It is known that physical properties of solar turbulent convection and oscillations strongly depend on magnetic field. In particular, recent observations from SOHO/MDI revealed significant changes of the wave properties in inclined magnetic field regions of sunspots, which affect helioseismic inferences. We use realistic 3D radiative MHD numerical simulations to investigate solar convection and oscillations and their relationship in the presence of inclined magnetic field. In the case of highly inclined and strong 1-1.5 kG field the solar convection develops filamentary structure and high-speed flows (Fig. 1a), which provide an explanation to the Evershed effect in sunspot penumbra (Kitiashvili, et al. 2009).

We are studying the interplay of star formation and its ’fuel’, the molecular gas (diffuse and dense) at selected positions along the major axis of M33. We have observed the ground-state transitions of HCN, HCO+, and 13CO using the IRAM 30m telescope. These data will complement existing CO, HI, Spitzer, and radio continuum maps. Furthermore, these data will be complemented by far-infrared maps of [CII], H2O, [OI], [NII], and the dust continuum taken with Herschel in the open time key project HERM33ES.

The existing information on asymptotic giant branch (AGB) and post-AGB objects from FIR and submm spectroscopy is still scarce. Observations from the ground are often very difficult to calibrate and show low S/N ratios. However, we expect to obtain in the near future an impressive amount of high-quality data, from the Herschel space telescope. ALMA is also expected to provide high-quality maps of submm lines.

The body of photometric and astrometric data on stars in the Galaxy has been growing very fast in recent years (Hipparcos/Tycho, OGLE-3, 2-Mass, DENIS, UCAC2, SDSS, RAVE, Pan Starrs, Hermes, . . .) and in two years ESA will launch the Gaia satellite, which will measure astrometric data of unprecedented precision for a billion stars. On account of our position within the Galaxy and the complex observational biases that are built into most catalogues, dynamical models of the Galaxy are a prerequisite full exploitation of these catalogues. On account of the enormous detail in which we can observe the Galaxy, models of great sophistication are required. Moreover, in addition to models we require algorithms for observing them with the same errors and biases as occur in real observational programs, and statistical algorithms for determining the extent to which a model is compatible with a given body of data.

JD5 reviewed the status of our knowledge of the Galaxy, the different ways in which we could model the Galaxy, and what will be required to extract our science goals from the data that will be on hand when the Gaia Catalogue becomes available.

The Spitzer mid-infrared (MIR) surveys, Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) and MIPSGAL have revealed a new view of the disk of the Milky Way. Hallmarks of the Galactic disk at MIR wavelengths with spatial resolution <2″ are bubbles/HII regions, infrared dark clouds, young stellar objects (YSOs)/star formation regions, diffuse dust and extended polycyclic aromatic hydrocarbons (PAHs), and more than 100 million publically available archived stars with measured flux densities at 7 wavelengths and positions accurate to 0.1″. At mid-IR wavelengths, the cool components in the Galaxy are preferentially bright and highlight physical processes that are not obvious at other wavelength regimes.

Spatial and temporal variations in the electron-to-proton mass ratio, μ, and in the fine-structure constant, α, are not present in the Standard Model of particle physics but they arise quite naturally in grant unification theories, multidimensional theories and in general when a coupling of light scalar fields to baryonic matter is considered. The light scalar fields are usually attributed to a negative pressure substance permeating the entire visible Universe and known as dark energy. This substance is thought to be responsible for a cosmic acceleration at low redshifts, z < 1. A strong dependence of μ and α on the ambient matter density is predicted by chameleon-like scalar field models. Calculations of atomic and molecular spectra show that different transitions have different sensitivities to changes in fundamental constants. Thus, measuring the relative line positions, Δ V, between such transitions one can probe the hypothetical variability of physical constants. In particular, interstellar molecular clouds can be used to test the matter density dependence of μ, since gas density in these clouds is ~15 orders of magnitude lower than that in terrestrial environment. We use the best quality radio spectra of the inversion transition of NH3 (J,K)=(1,1) and rotational transitions of other molecules to estimate the radial velocity offsets, Δ V ≡ Vrot - Vinv. The obtained value of Δ V shows a statistically significant positive shift of 23±4stat±3sys m s−1 (1σ). Being interpreted in terms of the electron-to-proton mass ratio variation, this gives Δμ/μ = (22±4stat±3sys)×10−9. A strong constraint on variation of the quantity F = α2/μ in the Milky Way is found from comparison of the fine-structure transition J=1-0 in atomic carbon C i with the low-J rotational lines in carbon monoxide 13CO arising in the interstellar molecular clouds: |Δ F/F| < 3×10−7. This yields |Δ α/α| < 1.5×10−7 at z = 0. Since extragalactic absorbers have gas densities similar to those in the ISM, the values of |Δ α/α| and |Δ μ/μ| at high-z are expected to be at the same level as estimated in the Milky Way providing no temporal dependence of α and μ is present. We re-analyzed and reviewed the available optical spectra of quasars to probe Δα/α from intervening absorbers. The Fe i system at z = 0.45 towards HE 0000–2340 provides one of the best opportunities for precise measurements of Δα/α at low redshift. The current estimate is Δα/α = (7±7)×10−6. With the updated sensitivity coefficients for the Fe ii lines we re-analyzed the z = 1.84 system from the high-resolution UVES/VLT spectrum of Q 1101–264 (FWHM = 3.8 km s−1) and found Δα/α = (4.0±2.8)×10−6. The most accurate upper limit on cosmological variability of α is obtained from the Fe ii system at z = 1.15 towards the bright quasar HE 0515–4414 (V=14.9): Δα/α = (-0.12±1.79)×10−6, or |Δα/α| < 2×10−6. The limit of 2×10−6 corresponds to the utmost accuracy which can be reached with available to date optical facilities.

The recent observational evidence for the current cosmic acceleration have stimulated renewed interest in alternative cosmologies, such as scenarios with interaction in the dark sector (dark matter and dark energy). In general, such models contain an unknown negative-pressure dark component coupled with the pressureless dark matter and/or with the baryons that results in an evolution for the Universe rather different from the one predicted by the standard ΛCDM model. In this work we test the observational viability of such scenarios by using the most recent galaxy cluster gas mass fraction versus redshift data (42 X-ray luminous, dynamically relaxed galaxy clusters spanning the redshift range 0.063 < z < 1.063), Allen et al. (2008), to place bounds on the parameter ε that characterizes the dark matter/dark energy coupling. The resulting are consistent with, and typically as constraining as, those derived from other cosmological data. Although a time-independent cosmological constant (ΛCDM model) is a good fit to these galaxy cluster data, an interacting energy component cannot yet be ruled out.

New low frequency radio telescopes currently being built open up the possibility of observing the 21 cm radiation from redshifts 200 > z > 30, also known as the dark ages, see Furlanetto, Oh, & Briggs(2006) for a review. At these high redshifts, Cosmic Microwave Background (CMB) radiation is absorbed by neutral hydrogen at its 21 cm hyperfine transition. This redshifted 21 cm signal thus carries information about the state of the early Universe and can be used to test fundamental physics. The 21 cm radiation probes a volume of the early Universe on kpc scales in contrast with CMB which probes a surface (of some finite thickness) on Mpc scales. Thus there is many orders of more information available, in principle, from the 21 cm observations of dark ages. We have studied the constraints these observations can put on the variation of fundamental constants (Khatri & Wandelt(2007)). Since the 21 cm signal depends on atomic physics it is very sensitive to the variations in the fine structure constant and can place constraints comparable to or better than the other astrophysical experiments (Δα/α= < 10−5) as shown in Figure 1. Making such observations will require radio telescopes of collecting area 10 - 106 km2 compared to ~ 1 km2 of current telescopes, for example LOFAR. We should also expect similar sensitivity to the electron to proton mass ratio. One of the challenges in observing this 21 cm cosmological signal is the presence of the synchrotron foregrounds which is many orders of magnitude larger than the cosmological signal but the two can be separated because of their different statistical nature (Zaldarriaga, Furlanetto, & Hernquist(2004)). Terrestrial EM interference from radio/TV etc. and Earth&s ionosphere poses problems for telescopes on ground which may be solved by going to the Moon and there are proposals for doing so, one of which is the Dark Ages Lunar Interferometer (DALI). In conclusion 21 cm cosmology promises a large wealth of data and provides the only way to observe the redshift range between recombination and reionization.

Studies of our own Galaxy and observations of external galaxies have suggested that stellar ultraviolet radiation can ionize vast volumes of a galaxy and that far-ultraviolet radiation impinging on neutral cloud surfaces is responsible for a large fraction of the observed far-infrared (FIR) spectral line emission that cools the gas (Crawford & al. (1985)). Fine structure (FS) emission lines can be used as tracers of nebular conditions such as density, excitation and ionization. By virtue of their different excitation potentials and critical densities, FS emission lines provide an insight into the energetics and chemical composition of the regions from which they originate. The far infrared [C ii]158 μm, [O i]145 μm and [O i]63 μm fine structure emission lines obtained with the Infrared Space Observatory (ISO) from 35 extragalactic sources are examined to investigate the chemical abundances and large scales physical properties of these sources. Line fluxes are compared with a grid of PDR models previously computed using the UCL_PDR code. We overplotted our model predictions against flux ratios from the [C ii]158 μm and [O i]63 μm and 145 μm ISO LWS fluxes. In this section we will only discuss the sensitivity of the ratios to changes in the input parameters. We find that the average radiation field G0 is 60–8 × 102 and the average density nH 104−9 × 104 cm−3. While ionised carbon, because of its ionisation potential, can be found in both neutral gas and ionised gas clouds, species such as ionised nitrogen [N ii], with ionisation potential of 14.53 eV, can arise only from H ii regions. The 11 sources that have detections of both [C ii] 158 μm and [N ii] 122 μm have mean and median [C ii]158/[N ii]122 flux ratios of 10.2 and 5.9 respectively. A H ii region [C ii]158/[N ii]122 ratio of 1.6 implies that H ii region contribute only 16% (mean case) and 27% (median case) of the overall [C ii] 158 μm flux that is observed. We used the above predicted H ii region [C ii]158/[N ii]122 ratio of 1.6 along with the observed [N ii] 122 μm fluxes, to correct the observed [C ii] 158 μm flux of these 11 sources for H ii region contributions. We estimate that 10-60% of the [C ii] is excited in ionised regions. When accounting for the contribution to the [C ii] 158 μm by H ii regions we found that our models fitted better the observations. We modeled the oxygen emission line profile emitted from an ensemble of PDRs and found a clear [O i] 63 μm self-absorbed profile. We estimate that approximately 20-70% of the [O i] 63 μm intensity may be suppressed through oxygen self-absorption depending on the physical parameters of the PDR regions. This work has been submitted for publication to MNRAS, Vasta et al. (2009).

In this contribution we discuss the origin of the extreme helium-rich stars which inhabit the blue main sequence (bMS) of the Galactic globular cluster Omega Centauri. In a scenario where the cluster is the surviving remnant of a dwarf galaxy ingested by the Milky Way many Gyr ago, the peculiar chemical composition of the bMS stars can be naturally explained by considering the effects of strong differential galactic winds, which develop owing to multiple supernova explosions in a shallow potential well.

We performed high-resolution three dimensional numerical simulations of relativistic MHD jets carrying an initially toroidal magnetic field responsible for the process of jet acceleration and collimation. We find that in the 3D case the toroidal field gives rise to strong current driven kink instabilities leading to jet wiggling. However, it appears to be able to maintain an highly relativistic spine along its full length.

Low-mass stars exhibit, at all stages of their evolution, the signatures of complex physical processes that require challenging modelling beyond standard stellar theory. In this review, we focus on lithium depletion in low-mass stars. After disecting the Li dip, we discuss how large scale mixing due to rotation and internal gravity waves may interact to explain this feature. We also briefly discuss the impact that is expected on Population II stars.

Consistent metallicities are now obtained in X-ray bright galaxies, using the Chandra ACIS and XMM PN, MOS and RGS detectors. With two temperature models, the Fe metallicity of the gas is typically solar, similar to Mg, Si, and S, but the O abundance is about half solar. These values are in conflict with models, which predict a metallicity 3-5 times higher and a Fe to O ratio near unity. This suggests that a significant fraction of metals are not becoming mixed into the hot galactic atmosphere.

Jets are found in a wide range of accreting young stars, from brown dwarfs to massive protostars, but their launch region(s) and their role in angular momentum extraction are still debated. Many observational constraints exist on jet properties, including jet widths, kinematics along and across the jet, possible rotation signatures, ejection/accretion ratio, depletion and molecular counterparts. This contribution compares popular models, in particular disk winds, with these constraints and with MHD numerical simulations, highlighting a few open issues.

We will present the relevant activities performed during the International Heliophysical Year (IHY) program during the 5 year period 2004 - 2008. The IHY was a major international effort that involved the deployment of new instrumentation, new observations from the ground and in space, and a strong education component. Under the United Nations Office for Outer Space program called Basic Space Science Initiative (UNBSSI), instrument arrays have been deployed to provide global measurements of heliophysical phenomena. As a result, significant scientific and educational collaborations emerged between the organizing groups and the host country teams. In view of the great successes achieved by the IHY during these years, we propose to continue the highly successful collaboration with the UN program to study the universal processes in the solar system that affect the interplanetary and terrestrial environments, and to continue to coordinate the deployment and operation of new and existing instrumentation arrays aimed at understanding the impacts of Space Weather on Earth and the near-Earth environment. To this end, we propose a new program, the International Space Weather Initiative (ISWI). The ISWI strongly complements the International Living With a Star (ILWS) program, providing more attention nationally, regionally, and internationally for the ILWS program. Based on a three-year program activity, the ISWI would provide the opportunity for scientists around the world to participate in this exciting quest to understand the effect of space disturbances on our Earth environment.

As a sequel to the Li observations by Balachandran, Lambert & Stauffer (1988, 1996) in 35 stars of the 50 Myr old cluster α Persei, we have obtained and analyzed high resolution spectra of another 51 stars. Following a reconsideration of the cluster membership of the stars (Prosser 1992, Makarov 2006, Mermilliod et al. 2008, and Patience et al. 2002), we discuss the Li abundances for 70 stars. With our larger sample, we reexamine the question of whether the scatter in Li abundance at a given Teff seen in young clusters at cool temperatures is real or not.

Water vapour is the principle source of opacity at infrared wavelengths in the earth's atmosphere. Measurements of atmospheric water vapour serve two primary purposes when considering operation of an observatory: long-term monitoring of precipital water vapour (PWV) is useful for characterizing potential observatory sites, and real-time monitoring of PWV is useful for optimizing use, in particular for mid-IR observations.

Galaxy clusters are large laboratories for magnetic plasma turbulence and therefore permit us to confront our theoretical concepts of magnetogenesis with detailed observations. Magnetic turbulence in clusters can be studied via the radio-synchrotron emission from the intra-cluster medium in the form of cluster radio relics and halos. The power spectrum of turbulent magnetic fields can be examined via Faraday rotation analysis of extended radio sources. In case of the Hydra A cool core, the observed magnetic spectrum can be understood in terms of a turbulence-mediated feedback loop between gas cooling and the jet activity of the central galaxy. Finally, methods to measure higher-order statistics of the magnetic field using Stokes-parameter correlations are discussed, which permit us to determine the power spectrum of the magnetic tension force. This fourth-order statistical quantity offers a way to discriminate between different magnetic turbulence scenarios and different field structures using radio polarimetric observations.

Abundance gradients are key parameters to constrain the chemical evolution of the galactic disk. In this review recent determinations for the radial gradient are described, including its slope as derived from different objects such as planetary nebulae, HII regions, cepheids, or B stars, and for different elements. Inner and outer limits for the radial gradient, as well as its time evolution, both related to the chemical evolution of the Galaxy, are also described. The possible existence of azimuthal and vertical gradients is also discussed.

The radio–infrared correlation holds within galaxies down to scales of about 50 pc (Hughes et al. 2006). It was explained as a direct and linear relationship between star formation and IR emission. However, one fact making the IR-star formation linkage less obvious is that the IR emission consists of at least two emission components, cold dust and warm dust. The cold dust emission may not be directly linked to the young stellar population. Furthermore, understanding the origin of the radio–IR correlation requires to discriminate between the two main components of the radio continuum emission, free-free and synchrotron emission. Although cosmic ray electrons originates also from the star forming regions (supernovae remnants; final episodes of massive stars), the synchrotron–IR correlation may not be as tight as thermal–IR correlation locally, as a result of convection and diffusion of the cosmic ray electrons from their place of birth. The magnetic field distribution may further modify the correlation.