJy, respectively) and a spectral index of -2 along with the 12 m specs (gain~0.029 K/Jy, Tsys~125 K, BW~1000 MHz). This showed the expected S/N to be ~16 for 1 hr of integration. 

I am not entirely sure why it is not detected. Could this be due to an pointing issue (but again Vela was detected)?
The pulsar could be weak at 8.6 GHz, but I feel that it should be detected!

Ben's plots (.pdf)

Looking at the total  power vs time

    I went back and looked at the total power vs time for the pulsar data. Was there a reason why B0329+54 was not detected?


    For each pulsar:

The plots show the results of the processing.

Average bandpasses of the data (.ps) (.pdf)

Plotting the total power vs time (.ps) (.pdf)


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