Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

Document #:

LIGO-P1800208-v7

Document type:

P - Publications

Abstract:

We present results from a semicoherent search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the \( \mathcal{J} \)-statistic, and by analysing data from Advanced LIGO's second observing run. In the frequency range searched, from \( 60 \) to \( 650\,\mathrm{Hz} \), we find no evidence of gravitational radiation. At \( 194.6\,\mathrm{Hz} \), the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95\% confidence) of \( h_0^{95\%} = 3.47 \times 10^{-25} \) when marginalising over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering.

Files in Document:

• Paper PDF (viterbi-o2-VersionSubmitted.pdf, file is not accessible)

Topics:

• Continuous Wave

Author Groups:

• LVC

Notes and Changes:

Version submitted to arXiv and the journal