Accession Number:

AD1095360

Title:

The NANOGrav 11 Yr Data Set: Limits on Gravitational Wave Memory

Descriptive Note:

Journal Article - Embargoed Full-Text

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC WASHINGTON United States

Report Date:

2020-01-20

Pagination or Media Count:

11.0

Abstract:

The mergers of supermassive black hole binaries SMBHBs promise to be incredible sources of gravitational waves GWs. While the oscillatory part of the merger gravitational waveform will be outside the frequency sensitivity range of pulsar timing arrays, the nonoscillatory GW memory effect is detectable. Further, any burst of GWs will produce GW memory, making memory a useful probe of unmodeled exotic sources and new physics. We searched the North American Nanohertz Observatory for Gravitational Waves NANOGrav 11 yr data set for GW memory. This data set is sensitive to very low-frequency GWs of similar to 3 to 400 nHz periods of similar to 11 yr-1 month. Finding no evidence for GWs, we placed limits on the strain amplitude of GW memory events during the observation period. We then used the strain upper limits to place limits on the rate of GW memory causing events. At a strain of 2.5 x 10-14, corresponding to the median upper limit as a function of source sky position, we set a limit on the rate of GW memory events at eta M similar to 2 x 1010iota pi3 at a distance of 1 Gpc. As a test of our analysis, we analyzed the NANOGrav 9 yr data set as well. This analysis found an anomolous signal, which does not appear in the 11 yr data set. This signal is not a GW, and its origin remains unknown.

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE