GBT22A-399

Targeted Shapiro-delay Observations of Five NANOGrav Binary Pulsars

Abstract

We propose to observe five binary millisecond pulsars (MSPs), which are all part of the North American Nanohertz Observatory for Gravitational Waves, at specific orbital phases during the GBT/22A semester. These observations are based on a proven strategy to better resolve timing effects due to the relativistic Shapiro time delay, which yields direct estimates of the component masses and system geometry. Such measures continue to have high impact in nuclear astrophysics and binary stellar evolution, and recent work by our team has shown that targeted observations of binary MSPs at specific orbital configurations -- particularly at superior conjunction -- dramatically increases sensitivity to the Shapiro delay. We specifically request to use the 1400-MHz receiver for all three sources across 7 observing sessions for a total of 35 hours during their transits through superior conjunction.

Investigators

Name	Institution
Emmanuel Fonseca *	British Columbia, University of; McGill University; West Virginia University
Paul Demorest	National Radio Astronomy Observatory
Megan DeCesar	George Mason University
David Kaplan	Wisconsin at Milwaukee, University of
Paul Ray	Naval Research Laboratory
Scott Ransom	National Radio Astronomy Observatory; Virginia, University of
Ingrid Stairs	British Columbia, University of
Thankful Cromartie	Cornell University; Virginia, University of; Naval Research Laboratory
Anne Archibald	Netherlands Institute for Radio Astronomy; McGill University; Newcastle University

* indicates the PI