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Intro Over this week, we observed using three telescopes (the 40ft, the 20m, and the GBT). We also analyzed pointings for candidates which we observed using the GBT. We learned that there is a lot more noise and RFI out there than pulsars. We also learned that observing is time consuming and that most of the time you don't get anything. Astronomy requires perseverance. Mostly we learned how to analyze the plots correctly so that candidates can be found and to find out if the candidates are either known pulsars or unlikely to be pulsars because of their DM. Because of our work here, we now have a better understanding of pulsars, why they are important, and observing in the radio. Noise Sometimes plots tend to look like a mess. Such occurrences are due to the presence of noise during the recording process. Noise is an always present force when looking for radio waves. Some plots with noise may look like this; Observing Our team observed using Green Bank's 40ft teaching telescope, the 20m telescope, and the GBT. We observed the galaxy Virgo A and the galactic center using the forty foot, having to observe twice to get the data we wanted for the latter. With the data we received, we found the brightness of both objects in Janskies and how large they are. We observed the same objects using the 20m through Skynet. This observation was less useful as it is still unclear as to how the graphs are supposed to be interpreted. Later in the week, we went through groups of pointings to find potential pulsars. Once we had our candidates, we were given time on the GBT from 5 am to 7 am. During this time, we operated the telescope with the assistance of graduate students Joe and Fernando. We also learned how to fold the data so it could be more easily interpreted. When our data was finally put into the final plot, we discovered that we had observed noise and one known pulsar. Micah Dingus, Tildon Johnson, Christian Lewis, Emily Schulman Broadway High School, Rowan County Senior High, Sherando High School, T.C. Williams High School Known Pulsars Although finding these may be discouraging, it is important we do. It helps us understand everything we can about the pulsar that was found. If a plot looks good and the DM checks out you get excited, but then if you run the R.A. and Dec through the ATNF catalogue, you may find that the pulsar has already been discovered. We found several this week. Conclusion Even though a new pulsar was not found, the team had an excellent time learning more about Radio Astronomy. We observed on three different telescopes and learned about the different ways of observing (remotely, with old technology, and with new technology). While all we found at the GBT was noise and a known pulsar, it was not wasted time. As Jocelyn Bell stated: It’s important to know where there are not things, as well as where there are. Acknowledgments http://www.astro.virginia.edu/~rsl4v/PSC/ http://pulsarsearchcollaboratory.com/ http://www.atnf.csiro.au/people/pulsar/psrcat/ http://www.space.com/14034-gallery-amazing-orion-nebula- photos.html And a special thanks to everyone that made this week all that it could be and a life long memory. RFI Many times while hunting for pulsars we come across a plot that is contaminated with RFI. This is radio signal that the telescope picks up from everyday sources. This pulsar was so bright that it dominated an entire pointing where 30 plots were of this pulsar. RFI can look similar to a pulsar but if you really pay attention you notice definite differences in the plots. In this plot the Pulse Profile and Time Domain are perfect, but the Sub-Band shows a narrow banned frequency, and the DM has no definite peak. Noise usually makes up a good percentage of the plots in a dataset. Noise could be from the equipment for the telescope, remnants from the Big Bang, or from the radio emissions of other objects in space. RFI and Pulsar emissions can be identified apart from the noise because the noise will be significantly lower than the radio waves of the RFI or Pulsar. This plot was obtained of the PSC website examples This pulsar is named B0942-13, or J0944- 1354. It has a spin down rate of 4.5256E-17 (s/s). We found this by running the R.A. and Dec through the ATNF Catalogue. This plot is from a follow up at the GBT for a candidate, we hoped that a pulsar would be found though all that was, was a conglomeration of noise. ---------------------------------------------------------------------------------------
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