HESS J1641-463, a very hard spectrum TeV gamma-ray source in the Galactic plane

HESS J1641-463 is a unique source discovered by the High Energy Stereoscopic System (H.E.S.S.) telescope array in the multi-TeV domain. The source had been previously hidden in the extended tail of emission from the bright nearby source HESS J1640-465. However, the analysis of the very-high-energy (VHE) data from the region at energies above 4 TeV revealed this new source at a significance level of 8.5$\sigma$. HESS J1641-463 showed a moderate flux level F(E > 1 TeV) = (3.64 +/- 0.44_stat +/- 0.73_sys) 10^-13 cm^-2s^-1, corresponding to 1.8% of the Crab Nebula flux above the same energy, and a hard spectrum with a photon index Gamma = 2.07 +/- 0.1_stat +/- 0.20_sys. The light curve was investigated for evidence of variability, but none was found on both short (28-min observation) and long (yearly) timescales. HESS J1641-463 is positionally coincident with the radio supernova remnant (SNR) G338.5+0.1. There is no clear X-ray counterpart of the SNR, although Chandra and XMM-Newton data reveal some weak emission that may be associated. If the emission from HESS J1641-463 is produced by cosmic ray protons colliding with the ambient gas, then the proton spectrum extends up to 0.1 PeV (99% confidence level) and likely to higher energies, > 0.27 PeV (90% confidence level). If this is the case, then HESS J1641-463 may be a member of a larger source population contributing to the Galactic cosmic-ray flux around the knee.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherland

Contribució a l'estudi cefàlic i mandibular del Bretó Cerdà

S'ha recorregut a l'estudi de 21 caps i 18 mandíbules de cavalls de raça Bretona Cerdana d'edat superior als 4-5 anys. S'han obtingut 35 mesures cefàliques i 9 mandibulars. A partir de les variables cefàliques s'han establert 19 índexs. S'exposen els estadístics bàsics -Mitjana, Valors Màxim i Mínim, i Coeficient de Variança-. Els valors cefàlics i mandibulars es comparen amb els d'Equus hemionus. A partir de les variables estudiades, es pot deduir que el Bretó Cerdà és braquicèfal, braquicraniot i braquiprosopi. Els caràcters amidats són caràcters molt homogenis.It has been studied 21 skulls and 18 mandibles from Bretó Cerdà» horses, all of them aged more than 4-5 years. It has obtained 35 cephalic and 9 mandibular measurements. From them it has been deduced 19 indexes. Main statistical values are exposed. Cephalic and mandibular values are compared with those from Equus hemionus, too. From the studied variables it is possible to stablish the «Bretó Cerda» as a brachicephal, brachicraniot and brachiprosopied horse. The measured values are very homogeneous.Se han estudiado 21 cráneos y 18 mandíbulas de caballos de raza Bretona Ceretana, con una edad superior a los 4-5 años. Se han obtenido 35 medidas cefálicas y 9 mandibulares. A partir de las variables cefálicas se han establecido 19 índices. Se exponen los estadísticos básicos -Media, Valores Máximo y Mínimo, y Coeficiente de Variación-. Los valores cefálicos y mandibulares se comparan con los de Equus hemionus. A partir de las variables estudiadas, se deduce que el Bretón Ceretano es braquicéfalo, braquicranioto y braquiprosopio. Los caracteres medidos son caracteres muy homogéneos

The impact of EU enlargement on migration flows

This document is a report commissioned by the Home Office in order to assess the magnitude of potential migration flows to the UK after the enlargement of the European Union (EU). The countries which are expected to join the EU on 1 May 2004 are Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia and Slovenia. The aim of the report is to provide extensive information that will be helpful in evaluating the migration potential from these countries to the UK. This is done by (i) describing the socio-economic situation of the accession countries nowadays and since the early 1990s and comparing it to that of the UK and Germany, (ii) critically reviewing the existing literature that attempts to predict the effects of the current EU enlargement on migration flows, (iii) analysing the so-called Southern enlargement (the accessions of Greece, Portugal and Spain) and comparing it to the current one, and (iv) presenting a quantitative analysis of the effect of the current enlargement on migration to the UK

Tests hidrodinàmics amb el codi multidimensional FLASH

El FLASH és un codi estable i flexible, desenvolupat a la Universitat de Chicago, que permet estudiar diferents fenòmens hidrodinàmics. L'objectiu futur és desenvolupar models multidimensionals centrats en el camp de les noves per a caracteritzar algunes fases complexes del fenomen, però degut a la complexitat del codi (més de 500000 línies de programació en C++ i Fortran90), la realització d'una simulació estel.lar necessita tenir un coneixement bàsic del FLASH. Per tant, l'objectiu d'aquest treball és la realització d'alguns tests numèrics per aprendre'n el funcionament. Però a la vegada, l'objectiu és doble, ja que per utilitzar una eina de treball com el FLASH, necessitem testejar el propi codi i comprovar que és capaç de resoldre correctament diferents problemes hidrodinàmics que ja s'han simulat prèviament. Així, s'han treballat els diferents tests i hem observat que el codi FLASH és eficaç per simular-los correctament i, per tant, podem esperar que serà un bon codi per a les futures simulacions estel.lars. D'altra banda, aquest primer contacte amb el codi ens ha permès familiaritzar-nos amb l'estructura, adquirir destresa en el seu ús i començar a entendre'l, tot deixant per a més endavant l'estudi detallat dels diferents models numèrics implementats en el codi i eines auxiliars de representació gràfica

Robust Oscillator-Mediated Phase Gates Driven by Low-Intensity Pulses

Robust qubit-qubit interactions mediated by bosonic modes are central to many quantum technologies. Existing proposals combining fast oscillator-mediated gates with dynamical decoupling require strong pulses or fast control over the qubit-boson coupling. Here, we present a method based on dynamical decoupling techniques that leads to faster-than-dispersive entanglement gates with low-intensity pulses. Our method is general, i.e., it is applicable to any quantum platform that has qubits interacting with bosonic mediators via longitudinal coupling. Moreover, the protocol provides robustness to fluctuations in qubit frequencies and control fields, while also being resistant to common errors such as frequency shifts and heating in the mediator as well as crosstalk effects. We illustrate our method with an implementation for trapped ions coupled via magnetic field gradients. With detailed numerical simulations, we show that entanglement gates with infidelities of $10^{-3}$ or $10^{-4}$ are possible with current or near-future experimental setups, respectively.Comment: 7+13 pages, 3+3 figures, 2 table