3,815 research outputs found

    The core size of the Fornax dwarf Spheroidal

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    We exploit the detection of three distinct stellar subpopulations in the red giant branch of the Fornax dwarf Spheroidal to probe its density distribution. This allows us to resolve directly the evolution with radius of the dark matter mass profile. We find that a cored dark matter halo provides a perfect fit to the data, being consistent with all three stellar populations well within 1-sigma, and for the first time we are able to put constraints on the core size of such a halo. With respect to previous work, we do not strengthen the statistical exclusion of a dark matter cusp in Fornax, but we find that Navarro-Frenk-White haloes would be required to have unrealistically large scale radii in order to be compatible with the data, hence low values of the concentration parameter. We are then forced to conclude that the Fornax dwarf Spheroidal sits within a dark matter halo having a constant density core, with a core size of between 0.6 and 1.8 kpc.Comment: MNRAS Letters, submitte

    The A(Kstop,π±Σ)AA(K^-_{stop},\pi^\pm\Sigma^\mp)A' reaction on p-shell nuclei

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    This letter is concerned with the study of the KstopAπ±ΣAK^-_{stop}A\rightarrow \pi^\pm\Sigma^\mp A' reaction in p-shell nuclei, i.e., 6,7Li^{6,7}Li, 9Be^9Be, 13C^{13}C and 16O^{16}O. The π±Σ/Kstop\pi^\pm\Sigma^\mp / K^-_{stop} emission rates are reported as a function of AA. These rates are discussed in comparison with previous findings. The ratio πΣ+/π+Σ\pi^-\Sigma^+/\pi^+\Sigma^- in p-shell nuclei is found to depart largely from that on hydrogen, which provides support for large in-medium effects possibly generated by the sub-threshold Λ(1405)\Lambda(1405). The continuum momentum spectra of prompt pions and free sigmas are also discussed as well as the π±Σ\pi^\pm\Sigma^\mp missing mass behavior and the link with the reaction mechanism. The apparatus used for the investigation is the FINUDA spectrometer operating at the DAΦ\PhiNE ϕ\phi-factory (LNF-INFN, Italy).Comment: 14 pages, 5 figures, accepted for publication in Phys. Lett.

    Levantamiento del templo G. parque arqueologico de Selinunte, Trapani. Sicilia. Informe general

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    El trabajo de campo al que se refiere la presente comunicaci\uf3n, se puede considerar como la fase inicial del proyecto de levantamiento del templo G de Selinunte, ya que si bien se han podido tomar muchos datos del mismo durante la campa\uf1a de verano del 2005, quedan algunas zonas donde no ha sido posible acceder, por lo que ser\ue1 preciso completar la informaci\uf3n conforme se vaya avanzando en el modelo. La dificultad mayor vendr\ue1 con la definici\uf3n del propio modelo 3D, labor de investigaci\uf3n avanzada ya que actualmente no existen t\ue9cnicas ni metodolog\uedas de referencia a nivel mundial en el uso de escaners l\ue1ser 3d aplicados al campo de la arquitectura. Esta segunda tarea la estamos llevando a cabo, los equipos de las dos universidades, a lo largo de este a\uf1o 2006 poniendo a punto estrategias y centr\ue1ndonos en aquellos elementos singulares del conjunto arquitect\uf3nico que, a juicio de los arque\uf3logos, merezca la pena documentar con mucha precisi\uf3n. Del resto se obtendr\ue1 un modelo m\ue1s simple y menos preciso, tarea que a pesar de ello tambi\ue9n nos va a llevar mucho tiempo. Lo que hemos realizado en esta campa\uf1a ha sido una aproximaci\uf3n rigurosa al levantamiento del templo con la gu\ueda de diversos expertos en el tema, de manera que primero hemos ensayado nuevas t\ue9cnicas, como la del uso de una gr\ufaa y la gesti\uf3n del esc\ue1ner por control remoto, en segundo lugar hemos experimentado con su uso en posiciones elevadas con el operador a su lado llevando al l\uedmite los tensores para conseguir la m\ue1xima estabilidad. Posteriormente hemos probado la toma de datos desde diversos \ue1ngulos, su posterior interconexi\uf3n y su vinculaci\uf3n con redes topogr\ue1ficas as\ued como con la toma de datos tradicional y fotogram\ue9trica y para finalizar, ensayar las opciones de modelado y gesti\uf3n de los datos obtenidos

    KiDS0239-3211: A new gravitational quadruple lens candidate

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    We report the discovery of a candidate to quadrupole gravitationally lensed system KiDS0239-3211 based on the public data release 3 of the KiDS survey and machine learning techniques

    Folic acid-functionalized graphene oxide nanosheets via plasma etching as a platform to combine NIR anticancer phototherapy and targeted drug delivery

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    PEGylated graphene oxide (GO) has shown potential as NIR converting agent to produce local heat useful in breast cancer therapy, since its suitable photothermal conversion, high stability in physiological fluids, biocompatibility and huge specific surface. GO is an appealing nanomaterial for potential clinical applications combining drug delivery and photothermal therapy in a single nano-device capable of specifically targeting breast cancer cells. However, native GO sheets have large dimensions (0.5-5 mu m) such that tumor accumulation after a systemic administration is usually precluded. Herein, we report a step-by-step synthesis of folic acid-functionalized PEGylated GO, henceforth named GO-PEG-Fol, with small size and narrow size distribution (similar to 30 +/- 5 nm), and the ability of efficiently converting NIR light into heat. GO-PEG-Fol consists of a nano-GO sheet, obtained by fragmentation of GO by means of non-equilibrium plasma etching, fully functionalized with folic acid-terminated PEG(2000) chains through amidic coupling and azide-alkyne click cycloaddition, which we showed as active targeting agents to selectively recognize breast cancer cells such as MCF7 and MDA-MB-231. The GO-PEG-Fol incorporated a high amount of doxorubicin hydrochloride (Doxo) (> 33%) and behaves as NIR-light-activated heater capable of triggering sudden Doxo delivery inside cancer cells and localized hyperthermia, thus provoking efficient breast cancer death. The cytotoxic effect was found to be selective for breast cancer cells, being the IC50 up to 12 times lower than that observed for healthy fibroblasts. This work established plasma etching as a cost-effective strategy to get functionalized nano-GO with a smart combination of properties such as small size, good photothermal efficiency and targeted cytotoxic effect, which make it a promising candidate as photothermal agent for the treatment of breast cancer

    Hypernuclear spectroscopy with K^- at rest on 7^7Li, 9^9Be, 13^{13}C and 16^{16}O

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    The FINUDA experiment collected data to study the production of hypernuclei on different nuclear targets. The hypernucleus formation occurred through the strangeness-exchange reaction K^-_{stop} + \; ^AZ \rightarrow \; ^A_{\Lambda}Z + \pi^-. From the analysis of the momentum of the emerging π\pi^-, binding energies and formation probabilities of Λ7^7_{\Lambda}Li, Λ9^9_{\Lambda}Be, Λ13^{13}_{\Lambda}C and Λ16^{16}_{\Lambda}O have been measured and are here presented. The behavior of the formation probability as a function of the atomic mass number A is also discussed.Comment: Accepted for publication in PL

    KiDS-SQuaD: The KiDS Strongly lensed Quasar Detection project

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    New methods have been recently developed to search for strong gravitational lenses, in particular lensed quasars, in wide-field imaging surveys. Here, we compare the performance of three different, morphology- and photometry- based methods to find lens candidates over the Kilo-Degree Survey (KiDS) DR3 footprint (440 deg2^2). The three methods are: i) a multiplet detection in KiDS-DR3 and/or Gaia-DR1, ii) direct modeling of KiDS cutouts and iii) positional offsets between different surveys (KiDS-vs-Gaia, Gaia-vs-2MASS), with purpose-built astrometric recalibrations. The first benchmark for the methods has been set by the recovery of known lenses. We are able to recover seven out of ten known lenses and pairs of quasars observed in the KiDS DR3 footprint, or eight out of ten with improved selection criteria and looser colour pre-selection. This success rate reflects the combination of all methods together, which, taken individually, performed significantly worse (four lenses each). One movelty of our analysis is that the comparison of the performances of the different methods has revealed the pros and cons of the approaches and, most of all, the complementarities. We finally provide a list of high-grade candidates found by one or more methods, awaiting spectroscopic follow-up for confirmation. Of these, KiDS 1042+0023 is to our knowledge the first confirmed lensed quasar from KiDS, exhibiting two quasar spectra at the same source redshift at either sides of a red galaxy, with uniform flux-ratio f1.25f\approx1.25 over the wavelength range 0.45μm<λ<0.75μm.0.45\mu\mathrm{m}<\lambda<0.75\mu\mathrm{m}.Comment: 12 pages, 4 figures, 4 tables, accepted for publication in MNRA
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