We analyzed the NANOGrav 12.5-year data set from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) for pulse jitter, the effect that individual pulses look different from the very stable average pulse shape.
In pulsar timing, we generally assume that the average shape of pulse profiles is stable over the timescale of decades; that is, that if we observe many pulses averaged together from one observation to the next, that they are intrinsically similar.
We report on our the high-precision timing of 45 millisecond pulsars in the third data set from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). In addition to providing the timing solutions for these pulsars, we introduce some new techniques in the timing, and discuss new astrometric and binary companion results.
We search for a gravitational-wave background (GWB) in the newly released 11-year dataset from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). While we find no significant evidence for a GWB, we place new constraints on a GWB from a population of inspiraling supermassive black-hole binaries, from a network of cosmic strings, and from a primordial GWB.
We present the polarization pulse profiles for 28 pulsars observed with the Arecibo Observatory as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) 11-year data set.
In order to fully optimize our current and future telescope observations of pulsars for precision timing experiments, we developed a comprehensive framework for determining pulse arrival-time uncertainties as a function of radio frequency and bandwidth. The optimal observing strategy is telescope- and pulsar-dependent.
We detected a second radio-frequency-dependent timing variation in the direction of the pulsar J1713+0747 in 2016 using the preliminary 12.5-year dataset from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). The first event was seen in 2008 as a dip in the "dispersion measure", a quantity describing the total electron density along the line of sight.
Using a simple microphone and a pair of metronomes, we describe a simple demonstration to illustrate the techniques we use to search for low-frequency gravitational waves. The code we use is available online and an adapted version of the demonstration could be used as an instructional laboratory investigation at the undergraduate or late high school level.