We present results of a search for continuously emitted gravitational radiation, directed at the brightest low-mass x-ray binary, Scorpius X-1. Our semicoherent analysis covers 10 days of LIGO S5 data ranging from 50–550 Hz, and performs an incoherent sum of coherent F-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and an angle-restricted one, using a prior derived from electromagnetic observations. Median strain upper limits of 1.3 × 10−24 and 8 × 10−25 are reported at 150 Hz for the standard and angle-restricted searches respectively. This proof-of-principle analysis was limited to a short observation time by unknown effects of accretion on the intrinsic spin frequency of the neutron star, but improves upon previous upper limits by factors of ∼1.4 for the standard, and 2.3 for the angle-restricted search at the sensitive region of the detector.

Directed search for gravitational waves from Scorpius X-1 with initial LIGO data / Aasi, J., Abbott, B.P., Abbott, R., Abbott, T., Abernathy, M.R., Acernese, F., Ackley, K., Adams, C., Adams, T., Addesso, P., Adhikari, R.X., Adya, V., Affeldt, C., Agathos, M., Agatsuma, K., Aggarwal, N., Aguiar, O.D., Ain, A., Ajith, P., Alemic, A., et al.. - In: PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY. - ISSN 1550-7998. - 91:6(2015). [10.1103/PhysRevD.91.062008]

Directed search for gravitational waves from Scorpius X-1 with initial LIGO data

Astone, P.;Di Palma, I.;Drago, M.;FRASCA, Sergio;LEACI, PAOLA;Majorana, E.;Mangano, V.;MEZZANI, FEDERICA;NATICCHIONI, LUCA;Pannarale, F.;RAPAGNANI, Piero;RICCI, Fulvio;Salemi, F.;
2015

Abstract

We present results of a search for continuously emitted gravitational radiation, directed at the brightest low-mass x-ray binary, Scorpius X-1. Our semicoherent analysis covers 10 days of LIGO S5 data ranging from 50–550 Hz, and performs an incoherent sum of coherent F-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and an angle-restricted one, using a prior derived from electromagnetic observations. Median strain upper limits of 1.3 × 10−24 and 8 × 10−25 are reported at 150 Hz for the standard and angle-restricted searches respectively. This proof-of-principle analysis was limited to a short observation time by unknown effects of accretion on the intrinsic spin frequency of the neutron star, but improves upon previous upper limits by factors of ∼1.4 for the standard, and 2.3 for the angle-restricted search at the sensitive region of the detector.
2015
Nuclear and High Energy Physics; Gravitational Waves
01 Pubblicazione su rivista::01a Articolo in rivista
Directed search for gravitational waves from Scorpius X-1 with initial LIGO data / Aasi, J., Abbott, B.P., Abbott, R., Abbott, T., Abernathy, M.R., Acernese, F., Ackley, K., Adams, C., Adams, T., Addesso, P., Adhikari, R.X., Adya, V., Affeldt, C., Agathos, M., Agatsuma, K., Aggarwal, N., Aguiar, O.D., Ain, A., Ajith, P., Alemic, A., et al.. - In: PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY. - ISSN 1550-7998. - 91:6(2015). [10.1103/PhysRevD.91.062008]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/938712
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