2013 Capstone Strasburg Presentation

Abstract

The four students from Strasburg’s Radio Astronomy Pulsar Search Team who participated in collecting this poster’s data are Rebecca Andrews, Morgan Carter, Madison Doehler, and Benjamin Miller. Each member shares the same mission in joining the Pulsar Search Collaboratory: their interest and passion to contribute to furthering our scientific knowledge of outer space. These individuals assist scientists in locating new pulsars and cataloging RFI for further scientific use and understanding. Altogether, these four students went through a total of 1,225 plots in the Pulsar Search Collaboratory’s dataset this year and located 55 known pulsars. Three of the four students are working towards college credit, but all of them find that their love for science and eagerness to learn makes this a worthwhile experience with or without credit. Next year, all Strasburg students will be taking advantage of the opportunity to earn college credit. In conclusion, all of the members find it an honor and a pleasure to be able to assist in using real time data to further our collective understanding of space.

Rebecca Andrews, Morgan Carter, Madison Doehler, Benjamin Miller

Period & Period Derivative

Pulsars emit beams of energy in the form of radiation at their magnetic poles. These magnetic poles are not the same as the poles from which the star rotates. Because of this, the beam may seem to pulse as the star turns, the beam cycling between facing the earth and facing away. These periodic detections of the beam as the pulsar spins are defined as the period of a pulsar. The Period Derivative (P-dot) of a pulsar is the first derivative of the period of that pulsar and is measured in seconds per seconds (s/s). It represents the rate of change of the period; i.e., how much the period is speeding up or slowing down over time. In the case of pulsar period derivatives, the value is always slowing down because the spin rate of pulsars decreases as time passes. Pulsars can be categorized by whether the pulsar has a slow spin-down rate, indicating a weak magnetic field, or a fast spin-down rate, indicating a stronger magnetic field. The P-Pdot Diagram charts the period and period derivative of known pulsars and can be used to group and compare pulsars in similar areas.

Characteristic Age

The Characteristic Age of a Pulsar approximates the measure of a pulsar’s real age. The characteristic age, denoted by τ (tau), can be found using the formula:

  where P is the pulsar’s period, and P-dot (also denoted by ) is the period derivative.

This calculation is typically valid using the assumption that the pulsar’s initial spin period was much smaller than observed today and that there is no magnetic field decay present. For example: The Characteristic Age of the Crab Pulsar

(P = 0.033s. P-dot=10-12.4)

 The actual age of this pulsar is estimated to be ~950 years.

Madison Doehler

Noise (85.59%) RFI (14.14%)

Known Pulsar (.00003%)

Rebecca Andrews

Noise (81.76%) RFI (18.12%)

Known Pulsar (.11%)

Morgan Carter

Noise (79.86%) RFI (20.02%)

Known Pulsar (.11%)

Ben Miller

Noise (88.53%) RFI (11.46%)

Known Pulsar (.012%)

Group Data

Noise (83.67%) RFI (16.20%) Known Pulsar (.13%)

Data Analysis: (Distribution of Plots)

Data Analysis: (RFI)

RFI stands for Radio Frequency Interference. It comes from man-made sources that interfere with the telescope. One can tell if the data is RFI if it has the obvious “snake bites” or if the plot displays a narrowband frequency.

Harmonics are a certain type of RFI that looks just like a pulsar except that the DM will appear to climax at 0.

Data Analysis: (Noise)Noise is what the telescope picks up when there is no signal. It looks like white noise with no real patterns.

Data Analysis: (Known Pulsar)Known Pulsars are pulsars that have been previously discovered. These pulsars are being tracked and recorded in the ATNF catalog.

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DM (cm-3pc) of Known Pulsars

DM (cm^-3 pc)

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Estimated Distance (in Kpc) of Known Pulsars

Estimated Distance (in Kpc)

DM vs. Estimated Distance

Our Known Pulsars in the Galaxy

Pulsar Properties

The Big Four1. High density due to a strong gravitational field2. Strong magnetic field3. High space velocity4. Fast spin period

Other Properties:• Slow down over time• Can emit different types of light

• Regular light • X-rays• Optical light • Gamma rays

• Pulses do not always emit radio waves• Pulses are not always the same brightness

Our Team2013

The Strasburg Radio Astronomy Pulsar Search Team formed during the summer of 2011. The students meet every

Wednesday after school to analyze datasets from the PSC, as well as monthly to discuss club objectives.

Estim

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Known Pulsars

Known Pulsars

Rebecca Andrews Morgan Carter

Madison Doehler Benjamin Miller