PSR J1400 – 1410 . Jessica Pal Rowan County Senior High School. Introduction. Results. J1400-1410 Spin Down . January 13, 2012 - Discovery Plot
Rowan County Senior High School
J1400-1410 Spin Down
January 13, 2012 - Discovery Plot
On January 13, 2012 I along with four other members in the Pulsar Search Collaboratory (Emily Phan, Sydney Dydin, and Anne Agee) analyzed this plot and submitted it as a potential candidate for review. Below is the plot I submitted.
Millisecond pulsars spin very rapidly. They are typically very old, recycled pulsars that have been “spun up” by the accretion of matter from a companion star. These millisecond pulsars are not loosing energy quickly so the spin down rate is very small. The regularity of their spin rates make them very useful for scientific experimentation.
To determine if a pulsar is an old recycled pulsar or a young pulsar the rate at which the pulsars is spinning down must be calculated. This is the derivative of the period is referred to as Pdot.
A pulsar is a rapidly rotating neutron star.Neutron stars are the super-dense remains of massive stars that have fused all available fuel in its core and have undergone gravitational collapse as a supernova. Pulsars emit radio waves from their magnetic field poles that can be collected by radio telescopes. Pulsars have very small diameters typically about 10 – 20 kilometers. Since the diameter of a pulsar has decreased by a large factor compared to its progenitor star, young pulsars spin very rapidly due to the conservation of angular momentum. A typical young pulsar may spin hundreds of times per second. In time pulsars lose energy in the form of electromagnetic and gravitational radiation, and in turn, the angular velocity of the pulsar decreases. It can take a typical pulsar millions of years to slow or “spin down”.
Millisecond pulsars are a special class of pulsars that are very old and have been spun up by the accretion of matter from a companion star, sometimes called recycled pulsars. These pulsars spin at incredible rates. The fastest rotating millisecond pulsar spins 714 times per second. Millisecond pulsars do not emit as much electromagnetic radiation and do not spin down as rapidly as non recycled pulsars. This results in a highly stable pulsar spin rate.
Millisecond pulsars will also be used in an array to potentially detect gravitational waves predicted by Einstein's theory of General Relativity. It is theorized that black holes, binary pulsar systems and other extreme events can generate gravitational waves that are strong enough to warp the fabric of space-time enough to effect the spin rate of millisecond pulsars. If so, the change in spin rate for the millisecond pulsars in the array should be observed.
My goals as part of the Pulsar Search Collaboratory included: learning how to analyze “real” data, like astronomers do, and hopefully discovering something extraordinary. I searched through 193 datasets finding more RFI than noise in my plots . I found a known pulsar and I also co-discovered a millisecond pulsar in a binary system, J1400-1410.
I analyzed four of the seven subplots in the plot above; 1) pulse profile, 2) time domain, 3) frequency subband, and 4) dispersion measure.. Each of the four subplots demonstrated characteristics of pulsars.
January 24, 2012 - Confirmation Plot
The graph above represents the plot I analyzed and three follow on observations of J1400-1410. The slope of the trend line is the P-dot, or how the spin rate of the pulsar changes over time. The P-dot is very small, indicating the spin rate does not change much over time.
Using an array of millisecond pulsars, astronomers can detect tiny changes in the pulse arrival times in order to detect the influence of gravitational waves.
J1400 – 1410 has a period of .0030839 sec and a period derivative of -2*10^-12. This means J1400-1410s spin rate is decreasing at a rate of 0.000000000002 rotations per second per second. That’s really slow!
Data Analysis Summary
Based on the location of J1400 – 1410 on the chart to the left, the pulsar should spin down within 100 Kiloyears.
On January 24, 2012, observations with the Green Bank Telescope at 800 MHz confirmed that the signal was astronomical and zeroed in on its position. The confirmation plot looks nosier than the discovery plot. This is due to pulsars emitting lower frequencies (350 MHz) more than higher frequencies.
This pulsar is a millisecond pulsar with a spin rate of 324.24 times per second. It will be part of a timing array that may lead to the first direct detection of gravitational waves as predicted by Einstein.
Observation plots of 1400-1410
Mrs. Carter and I in front of the GBT.
Sarah Scoles, my sister Shabina, and I in the Control room of the GBT.
I had the opportunity to travel to Green Bank, West Virginia, on January 23, 2012 and see the World’s Largest Fully Steerable Telescope, the GBT. It was a wonderful experience!
This graph shows the classification distribution of plots that I analyzed. As the graph shows, I analyzed more RFI than Noise. I also found one known pulsar and a new pulsar.