First searches for gravitational waves from r -modes of the Crab pulsar

We present the first searches for gravitational waves from r-modes of the Crab pulsar, coherently and separately integrating data from three stretches of the first two observing runs of Advanced LIGO using the F-statistic. The second run was divided in two by a glitch of the pulsar roughly halfway through. The frequencies and derivatives searched were based on radio measurements of the pulsar’s spin-down parameters as described in Caride et al., Phys. Rev. D 100, 064013 (2019). We did not find any evidence of gravitational waves. Our best 90% confidence upper limits on gravitational wave intrinsic strain were 1.5× 10−25 for the first run, 1.3× 10−25 for the first stretch of the second run, and 1.1×10−25 for the second stretch of the second run. These are the first upper limits on gravitational waves from r-modes of a known pulsar to beat its spin-down limit, and they do so by more than an order of magnitude in amplitude or two orders of magnitude in luminosity.

[1]  P. K. Panda,et al.  Open data from the first and second observing runs of Advanced LIGO and Advanced Virgo , 2019, 1912.11716.

[2]  M. J. Williams,et al.  Gravitational-wave Constraints on the Equatorial Ellipticity of Millisecond Pulsars , 2020, The Astrophysical Journal Letters.

[3]  M. Papa,et al.  First Search for r-mode Gravitational Waves from PSR J0537–6910 , 2020, The Astrophysical Journal.

[4]  H. Kurokawa,et al.  Beating the spin-down limit on gravitational wave emission from the crab pulsar , 2020 .

[5]  Anand Sengupta.et.al..  Searches for continuous gravitational waves from fifteen supernova remnants and fomalhaut b with Advanced LIGO , 2018 .

[6]  F. Cipolletta,et al.  Physics and astrophysics of neutron stars , 2015 .

[7]  A. Lyne,et al.  45 years of rotation of the Crab pulsar , 2014, 1410.0886.

[8]  R. Blandford,et al.  The surprising Crab pulsar and its nebula: a review , 2013, Reports on progress in physics. Physical Society.

[9]  A. Lyne,et al.  A study of 315 glitches in the rotation of 102 pulsars , 2011, 1102.1743.

[10]  P. Jaranowski,et al.  Searching for gravitational waves from known pulsars using the and statistics , 2010, 1004.0324.

[11]  B. Krishnan,et al.  Searching for gravitational waves from Cassiopeia A with LIGO , 2008, 0802.3332.

[12]  R. Romani,et al.  Fitting Pulsar Wind Tori. II. Error Analysis and Applications , 2007, 0710.4168.

[13]  S. Yoshida,et al.  R-mode oscillations of rapidly rotating barotropic stars in general relativity: analysis by the relativistic Cowling approximation , 2004, astro-ph/0406283.

[14]  Y. Levin,et al.  Crust–core coupling and r‐mode damping in neutron stars: a toy model , 2000, astro-ph/0006028.

[15]  N. Stergioulas,et al.  On the Relevance of the r-Mode Instability for Accreting Neutron Stars and White Dwarfs , 1998, astro-ph/9806089.

[16]  Lars Bildsten,et al.  Gravitational Radiation and Rotation of Accreting Neutron Stars , 1998, astro-ph/9804325.

[17]  N. Andersson.  A New Class of Unstable Modes of Rotating Relativistic Stars , 1997, gr-qc/9706075.

[18]  S. Morsink,et al.  Axial Instability of Rotating Relativistic Stars , 1997, gr-qc/9706073.

[19]  R. S. Pritchard,et al.  23 years of Crab pulsar rotational history , 1993 .

[20]  Andrew G. Lyne,et al.  Glitches as probes of neutron star interiors , 1992, Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences.

[21]  J. Papaloizou,et al.  Non-radial oscillations of rotating stars and their relevance to the short-period oscillations of cataclysmic variables , 1978 .

[22]  V. Trimble.  THE DISTANCE TO THE CRAB NEBULA AND NP 0532 , 1973 .

[23]  F. S. Prout.  Philosophical Transactions of the Royal Society of London , 2009, The London Medical Journal.