A Caltech Library Service

Limits on Anisotropy in the Nanohertz Stochastic Gravitational Wave Background

Taylor, S. R. and Mingarelli, C. M. F. (2015) Limits on Anisotropy in the Nanohertz Stochastic Gravitational Wave Background. Physical Review Letters, 115 (4). Art. No. 041101. ISSN 0031-9007.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


The paucity of observed supermassive black hole binaries (SMBHBs) may imply that the gravitational wave background (GWB) from this population is anisotropic, rendering existing analyses suboptimal. We present the first constraints on the angular distribution of a nanohertz stochastic GWB from circular, inspiral-driven SMBHBs using the 2015 European Pulsar Timing Array data. Our analysis of the GWB in the ∼2–90  nHz band shows consistency with isotropy, with the strain amplitude in l>0 spherical harmonic multipoles ≲40% of the monopole value. We expect that these more general techniques will become standard tools to probe the angular distribution of source populations.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Taylor, S. R.0000-0003-0264-1453
Mingarelli, C. M. F.0000-0002-4307-1322
Additional Information:© 2015 American Physical Society. Received 21 May 2015; published 22 July 2015. This work was carried out under the aegis of the EPTA. Part of this work is based on observations with the 100-m telescope of the Max-Planck-Institut für Radioastronomie (MPIfR) at Effelsberg. The Nançay Radio Observatory is operated by the Paris Observatory, associated to the French Centre National de la Recherche Scientifique (CNRS). We acknowledge financial support from “Programme National de Cosmologie and Galaxies” (PNCG) of CNRS/INSU, France. Pulsar research at the Jodrell Bank Centre for Astrophysics and the observations using the Lovell telescope is supported by a consolidated grant from the STFC in the UK. The Westerbork Synthesis Radio Telescope is operated by the Netherlands Institute for Radio Astronomy (ASTRON) with support from The Netherlands Foundation for Scientific Research NWO. S. R. T. acknowledges the support of the STFC and the RAS. This research was in part supported by S. R. T’s appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, administered by Oak Ridge Associated Universities through a contract with NASA. C. M. F. M. was supported by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme. This research was performed in part using the Zwicky computer cluster at Caltech supported by NSF under MRI-R2 award No. PHY-0960291 and by the Sherman Fairchild Foundation. This work was in part performed using the Darwin Supercomputer of the University of Cambridge High Performance Computing Service, provided by Dell Inc. using Strategic Research Infrastructure Funding from the Higher Education Funding Council for England and funding from the STFC. A. S. and J. G. are supported by the Royal Society. L. L. was supported by a Junior Research Fellowship at Trinity Hall College, Cambridge University. S. A. S. acknowledges funding from an NWO Vidi fellowship (PI: J. W. T. H.). R. N. C. acknowledges the support of the International Max Planck Research School Bonn/Cologne and the Bonn-Cologne Graduate School. K. J. L. is supported by the National Natural Science Foundation of China (Grant No. 11373011). R. vH. is supported by NASA Einstein Fellowship grant PF3-140116. J. W. T. H. acknowledges funding from an NWO Vidi fellowship and ERC Starting Grant ‘DRAGNET’ (337062). P. L. acknowledges the support of the International Max Planck Research School Bonn/Cologne. K. L. acknowledges the financial support by the European Research Council for the ERC Synergy Grant BlackHoleCam under Contract No. 610058. S. O. is supported by the Alexander von Humboldt Foundation. The authors also acknowledge support of NSF Award No. PHY-1066293 and the hospitality of the Aspen Center for Physics.
Funding AgencyGrant Number
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Institut national des sciences de l'Univers (INSU)UNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)UNSPECIFIED
Royal Astronomical SocietyUNSPECIFIED
NASA Postdoctoral ProgramUNSPECIFIED
Marie Curie FellowshipUNSPECIFIED
Sherman Fairchild FoundationUNSPECIFIED
Higher Education Funding Council for EnglandUNSPECIFIED
Cambridge University, Trinity Hall CollegeUNSPECIFIED
International Max Planck Research SchoolUNSPECIFIED
Bonn-Cologne Graduate SchoolUNSPECIFIED
National Natural Science Foundation of China11373011
NASA Einstein FellowshipPF3-140116
European Research Council (ERC)337062
European Research Council (ERC)610058
Alexander von Humboldt FoundationUNSPECIFIED
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2015-38
Issue or Number:4
Classification Code:PACS numbers: 04.80.Nn, 04.30.-w, 97.60.Gb, 98.65.Fz
Record Number:CaltechAUTHORS:20150728-094312785
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:59032
Deposited By: Tony Diaz
Deposited On:28 Jul 2015 17:00
Last Modified:09 Mar 2020 13:19

Repository Staff Only: item control page