| 1. |
- Ahrens, Maryon, et al.
(author)
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Multi-messenger Observations of a Binary Neutron Star Merger
- 2017
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In: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 848:2
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Journal article (peer-reviewed)abstract
- 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 similar to 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 deg(2) 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 M-circle dot. 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 similar to 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 similar to 10 days. Following early non-detections, X-ray and radio emission were discovered at the transient's position similar to 9 and similar to 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.
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| 2. |
- Fontana, Enrico, et al.
(author)
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Nominated procurement and the indirect control of nominated sub-suppliers: Evidence from the Sri Lankan apparel supply chain
- 2021
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In: Journal of Business Research. - : Elsevier BV. - 0148-2963 .- 1873-7978. ; 127, s. 179-192
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Journal article (peer-reviewed)abstract
- This article describes and discusses nominated procurement as a means through which buyers select sub-suppliers to achieve sustainability compliance upstream in emerging economies' supply chains. Hence, it critically examines the ways buyers articulate nominated procurement and the unfolding supply chain consequences. Based on in-depth interviews and fieldwork in the Sri Lankan apparel supply chain, the findings indicate that buyers accomplish sustainability compliance among their sub-suppliers while prioritizing their own business agenda. In doing so, however, buyers perpetuate “suboptimal compliance” of raw material suppliers and “sandwiching” of direct suppliers as harmful consequences on the supply chain. These consequences link theoretically with commercial, geographical, compliance and extended-compliance pressure. This article contributes to the advancement of the Sustainable Supply Chain Management literature by theorizing about nominated procurement, direct and indirect pressure, and pointing to the supply chain consequences beyond achievements in sustainability compliance.
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| 3. |
- Morosan, D. E., et al.
(author)
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LOFAR tied-array imaging of Type III solar radio bursts
- 2014
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 568, s. articl no. A67-
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Journal article (peer-reviewed)abstract
- Context. The Sun is an active source of radio emission which is often associated with energetic phenomena such as solar flares and coronal mass ejections (CMEs). At low radio frequencies (
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