Look, up in the sky!

By: Lucas Bolyard, Luis Garcia, and Zach Ewen.

Prep Fold PlotsLooking at Pointings in the sky

Up until this point in time, Team Disney has gone through both data sets, viewed pointings in the sky with the GBT, and were left with the task of presenting and evaluating data.

We had our scheduled GBT time 19:55 – 20:40 LST, and we did our observations. We took a few minutes of data on some suspected pulsars, and in the end, we won the privilege to choose the next area of a drift scan survey, and chose 7 degrees north. And after we ran the scan, we received data to analyse. We went though multiple prep fold plots and single pulse profiles.

Potential Candidates

Here are the most promising plots that we found.

How to evaluate data

Tips for finding a pulsar. (prep fold plot and single pulse profile)

Look first at the pulse profile (prep fold plots only), and look to see if there are distinguished peaks and no crazy RFI.

In a single pulse profile, look first at the DM versus Time graph, then look for the strength of the dots at a single DM.

After looking at the pulse profile (prep fold plot only), check the Time Domain for dark vertical lines that correspond with the pulse profile. Afterwards, look at the Chi squared to make sure it is “roughly diagonal.”-Duncan Lorimer Then after completing this, check the sub-band plot, and make sure it corresponds with the Time Domain.

Following the examination of the DM versus Time graph, check the Signal-to-Noise graph and also check the Number of Pulses to DM. Make sure on all three graphs have a same DM.

Lastly when evaluating prep fold plots, look at the DM graph; make sure it peaks and is not at zero, for if the DM were to be at zero, then you will have detected RFI.

Conclusion

Through this program, we learned how to look for potential pulsar candidates through GBT drift scan data. We analysed data from a drift scan conducted early Wednesday morning. We searched through many prep fold plots and some single pulse profiles. We made a step by step procedure to evaluate and analyse GBT pointings individually. Now, we are able to apply our knowledge of prep fold plots and single pulse profiles to search the data base in hopes of discovering new pulsars.

AcknowledgementsWe want to thank the PSC, Greenbank and all it’s staff, the teachers for helping, and our fellow peers. Also, we would like to thank the ATNF and www.mpifr-bonn.mpg.de for having all of the data we needed in one useful place!

Prep fold plot showing RFI.

Here to the left we have pictured a perfect single pulse profile.

(J0034-0721).

And pictured here we have some more crazy RFI.

Prep fold plot showing a pulsar and look at the pulse profile, Time Domain, Chi squared, sub-band plot, and the DM graph.

This pulse was recorded at a frequency of 350 MHz and clearly shows a pulse at a DM of 250. Since the DM is reasonable, we have strong reason to believe this might in fact be a pulsar.

This pulsar showed very interesting qualities, a very strong pulse at a DM of 15. This lead to more observations, and has been confirmed as a pulsar, but it has yet to be published.

In this plot, we see a potential pulsar. Although there is some noise in the profile and the time domain, vertical dark lines are still visible. The sub-band also corresponds and the DM is not zero, a strong indicator of a possible pulsar.

This profile shows how every pulsar is unique. These strong triple peaks are the equivalent of a finger print. The time domain is clear, as well as the sub-band, and the DM is at a peak of 40.

These peaks are very strong, the lines in the time domain are very well defined and line up right under the profile. The sub-band is strong throughout the range of frequency and the DM is not zero.