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Many forefront astrophysical studies are based on imaging survey data. There is a clear need to complement them with dedicated spectroscopic surveys, especially at medium and high resolution. While some 4-m class instruments exist or have been planned, a real gain can be obtained by transforming the CFHT in a 10-m telescope to perform wide-field, high-multiplexing, multi object spectroscopy by the end of 2020. This talk will report on the scientific and technical results from the current conceptual design study. Some innovative design solutions have been proposed to meet technical and programmatic requirements with existing technologies.

Il futuro degli studi exoplanetari e’ chiaramente focalizzato attorno ad osservazioni nell’ottico e nel vicino Infrarosso. Tuttavia l’eventuale realizzazione di una grande missione per astronomia X con un telescopio focalizzante con area efficace di almeno 2 sq. m. pone la questione se nel campo degli studi esoplanetari ci sia una qualche interessante spazio per le osservazioni in raggi X. Sulla scorta del risultati del lavoro in progress per la scrittura del WP/WB per Athena+ illustrero’ brevemente le possibilita’ di condurre studi esoplanetari in banda X. Mi soffermero’ sia sulla rivelabilita’ in fotometria a larga banda dei transiti e su le informazioni che si potrebbero estrarre dalle curve di luce in banda X, che sulle, meno certe, possibilita’ di cercare traccianti spettroscopici sulla base delle nostre attuali conoscenze dei corpi del Sistema Solare.

High-energy observations of gamma-ray bursts (GRBs) with the Fermi satellite have enabled detailed studies of the temporal and spectral behaviour over seven decades in energy (from 8 keV to ~100 GeV) and provided new insight into the emission mechanisms of these powerful outbursts. I will briefly outline some highlights from Fermi GRBs observations, along with their possible implications. Key observational results include: 1) the detection of an additional spectral component at GeV energies; 2) the late onset and longer duration of the high-energy (>100 MeV) emission, compared to the low-energy (<1 MeV) prompt emission; 3) stringent limits on the variation of the speed of light with photon energy; 4) evidence for a subset of extremely relativistic and energetic stellar explosions, challenging some of the most popular GRB models.

Impacts of falling fragments observed after the eruption of a filament in a solar flare on June 7, 2011 are similar to those inferred for accretion flows on young stellar objects. As imaged in the UV/EUV by the Atmospheric Imaging Assembly on-board the Solar Dynamics Observatory, many impacts of dark, dense matter display uncommonly intense, compact brightenings. High-resolution hydrodynamic simulations show that such bright hot spots occur when high-density plasma impacts at several hundred km/s, producing high-energy emission as in stellar accretion. Implications are discussed.

I present broad-band (350-2500nm) mid-resolution X-Shooter/VLT spectra of three accreting young stellar objects with spectral types between M5 and M8, i.e. near or within the brown dwarf regime. These observations provide a rich database of accretion diagnostics from the Br$\gamma$ and Pa$\beta$ lines in the near-IR to the Balmer jump in the UV including the full optical band with the Balmer series and He\,$\lambda$5876 and the Ca\,IRT. Finally, outflows can be traced through forbidden line emission. In this talk I focus on three of the most interesting targets from our survey: (1) FU\,Tau\,A, overluminous in the HR diagram with respect to predictions of pre-main sequence evolutionary models; (2) TWA-27 (alias 2M1207-39), the planet-hosting prototype for an accreting brown dwarf; (3) Par-Lup3-4, a young stellar object with edge-on disk driving a jet.

The Hi-C (High resolution Coronal imager) sounding rocket has provided the highest resolution EUV solar coronal images ever obtained, resolving structures down to ~0.3 arcsec. The unprecedented spatial and temporal resolution of Hi-C data has revealed several new features, including highly braided coronal loops undergoing reconnection, and very rapid variability (down to ~15s) in the moss of bright hot loops. I will review some of the first results obtained from Hi-C data, focusing on the new insights they provide in coronal heating. I will also present a very brief overview of the Interface Region Imaging Spectrograph (IRIS), which will be launched on June 26th 2013.

X-ray sources with very few counts can be identified with low-noise in X-ray detectors, especially for the Advanced CCD Imaging Spectrometer (ACIS-I) camera on board the Chandra X-ray Observatory. Most of these studies concerns to the large populations of faint X-ray sources associated with pre- main sequence stars (PMS). Several of these sources seems to be faint enough for parametric spectral modeling, even in case of simple thermal models. On last years, some attempts were performed to estimates the intrinsic broadband X-ray fluxes and absorption from gas along the line of sight to these sources. However, the relationship between absorption (NH), temperatures (kT), intrinsic flux (F) and their respective errors, with the source count statistic, are unknown. Here, based on an extensive set of X-ray spectral simulations (~80000), we present the relationship between these quantities in terms of the source counts, as well as, the flux error estimation in terms of NH, kT ans photon statistic of the sources. In perspective, this study can offer a precise tool for better tailored observational proposals.

Anisotropic emission of gravitational waves during the coalescence of supermassive black hole binaries can deliver a large “kick” velocity to the new BH (v~10^₃ km/s). N-body simulations predict that, for kick velocities larger than 40% of the galactic escape velocity, the BH may experience long lived (few Gyr) oscillations with amplitudes comparable with the size of the galactic core (~10^2 pc), suggesting that offset BHs may be common, even in nearby ellipticals. In order to search for such offsets, we perform a photometric analysis of a sample of 14 “core” elliptical galaxies using archival HST observations. Typical recovered offsets are within 1% of the core radius. In contrast, statistical arguments based on N-body simulations show that the typical probability to observe an offset larger than 0.1 core radii (~10 pc) is of order of 70% for a single galaxy. This is derived under the assumption that the BH binary coalescence produced a moderately large kick (v ~ 250 km/s) at the time of the last merger. Assuming that all galaxies in the sample experienced at least one such merger during their lifetime, the probability to observe no offsets larger than 1% the core radius over the sample is of order of 10^-8.

Nearby star-forming regions are ideal laboratories to study high-energy emission of different stellar populations, from very massive stars to brown dwarfs. NGC 2023 is a reflection nebula situated to the south of the Orion B. In this work, we present a comprehensive study of X-ray emitters in the region of NGC 2023 and its surroundings. We combine optical and infrared data to determine physical properties (mass, temperature, luminosity, presence of accretion disks) of the stars detected in an XMM-Newton observation. This study has allowed us to analyze spectral energy distribution of these stars for the first time and determine their evolutionary stage. Properties of the X-ray emitting plasma of these stars are compared to those found in other nearby star-forming regions. The results indicate that the stars that are being formed in this region have characteristics, in terms of physical properties and luminosity function, similar to those found in the Taurus-Auriga molecular complex. In addition we will present the first results for the study of Orion B molecular cloud carried out with Infrared and X-ray photometry, where we found 604 source in the X-ray observations.

Activity cycles are of major interest to understand the solar physics and the influence of the Sun in the Earth’s climate. The effects of solar activity in the Earth are mainly produced by the high energy photons and particles. The solar coronal cycle varies as much as a factor of 50, as measured in terms of Lx. But there is little known on the amplitude of this cycle in the past. So far there were only three stars others than the Sun with a known coronal cycle, all of them in rather old K dwarfs with low activity levels. In a recent paper we have found the coronal cycle of Iota Horologii, the star with the shortest chromospheric cycle known to date. This star represents the first coronal cycle in an active star, in a G dwarf, and in a young star. Iota Hor is a solar-like star with an age of ~600 Myr, the age at which the life appeared on Earth. This cycle may represent the first coronal cycles in the evolution of a solar-like star.