As i mentioned in a previous post, student projects as part of POS was to observe a pulsar & a calibrator using the ORT and infer properties of the pulsar such as period of the pulsar, flux density and dispersion measure (and therefore distance to the pulsar). We were given a list of pulsars (refer to the post aforementioned) & corresponding calibrators and asked to choose one pair.
To be noted here that a calibrator for a pulsar cannot be more than +/- 5 degrees away from the pulsar as the atmospheric response is different at different angles. And we need the pulsar & the calibrator to have the same atmospheric response (DUH!).
Choosing a pulsar was the first problem. I looked up properties (period, profile width and strength) of each of the pulsars from ATNF and NED and chose a pulsar which i felt was interesting (slide 3). ORT observes at 326.5 MHz and the next step was to estimate the strength of the pulsar at the ORT observing frequency (slide 8).
This is needed before observations start as the telescope response can be set according to the strength of the source.
Having observed the pulsar, SIGPROC was used to reduce and analyze the time series data. I am not going to delve into the process now. Before i end, there is one more interesting thing we found during data analysis.
Slides 24 & 25 might not make much sense but note slides 26 & 27.
The x-axis is the frequency of observation and the y-axis is flux (in random units). It is obvious from here that the telescope itself has a frequency dependent response function. Not to brag but i discovered this on my own and the faculty admitted to their being such a problem (for quite a while) and that it was being corrected.