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University of Texas Rio Grande Valley

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Articles 481 - 510 of 832

Full-Text Articles in Astrophysics and Astronomy

Localization And Broadband Follow-Up Of The Gravitational-Wave Transient Gw150914, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Jul 2016

Localization And Broadband Follow-Up Of The Gravitational-Wave Transient Gw150914, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter we describe the low-latency analysis of the GW data and present the sky localization of the first observed compact binary merger. We summarize the …

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Supplement:“Localization And Broadband Follow-Up Of The Gravitational-Wave Transient Gw150914”(2016, Apjl, 826, L13), B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Martin Beroiz, T. Peñuela, Nicolas A. Pereyra, Matthew Benacquista Jul 2016

Supplement:“Localization And Broadband Follow-Up Of The Gravitational-Wave Transient Gw150914”(2016, Apjl, 826, L13), B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Martin Beroiz, T. Peñuela, Nicolas A. Pereyra, Matthew Benacquista

Physics & Astronomy Faculty Publications

This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands.

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High-Energy Neutrino Follow-Up Search Of Gravitational Wave Event Gw150914 With Antares And Icecube, S. Adrián-Martínez, A. Albert, M. André, H. P. Daveloza, Joey S. Key, S. R. Morriss, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Jun 2016

High-Energy Neutrino Follow-Up Search Of Gravitational Wave Event Gw150914 With Antares And Icecube, S. Adrián-Martínez, A. Albert, M. André, H. P. Daveloza, Joey S. Key, S. R. Morriss, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We present the high-energy-neutrino follow-up observations of the first gravitational wave transient GW150914 observed by the Advanced LIGO detectors on September 14, 2015. We search for coincident neutrino candidates within the data recorded by the IceCube and Antares neutrino detectors. A possible joint detection could be used in targeted electromagnetic follow-up observations, given the significantly better angular resolution of neutrino events compared to gravitational waves. We find no neutrino candidates in both temporal and spatial coincidence with the gravitational wave event. Within ±500 s of the gravitational wave event, the number of neutrino candidates detected by IceCube and Antares were …

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Search For Transient Gravitational Waves In Coincidence With Short-Duration Radio Transients During 2007-2013, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Jun 2016

Search For Transient Gravitational Waves In Coincidence With Short-Duration Radio Transients During 2007-2013, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We present an archival search for transient gravitational-wave bursts in coincidence with 27 single-pulse triggers from Green Bank Telescope pulsar surveys, using the LIGO, Virgo, and GEO interferometer network. We also discuss a check for gravitational-wave signals in coincidence with Parkes fast radio bursts using similar methods. Data analyzed in these searches were collected between 2007 and 2013. Possible sources of emission of both short-duration radio signals and transient gravitational-wave emission include starquakes on neutron stars, binary coalescence of neutron stars, and cosmic string cusps. While no evidence for gravitational-wave emission in coincidence with these radio transients was found, the …

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Properties Of The Binary Black Hole Merger Gw150914, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Jun 2016

Properties Of The Binary Black Hole Merger Gw150914, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 3⁢6+5−4⁢��⊙ and 2⁢9+4−4⁢��⊙; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black …

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Gw151226: Observation Of Gravitational Waves From A 22-Solar-Mass Binary Black Hole Coalescence, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Jun 2016

Gw151226: Observation Of Gravitational Waves From A 22-Solar-Mass Binary Black Hole Coalescence, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, …

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Gw150914: First Results From The Search For Binary Black Hole Coalescence With Advanced Ligo, B. P. Abbott, R. Abbott, T. D. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Jun 2016

Gw150914: First Results From The Search For Binary Black Hole Coalescence With Advanced Ligo, B. P. Abbott, R. Abbott, T. D. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

On September 14, 2015, at 0950:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015 GW150914 was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

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Observing Gravitational-Wave Transient Gw150914 With Minimal Assumptions, B. P. Abbott, R. Abbott, T. D. Abbott, Mario C. Diaz, Joey S. Key, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Jun 2016

Observing Gravitational-Wave Transient Gw150914 With Minimal Assumptions, B. P. Abbott, R. Abbott, T. D. Abbott, Mario C. Diaz, Joey S. Key, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

The gravitational-wave signal GW150914 was first identified on September 14, 2015, by searches for short-duration gravitational-wave transients. These searches identify time-correlated transients in multiple detectors with minimal assumptions about the signal morphology, allowing them to be sensitive to gravitational waves emitted by a wide range of sources including binary black hole mergers. Over the observational period from September 12 to October 20, 2015, these transient searches were sensitive to binary black hole mergers similar to GW150914 to an average distance of ∼600 Mpc. In this paper, we describe the analyses that first detected GW150914 as well as the parameter estimation …

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Sensitivity Of The Advanced Ligo Detectors At The Beginning Of Gravitational Wave Astronomy, D. V. Martynov, E. D. Hall, B. P. Abbott, R. Abbott, T. D. Abbott, C. Adams, R. X. Adhikari, R. A. Anderson, Volker Quetschke, G. Valdes Jun 2016

Sensitivity Of The Advanced Ligo Detectors At The Beginning Of Gravitational Wave Astronomy, D. V. Martynov, E. D. Hall, B. P. Abbott, R. Abbott, T. D. Abbott, C. Adams, R. X. Adhikari, R. A. Anderson, Volker Quetschke, G. Valdes

Physics & Astronomy Faculty Publications

The Laser Interferometer Gravitational Wave Observatory (LIGO) consists of two widely separated 4 km laser interferometers designed to detect gravitational waves from distant astrophysical sources in the frequency range from 10 Hz to 10 kHz. The first observation run of the Advanced LIGO detectors started in September 2015 and ended in January 2016. A strain sensitivity of better than 10-23/Hz was achieved around 100 Hz. Understanding both the fundamental and the technical noise sources was critical for increasing the astrophysical strain sensitivity. The average distance at which coalescing binary black hole systems with individual masses of 30 M could be …

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Tests Of General Relativity With Gw150914, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Joey S. Key, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov May 2016

Tests Of General Relativity With Gw150914, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Joey S. Key, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following …

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New Discoveries From The Arecibo 327 Mhz Drift Pulsar Survey Radio Transient Search, J. S. Deneva, Kevin Stovall, M. A. Mclaughlin, M. Bagchi, S. D. Bates, P. C.C. Freire, Jose Guadalupe Martinez, Fredrick Jenet Apr 2016

New Discoveries From The Arecibo 327 Mhz Drift Pulsar Survey Radio Transient Search, J. S. Deneva, Kevin Stovall, M. A. Mclaughlin, M. Bagchi, S. D. Bates, P. C.C. Freire, Jose Guadalupe Martinez, Fredrick Jenet

Physics & Astronomy Faculty Publications

We present Clusterrank, a new algorithm for identifying dispersed astrophysical pulses. Such pulses are commonly detected from Galactic pulsars and rotating radio transients (RRATs), which are neutron stars with sporadic radio emission. More recently, isolated, highly dispersed pulses dubbed fast radio bursts (FRBs) have been identified as the potential signature of an extragalactic cataclysmic radio source distinct from pulsars and RRATs. Clusterrank helped us discover 14 pulsars and 8 RRATs in data from the Arecibo 327 MHz Drift Pulsar Survey (AO327). The new RRATs have DMs in the range 23.5-86.6 pc cm-3 and periods in the range 0.172-3.901 s. The …

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The Nanograv Nine-Year Data Set: Limits On The Isotropic Stochastic Gravitational Wave Background, Z. Arzoumanian, A. Brazier, S. Burke-Spolaor, S. J. Chamberlin, S. Chatterjee, B. Christy, J. M. Cordes, N. J. Cornish, Fredrick A. Jenet, Jing Luo Apr 2016

The Nanograv Nine-Year Data Set: Limits On The Isotropic Stochastic Gravitational Wave Background, Z. Arzoumanian, A. Brazier, S. Burke-Spolaor, S. J. Chamberlin, S. Chatterjee, B. Christy, J. M. Cordes, N. J. Cornish, Fredrick A. Jenet, Jing Luo

Physics & Astronomy Faculty Publications

We compute upper limits on the nanohertz-frequency isotropic stochastic gravitational wave background (GWB) using the 9 year data set from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration. Well-tested Bayesian techniques are used to set upper limits on the dimensionless strain amplitude (at a frequency of 1 yr-1) for a GWB from supermassive black hole binaries of Agw < 1.5 × 10-15. We also parameterize the GWB spectrum with a broken power-law model by placing priors on the strain amplitude derived from simulations of Sesana and McWilliams et al. Using Bayesian model selection we find that the data favor a broken power law to a pure power law with odds ratios of 2.2 and 22 to one for the Sesana and McWilliams prior models, respectively. Using the broken power-law analysis we construct posterior distributions on environmental factors that drive the binary to the GW-driven regime including the stellar mass density for stellar-scattering, mass accretion rate for circumbinary disk interaction, and orbital eccentricity for eccentric binaries, marking the first time that the shape of the GWB spectrum has been used to make astrophysical inferences. Returning to a power-law model, we place stringent limits on the energy density of relic GWs, Ωgw(f)h2 < 4.2 × 10-10. Our limit on the cosmic string GWB, Ωgw(f)h2 < 2.2 × 10-10, translates to a conservative limit on the cosmic string tension with Gμ < 3.3 × 10-8, a factor of four better than the joint Planck and high-l cosmic microwave background data from other experiments.

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Gw150914: Implications For The Stochastic Gravitational-Wave Background From Binary Black Holes, B. P. Abbott, R. Abbott, Hernan P. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, Marc E. Normandin, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Mar 2016

Gw150914: Implications For The Stochastic Gravitational-Wave Background From Binary Black Holes, B. P. Abbott, R. Abbott, Hernan P. Daveloza, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, Marc E. Normandin, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses 30M, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near 25 Hz), …

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Gw150914: The Advanced Ligo Detectors In The Era Of First Discoveries, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Hernan P. Daveloza, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Mar 2016

Gw150914: The Advanced Ligo Detectors In The Era Of First Discoveries, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Hernan P. Daveloza, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10-23/Hz at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was …

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Accessing The Exceptional Points Of Parity-Time Symmetric Acoustics, Chengzhi Shi, Marc Dubois, Yun Chen, Lei Cheng, Hamidreza Ramezani, Yuan Wang, Xiang Zhang Mar 2016

Accessing The Exceptional Points Of Parity-Time Symmetric Acoustics, Chengzhi Shi, Marc Dubois, Yun Chen, Lei Cheng, Hamidreza Ramezani, Yuan Wang, Xiang Zhang

Physics & Astronomy Faculty Publications

Parity-time (PT) symmetric systems experience phase transition between PT exact and broken phases at exceptional point. These PT phase transitions contribute significantly to the design of single mode lasers, coherent perfect absorbers, isolators, and diodes. However, such exceptional points are extremely difficult to access in practice because of the dispersive behaviour of most loss and gain materials required in PT symmetric systems. Here we introduce a method to systematically tame these exceptional points and control PT phases. Our experimental demonstration hinges on an active acoustic element that realizes a complex-valued potential and simultaneously controls the multiple interference in the structure. …

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First Low Frequency All-Sky Search For Continuous Gravitational Wave Signals, J. Aasi, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Feb 2016

First Low Frequency All-Sky Search For Continuous Gravitational Wave Signals, J. Aasi, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

In this paper we present the results of the first low frequency all-sky search of continuous gravitational wave signals conducted on Virgo VSR2 and VSR4 data. The search covered the full sky, a frequency range between 20 and 128 Hz with a range of spin-down between -1.0×10-10 and +1.5×10-11 Hz/s, and was based on a hierarchical approach. The starting point was a set of short fast Fourier transforms, of length 8192 s, built from the calibrated strain data. Aggressive data cleaning, in both the time and frequency domains, has been done in order to remove, as much as possible, the …

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Astrophysical Implications Of The Binary Black Hole Merger Gw150914, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Feb 2016

Astrophysical Implications Of The Binary Black Hole Merger Gw150914, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

The discovery of the gravitational-wave (GW) source GW150914 with the Advanced LIGO detectors provides the first observational evidence for the existence of binary black hole (BH) systems that inspiral and merge within the age of the universe. Such BH mergers have been predicted in two main types of formation models, involving isolated binaries in galactic fields or dynamical interactions in young and old dense stellar environments. The measured masses robustly demonstrate that relatively \"heavy\" BHs (≳25 M⊙) can form in nature. This discovery implies relatively weak massive-star winds and thus the formation of GW150914 in an environment with a metallicity …

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Search Of The Orion Spur For Continuous Gravitational Waves Using A Loosely Coherent Algorithm On Data From Ligo Interferometers, J. Aasi, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Feb 2016

Search Of The Orion Spur For Continuous Gravitational Waves Using A Loosely Coherent Algorithm On Data From Ligo Interferometers, J. Aasi, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

We report results of a wideband search for periodic gravitational waves from isolated neutron stars within the Orion spur towards both the inner and outer regions of our Galaxy. As gravitational waves interact very weakly with matter, the search is unimpeded by dust and concentrations of stars. One search disk (A) is 6.87° in diameter and centered on 20h10m54.71s+33°33′25.29′′, and the other (B) is 7.45° in diameter and centered on 8h35m20.61s-46°49′25.151′′. We explored the frequency range of 50-1500 Hz and frequency derivative from 0 to -5×10-9 Hz/s. A multistage, loosely coherent search program allowed probing more deeply than before in …

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All-Sky Search For Long-Duration Gravitational Wave Transients With Initial Ligo, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Hernan P. Daveloza, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Feb 2016

All-Sky Search For Long-Duration Gravitational Wave Transients With Initial Ligo, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Hernan P. Daveloza, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% …

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Observation Of Gravitational Waves From A Binary Black Hole Merger, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Feb 2016

Observation Of Gravitational Waves From A Binary Black Hole Merger, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10-21. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater …

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Upper Limits On The Rates Of Binary Neutron Star And Neutron Star–Black Hole Mergers From Advanced Ligo's First Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Jan 2016

Upper Limits On The Rates Of Binary Neutron Star And Neutron Star–Black Hole Mergers From Advanced Ligo's First Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

We report here the non-detection of gravitational waves from the merger of binary–neutron star systems and neutron star–black hole systems during the first observing run of the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO). In particular, we searched for gravitational-wave signals from binary–neutron star systems with component masses ∈[1,3]M⊙ and component dimensionless spins <0.05. We also searched for neutron star–black hole systems with the same neutron star parameters, black hole mass ∈[2,99]M⊙, and no restriction on the black hole spin magnitude. We assess the sensitivity of the two LIGO detectors to these systems and find that they could have detected the merger of binary–neutron star systems with component mass distributions of 1.35 ± 0.13 M⊙ at a volume-weighted average distance of ∼70 Mpc, and for neutron star–black hole systems with neutron star masses of 1.4 M⊙ and black hole masses of at least 5 M⊙, a volume-weighted average distance of at least ∼110 Mpc. From this we constrain with …

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Improved Analysis Of Gw150914 Using A Fully Spin-Precessing Waveform Model, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Jan 2016

Improved Analysis Of Gw150914 Using A Fully Spin-Precessing Waveform Model, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

This paper presents updated estimates of source parameters for GW150914, a binary black-hole coalescence event detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) in 2015 [Abbott et al. Phys. Rev. Lett. 116, 061102 (2016).]. Abbott et al. [Phys. Rev. Lett. 116, 241102 (2016).] presented parameter estimation of the source using a 13-dimensional, phenomenological precessing-spin model (precessing IMRPhenom) and an 11-dimensional nonprecessing effective-one body (EOB) model calibrated to numerical-relativity simulations, which forces spin alignment (nonprecessing EOBNR). Here, we present new results that include a 15-dimensional precessingspin waveform model (precessing EOBNR) developed within the EOB formalism. We find good agreement with the …

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Binary Black Hole Mergers In The First Advanced Ligo Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Jan 2016

Binary Black Hole Mergers In The First Advanced Ligo Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

The first observational run of the Advanced LIGO detectors, from September 12, 2015 to January 19, 2016, saw the first detections of gravitational waves from binary black hole mergers. In this paper, we present full results from a search for binary black hole merger signals with total masses up to 100M· and detailed implications from our observations of these systems. Our search, based on general-relativistic models of gravitational-wave signals from binary black hole systems, unambiguously identified two signals, GW150914 and GW151226, with a significance of greater than 5s over the observing period. It also identified a third possible signal, LVT151012, …

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Effect Of Polymer Concentration, Rotational Speed, And Solvent Mixture On Fiber Formation Using Forcespinning, Nancy Obregon, Victor Agubra, Madhab Pokhrel, Howard Campos, David Flores, David De La Garza, Yuanbing Mao, Javier Macossay, Mataz Alcoutlabi Jan 2016

Effect Of Polymer Concentration, Rotational Speed, And Solvent Mixture On Fiber Formation Using Forcespinning, Nancy Obregon, Victor Agubra, Madhab Pokhrel, Howard Campos, David Flores, David De La Garza, Yuanbing Mao, Javier Macossay, Mataz Alcoutlabi

Physics & Astronomy Faculty Publications

Polycaprolactone (PCL) fibers were produced using Forcespinning® (FS). The effects of PCL concentration, solvent mixture, and the spinneret rotational speed on fiber formation were evaluated. The concentration of the polymer in the solvents was a critical determinant of the solution viscosity. Lower PCL concentrations resulted in low solution viscosities with a correspondingly low fiber production rate with many beads. Bead-free fibers with high production rate and uniform fiber diameter distribution were obtained from the optimum PCL concentration (i.e., 12.5 wt%) with tetrahydrofuran (THF) as the solvent. The addition of N, N-dimethylformamide (DMF) to the THF solvent promoted the gradual formation …

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Mapping Gravitational-Wave Backgrounds Of Arbitrary Polarisation Using Pulsar Timing Arrays, Jonathan Gair, Joseph D. Romano, Stephen R. Taylor Dec 2015

Mapping Gravitational-Wave Backgrounds Of Arbitrary Polarisation Using Pulsar Timing Arrays, Jonathan Gair, Joseph D. Romano, Stephen R. Taylor

Physics & Astronomy Faculty Publications

We extend our previous work on mapping gravitational-wave backgrounds using techniques borrowed from the analysis of cosmic microwave background data to backgrounds which have non-general-relativity (non-GR) polarisations. Our analysis and results are presented in the context of pulsar timing array observations, but the overarching methods are general, and can be easily applied to LIGO or eLISA observations using appropriately modified response functions. Analytic expressions for the pulsar timing response to gravitational waves with non-GR polarisation are given for each mode of a spin-weighted spherical-harmonic decomposition of the background, which permit the signal to be mapped across the sky to any …

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Coherent Network Analysis For Continuous Gravitational Wave Signals In A Pulsar Timing Array: Pulsar Phases As Extrinsic Parameters, Yan Wang, Soumya D. Mohanty, F. A. Jenet Dec 2015

Coherent Network Analysis For Continuous Gravitational Wave Signals In A Pulsar Timing Array: Pulsar Phases As Extrinsic Parameters, Yan Wang, Soumya D. Mohanty, F. A. Jenet

Physics & Astronomy Faculty Publications

Supermassive black hole binaries are one of the primary targets of gravitational wave (GW) searches using pulsar timing arrays (PTAs). GW signals from such systems are well represented by parameterized models, allowing the standard Generalized Likelihood Ratio Test (GLRT) to be used for their detection and estimation. However, there is a dichotomy in how the GLRT can be implemented for PTAs: there are two possible ways in which one can split the set of signal parameters for semi-analytical and numerical extremization. The straightforward extension of the method used for continuous signals in ground-based GW searches, where the so-called pulsar phase …

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The Nanograv Nine-Year Data Set: Observations Arrival Time Measurements And Analysis Of 37 Millisecond Pulsars, Z. Arzoumanian, Zaven Arzoumanian, Adam Brazier, Sarah Burke-Spolaor, Sydney Chamberlin, Shami Chatterjee, Brian Christy, James M. Cordes, Neil Cornish, Fredrick A. Jenet, Jing Luo Nov 2015

The Nanograv Nine-Year Data Set: Observations Arrival Time Measurements And Analysis Of 37 Millisecond Pulsars, Z. Arzoumanian, Zaven Arzoumanian, Adam Brazier, Sarah Burke-Spolaor, Sydney Chamberlin, Shami Chatterjee, Brian Christy, James M. Cordes, Neil Cornish, Fredrick A. Jenet, Jing Luo

Physics & Astronomy Faculty Publications

We present high-precision timing observations spanning up to nine years for 37 millisecond pulsars monitored with the Green Bank and Arecibo radio telescopes as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project. We describe the observational and instrumental setups used to collect the data, and methodology applied for calculating pulse times of arrival; these include novel methods for measuring instrumental offsets and characterizing low signal-to-noise ratio timing results. The time of arrival data are fit to a physical timing model for each source, including terms that characterize time-variable dispersion measure and frequency-dependent pulse shape evolution. In …

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On The Disk Wind Mass Loss Rates In Qsos, Nicolas A. Pereyra Nov 2015

On The Disk Wind Mass Loss Rates In Qsos, Nicolas A. Pereyra

Physics & Astronomy Faculty Publications

We derive here a relatively simple expression for the total wind mass loss rates in QSOs within the accretion disk wind scenario. We show that the simple expression derived here for QSO disk wind mass loss rate is in a very good agreement with the more “exact” values obtained through significantly more complex and detailed numerically intensive 2.5D time-dependent simulations. Additionally we show that for typical QSO parameters, the disk itself will be emitting mostly in the UV/optical spectrum, in turn implying that the X-ray emission from QSOs likely is produced through some physical mechanism acting at radii smaller than …

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Searches For Continuous Gravitational Waves From Nine Young Supernova Remnants, J. Aasi, B. P. Abbott, R. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov Nov 2015

Searches For Continuous Gravitational Waves From Nine Young Supernova Remnants, J. Aasi, B. P. Abbott, R. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

We describe directed searches for continuous gravitational waves (GWs) in data from the sixth Laser Interferometer Gravitational-wave Observatory (LIGO) science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target's parameters are uncertain enough to warrant two searches, for a total of 10. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering -statistic. We found …

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On The Formation And Evolution Of The First Be Star In A Black Hole Binary Mwc 656, M. Grudzinska, K. Belczynski, J. Casares, S. E. De Mink, J. Ziolkowski, I. Negueruela, M. Ribó, I. Ribas, J. M. Paredes, A. Herrero, M. Benacquista Oct 2015

On The Formation And Evolution Of The First Be Star In A Black Hole Binary Mwc 656, M. Grudzinska, K. Belczynski, J. Casares, S. E. De Mink, J. Ziolkowski, I. Negueruela, M. Ribó, I. Ribas, J. M. Paredes, A. Herrero, M. Benacquista

Physics & Astronomy Faculty Publications

We find that the formation of MWC 656 (the first Be binary containing a black hole) involves a common envelope phase and a supernova explosion. This result supports the idea that a rapidly rotating Be star can emerge out of a common envelope phase, which is very intriguing because this evolutionary stage is thought to be too fast to lead to significant accretion and spin up of the B star.We predict ~10-100 of B-BH binaries to currently reside in the Galactic disc, among which around 1/3 contain a Be star, but there is only a small chance to observe a …

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