In: Child abuse & neglect: the international journal ; official journal of the International Society for the Prevention of Child Abuse and Neglect, Volume 38, Issue 7, p. 1267-1274
This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record Armano, Michele, et al. "Spacecraft and interplanetary contributions to the magnetic environment on-board LISA Pathfinder." Monthly Notices of the Royal Astronomical Society 494.2 (2020): 3014-3027. is available online at: https://academic.oup.com/mnras/article-abstract/494/2/3014/5822062?redirectedFrom=fulltext ; LISA Pathfinder (LPF) has been a space-based mission designed to test new technologies that will be required for a gravitational wave observatory in space. Magnetically driven forces play a key role in the instrument sensitivity in the low-frequency regime (mHz and below), the measurement band of interest for a space-based observatory. The magnetic field can couple to the magnetic susceptibility and remanent magnetic moment from the test masses and disturb them from their geodesic movement. LPF carried on-board a dedicated magnetic measurement subsystem with noise levels of 10 nT Hz-1/2 from 1 Hz down to 1 mHz. In this paper we report on the magnetic measurements throughout LPF operations. We characterize the magnetic environment within the spacecraft, study the time evolution of the magnetic field and its stability down to 20 µHz, where we measure values around 200 nT Hz-1/2¿, and identify two different frequency regimes, one related to the interplanetary magnetic field and the other to the magnetic field originating inside the spacecraft. Finally, we characterize the non-stationary component of the fluctuations of the magnetic field below the mHz and relate them to the dynamics of the solar wind. ; This work has been made possible by the LISA Pathfindermission, which is part of the space-science program ofthe European Space Agency. The French contribution hasbeen supported by CNES (Accord Specific de projet CNES1316634/CNRS 103747), the CNRS, the Observatoire deParis and the University Paris-Diderot. E. P. and H. I. wouldalso like to acknowledge the financial support of the Uni-vEarthS Labex program at Sorbonne Paris CiteÌ↪A (ANR-10-LABX-0023 and ANR-11- IDEX-0005-02). The Albert-Einstein-Institut acknowledges the support of the GermanSpace Agency, DLR. The work is supported by the Fed-eral Ministry for Economic Affairs and Energy based on aresolution of the German Bundestag (FKZ 50OQ0501 andFKZ 50OQ1601). The Italian contribution has been sup-ported by Agenzia Spaziale Italiana and Instituto Nazionaledi Fisica Nucleare. The Spanish contribution has been sup-ported by Contracts No. AYA2010-15709 (MICINN), No.ESP2013-47637-P, and No. ESP2015-67234-P (MINECO).M. N. acknowledges support from Fundación General CSIC(Programa ComFuturo). F. R. acknowledges support froma Formación de Personal Investigador (MINECO) contract.The Swiss contribution acknowledges the support of theSwiss Space Office (SSO) via the PRODEX Programme ofESA. L. F. acknowledges the support of the Swiss NationalScience Foundation. The UK groups wish to acknowledgesupport from the United Kingdom Space Agency (UKSA),the University of Glasgow, the University of Birmingham,Imperial College, and the Scottish Universities Physics Al-liance (SUPA). J.I.T. and J.S. acknowledge the support ofthe U.S. National Aeronautics and Space Administration(NASA). ; Peer Reviewed ; Postprint (author's final draft)
United States National Science Foundation (NSF) ; Science and Technology Facilities Council (STFC) of the United Kingdom ; Max-Planck-Society (MPS) ; State of Niedersachsen/Germany ; Australian Research Council ; International Science Linkages program of the Commonwealth of Australia ; Council of Scientific and Industrial Research of India ; Department of Science and Technology, India ; Science & Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educaci, Cultura i Universitats of the Govern de les Illes Balears ; Foundation for Fundamental Research on Matter - Netherlands Organization for Scientific Research ; Polish Ministry of Science and Higher Education ; FOCUS Programme of Foundation for Polish Science ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Hungarian Scientific Research Fund (OTKA) ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; NSF ; STFC ; MPS ; INFN ; CNRS ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: ST/I006285/1 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/J00166X/1 ; Science and Technology Facilities Council: ST/L000911/1 Gravitational Waves ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: PPA/G/S/2002/00652 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000911/1 ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/I006277/1 ; Science and Technology Facilities Council: ST/H002359/1 ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/K00137X/1 ; Science and Technology Facilities Council: ST/M006735/1 ; Science and Technology Facilities Council: ST/M000931/1 ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; 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 no evidence of GW signals. We set 95% confidence upper limits as strong (low) as 4 x 10(-25) on intrinsic strain, 2 x 10(-7) on fiducial ellipticity, and 4 x 10(-5) on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.
Australian Research Council ; International Science Linkages program of the Commonwealth of Australia ; Council of Scientific and Industrial Research of India, Department of Science and Technology, India ; Science and Engineering Research Board, India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat ; Cultura i Universitats of the Govern de les Illes Balears ; Foundation for Fundamental Research on Matter - Netherlands Organisation for Scientific Research ; National Science Centre of Poland ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Hungarian Scientific Research Fund ; Lyon Institute of Origins ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; Conselleria d'Educacio ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000962/1 Gravitational Waves ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/I006285/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: ST/N000064/1 ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; 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 x 10(-10) and +1.5 x 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 effect of disturbances of instrumental origin. On each data set a number of candidates has been selected, using the Frequency Hough transform in an incoherent step. Only coincident candidates among VSR2 and VSR4 have been examined in order to strongly reduce the false alarm probability, and the most significant candidates have been selected. The criteria we have used for candidate selection and for the coincidence step greatly reduce the harmful effect of large instrumental artifacts. Selected candidates have been subject to a follow-up by constructing a new set of longer fast Fourier transforms followed by a further incoherent analysis, still based on the Frequency Hough transform. No evidence for continuous gravitational wave signals was found, and therefore we have set a population-based joint VSR2-VSR4 90% confidence level upper limit on the dimensionless gravitational wave strain in the frequency range between 20 and 128 Hz. This is the first all-sky search for continuous gravitational waves conducted, on data of ground-based interferometric detectors, at frequencies below 50 Hz. We set upper limits in the range between about 10(-24) and 2 x 10(-23) at most frequencies. Our upper limits on signal strain show an improvement of up to a factor of similar to 2 with respect to the results of previous all-sky searches at frequencies below 80 Hz.