The origin of ultra-high energy cosmic rays (UHECR) has been widely regarded as one ofthe major questions in the frontiers of particle astrophysics. Gamma ray bursts (GRB), themost violent explosions in the universe second only to the Big Bang, have been a popularcandidate site for UHECR productions. The recent IceCube report on the non-observation ofGRB induced neutrinos therefore attracts wide attention. This dilemma requires aresolution: either the assumption of GRB as UHECR accelerator is to be abandoned or theexpected GRB induced neutrino yield was wrong. It has been pointed out that IceCube hasoverestimated the neutrino flux at GRB site by a factor of ~5. In this paper we pointout that, in addition to the issue of neutrino production at source, the neutrinooscillation and the possible neutrino decay during their flight from GRB to Earth shouldfurther reduce the detectability of IceCube, which is most sensitive to the muon-neutrinoflavor as far as point-source identification is concerned. Specifically, neutrinooscillation will reduce the muon-neutrino flavor ratio from 2/3 per neutrino at GRB sourceto 1/3 on Earth, while neutrino decay, if exists and under the assumption of normalhierarchy of mass eigenstates, would result in a further reduction of muon-neutrino ratioto 1/8. With these in mind, we note that there have been efforts in recent years inpursuing other type of neutrino telescopes based on Askaryan effect, which can inprinciple observe and distinguish all three flavors with comparable sensitivities. Suchnew approach may therefore be complementary to IceCube in shedding more lights on thiscosmic accelerator question.

The dynamical state of a multiple planet system reflects the underlying processes of planet formation and orbital evolution. Radial velocity planet searches have yielded several systems that appear to be in or near a low-order mean-motion resonance, including several near a 2:1 mean-motion ratio. Still more systems apparently contain one eccentric planet. We demonstrate that many of these systems are indistinguishable from a system with two planets in a 2:1 mean-motion ratio, and outline a framework for determining how often the observed, apparently-single planets are likely to have such a second planet present.

The analysis of mid-IR emission suggests that a population of PAH-related very smallgrains containing a few hundreds of atoms are present in the deep regions of molecularclouds,although no specific species has been identified yet. In this review,we discussseveral candidates for these grains: neutral and ionised PAH clusters and complexes ofPAHs with Si atoms. The theoretical modelling of the properties of such molecularcomplexes or nanograins is a challenging task. We first present an overview of quantumchemistry derived models which can be efficiently used on-the-fly in extensive sampling ofthe potential energy surfaces,as required by structural optimization,classical moleculardynamics or Monte Carlo algorithms. From the simulations,various observables can bedetermined,such as the binding energies,finite temperature IR spectra,nucleation andevaporation rates. We discuss the relevance of those candidates in the molecular cloudsphotodissociation regions and propose constrains and perspectives for the nature and sizeof those very small grains.

Observations of the interstellar medium (ISM) reveal its fractalstructure over a large range of scales. The quantitative description shows that the ISM consists mainly of surfaces, so that the stellar UV-radiation can deeply penetrate intothe ISM and in consequence dominates its physical and chemical conditions. Thus, the bulk of the ISM can be identified as photon dominated regions (PDRs). A simple model with the proper fractal characteristics is that of an ensemble of spherical clumps with a power-law mass spectrum and a power-law mass-size relation. Hence, we model the FIR line emission of the molecular gasby the integrated emission of such an ensemble, calculating the emission of individual clumps with the KOSMA-τ PDR code. This clumpy PDR-model, with observationally constrained parameters, is fitted to the CO, [C i], and [O i] emission along the Galactic plane as observed by the FIRAS instrument abord the COBE satellite. The FIR line intensity distribution with Galactic longitude is reproduced within factors of about 2. The predicted [C ii] 158 μm line intensity and FIR continuum emission also coincide with the observations.

During its mission Gaia will give access to a so far never reached astrometric accuracy of a large number of Solar System objects. Nevertheless some of these Gaia observations could be efficiently completed by ground-based observations. This will allow us to get a better understanding of the dynamical and physical properties of these objects. We present a general overview of these cases.

The number of experiments on-board Lomonosov spacecraft are preparing now at SINP MSU inco-operation with other organisations. The main idea of Lomonosov mission is to studyextreme astrophysical phenomena, such as cosmic gamma-ray bursts and ultra-high energycosmic rays. These phenomena connect with processes occurred in very distant astrophysicalobjects of the Early Universe and give us information about first stages of Universeevolution. Thus, the Lomonosov mission scientific equipment includes several instrumentsfor gamma-ray burst observation in optics, ultra-violet, X-rays and gamma-rays and thewide aperture telescope for ultra-high energy particle study by detection of ionisationlight along its tracks in the atmosphere. The main parameters and a brief description ofthese instruments are presented.

This is the manuscript of an "interactive seminar" from the programme of the EuroWinter School. These seminars were designed to illustrate areas of science that will be accessible to the VLTI and its first-generation instruments. This paper discusses the use of optical/IR interferometers to investigate the limb-darkening of stars, with particular emphasis on models with a one or two free parameters i.e. the kind of models that will be constrained by data from the first-generation VLTI. For this reason the paper is not a comprehensive treatment of limb-darkening measurement. Ideas from the introductory lectures of the School are illustrated here, using real data on a Mira variable star from the COAST interferometer.

I present a personal summary of the first ARENA conference on the prospects of building large astronomical infrastructures at the Concordia station in Antarctica, and my view on our progress to date in achieving this goal. Inparticular, I discuss the basic scientific, technical, and political conditions which I believe must be satisfied in order to develop a world-classinternational astronomical facility at Concordia.


ArTeMiS is a bolometer camera that will be installed at the APEX submillimeter telescope in Chile in 2010. This instrument will be a powerful tool for scientists with its three focal planes that will operate simultaneously in background limited conditions at 200, 350 and 450 microns (5760 pixels in total). A prototype called p-ArTeMiS has been tested at APEX in 2007 and thanks to its good performances, the team has been able to conduct scientific projects in star formation and on debris disks. This paper summarises the details of the ArTeMiS project, with a description of the detectors, the optics, the cryogenics and the electronics. We will also present the undergoing studies at CEA on detectors for the future submillimeter space missions.

The wealth of data in the past decades, and especially in the past 15 years has transformed our picture of the gas around the Milky Way and other spiral galaxies. There is good evidence for extraplanar gas that is a few kpc in height and is seen in all gaseous phases: neutral; warm atomic; and hot, X-ray emitting gas. This medium is seen not only around the Milky Way, but other spiral galaxies and it is related to the star formation rate, so it is likely produced by the activity in the disk through a galactic fountain. More extended examples of halo gas are seen, such as the HVC around the Milky Way and around M 31. This gas is typically 10–20 kpc from the galaxy and is not seen beyond 50 kpc. This gas is most likely being accreted. A hot dilute halo (106 K) is present with a similar size, although its size is poorly determined.

An ongoing controversy surrounds the relative amounts of outflow from the disk and accretion onto galaxies such as the Milky Way. There is good evidence for accretion of cold material onto the Milky Way and other galaxies, but it is not clear if there is enough to modify the gas content and star formation properties in the disk. The reservoir of accretion material is as yet unidentified. Some of these findings may be related to the issue that galaxies are baryon-poor: their baryon to dark matter ratio is well below the cosmological value. The absence of baryons may be due to extremely violent outflow events in the early stages of galaxy formation. We may be able to understand this stage of galaxy evolution by applying our deepening understanding of our local disk-halo environment.

This paper reviews the overall principles of astronomical spectrographs and the design rules that cover low, medium, and high spectral resolution instruments. Several examples of spectrograph designs are described that are easy to build and are optimised for amateur telescopes. Results are given for each of these instruments. Despite the modest size of amateur telescopes, we show that high performance spectrographs in the hands of amateur astronomers provide access to some specialised areas where the amateur could contribute to useful astrophysical work.

Assuming that the extended emission (EE) with broad dynamic range is a common property ofshort duration bursts, we propose a two-jet model which can describe both short mainepisode of hard spectra emission, specific for short bursts, and softer spectra EE by thedifferent off axis position of the observer. The model involves a short-duration jet,which is powered by heating due to νν̅ annihilation, and a long-lived Blandford–Znajek (BZ)jet with a significantly narrow opening angle. We also discuss observational tests oftwo-jet model.

The mid-infrared emission of Polycyclic Aromatic Hydrocarbons is found in many phases ofthe interstellar medium. Towards cold dense clouds,however,the emission is heavilyquenched. In these regions molecules are found to efficiently freeze-out on interstellargrains forming thin layers of ices. PAHs are highly non-volatile molecules and are alsoexpected to freeze-out. PAHs trapped in interstellar ices are likely to participate in theoverall chemistry,leading to the formation of cations and complex molecules in thesolid-state. The work presented here aims to experimentally study the chemical reactionsthat PAHs undergo upon vacuum ultraviolet irradiation when trapped in interstellarH2O ice.

The PAMELA satellite-borne experiment was launched from the Baikonur launch site on the 15th of June 2006. Since July 2006 it is daily delivering to ground 16 GBytes of data. The instrument is composed by a magnetic spectrometer, a time-of-flight system, a silicon-tungsten electromagnetic calorimeter, a neutron detector and anticoincidence scintillators. The primary scientific goal is to searching for evidence of dark matter particle annihilations studying antiparticles fluxes. Preliminary results concerning antiproton-proton and positron-electron ratios are presented.

We have identified over 1000 candidate Young StellarObjects (YSOs) in the Large Magellanic Cloud as part of the Spitzer Space Telescope Surveying the Agents of a Galaxy's Evolution (SAGE) Legacy program. The YSOs, detected by their excess infrared emission above a stellar photosphere, representearly stages of evolution, still surrounded by disks and/or infalling envelopes.The candidate YSOs were selected from regions of color-magnitude space least confused with other IR-bright populations.Our YSO list is therefore biased towards intermediate- to high-mass and young evolutionarystages, because these overlap less with galaxies and evolved starsin color-magnitude space.We derived masses of the YSOs from SED-fitting, and extrapolated the mass function usinga standard IMF to compute a current star formation rate of ~0.06 M๏/yr, which is at the low-end ofestimates based on total ultraviolet and infrared flux from the galaxy (~0.05-0.25 M๏/yr); and consistent with the expectation that our current YSO list is incomplete.High spatial resolution K_dark- and L-band observations at Dome C could distinguish the lower-mass YSOs from galaxies, based on their morphologies(diffuse vs. point sources).This will add thousands more YSOs to our census and improve our estimates of star formationrate, molecular cloud lifetimes, and hierarchical star formation.In addition, the high spatial resolution Dome C observations can detect multiplicity in the SAGE-identified YSOs which can be incorporated into our YSO SED models.

We present a beam combining technique capable of directinstantaneous imaging. The particularity is that the image (or PSID, point source intensity distribution) is formed in apupil plane. We present the concept on a theoretical basis,comment on the PSID for on- and off-axis sources and finallycompare it to Fizeau imaging. Future experiments and reflectionsabout this concept are finally considered.

Two exercises are proposed to illustrate the simple linear regression. The first one is based on the famous Galton's data set on heredity. We use the lm R command and get coefficients estimates, standard error of the error, R2, residuals …In the second example, devoted to data related to the vapor tension of mercury, we fit a simple linear regression, predict values, and anticipate on multiple linear regression.

This pratical session is an excerpt from practical exercises proposed by A. Dalalyan at EPNC (see Exercises 1 and 2 of http://certis.enpc. fr/∼dalalyan/Download/TP_ENPC_4.pdf).

In this paper we examine the effects introduced in the luminosityfunction of white dwarf stars by a change of the gravitationalconstant during the life of the Universe. A decrease of G inducesthe expansion of the star and accelerates its cooling. This effecthas noticeable effects on the luminosity function and can be used toset upper bounds on the rate of change of G. Preliminary resultsindicate that Ġ/G ≤ 10-13 yr-1. These values are thebest ever obtained and will improve as the white dwarf luminosityfunction will improve.