DSpace Community:http://hdl.handle.net/2440/123532018-03-21T03:27:57Z2018-03-21T03:27:57ZFirst narrow-band search for continuous gravitational waves from known pulsars in advanced detector dataAbbott, B.Abbott, R.Abbott, T.Acernese, F.Ackley, K.Adams, C.Adams, T.Addesso, P.Adhikari, R.Adya, V.Affeldt, C.Afrough, M.Agarwal, B.Agathos, M.Agatsuma, K.Aggarwal, N.Aguiar, O.Aiello, L.Ain, A.Allen, B.et al.http://hdl.handle.net/2440/1111422018-03-20T23:29:12Z2017-01-01T00:00:00ZTitle: First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Author: Abbott, B.; Abbott, R.; Abbott, T.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R.; Adya, V.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O.; Aiello, L.; Ain, A.; Allen, B.; et al.
Abstract: Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far.2017-01-01T00:00:00ZEstimating the contribution of dynamical ejecta in the kilonova associated with GW170817Abbott, B.Abbott, R.Abbott, T.Acernese, F.Ackley, K.Adams, C.Adams, T.Addesso, P.Adhikari, R.Adya, V.Affeldt, C.Afrough, M.Agarwal, B.Agathos, M.Agatsuma, K.Aggarwal, N.Aguiar, O.Aiello, L.Ain, A.Ajith, P.et al.http://hdl.handle.net/2440/1111202018-03-19T22:37:30Z2017-01-01T00:00:00ZTitle: Estimating the contribution of dynamical ejecta in the kilonova associated with GW170817
Author: Abbott, B.; Abbott, R.; Abbott, T.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R.; Adya, V.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O.; Aiello, L.; Ain, A.; Ajith, P.; et al.
Abstract: The source of the gravitational-wave (GW) signal GW170817, very likely a binary neutron star merger, was also observed electromagnetically, providing the first multi-messenger observations of this type. The two-week-long electromagnetic (EM) counterpart had a signature indicative of an r-process-induced optical transient known as a kilonova. This Letter examines how the mass of the dynamical ejecta can be estimated without a direct electromagnetic observation of the kilonova, using GW measurements and a phenomenological model calibrated to numerical simulations of mergers with dynamical ejecta. Specifically, we apply the model to the binary masses inferred from the GW measurements, and use the resulting mass of the dynamical ejecta to estimate its contribution (without the effects of wind ejecta) to the corresponding kilonova light curves from various models. The distributions of dynamical ejecta mass range between ${M}_{\mathrm{ej}}={10}^{-3}-{10}^{-2}\,{M}_{\odot }$ for various equations of state, assuming that the neutron stars are rotating slowly. In addition, we use our estimates of the dynamical ejecta mass and the neutron star merger rates inferred from GW170817 to constrain the contribution of events like this to the r-process element abundance in the Galaxy when ejecta mass from post-merger winds is neglected. We find that if gsim10% of the matter dynamically ejected from binary neutron star (BNS) mergers is converted to r-process elements, GW170817-like BNS mergers could fully account for the amount of r-process material observed in the Milky Way.2017-01-01T00:00:00ZFirst low-frequency Einstein@Home all-sky search for continuous gravitational waves in Advanced LIGO dataAbbott, B.Abbott, R.Abbott, T.Acernese, F.Ackley, K.Adams, C.Adams, T.Addesso, P.Adhikari, R.Adya, V.Affeldt, C.Afrough, M.Agarwal, B.Agatsuma, K.Aggarwal, N.Aguiar, O.Aiello, L.Ain, A.Allen, B.Allen, G.et al.http://hdl.handle.net/2440/1111192018-03-19T22:36:57Z2017-01-01T00:00:00ZTitle: First low-frequency Einstein@Home all-sky search for continuous gravitational waves in Advanced LIGO data
Author: Abbott, B.; Abbott, R.; Abbott, T.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R.; Adya, V.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agatsuma, K.; Aggarwal, N.; Aguiar, O.; Aiello, L.; Ain, A.; Allen, B.; Allen, G.; et al.
Abstract: We report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the first Advanced LIGO observing run. This search investigates the low frequency range of Advanced LIGO data, between 20 and 100 Hz, much of which was not explored in initial LIGO. The search was made possible by the computing power provided by the volunteers of the Einstein@Home project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population, corresponding to a sensitivity depth of 48.7[1/√Hz]. At the frequency of best strain sensitivity, near 100 Hz, we set 90% confidence upper limits of 1.8 × 10⁻²⁵. At the low end of our frequency range, 20 Hz, we achieve upper limits of 3.9 × 10⁻²⁴. At 55 Hz we can exclude sources with ellipticities greater than 10⁻⁵ within 100 pc of Earth with fiducial value of the principal moment of inertia of 10³⁸ kg m².2017-01-01T00:00:00ZBaryon asymmetry generation in the E6CHMNevzorov, R.Thomas, A.http://hdl.handle.net/2440/1111182018-03-19T22:36:16Z2017-01-01T00:00:00ZTitle: Baryon asymmetry generation in the E6CHM
Author: Nevzorov, R.; Thomas, A.
Abstract: Abstract not available2017-01-01T00:00:00Z