We conduct an all-sky search for continuous gravitational waves in the LIGO O2 data from Hanford and Livingston detectors. nearly-monochromatic signals with frequency between 20.0 Hz 585.15 spin-down -2.6e-9 Hz/s 2.6e-10 Hz/s. deploy on Einstein@Home volunteer-computing project follow-up waveforms associated most significant results eight further search-stages, reaching best sensitivity ever achieved by survey up to 500 Hz. Six of inspected pass all stages but they are hardware-injections,...

We present the early release of atlas continuous gravitational waves covering frequencies from 20 Hz to 1500 and spindowns -5e-10 5e-10 Hz/s. Compared previous we have greatly expanded parameter space, now also provide polarization-specific data - both for signal-to-noise ratios upper limits. Continuous wave searches are computationally difficult take a long time complete. The enables new be performed using modest computing power. To allow start sooner, releasing this early, before our...

We demonstrate a breakthrough in the capabilities of robust, broad-parameter space searches for continuous gravitational waves. With large scale search waves on O1 LIGO data, we prove that our Falcon achieves sensitivity improvements expected from use long coherence length, while maintaining computational expense within manageable bounds. On these data set most constraining upper limits wave amplitude band 100--200 Hz. provide full outlier lists and near 0-spin-down suitable analysis signals...

We present the results of an all-sky search for continuous gravitational-wave signals with frequencies in 500-1700 Hz range targeting neutron stars ellipticity 10^{-8}. The is done on LIGO O2 data using Falcon analysis pipeline. presented here double sensitivity over any other result same [B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration), Phys. Rev. D 100, 024004 (2019)PRVDAQ2470-001010.1103/PhysRevD.100.024004, C. Palomba al., Lett. 123, 171101...

We present the first atlas of continuous gravitational wave sky, produced using LIGO O3a public data. For each 0.045 Hz frequency band and every point on sky provides amplitude upper limits, signal-to-noise ratios (SNRs), frequencies where search measures maximum SNR. The approximately top 1.5% results are reanalyzed with a series more sensitive searches purpose finding high SNR long coherence signals from isolated neutron stars. However, these do not reveal presence such signals. presented...

We present the results of an all-sky search for continuous gravitational wave signals with frequencies in 1700--2000 Hz range from neutron stars ellipticity $\ensuremath{\approx}{10}^{\ensuremath{-}8}$. The employs Falcon analysis pipeline [V. Dergachev and M. A. Papa, Phys. Rev. Lett. 123, 101101 (2019)] on LIGO O2 public data. Our improve by a factor greater than 5 over [B. P. Abbott et al. (LIGO Scientific Virgo Collaborations), D 100, 024004 (2019)]. This is huge leap forward: it takes...

We introduce a "loosely coherent" method for detection of continuous gravitational waves that bridges the gap between semi-coherent and purely coherent methods. Explicit control over accepted families signals is used to increase sensitivity power-based statistic while avoiding high computational costs conventional matched filters. Several examples as well prototype implementation are discussed.

We present the results of an all-sky search for continuous gravitational wave signals with frequencies in 20--500 Hz range from neutron stars ellipticity $\ensuremath{\approx}{10}^{\ensuremath{-}8}$. This frequency region is particularly hard to probe because quadratic dependence signal strength on frequency. The employs Falcon analysis pipeline [Dergachev and Papa, Phys. Rev. Lett. 123, 101101 (2019)] LIGO O2 public data. Compared previous analyses coherence length has been quadrupled, a...

We introduce a high-performance implementation of loosely coherent statistic sensitive to signals spanning finite-dimensional manifold in parameter space. Results from full scale simulations on Gaussian noise are discussed, as well implications for future searches continuous gravitational waves. demonstrate an improvement more than order magnitude analysis speed over previously available algorithms. As waves computationally limited, the large speedup results gain sensitivity.

We present the results of an all-sky search for continuous gravitational wave signals with frequencies in 200--600 Hz range and frequency derivative (spindown) from $\ensuremath{-}1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ through $1.11\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}\text{ }\text{ }\mathrm{Hz}/\mathrm{s}$. Together [ Phys. Rev. Lett. 123, 101101 (2019)], this completes survey between 20 to 600 on O1 data. It also demonstrates scalability our a...

We report results of a search for continuous gravitational waves from region covering the globular cluster Terzan 5 and Galactic Center. Continuous are expected fast-spinning, slightly nonaxisymmetric isolated neutron stars as well more exotic objects. The regions that we target believed to be unusually abundant in stars. use new loosely coherent method allows one reach unprecedented levels sensitivity this type search. covers frequency band 475--1500 Hz time derivatives range...

Analysis of experimental data must sometimes deal with abrupt changes in the distribution measured values. Setting upper limits on signals usually involves a veto procedure that excludes not described by an assumed statistical model. We show how to implement estimates physical quantities (such as limits) are valid without assuming particular family distributions, while still providing close optimal values when is from expected Gaussian or exponential). This new technique can compute...

We present a mechanical rotation sensor consisting of balance pivoting on tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and the new field rotational seismology. The position used is an air-core linear variable differential transformer with demonstrated noise floor \documentclass[12pt]{minimal}\begin{document}${1}{\,\times\, 10^{-11}}\textrm { m}/\sqrt{\textrm...

Broadband all-sky searches for continuous gravitational waves (CW) from isolated neutron stars typically yield a number of significant candidates that are discarded through hierarchical semi-coherent and coherent follow-up searches. However, these target purely sources do not take into account possible phase modulations to the signals due companion objects in binary orbits. If source object is orbit, signal-to-noise ratio (SNR) signal will diminish mismatch between waveform template used...

De novo assembly is a widely used methodology in bioinformatics. However, the conventional short-read based de incapable of reliably reconstructing large-scale structures human genomes. Recently, novel optical label technology has enabled reliable assembly. Despite its advantage genome analysis, this new requires more computationally intensive alignment algorithm than counterpart. For example, run-time on order 10; 000 hours sequential CPU. Therefore, to practically apply research,...

A compact tilt accelerometer with high sensitivity at low frequency was designed to provide corrections for the feedback signal of Advanced Laser Interferometer Gravitational Wave Observatory active seismic attenuation system. It has been developed using a Tungsten Carbide ceramic knife-edge hinge avoid mechanical 1/f noise believed be intrinsic in polycrystalline metallic flexures. Design and construction details are presented; prototype data acquisition control limitations discussed. The...

The direct detection of continuous gravitational waves from pulsars is a much anticipated discovery in the emerging field multimessenger wave (GW) astronomy. Because putative pulsar signals are exceedingly weak large amounts data need to be integrated achieve desired sensitivity. Contemporary searches use ingenious ad hoc methods reduce computational complexity. In this paper we provide analytical expressions for Fourier transform realistic signals. This provides description manifold domain,...

The search for continuous gravitational waves demands computationally efficient algorithms that can handle highly non-linear parameter spaces. Loosely coherent establish upper limits and detect signals by analyzing families of templates as a single unit. We describe new loosely intended all-sky searches over medium scale coherence lengths (3-300 hours).

De novo assembly is a widely used methodology in bioinformatics. However, the conventional short-read-based de incapable of reliably reconstructing large-scale structures human genomes. Recently, novel optical label-based technology has enabled reliable assembly. Despite its advantage genome analysis, this new requires more computationally intensive alignment algorithm than counterpart. For example, runtime on order 10,000 hours sequential CPU. Therefore, to practically apply research,...

Upper limits and confidence intervals are a convenient way to present experimental results. With modern experiments producing more data, it is often necessary reduce the volume of results for distribution. A common approach take maximum over set upper limits, which yields an limit valid entire set. This, however, can result in significant sensitivity loss, because we discard constraining data. In this paper, introduce that allow one summarize with small relaxation constraints. toy example...

Accurate determination of gravitational wave source parameters relies on transforming between the and detector frames. All-sky searches for continuous sources are computationally expensive, in part, because barycentering transformation time delays to a solar system frame. This expense is exacerbated by complicated modulation induced signal templates. We investigate approximations determining signals received with respect barycenter. A highly nonlinear conventional computation transformed...