Late time afterglow observations reveal a collimated relativistic jet in the ejecta of the binary neutron star merger GW170817

The binary neutron star (BNS) merger GW170817 was the first astrophysical source detected in gravitational waves and multi-wavelength electromagnetic radiation. The almost simultaneous observation of a pulse of gamma-rays proved that BNS mergers are associated with at least some short gamma-ray bursts (GRBs). However, the gamma-ray pulse was faint, casting doubts on the association of BNS mergers with the luminous, highly relativistic outflows of canonical short GRBs. Here we show that structured jets with a relativistic, energetic core surrounded by slower and less energetic wings produce afterglow emission that brightens characteristically with time, as recently seen in the afterglow of GW170817. Initially, we only see the relatively slow material moving towards us. As time passes, larger and larger sections of the outflow become visible, increasing the luminosity of the afterglow. The late appearance and increasing brightness of the multi-wavelength afterglow of GW170817 allow us to constrain the geometry of its ejecta and thus reveal the presence of an off-axis jet pointing about 30 degrees away from Earth. Our results confirm a single origin for BNS mergers and short GRBs: GW170817 produced a structured outflow with a highly relativistic core and a canonical short GRB. We did not see the bright burst because it was beamed away from Earth. However, approximately one in 20 mergers detected in gravitational waves will be accompanied by a bright, canonical short GRB.Comment: Models updated with new data and added references. Accepted for publication in PRL, 8 pages, 7 figures and 1 table. A grid of models, jet properties, and python interpolating routine is available at http://www.science.oregonstate.edu/~lazzatid/cocoon.htm

Structure, Deformations and Gravitational Wave Emission of Magnetars

Neutron stars can have, in some phases of their life, extremely strong magnetic fields, up to 10^15-10^16 G. These objects, named magnetars, could be powerful sources of gravitational waves, since their magnetic field could determine large deformations. We discuss the structure of the magnetic field of magnetars, and the deformation induced by this field. Finally, we discuss the perspective of detection of the gravitational waves emitted by these stars.Comment: 11 pages, 2 figures, prepared for 19th International Conference on General Relativity and Gravitation (GR19), Mexico City, Mexico, July 5-9, 201

HCI at the boundary of work and life

The idea behind this Special Issue originates in a workshop on HCI and CSCW research related to work and non-work-life balance organized in conjunction with the ECSCW 2013 conference by the issue co-editors. Fifteen papers were originally submitted for possible inclusion in this Special Issue, and four papers were finally accepted for publication after two rounds of rigorous peer review. The four accepted papers explore, in different ways, HCI at the boundary of work and life. In this editorial, we offer a description of the overall theme and rationale for the Special Issue, including an introduction on the topic relevance and background, and a reflection on how the four accepted papers further current research and debate on the topic

Expanding the spectrum of EWSR1-PATZ1 rearranged CNS tumors: An infantile case with leptomeningeal dissemination

We report on a case of EWSR1-PATZ1 rearranged brain tumor occurring in a 17 month-old child, originally interpreted as an infantile glioblastoma. Our case shows important analogies with the 2 previously reported cases, including the intraventricular location, the histologic appearance (pushing borders, oligodendrocyte-like morphology, rich vascular network) and the glioneural immunophenotype, supporting the role of these features as relevant clues to the diagnosis. On the other hand, our case displays unique characteristics, i.e. the onset in an infant, the presence of a focal high-grade component and the leptomeningeal dissemination, pointing to the importance of considering this entity in the differential diagnosis of an infantile glial/glioneural tumor

Not only dominant, not only optic atrophy: expanding the clinical spectrum associated with OPA1 mutations

Background: Heterozygous mutations in OPA1 are a common cause of autosomal dominant optic atrophy, sometimes associated with extra-ocular manifestations. Few cases harboring compound heterozygous OPA1 mutations have been described manifesting complex neurodegenerative disorders in addition to optic atrophy. Results: We report here three patients: one boy showing an early-onset mitochondrial disorder with hypotonia, ataxia and neuropathy that was severely progressive, leading to early death because of multiorgan failure; two unrelated sporadic girls manifesting a spastic ataxic syndrome associated with peripheral neuropathy and, only in one, optic atrophy. Using a targeted resequencing of 132 genes associated with mitochondrial disorders, in two probands we found compound heterozygous mutations in OPA1: in the first a 5 nucleotide deletion, causing a frameshift and insertion of a premature stop codon (p.Ser64Asnfs*7), and a missense change (p.Ile437Met), which has recently been reported to have clinical impact; in the second, a novel missense change (p.Val988Phe) co-occurred with the p.Ile437Met substitution. In the third patient a homozygous mutation, c.1180G > A (p.Ala394Thr) in OPA1 was detected by a trio-based whole exome sequencing approach. One of the patients presented also variants in mitochondrial DNA that may have contributed to the peculiar phenotype. The deleterious effect of the identified missense changes was experimentally validated in yeast model. OPA1 level was reduced in available patients\u2019 biological samples, and a clearly fragmented mitochondrial network was observed in patients\u2019 fibroblasts. Conclusions: This report provides evidence that bi-allelic OPA1 mutations may lead to complex and severe multi-system recessive mitochondrial disorders, where optic atrophy might not represent the main feature

Magnetic Field Generation in Stars

Enormous progress has been made on observing stellar magnetism in stars from the main sequence through to compact objects. Recent data have thrown into sharper relief the vexed question of the origin of stellar magnetic fields, which remains one of the main unanswered questions in astrophysics. In this chapter we review recent work in this area of research. In particular, we look at the fossil field hypothesis which links magnetism in compact stars to magnetism in main sequence and pre-main sequence stars and we consider why its feasibility has now been questioned particularly in the context of highly magnetic white dwarfs. We also review the fossil versus dynamo debate in the context of neutron stars and the roles played by key physical processes such as buoyancy, helicity, and superfluid turbulence,in the generation and stability of neutron star fields. Independent information on the internal magnetic field of neutron stars will come from future gravitational wave detections. Thus we maybe at the dawn of a new era of exciting discoveries in compact star magnetism driven by the opening of a new, non-electromagnetic observational window. We also review recent advances in the theory and computation of magnetohydrodynamic turbulence as it applies to stellar magnetism and dynamo theory. These advances offer insight into the action of stellar dynamos as well as processes whichcontrol the diffusive magnetic flux transport in stars.Comment: 41 pages, 7 figures. Invited review chapter on on magnetic field generation in stars to appear in Space Science Reviews, Springe

Gravitational waves from single neutron stars: an advanced detector era survey

With the doors beginning to swing open on the new gravitational wave astronomy, this review provides an up-to-date survey of the most important physical mechanisms that could lead to emission of potentially detectable gravitational radiation from isolated and accreting neutron stars. In particular we discuss the gravitational wave-driven instability and asteroseismology formalism of the f- and r-modes, the different ways that a neutron star could form and sustain a non-axisymmetric quadrupolar "mountain" deformation, the excitation of oscillations during magnetar flares and the possible gravitational wave signature of pulsar glitches. We focus on progress made in the recent years in each topic, make a fresh assessment of the gravitational wave detectability of each mechanism and, finally, highlight key problems and desiderata for future work.Comment: 39 pages, 12 figures, 2 tables. Chapter of the book "Physics and Astrophysics of Neutron Stars", NewCompStar COST Action 1304. Minor corrections to match published versio

Strongly magnetized pulsars: explosive events and evolution

Well before the radio discovery of pulsars offered the first observational confirmation for their existence (Hewish et al., 1968), it had been suggested that neutron stars might be endowed with very strong magnetic fields of $10^{10}$-$10^{14}$G (Hoyle et al., 1964; Pacini, 1967). It is because of their magnetic fields that these otherwise small ed inert, cooling dead stars emit radio pulses and shine in various part of the electromagnetic spectrum. But the presence of a strong magnetic field has more subtle and sometimes dramatic consequences: In the last decades of observations indeed, evidence mounted that it is likely the magnetic field that makes of an isolated neutron star what it is among the different observational manifestations in which they come. The contribution of the magnetic field to the energy budget of the neutron star can be comparable or even exceed the available kinetic energy. The most magnetised neutron stars in particular, the magnetars, exhibit an amazing assortment of explosive events, underlining the importance of their magnetic field in their lives. In this chapter we review the recent observational and theoretical achievements, which not only confirmed the importance of the magnetic field in the evolution of neutron stars, but also provide a promising unification scheme for the different observational manifestations in which they appear. We focus on the role of their magnetic field as an energy source behind their persistent emission, but also its critical role in explosive events.Comment: Review commissioned for publication in the White Book of "NewCompStar" European COST Action MP1304, 43 pages, 8 figure

Tangible Data Souvenirs as a Bridge between a Physical Museum Visit and Online Digital Experience

This paper presents the design, implementation, use and evaluation of a tangible data souvenir for an interactive museum exhibition. We define a data souvenir as the materialisation of the personal visiting experience: a data souvenir is dynamically created on the basis of data recorded throughout the visit and therefore captures and represents the experience as lived. The souvenir provides visitors with a memento of their visit and acts as a gateway to further online content. A step further is to enable visitors to contribute, in other words the data souvenir can become a means to collect visitor-generated content. We discuss the rationale behind the use of a data souvenir, the design process and resulting artefacts, and the implementation of both the data souvenir and online content system. Finally we examine the installation of the data souvenirs as part of a long-lasting exhibition: the use of this souvenir by visitors has been logged over seven months and issues around the gathering of user-generated content in such a way are discussed. Keywords: Tangible interaction; data souvenir; museums; user-generated content

SN 2017gci: a nearby Type I Superluminous Supernova with a bumpy tail

We thank the anonymous referee for the very useful comments, which contributed to improve the manuscript. AF is partially supported by the PRIN-INAF 2017 with the project Towards the SKA and CTA era: discovery, localisation, and physics of transients sources (P.I. M. Giroletti). These observations made use of the LCO network. DAH, CP, DH, and JB are supported by NSF Grant AST1911225 and NASA Grant 80NSSC19k1639. TMB was funded by the CONICYT PFCHA/DOCTORADOBECAS CHILE/201772180113. MG is supported by the Polish NCN MAESTRO grant 2014/14/A/ST9/00121. TWC acknowledges the funding provided by the Alexander von Humboldt Foundation and the EU Funding under Marie Sklodowska-Curie grant agreement No 842471, and Thomas Kruhler for reducing X-Shooter spectrum. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). CPG acknowledges support from EU/FP7ERC grant no. [615929]. GL was supported by a research grant (19054) from VILLUM FONDEN. MN is supported by a Royal Astronomical Society Research Fellowship. RL is supported by a Marie Sklodowska-Curie Individual Fellowship within the Horizon 2020 European Union (EU) Framework Programme for Research and Innovation (H2020-MSCA-IF-2017-794467). GT acknowledges partial support by the National Science Foundation under Award No. AST-1909796. Research by SV is supported by NSF grants AST-1813176 and AST-2008108. Some of the observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution under program 2018A-UAO-G16 (PI Terreran). Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration under program NW440 (PI Fong). The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. W. M. Keck Observatory and MMT Observatory accesswas supported by Northwestern University and the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 199.D-0143, 0100.D-0751(B), 0101.D-0199(B), 099.A-9025(A), 0100.A-9099(A)099.A-9099 and 0100.A-9099. This work makes use of observations from the LCO network. Part of the funding for GROND (both hardware as well as personnel) was generously granted from the Leibniz-Prize to Prof. G. Hasinger (DFG grant HA 1850/28-1). The Pan-STARRS1 Surveys (PS1) have been made possible through contributions of the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg, and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration Grants No.s NNX08AR22G, NNX12AR65G, and NNX14AM74G, the National Science Foundation under Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory and the Gordon and Betty Moore foundation. TheATLAS surveys are funded through NASA grants NNX12AR55G. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This research made use of TARDIS, a community-developed software package for spectral synthesis in supernovae (Kerzendorf & Sim 2014). The development of TARDIS received support from the Google Summer of Code initiative and from ESA's Summer of Code in Space program. TARDIS makes extensive use of Astropy and PyNE.This article has been accepted for publication in MNRAS published by Oxford University Press on behalf of the Royal Astronomical SocietyWe present and discuss the optical spectrophotometric observations of the nearby (z = 0.087) Type I superluminous supernova (SLSN I) SN 2017gci, whose peak K-corrected absolute magnitude reaches M-g = -21.5 mag. Its photometric and spectroscopic evolution includes features of both slow- and of fast-evolving SLSN I, thus favoring a continuum distribution between the two SLSN-I subclasses. In particular, similarly to other SLSNe I, the multiband light curves (LCs) of SN 2017gci show two re-brightenings at about 103 and 142 d after the maximum light. Interestingly, this broadly agrees with a broad emission feature emerging around 6520 angstrom after similar to 51 d from the maximum light, which is followed by a sharp knee in the LC. If we interpret this feature as H alpha, this could support the fact that the bumps are the signature of late interactions of the ejecta with a (hydrogen-rich) circumstellar material. Then we fitted magnetar- and CSM-interaction-powered synthetic LCs on to the bolometric one of SN 2017gci. In the magnetar case, the fit suggests a polar magnetic field B-p similar or equal to 6 x 10(14) G, an initial period of the magnetar P-initial similar or equal to 2.8 ms, an ejecta mass M-ejecta similar or equal to 9M(circle dot) and an ejecta opacity kappa similar or equal to 0.08 cm(2) g(-1). A CSM-interaction scenario would imply a CSM mass similar or equal to 5 M-circle dot and an ejecta mass similar or equal to 12M(circle dot). Finally, the nebular spectrum of phase + 187 d was modeled, deriving a mass of similar or equal to 10 M-circle dot for the ejecta. Our models suggest that either a magnetar or CSM interaction might be the power sources for SN 2017gci and that its progenitor was a massive (40 M-circle dot) star.PRIN-INAF 2017National Science Foundation (NSF) AST1911225 AST-1813176 AST-2008108CONICYT PFCHA/DOCTORADOBECAS CHILE/2017 72180113Polish NCN MAESTRO 2014/14/A/ST9/00121Alexander von Humboldt FoundationEuropean Commission 842471European Commission 839090European Commission PGC2018-095317-B-C21VILLUM FONDEN 19054Royal Astronomical Society Research FellowshipMarie Sklodowska-Curie Individual Fellowship within the Horizon 2020 European Union (EU) Framework Programme for Research and Innovation H2020-MSCA-IF-2017-794467National Science Foundation (NSF) AST-1909796 AST-1238877University of Arizona 2018A-UAO-G16Smithsonian Institution 2018A-UAO-G16National Aeronautics & Space Administration (NASA) NW440 NNX08AR22G NNX12AR65G NNX14AM74GW.M. Keck FoundationNorthwestern UniversityCenter for Interdisciplinary Exploration and Research in Astrophysics (CIERA)European Organisation for Astronomical Research in the Southern Hemisphere 199.D-0143 0100.D-0751(B) 0101.D-0199(B) 099.A-9025(A) 0100.A-9099(A)099.A-9099 0100.A-9099German Research Foundation (DFG)European Commission HA 1850/28-1National Aeronautics & Space Administration (NASA) NNX12AR55G 80NSSC19k1639Google Summer of Code initiativeESA's Summer of Code in Space programEuropean Commission 61592