GBT25A-378

Measuring Scintillation-Arc Variations in NANOGrav Binary Pulsars

Abstract

We propose to observe 2 binary millisecond pulsars currently being monitored by NANOGrav using high time/frequency resolution. We have found the presence of well characterized "scintillation arcs", which are parabolic intensity features in the Fourier transform of dynamic spectra. Our objective is to analyze the variations in the scintillation arc curvatures for these two pulsars over one orbital phase. Recent work demonstrates that scintillation arcs can be used to directly measure key features of the interstellar medium and orbital geometry, especially if independent estimates of the pulsar distance and proper motion are known through high-precision timing of PTA data. By combining arc-based measurements of geometry with radio-timing measurements, we will be able to derive intrinsic properties of orbital systems, such as the pulsar and companion masses. We request to observe each source with the PF/820-MHz receiver. As described in the proposal, for each of the two pulsars, we seek 2-hour observing sessions, allocating 18 randomly scheduled sessions over the course of one observing year. This totals to an observing time of 36 hrs per source, making the aggregate of 72 hrs for this program.

Investigators

Name	Institution
Swarali Shivraj Patil *	West Virginia University
Emmanuel Fonseca	British Columbia, University of; McGill University; West Virginia University
Joseph Glaser	West Virginia University
Megan DeCesar	George Mason University
Natalia Lewandowska	New York at Oswego, State University of
James McKee	Hull, University of
Jim Cordes	Cornell University
Jacob Turner	Green Bank Observatory; West Virginia University
Stella Ocker	Carnegie Institute of Washington; California Institute of Technology
Benetge Perera	National Astronomy and Ionosphere Center ; West Virginia University; Florida, University of Central
Thankful Cromartie	Cornell University; Virginia, University of; Naval Research Laboratory
Maura McLaughlin	West Virginia University
Michael Lam	Cornell University; Rochester Institute of Technology; West Virginia University; SETI Institute
Daniel Stinebring	Oberlin College
Robert Main	McGill University
Ingrid Stairs	British Columbia, University of
Lydia Guertin	Academia Sinica
Timothy Dolch	Cornell University; Oberlin College; Hillsdale College

* indicates the PI