Prospects for improving the sensitivity of KAGRA gravitational wave detector

KAGRA is a new gravitational wave detector which aims to begin joint observation with Advanced LIGO and Advanced Virgo from late 2019. Here, we present KAGRA's possible upgrade plans to improve the sensitivity in the decade ahead. Unlike other state-of-the-art detectors, KAGRA requires different investigations for the upgrade since it is the only detector which employs cryogenic cooling of the test mass mirrors. In this paper, investigations on the upgrade plans which can be realized by changing the input laser power, increasing the mirror mass, and injecting frequency dependent squeezed vacuum are presented. We show how each upgrade affects to the detector frequency bands and also discuss impacts on gravitational-wave science. We then propose an effective progression of upgrades based on technical feasibility and scientific scenarios

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10: 11: 58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2(-6.0)(+8.4)M-circle dot and 19.4(-5.9)(+5.3)M(circle dot) (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, chi(eff) = -0.12(-0.30)(+0.21) . This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880(-390)(+450) Mpc corresponding to a redshift of z = 0.18(-0.07)(+0.08) . We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m(g) <= 7.7 x 10(-23) eV/c(2). In all cases, we find that GW170104 is consistent with general relativity

First measurement of the Hubble Constant from a Dark Standard Siren using the Dark Energy Survey Galaxies and the LIGO/Virgo Binary–Black-hole Merger GW170814

International audienceWe present a multi-messenger measurement of the Hubble constant H 0 using the binary–black-hole merger GW170814 as a standard siren, combined with a photometric redshift catalog from the Dark Energy Survey (DES). The luminosity distance is obtained from the gravitational wave signal detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Collaboration (LVC) on 2017 August 14, and the redshift information is provided by the DES Year 3 data. Black hole mergers such as GW170814 are expected to lack bright electromagnetic emission to uniquely identify their host galaxies and build an object-by-object Hubble diagram. However, they are suitable for a statistical measurement, provided that a galaxy catalog of adequate depth and redshift completion is available. Here we present the first Hubble parameter measurement using a black hole merger. Our analysis results in , which is consistent with both SN Ia and cosmic microwave background measurements of the Hubble constant. The quoted 68% credible region comprises 60% of the uniform prior range [20, 140] km s−1 Mpc−1, and it depends on the assumed prior range. If we take a broader prior of [10, 220] km s−1 Mpc−1, we find (57% of the prior range). Although a weak constraint on the Hubble constant from a single event is expected using the dark siren method, a multifold increase in the LVC event rate is anticipated in the coming years and combinations of many sirens will lead to improved constraints on H 0

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 InterferometerGravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimatesof 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 wedescribe the low-latency analysis of the GW data and present the sky localization of the first observed compactbinary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-rayCoordinates Network circulars, giving an overview of the participating facilities, the GW sky localizationcoverage, 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 broadbandcampaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broadcapabilities of the transient astronomy community and the observing strategies that have been developed to pursueneutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-upcampaign are being disseminated in papers by the individual teams

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

Detecting Genetic Isolation in Human Populations: A Study of European Language Minorities

The identification of isolation signatures is fundamental to better understand the genetic structure of human populations and to test the relations between cultural factors and genetic variation. However, with current approaches, it is not possible to distinguish between the consequences of long-term isolation and the effects of reduced sample size, selection and differential gene flow. To overcome these limitations, we have integrated the analysis of classical genetic diversity measures with a Bayesian method to estimate gene flow and have carried out simulations based on the coalescent. Combining these approaches, we first tested whether the relatively short history of cultural and geographical isolation of four "linguistic islands" of the Eastern Alps (Lessinia, Sauris, Sappada and Timau) had left detectable signatures in their genetic structure. We then compared our findings to previous studies of European population isolates. Finally, we explored the importance of demographic and cultural factors in shaping genetic diversity among the groups under study. A combination of small initial effective size and continued genetic isolation from surrounding populations seems to provide a coherent explanation for the diversity observed among Sauris, Sappada and Timau, which was found to be substantially greater than in other groups of European isolated populations. Simulations of micro-evolutionary scenarios indicate that ethnicity might have been important in increasing genetic diversity among these culturally related and spatially close populations. © 2013 Capocasa et al

Herramientas aportadas por TIC: La implementación de un laboratorio virtual en clases de genética

El uso de laboratorios virtuales o simuladores es una alternativa para la enseñanza práctica en Biología. En el presente trabajo, se clasificó laboratorios virtuales que desarrollen conceptos de Genética Mendeliana e identificó los niveles de comprensión alcanzados mediante el uso de un laboratorio virtual en alumnos de cuarto año de dos Instituciones secundarias de la ciudad de Córdoba. Este recurso colaboró en la comprensión del concepto Genotipo y Fenotipo, por lo cual promovemos la implementación de esta herramienta educativa, ya que permite visualizar fenómenos y promover el aprendizaje de los conceptos científicos a la vez que motiva alos alumnos.Fil: García Capocasa, María Constanza. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Taller de Investigación Educativa I y II; Argentina.Fil: Mari, Macarena M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Taller de Investigación Educativa I y II; Argentina.Fil: Malin Vilar, Tania G. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Taller de Investigación Educativa I y II; Argentina.Fil: Valeiras, Nora. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Taller de Investigación Educativa I y II; Argentina.Educación General (incluye capacitación, pedagogía y didáctica

Un análisis de los discursos de diferentes actores sobre la diversidad biológica y su enseñanza

Fil: Bermúdez, Gonzalo M. A. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Profesorado en Ciencias Biológicas. Cátedra de Didáctica Especial; Argentina.Fil: García Capocasa, María Constanza. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Profesorado en Ciencias Biológicas. Cátedra de Didáctica Especial; Argentina.Fil: Battistón, Luisina Valeria. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Profesorado en Ciencias Biológicas. Cátedra de Didáctica Especial; Argentina.Es necesario reconocer que en nuestra cultura cuando se habla de ecología se utilizan dos significados del término: como movimiento social –ecologismo- o como disciplina biológica. Asociado a este concepto, la biodiversidad –o diversidad biológica- suele ser utilizada en el ámbito cotidiano tanto como en el científico debido a la difusión de los medios de comunicación ya los importantes recursos que se destinan a la investigación de los distintos aspectos de la biodiversidad. En el sistema educativo, los discursos escritos acerca de qué debe enseñarse se encuentran, en primer lugar, en los programas oficiales nacionales y jurisdiccionales. Luego, las distintas instituciones, mediante sus proyectos y programas de centro, establecen los contenidos de la enseñanza de acuerdo a criterios propios. Los docentes con sus clases, definen el último eslabón del gradiente de concreción curricular, en la interacción con sus alumnos y con un objeto de conocimiento particular. En el marco de la teoría de la transposición didáctica también forman parte importante de la “esfera de los que piensan” (noosfera) los científicos, productores de saber sabio ecológico. El propósito del presente trabajo fue analizar los discursos de diferentes actores de la noosfera (docentes, ecólogos y didactas) sobre la biodiversidad y su enseñanza. Se realizaron entrevistas semi- estructuradas a: (a) seis docentes de Biología de la provincia de Córdoba, (b) diez científicos de distintas áreas relacionadas con la biodiversidad de Argentina, y (c) a seis didactas de distintas provincias de Argentina y de España. Se registró y luego se transcribió el audio de cada entrevista. A modo de síntesis de los resultados encontramos que todos los docentes enseñan el tema de la biodiversidad en sus clases, lo consideran importante para sus materias, aunque tienen trayectos de formación, conocimientos y metodologías de enseñanza diferentes. La mayoría de los ecólogos destaca la importancia de la biodiversidad y su conservación, y reconocen la polisemia del concepto. La mayoría de los didactas advierte un cierto distanciamiento entre las actuales posturas sobre enseñanza y aprendizaje y algunas prácticas actuales, además de sugerir lineamientos para la enseñanza que retoman aspectos sociales y biológicos de la biodiversidad.Fil: Bermúdez, Gonzalo M. A. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Profesorado en Ciencias Biológicas. Cátedra de Didáctica Especial; Argentina.Fil: García Capocasa, María Constanza. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Profesorado en Ciencias Biológicas. Cátedra de Didáctica Especial; Argentina.Fil: Battistón, Luisina Valeria. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Profesorado en Ciencias Biológicas. Cátedra de Didáctica Especial; Argentina.Otras Ciencias de la Educació

Una propuesta de enseñanza de didáctica general y didáctica especial en la formación inicial de profesores de biología (Córdoba, Argentina)

La profesionalidad docente puede considerarse como uno de los aspectos característicos de las tendencias actuales en el campo de la didáctica y de la educación (Camilloni, 2016). De hecho, una de las preocupaciones de la gestión universitaria en Argentina está centrada más que nunca en transformar la formación de los profesores para la educación secundaria (Rasetto, 2012). De hecho, una de las preocupaciones de la gestión universitaria en Argentina está centrada más que nunca en transformar la formación de los profesores para la educación secundaria, recuperando la centralidad de la enseñanza como eje de la actividad profesional, la articulación teoría-práctica, la investigación educativa, la contextualización en los distintos ámbitos de intervención docente, así como también, los fundamentos éticos y el compromiso social de la tarea educativa (Rasetto, 2012). En esta ponencia relatamos la génesis y algunas experiencias que emergen del desarrollo de una propuesta de trabajo en las cátedras de Didáctica General (DG) y Didáctica Especial (DE) del quinto y sexto semestre, respectivamente, de la carrera de Profesorado en Ciencias Biológicas en la Universidad Nacional de Córdoba, Argentina. Con ello, nos proponemos no sólo dar sentido a nuestros posicionamientos epistemológicos, ideológicos, teórico-metodológicos -lo que abordaremos a continuación-, sino también, seguidamente, recuperar la reflexión a partir de la experiencia (Larrosa, 2006) como profesores de DG y DE