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- Marconi, A., et al.
(author)
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ELT-HIRES, the high resolution spectrograph for the ELT : results from the Phase A study
- 2018
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In: GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY VII. - : SPIE-INT SOC OPTICAL ENGINEERING. - 9781510619586
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Conference paper (peer-reviewed)abstract
- We present the results from the phase A study of ELT-HIRES, an optical-infrared High Resolution Spectrograph for ELT, which has just been completed by a consortium of 30 institutes from 12 countries forming a team of about 200 scientists and engineers. The top science cases of ELT-HIRES will be the detection of life signatures from exoplanet atmospheres, tests on the stability of Nature's fundamental couplings, the direct detection of the cosmic acceleration. However, the science requirements of these science cases enable many other groundbreaking science cases. The baseline design, which allows to fulfil the top science cases, consists in a modular fiber fed cross-dispersed echelle spectrograph with two ultra-stable spectral arms providing a simultaneous spectral range of 0.4-1.8 pm at a spectral resolution of 100, 000. The fiber-feeding allows ELT-HIRES to have several, interchangeable observing modes including a SCAO module and a small diffraction-limited IFU.
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- Marconi, A., et al.
(author)
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EELT-HIRES the high-resolution spectrograph for the E-ELT
- 2016
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In: GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY VI. - : SPIE. - 9781510601963
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Conference paper (peer-reviewed)abstract
- The first generation of E-ELT instruments will include an optical infrared High Resolution Spectrograph, conventionally indicated as EELT-HIRES, which will be capable of providing unique breakthroughs in the fields of exoplanets, star and planet formation, physics and evolution of stars and galaxies, cosmology and fundamental physics. A 2-year long phase A study for EELT-HIRES has just started and will be performed by a consortium composed of institutes and organisations from Brazil, Chile, Denmark, France, Germany, Italy, Poland, Portugal, Spain, Sweden, Switzerland and United Kingdom. In this paper we describe the science goals and the preliminary technical concept for EELT-HIRES which will be developed during the phase A, as well as its planned development and consortium organisation during the study.
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- Cheetham, A. C., et al.
(author)
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Spectral and orbital characterisation of the directly imaged giant planet HIP 65426 b
- 2019
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 622
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Journal article (peer-reviewed)abstract
- HIP 65426 b is a recently discovered exoplanet imaged during the course of the SPHERE-SHINE survey. Here we present new L' and M' observations of the planet from the NACO instrument at the VLT from the NACO-ISPY survey, as well as a new Y-H spectrum and K-band photometry from SPHERE-SHINE. Using these data, we confirm the nature of the companion as a warm, dusty planet with a mid-L spectral type. From comparison of its SED with the BT-Settl atmospheric models, we derive a best-fit effective temperature of T-eff = 1618 +/- 7 K, surface gravity log g = 3 : 78(-0.03)(+0.04) and radius R = 1.17 +/- 0.04 R-J (statistical uncertainties only). Using the DUSTY and COND isochrones we estimate a mass of 8 +/- 1 MJ. Combining the astrometric measurements from our new datasets and from the literature, we show the first indications of orbital motion of the companion (2.6 sigma significance) and derive preliminary orbital constraints. We find a highly inclined orbit (i = 107(+13)(-10) deg) with an orbital period of 800(+1200)(-400) yr. We also report SPHERE sparse aperture masking observations that investigate the possibility that HIP 65426 b was scattered onto its current orbit by an additional companion at a smaller orbital separation. From this data we rule out the presence of brown dwarf companions with masses greater than 16 M-J at separations larger than 3AU, significantly narrowing the parameter space for such a companion.
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- Paolucci, F., et al.
(author)
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Interoperable multi-domain delay-aware provisioning using Segment Routing monitoring and BGP-LS advertisement
- 2016
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In: ECOC 2016 42th European Conference on Optical Communication Proceedings, September 18 - 22, 2016, Düsseldorf, Germany. - : Institute of Electrical and Electronics Engineers (IEEE). - 9783800742745 ; , s. 190-192
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Conference paper (peer-reviewed)abstract
- This paper demonstrates a multi-domain SDN orchestrator using delay information to provision network services using BGP-LS and a novel monitoring system enabled by Segment Routing. Moreover, it is the first implementation and interoperability of the BGP-LS extensions for TE metrics.
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- Massarotti, D., et al.
(author)
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What happens in Josephson junctions at high critical current densities
- 2017
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In: Fizika Nizkih Temperatur. - : AIP Publishing. - 1816-0328 .- 0132-6414. ; 43:7, s. 816-823
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Journal article (peer-reviewed)abstract
- The impressive advances in material science and nanotechnology are more and more promoting the use of exotic barriers and/or superconductors, thus paving the way to new families of Josephson junctions. Semiconducting, ferromagnetic, topological insulator and graphene barriers are leading to unconventional and anomalous aspects of the Josephson coupling, which might be useful to respond to some issues on key problems of solid state physics. However, the complexity of the layout and of the competing physical processes occurring in the junctions is posing novel questions on the interpretation of their phenomenology. We classify some significant behaviors of hybrid and unconventional junctions in terms of their first imprinting, i.e. current-voltage curves, and propose a phenomenological approach to describe some features of junctions characterized by relatively high critical current densities Jc. Accurate arguments on the distribution of switching currents will provide quantitative criteria to understand physical processes occurring in high-Jc junctions. These notions are universal and apply to all kinds of junctions. PACS: 74.72.-h Cuprate superconductors; 85.25.Cp Josephson devices; 74.50.+r Tunneling phenomena; Josephson effects.
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- Muhammad, Ajmal, et al.
(author)
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On the Scalability of Connectivity Services in a Multi-Operator Orchestrator Sandbox
- 2018
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In: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781943580385
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Conference paper (peer-reviewed)abstract
- The paper investigates the performance of a multi-domain orchestrator (MdO) deployed in a real multi-domain European testbed. Results show how the MdO prototype scales well with the number of domains advertised and connectivity services provisioned.
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- Sgambelluri, A., et al.
(author)
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Orchestrating QoS-based Connectivity Services in a Multi-Operator Sandbox
- 2019
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In: Journal of Optical Communications and Networking. - : OPTICAL SOC AMER. - 1943-0620 .- 1943-0639. ; 11:2, s. A196-A208
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Journal article (peer-reviewed)abstract
- One of the main features of 5G networks is the coordinated orchestration of both information technology (IT) and connectivity resources. This enables the deployment of a flexible and programmable architecture able to provision end-to-end services with different (and sometimes quite) stringent quality of service (QoS) constraints. In this paradigm, service orchestration may take place over single or multiple administrative domains. The 5G Exchange (5GEx) project, building on the software-defined network and the network function virtualization (NFV) concepts, targets the design and the implementation of a multi-domain orchestrator (MdO) prototype for the automatic provisioning of network service across multiple administrative domains. This paper presents an architectural solution, designed and implemented in the context of the 5GEx MdO prototype, that can be used to establish end-to-end connectivity tunnels with QoS constraints (i.e., bandwidth and/or end-to-end delay) connecting virtualized network functions deployed in remote data centers controlled by different providers by means of an innovative stateful backward recursive path-computation-element based computation procedure. The proposed solution has been experimentally validated in terms of scalability, reliability, and end-to-end workflow proof-of-concept. Results show how the designed solution permits the automatic establishment of QoS-based end-to-end tunnels spanning across multi-technology and multi-operator network domains. The orchestration scheme does not present scalability issues for either the advertisement of resources or for the provisioning of connectivity services. Moreover, no issues have been identified from the reliability point of view.
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- Arpaia, Riccardo, 1985, et al.
(author)
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High-temperature superconducting nanowires for photon detection
- 2015
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In: Physica C: Superconductivity and its Applications. - : Elsevier BV. - 0921-4534. ; 509, s. 16-21
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Journal article (peer-reviewed)abstract
- The possible use of high-temperature superconductors (HTS) for realizing superconducting nanowire single-photon detectors is a challenging, but also promising, aim because of their ultrafast electron relaxation times and high operating temperatures. The state-of-the-art HTS nanowires with a 50-nm thickness and widths down to 130 nm have been fabricated and tested under a 1550-nm wavelength laser irradiation. Experimental results presenting both the amplitude and rise times of the photoresponse signals as a function of the normalized detector bias current, measured in a wide temperature range, are discussed. The presence of two distinct regimes in the photoresponse temperature dependence is clearly evidenced, indicating that there are two different response mechanisms responsible for the HTS photoresponse mechanisms.
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