A 2D position sensitive germanium detector for spectroscopy and polarimetry of high-energetic x-rays

We report on a first prototype 2D μ-strip germanium detector, developed at IKP-Jülich, and its performance test at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Beside an accurate determination of the detector response function, the polarization sensitivity has been addressed in this study. For this purpose photon beams at energies of 60 keV and 210 keV have been used

Relativistic quantum dynamics in strong fields: Photon emission from heavy, few-electron ions

Recent progress in the study of the photon emission from highly-charged heavy ions is reviewed. These investigations show that high-$Z$ ions provide a unique tool for improving the understanding of the electron-electron and electron-photon interaction in the presence of strong fields. Apart from the bound-state transitions, which are accurately described in the framework of Quantum Electrodynamics, much information has been obtained also from the radiative capture of (quasi-) free electrons by high-$Z$ ions. Many features in the observed spectra hereby confirm the inherently relativistic behavior of even the simplest compound quantum systems in Nature.Comment: Version 18/11/0

Bone marrow adipose tissue is a unique adipose subtype with distinct roles in glucose homeostasis

Bone marrow adipose tissue (BMAT) comprises >10% of total adipose mass, yet unlike white or brown adipose tissues (WAT or BAT) its metabolic functions remain unclear. Herein, we address this critical gap in knowledge. Our transcriptomic analyses revealed that BMAT is distinct from WAT and BAT, with altered glucose metabolism and decreased insulin responsiveness. We therefore tested these functions in mice and humans using positron emission tomography-computed tomography (PET/CT) with 18F-fluorodeoxyglucose. This revealed that BMAT resists insulin- and cold-stimulated glucose uptake, while further in vivo studies showed that, compared to WAT, BMAT resists insulin-stimulated Akt phosphorylation. Thus, BMAT is functionally distinct from WAT and BAT. However, in humans basal glucose uptake in BMAT is greater than in axial bones or subcutaneous WAT and can be greater than that in skeletal muscle, underscoring the potential of BMAT to influence systemic glucose homeostasis. These PET/CT studies characterise BMAT function in vivo, establish new methods for BMAT analysis, and identify BMAT as a distinct, major adipose tissue subtype

Joint Constraints on Galactic Diffuse Neutrino Emission from the ANTARES and IceCube Neutrino Telescopes

[EN] The existence of diffuse Galactic neutrino production is expected from cosmic-ray interactions with Galactic gas and radiation ¿elds. Thus, neutrinos are a unique messenger offering the opportunity to test the products of Galactic cosmic-ray interactions up to energies of hundreds of TeV. Here we present a search for this production using ten years of Astronomy with a Neutrino Telescope and Abyss environmental RESearch (ANTARES) track and shower data, as well as seven years of IceCube track data. The data are combined into a joint likelihood test for neutrino emission according to the KRAg model assuming a 5 PeV per nucleon Galactic cosmic-ray cutoff. No signi¿cant excess is found. As a consequence, the limits presented in this Letter start constraining the model parameter space for Galactic cosmic-ray production and transport.Albert, A.; Andre, M.; Anghinolfi, M.; Ardid Ramírez, M.; Aubert, J-.; Aublin, J.; Avgitas, T.... (2018). Joint Constraints on Galactic Diffuse Neutrino Emission from the ANTARES and IceCube Neutrino Telescopes. The Astrophysical Journal. 868(2):1-7. https://doi.org/10.3847/2041-8213/aaeecfS178682Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Anderson, T. (2017). Search for Astrophysical Sources of Neutrinos Using Cascade Events in IceCube. The Astrophysical Journal, 846(2), 136. doi:10.3847/1538-4357/aa8508Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., … Archinger, M. (2015). A COMBINED MAXIMUM-LIKELIHOOD ANALYSIS OF THE HIGH-ENERGY ASTROPHYSICAL NEUTRINO FLUX MEASURED WITH ICECUBE. The Astrophysical Journal, 809(1), 98. doi:10.1088/0004-637x/809/1/98Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., … Anderson, T. (2017). All-sky Search for Time-integrated Neutrino Emission from Astrophysical Sources with 7 yr of IceCube Data. The Astrophysical Journal, 835(2), 151. doi:10.3847/1538-4357/835/2/151Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Anderson, T. (2017). Constraints on Galactic Neutrino Emission with Seven Years of IceCube Data. The Astrophysical Journal, 849(1), 67. doi:10.3847/1538-4357/aa8dfbAartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Ansseau, I. (2017). The IceCube Neutrino Observatory: instrumentation and online systems. Journal of Instrumentation, 12(03), P03012-P03012. doi:10.1088/1748-0221/12/03/p03012Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., … Berenji, B. (2012). FERMI-LAT OBSERVATIONS OF THE DIFFUSE γ-RAY EMISSION: IMPLICATIONS FOR COSMIC RAYS AND THE INTERSTELLAR MEDIUM. The Astrophysical Journal, 750(1), 3. doi:10.1088/0004-637x/750/1/3Adrián-Martínez, S., Ageron, M., Aguilar, J. A., Samarai, I. A., Albert, A., André, M., … Ardid, M. (2012). The positioning system of the ANTARES Neutrino Telescope. Journal of Instrumentation, 7(08), T08002-T08002. doi:10.1088/1748-0221/7/08/t08002Ageron, M., Aguilar, J. A., Al Samarai, I., Albert, A., Ameli, F., André, M., … Ardid, M. (2011). ANTARES: The first undersea neutrino telescope. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 656(1), 11-38. doi:10.1016/j.nima.2011.06.103Ahn, H. S., Allison, P., Bagliesi, M. G., Beatty, J. J., Bigongiari, G., Childers, J. T., … Zinn, S. Y. (2010). DISCREPANT HARDENING OBSERVED IN COSMIC-RAY ELEMENTAL SPECTRA. The Astrophysical Journal, 714(1), L89-L93. doi:10.1088/2041-8205/714/1/l89Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Basa, S. (2017). New constraints on all flavor Galactic diffuse neutrino emission with the ANTARES telescope. Physical Review D, 96(6). doi:10.1103/physrevd.96.062001Antoni, T., Apel, W. D., Badea, A. F., Bekk, K., Bercuci, A., Blümer, J., … Zabierowski, J. (2005). KASCADE measurements of energy spectra for elemental groups of cosmic rays: Results and open problems. Astroparticle Physics, 24(1-2), 1-25. doi:10.1016/j.astropartphys.2005.04.001Apel, W. D., Arteaga-Velázquez, J. C., Bekk, K., Bertaina, M., Blümer, J., Bozdog, H., … Cossavella, F. (2013). KASCADE-Grande measurements of energy spectra for elemental groups of cosmic rays. Astroparticle Physics, 47, 54-66. doi:10.1016/j.astropartphys.2013.06.004Gaggero, D., Grasso, D., Marinelli, A., Taoso, M., & Urbano, A. (2017). Diffuse Cosmic Rays Shining in the Galactic Center: A Novel Interpretation of H.E.S.S. and Fermi-LAT γ -Ray Data. Physical Review Letters, 119(3). doi:10.1103/physrevlett.119.031101Gaggero, D., Grasso, D., Marinelli, A., Urbano, A., & Valli, M. (2015). THE GAMMA-RAY AND NEUTRINO SKY: A CONSISTENT PICTURE OF FERMI -LAT, MILAGRO, AND ICECUBE RESULTS. The Astrophysical Journal, 815(2), L25. doi:10.1088/2041-8205/815/2/l25Gaggero, D., Urbano, A., Valli, M., & Ullio, P. (2015). Gamma-ray sky points to radial gradients in cosmic-ray transport. Physical Review D, 91(8). doi:10.1103/physrevd.91.083012Vladimirov, A. E., Digel, S. W., Jóhannesson, G., Michelson, P. F., Moskalenko, I. V., Nolan, P. L., … Strong, A. W. (2011). GALPROP WebRun: An internet-based service for calculating galactic cosmic ray propagation and associated photon emissions. Computer Physics Communications, 182(5), 1156-1161. doi:10.1016/j.cpc.2011.01.01

ANTARES and IceCube Combined Search for Neutrino Point-like and Extended Sources in the Southern Sky

[EN] A search for point-like and extended sources of cosmic neutrinos using data collected by the ANTARES and IceCube neutrino telescopes is presented. The data set consists of all the track-like and shower-like events pointing in the direction of the Southern Sky included in the nine-year ANTARES point-source analysis, combined with the throughgoing track-like events used in the seven-year IceCube point-source search. The advantageous ¿eld of view of ANTARES and the large size of IceCube are exploited to improve the sensitivity in the Southern Sky by a factor of ~2 compared to both individual analyses. In this work, the Southern Sky is scanned for possible excesses of spatial clustering, and the positions of preselected candidate sources are investigated. In addition, special focus is given to the region around the Galactic Center, whereby a dedicated search at the location of SgrA* is performed, and to the location of the supernova remnant RXJ 1713.7-3946. No signi¿cant evidence for cosmic neutrino sources is found, and upper limits on the ¿ux from the various searches are presented.The authors of the IceCube Collaboration acknowledge the support from the following agencies and institutions: USA-U.S. National Science Foundation-Office of Polar Programs, U.S. National Science Foundation-Physics Division, Wisconsin Alumni Research Foundation, Center for High Throughput Computing (CHTC) at the University of Wisconsin-Madison, Open Science Grid (OSG), Extreme Science and Engineering Discovery Environment (XSEDE), U.S. Department of Energy-National Energy Research Scientific Computing Center, Particle astrophysics research computing center at the University of Maryland, Institute for Cyber-Enabled Research at Michigan State University, and Astroparticle physics computational facility at Marquette University; Belgium-Funds for Scientific Research (FRS-FNRS and FWO), FWO Odysseus and Big Science programmes, and Belgian Federal Science Policy Office (Belspo); Germany-Bundesministerium fur Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Initiative and Networking Fund of the Helmholtz Association, Deutsches Elektronen Synchrotron (DESY), and High Performance Computing Cluster of the RWTH Aachen; Sweden-Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation; Australia - Australian Research Council; Canada-Natural Sciences and Engineering Research Council of Canada, Calcul Quebec, Compute Ontario, Canada Foundation for Innovation, WestGrid, and Compute Canada; Denmark-Villum Fonden, Danish National Research Foundation (DNRF), Carlsberg Foundation; New Zealand-Marsden Fund; Japan-Japan Society for Promotion of Science (JSPS) and Institute for Global Prominent Research (IGPR) of Chiba University; Korea-National Research Foundation of Korea (NRF); Switzerland-Swiss National Science Foundation (SNSF); United Kingdom-Department of Physics, University of Oxford.Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.; Aublin, J.... (2020). ANTARES and IceCube Combined Search for Neutrino Point-like and Extended Sources in the Southern Sky. The Astrophysical Journal. 892(2):1-12. https://doi.org/10.3847/1538-4357/ab7afbS112892

Combined search for neutrinos from dark matter self-annihilation in the Galactic Center with ANTARES and IceCube

[EN] We present the results of the first combined dark matter search targeting the Galactic Center using the ANTARES and IceCube neutrino telescopes. For dark matter particles with masses from 50 to 1000 GeV, the sensitivities on the self-annihilation cross section set by ANTARES and IceCube are comparable, making this mass range particularly interesting for a joint analysis. Dark matter self-annihilation through the ¿+¿¿, ¿+¿¿, b¯b, and W+W¿ channels is considered for both the Navarro-Frenk-White and Burkert halo profiles. In the combination of 2101.6 days of ANTARES data and 1007 days of IceCube data, no excess over the expected background is observed. Limits on the thermally averaged dark matter annihilation cross section h¿A¿i are set. These limits present an improvement of up to a factor of 2 in the studied dark matter mass range with respect to the individual limits published by both collaborations. When considering dark matter particles with a mass of 200 GeV annihilating through the ¿þ¿¿ channel, the value obtained for the limit is 7.44 × 10¿24 cm3 s¿1 for the Navarro-Frenk-White halo profile. For the purpose of this joint analysis, the model parameters and the likelihood are unified, providing a benchmark for forthcoming dark matter searches performed by neutrino telescopes.The authors from the ANTARES Collaboration acknowledge the financial support of the following funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et auxenergies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11IDEX-0005-02), Labex OCEVU (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Junta de Andalucia (ref. SOMM17/6104/UGR), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and CC-IN2P3 for the computing facilities. The authors from the IceCube Collaboration gratefully acknowledge the support from the following agencies and institutions: USA-U.S. National Science Foundation-Office of Polar Programs, U.S. National Science Foundation-Physics Division, Wisconsin Alumni Research Foundation, Center for High Throughput Computing (CHTC) at the University of Wisconsin-Madison, Open Science Grid (OSG), Extreme Science and Engineering Discovery Environment (XSEDE), U.S. Department of Energy-National Energy Research Scientific Computing Center, Particle astrophysics research computing center at the University of Maryland, Institute for Cyber-Enabled Research at Michigan State University, and Astroparticle physics computational facility at Marquette University; Belgium-Funds for Scientific Research (FRS-FNRS and FWO), FWO Odysseus and Big Science programmes, and Belgian Federal Science Policy Office (Belspo); Germany-Bundesministerium fur Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Initiative and Networking Fund of the Helmholtz Association, Germany-Deutsches Elektronen Synchrotron (DESY), and High Performance Computing cluster of the RWTH Aachen; Sweden-Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation; Australia-Australian Research Council; Canada-Natural Sciences and Engineering Research Council of Canada, Calcul Quebec, Compute Ontario, Canada Foundation for Innovation, WestGrid, and Compute Canada; Denmark-Villum Fonden, Danish National Research Foundation (DNRF), Carlsberg Foundation; New Zealand-Marsden Fund; Japan-Japan Society for Promotion of Science (JSPS) and Institute for Global Prominent Research (IGPR) of Chiba University; Korea-National Research Foundation of Korea (NRF); Switzerland-Swiss National Science Foundation (SNSF); United Kingdom-Department of Physics, University of Oxford. The IceCube collaboration acknowledges the significant contributions to this manuscript from Sebastian Baur, Nadege Iovine and Sara Rebecca Gozzini.Albert, A.; Andre, M.; Anghinolfi, M.; Ardid Ramírez, M.; Aubert, J.; Aublin, J.; Baret, B.... (2020). Combined search for neutrinos from dark matter self-annihilation in the Galactic Center with ANTARES and IceCube. Physical Review D: covering particles, fields, gravitation, and cosmology. 102(8):1-13. https://doi.org/10.1103/PhysRevD.102.082002S113102

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