Benefits of Artificially Generated Gravity Gradients for Interferometric Gravitational-Wave Detectors

We present an approach to experimentally evaluate gravity gradient noise, a potentially limiting noise source in advanced interferometric gravitational wave (GW) detectors. In addition, the method can be used to provide sub-percent calibration in phase and amplitude of modern interferometric GW detectors. Knowledge of calibration to such certainties shall enhance the scientific output of the instruments in case of an eventual detection of GWs. The method relies on a rotating symmetrical two-body mass, a Dynamic gravity Field Generator (DFG). The placement of the DFG in the proximity of one of the interferometer's suspended test masses generates a change in the local gravitational field detectable with current interferometric GW detectors.Comment: 16 pages, 4 figure

GLADE+: An Extended Galaxy Catalogue for Multimessenger Searches with Advanced Gravitational-wave Detectors

We present GLADE+, an extended version of the GLADE galaxy catalogue introduced in our previous paper for multimessenger searches with advanced gravitational-wave detectors. GLADE+ combines data from six separate but not independent astronomical catalogues: the GWGC, 2MPZ, 2MASS XSC, HyperLEDA, and WISExSCOSPZ galaxy catalogues, and the SDSS-DR16Q quasar catalogue. To allow corrections of CMB-frame redshifts for peculiar motions, we calculated peculiar velocities along with their standard deviations of all galaxies having $B$-band magnitude data within redshift $z=0.05$ using the "Bayesian Origin Reconstruction from Galaxies" formalism. GLADE+ is complete up to luminosity distance $d_L=47^{+4}_{-2}$ Mpc in terms of the total expected $B$-band luminosity of galaxies, and contains all of the brightest galaxies giving 90\% of the total $B$-band and $K$-band luminosity up to $d_L\simeq 130$ Mpc. We include estimations of stellar masses and individual binary neutron star merger rates for galaxies with $W1$ magnitudes. These parameters can help in ranking galaxies in a given gravitational wave localization volume in terms of their likelihood of being hosts, thereby possibly reducing the number of pointings and total integration time needed to find the electromagnetic counterpart.Comment: 9 pages, 4 figures, accepted for publication in MNRA

Search for Transient Gravitational-wave Signals Associated with Magnetar Bursts during Advanced LIGO's Second Observing Run

We present the results of a search for short- and intermediate-duration gravitational-wave signals from four magnetar bursts in Advanced LIGO' s second observing run. We find no evidence of a signal and set upper bounds on the root sum squared of the total dimensionless strain (h(rss)) from incoming intermediate-duration gravitational waves ranging from 1.1 x 10(-22) at 150 Hz to 4.4 x 10(-22) at 1550 Hz at 50% detection efficiency. From the known distance to the magnetar SGR 1806-20 (8.7 kpc), we can place upper bounds on the isotropic gravitational-wave energy of 3.4 x 10(44) erg at 150 Hz assuming optimal orientation. This represents an improvement of about a factor of 10 in strain sensitivity from the previous search for such signals, conducted during initial LIGO' s sixth science run. The short-duration search yielded upper limits of 2.1 x 10(44) erg for short white noise bursts, and 2.3 x 10(47) erg for 100 ms long ringdowns at 1500 Hz, both at 50% detection efficiency

Meet the researchers: an alternative method of engaging patients with research in mesothelioma.

There are new ways to engage people with science and research but many patient support groups and charitable organisations still hold traditional meetings to provide updates on their activities and to report new developments in their field of interest. These meetings often feature presentations given by medical doctors or, in the case of research-focussed organisations, by research scientists.Receiving feedback from people who are confused and sometimes upset by some types of information, and the way it is presented at meetings, made us think about better ways for researchers to discuss their ideas for new research, or share the findings from completed projects, with patients and members of the public.This article describes a method of public engagement called "Meet the Researchers" that enables people to hear about current trends in research face to face with the researchers planning or conducting it. "Meet the Researchers" is designed to promote discussion and allow questions to be asked in a relaxed and informal way, in small groups, which is less daunting than asking questions in front of a conference audience. The aim is to break down the barriers between researchers and patients, and enable conversations that will lead to meaningful engagement and a better understanding of research. Additionally we aim to improve understanding of how results are passed on to doctors and nurses and translated into improvements in patient care.The method was tested with patients and was rated very highly by them in the feedback they gave. Abstract:Background Innovative approaches to engaging people with science exist but are often framed around interactive events or social media technologies. Notwithstanding the availability of novel approaches, many patient support groups and charitable organisations continue to hold traditional meetings and seminars to provide information and updates on their activities, and report on developments in their field of interest. In the case of research-focussed organisations, these meetings often take the form of presentations delivered by clinical experts or research scientists.Observation of mesothelioma patients, their relatives, friends and carers attending scientific or clinical-themed meetings has shown that they can be confused, and sometimes distressed, by presentations. This can be due to didactic presentations that are not properly targeted to this audience and a lack of a general overview or summary at the end of meetings that would provide some simple take home messages. This experience motivated the development of a less formal method of sharing complex information and ideas in a simplified manner. "Meet the Researchers" aims to make researchers accessible to patients in order to raise awareness and understanding of research and to explain how research translates into, and informs practice. This approach encourages the use of plain English, removes the tendency to rely on PowerPoint slides to convey the message and moreover, provides an opportunity for researchers to hear patients' views. Methods Small groups of participants met face to face with the researchers planning or conducting research into their condition, and discussed the topics in a relaxed and informal way. The researchers spent a minimum of 20-min with each group before moving on to the next. Info-graphics on a portable device or printed hand-outs in plain English were allowed but no formal presentations were made. Results Our method has been evaluated using feedback data from three annual events held from 2016 to 2018: 100% of participants indicated that they liked the format "very much"(76.0%) or "quite a lot"(24.0%); 80.4% found the topics "very interesting" and 75.9% found it "very easy" to ask questions. Free text comments revealed themes of 'hope' and 'altruism'. Researchers also reported benefits from participation such as learning about patient' priorities and networking. Conclusion "Meet the Researchers" provides a unique opportunity for mesothelioma researchers and patients, relatives and carers to interact on a more equal footing. It stimulates discussion, promotes understanding and provides a more informal setting for non-professional participants to ask questions. It is a format that could easily be adapted for use in other conditions

Upper Limits on the Rates of Binary Neutron Star and Neutron Star-Black Hole Mergers from Advanced Ligo's First Observing Run

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 Advanced 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±0.13M at a volume-weighted average distance of ∼ 70 Mpc, and for neutron-star–black-hole systems with neutron star masses of 1.4M and black hole masses of at least 5M , a volume-weighted average distance of at least ∼ 110 Mpc. From this we constrain with 90% confidence the merger rate to be less than 12,600 Gpc−3 yr−1 for binary-neutron star systems and less than 3,600 Gpc−3 yr−1 for neutron-star–black-hole systems. We discuss the astrophysical implications of these results, which we find to be in tension with only the most optimistic predictions. However, we find that if no detection of neutron-star binary mergers is made in the next two Advanced LIGO and Advanced Virgo observing runs we would place significant constraints on the merger rates

Gravitational Waves From Known Pulsars: Results From The Initial Detector Era

We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom