Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Localization and broadband follow-up of the gravitational-wave transient GW150914

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 follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams

Localization and broadband follow-up of the gravitational-wave transient GW150914

A gravitational-wave transient was identified in data recorded by the Advanced LIGO detectors on 2015 September 14. The event candidate, 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 gravitational wave data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network Circulars, giving an overview of the participating facilities, the gravitational wave sky localization coverage, the timeline and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the electromagnetic data and results of the electromagnetic follow-up campaign will be disseminated in the papers of the individual teams

Many Labs 5: Testing Pre-Data-Collection Peer Review as an Intervention to Increase Replicability

none172siReplication studies in psychological science sometimes fail to reproduce prior findings. If these studies use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data-collection peer review by experts may address shortcomings and increase replicability rates. We selected 10 replication studies from the Reproducibility Project: Psychology (RP:P; Open Science Collaboration, 2015) for which the original authors had expressed concerns about the replication designs before data collection; only one of these studies had yielded a statistically significant effect (p <.05). Commenters suggested that lack of adherence to expert review and low-powered tests were the reasons that most of these RP:P studies failed to replicate the original effects. We revised the replication protocols and received formal peer review prior to conducting new replication studies. We administered the RP:P and revised protocols in multiple laboratories (median number of laboratories per original study = 6.5, range = 3–9; median total sample = 1,279.5, range = 276–3,512) for high-powered tests of each original finding with both protocols. Overall, following the preregistered analysis plan, we found that the revised protocols produced effect sizes similar to those of the RP:P protocols (Δr =.002 or.014, depending on analytic approach). The median effect size for the revised protocols (r =.05) was similar to that of the RP:P protocols (r =.04) and the original RP:P replications (r =.11), and smaller than that of the original studies (r =.37). Analysis of the cumulative evidence across the original studies and the corresponding three replication attempts provided very precise estimates of the 10 tested effects and indicated that their effect sizes (median r =.07, range =.00–.15) were 78% smaller, on average, than the original effect sizes (median r =.37, range =.19–.50).mixedEbersole C.R.; Mathur M.B.; Baranski E.; Bart-Plange D.-J.; Buttrick N.R.; Chartier C.R.; Corker K.S.; Corley M.; Hartshorne J.K.; IJzerman H.; Lazarevic L.B.; Rabagliati H.; Ropovik I.; Aczel B.; Aeschbach L.F.; Andrighetto L.; Arnal J.D.; Arrow H.; Babincak P.; Bakos B.E.; Banik G.; Baskin E.; Belopavlovic R.; Bernstein M.H.; Bialek M.; Bloxsom N.G.; Bodroza B.; Bonfiglio D.B.V.; Boucher L.; Bruhlmann F.; Brumbaugh C.C.; Casini E.; Chen Y.; Chiorri C.; Chopik W.J.; Christ O.; Ciunci A.M.; Claypool H.M.; Coary S.; Colic M.V.; Collins W.M.; Curran P.G.; Day C.R.; Dering B.; Dreber A.; Edlund J.E.; Falcao F.; Fedor A.; Feinberg L.; Ferguson I.R.; Ford M.; Frank M.C.; Fryberger E.; Garinther A.; Gawryluk K.; Ashbaugh K.; Giacomantonio M.; Giessner S.R.; Grahe J.E.; Guadagno R.E.; Halasa E.; Hancock P.J.B.; Hilliard R.A.; Huffmeier J.; Hughes S.; Idzikowska K.; Inzlicht M.; Jern A.; Jimenez-Leal W.; Johannesson M.; Joy-Gaba J.A.; Kauff M.; Kellier D.J.; Kessinger G.; Kidwell M.C.; Kimbrough A.M.; King J.P.J.; Kolb V.S.; Kolodziej S.; Kovacs M.; Krasuska K.; Kraus S.; Krueger L.E.; Kuchno K.; Lage C.A.; Langford E.V.; Levitan C.A.; de Lima T.J.S.; Lin H.; Lins S.; Loy J.E.; Manfredi D.; Markiewicz L.; Menon M.; Mercier B.; Metzger M.; Meyet V.; Millen A.E.; Miller J.K.; Montealegre A.; Moore D.A.; Muda R.; Nave G.; Nichols A.L.; Novak S.A.; Nunnally C.; Orlic A.; Palinkas A.; Panno A.; Parks K.P.; Pedovic I.; Pekala E.; Penner M.R.; Pessers S.; Petrovic B.; Pfeiffer T.; Pienkosz D.; Preti E.; Puric D.; Ramos T.; Ravid J.; Razza T.S.; Rentzsch K.; Richetin J.; Rife S.C.; Rosa A.D.; Rudy K.H.; Salamon J.; Saunders B.; Sawicki P.; Schmidt K.; Schuepfer K.; Schultze T.; Schulz-Hardt S.; Schutz A.; Shabazian A.N.; Shubella R.L.; Siegel A.; Silva R.; Sioma B.; Skorb L.; de Souza L.E.C.; Steegen S.; Stein L.A.R.; Sternglanz R.W.; Stojilovic D.; Storage D.; Sullivan G.B.; Szaszi B.; Szecsi P.; Szoke O.; Szuts A.; Thomae M.; Tidwell N.D.; Tocco C.; Torka A.-K.; Tuerlinckx F.; Vanpaemel W.; Vaughn L.A.; Vianello M.; Viganola D.; Vlachou M.; Walker R.J.; Weissgerber S.C.; Wichman A.L.; Wiggins B.J.; Wolf D.; Wood M.J.; Zealley D.; Zezelj I.; Zrubka M.; Nosek B.A.Ebersole, C. R.; Mathur, M. B.; Baranski, E.; Bart-Plange, D. -J.; Buttrick, N. R.; Chartier, C. R.; Corker, K. S.; Corley, M.; Hartshorne, J. K.; Ijzerman, H.; Lazarevic, L. B.; Rabagliati, H.; Ropovik, I.; Aczel, B.; Aeschbach, L. F.; Andrighetto, L.; Arnal, J. D.; Arrow, H.; Babincak, P.; Bakos, B. E.; Banik, G.; Baskin, E.; Belopavlovic, R.; Bernstein, M. H.; Bialek, M.; Bloxsom, N. G.; Bodroza, B.; Bonfiglio, D. B. V.; Boucher, L.; Bruhlmann, F.; Brumbaugh, C. C.; Casini, E.; Chen, Y.; Chiorri, C.; Chopik, W. J.; Christ, O.; Ciunci, A. M.; Claypool, H. M.; Coary, S.; Colic, M. V.; Collins, W. M.; Curran, P. G.; Day, C. R.; Dering, B.; Dreber, A.; Edlund, J. E.; Falcao, F.; Fedor, A.; Feinberg, L.; Ferguson, I. R.; Ford, M.; Frank, M. C.; Fryberger, E.; Garinther, A.; Gawryluk, K.; Ashbaugh, K.; Giacomantonio, M.; Giessner, S. R.; Grahe, J. E.; Guadagno, R. E.; Halasa, E.; Hancock, P. J. B.; Hilliard, R. A.; Huffmeier, J.; Hughes, S.; Idzikowska, K.; Inzlicht, M.; Jern, A.; Jimenez-Leal, W.; Johannesson, M.; Joy-Gaba, J. A.; Kauff, M.; Kellier, D. J.; Kessinger, G.; Kidwell, M. C.; Kimbrough, A. M.; King, J. P. J.; Kolb, V. S.; Kolodziej, S.; Kovacs, M.; Krasuska, K.; Kraus, S.; Krueger, L. E.; Kuchno, K.; Lage, C. A.; Langford, E. V.; Levitan, C. A.; de Lima, T. J. S.; Lin, H.; Lins, S.; Loy, J. E.; Manfredi, D.; Markiewicz, L.; Menon, M.; Mercier, B.; Metzger, M.; Meyet, V.; Millen, A. E.; Miller, J. K.; Montealegre, A.; Moore, D. A.; Muda, R.; Nave, G.; Nichols, A. L.; Novak, S. A.; Nunnally, C.; Orlic, A.; Palinkas, A.; Panno, A.; Parks, K. P.; Pedovic, I.; Pekala, E.; Penner, M. R.; Pessers, S.; Petrovic, B.; Pfeiffer, T.; Pienkosz, D.; Preti, E.; Puric, D.; Ramos, T.; Ravid, J.; Razza, T. S.; Rentzsch, K.; Richetin, J.; Rife, S. C.; Rosa, A. D.; Rudy, K. H.; Salamon, J.; Saunders, B.; Sawicki, P.; Schmidt, K.; Schuepfer, K.; Schultze, T.; Schulz-Hardt, S.; Schutz, A.; Shabazian, A. N.; Shubella, R. L.; Siegel, A.; Silva, R.; Sioma, B.; Skorb, L.; de Souza, L. E. C.; Steegen, S.; Stein, L. A. R.; Sternglanz, R. W.; Stojilovic, D.; Storage, D.; Sullivan, G. B.; Szaszi, B.; Szecsi, P.; Szoke, O.; Szuts, A.; Thomae, M.; Tidwell, N. D.; Tocco, C.; Torka, A. -K.; Tuerlinckx, F.; Vanpaemel, W.; Vaughn, L. A.; Vianello, M.; Viganola, D.; Vlachou, M.; Walker, R. J.; Weissgerber, S. C.; Wichman, A. L.; Wiggins, B. J.; Wolf, D.; Wood, M. J.; Zealley, D.; Zezelj, I.; Zrubka, M.; Nosek, B. A

Localization and broadband follow-up of the gravitational-wave transient GW150914

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 follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams