The low metallicity interstellar medium of dwarf galaxies gives a different picture in the far infrared(FIR)/submillimetre(submm)wavelengths than the more metal-rich galaxies. Excess emission is often found in the submm beginning at or beyond 500 μm. Even without taking this excess emission into account as a possible dust component, higher dust-to-gas mass ratios (DGR) are often observed compared to that expected from their metallicity for moderately metal-poor galaxies. The Spectral Energy Distributions (SEDs) of the lowest metallicity galaxies, however, give very low dust masses and excessively low values of DGR, inconsistent with the amount of metals expected to be captured into dust if we presume the usual linear relationship holding for all metallicities, including the more metal-rich galaxies. This transition seems to appear near metalllicities of 12 + log(O/H) 8.0 - 8.2. These results rely on accurately quantifying the total molecular gas reservoir, which is uncertain in low metallicity galaxies due to the difficulty in detecting CO(1-0) emission. Dwarf galaxies show an exceptionally high [CII] 158 μm/CO (1-0) ratio which may be indicative of a significant reservoir of ‘CO-free’ molecular gas residing in the photodissociated envelope, and not traced by the small CO cores.

We briefly review the assumptions and methods required to construct NLTE line-blanketed model atmospheres of hot stars. We describe our new grid of NLTE model atmospheres covering the parameter range of O stars at various metallicities. We have applied these new models to the analysis of HST/STIS and FUSE UV spectra of O stars in the SMC. This analysis leads us to revise down the effective temperature scale of O-type stars.

The Aditya-L1 is the first space-based solar observatory of the Indian Space Research Organization (ISRO). The spacecraft will carry seven payloads providing uninterrupted observations of the Sun from the first Lagrangian point. Aditya-L1 comprises four remote sensing instruments, viz. a coronagraph observing in visible and infrared, a full disk imager in Near Ultra-Violet (NUV), and two full-sun integrated spectrometers in soft X-ray and hard X-ray. In addition, there are three instruments for in-situ measurements, including a magnetometer, to study the magnetic field variations during energetic events. Aditya-L1 is truly a mission for multi-messenger solar astronomy from space that will provide comprehensive observations of the Sun across the electromagnetic spectrum and in-situ measurements in a broad range of energy, including magnetic field measurements at L1.

This review summarises those observations which relate to the existence of dust in planetary nebulae. The most direct evidence for dust, namely infrared emission by grains, is considered in Section 2. Section 3 describes a variety of optical and ultraviolet observations which bear more indirectly on the properties of the dust, while Section 4 discusses the power sources of the observed infrared emission. The peculiar nebulae A 30 and A 78 are considered in Section 5, and Section 6 concludes with a discussion of the various infrared features which have been observed in emission from planetary nebulae.

Light fluctuations have been found in all 22 QSOs studied by measurement of plates from the Harvard collection, which cover the last eighty years. The conclusions of this study are: (i) There appear to be at least three general classes of variation: (a) erratic, small-amplitude variations, (b) erratic, large-amplitude variations, and (c) slow quasi-periodic variations, e.g. as in 3C 273; (ii) No significant differences were detected between the rates of rise and decline of luminosity; (iii) Definite secular trends over at least 50 years were found in 5 QSOs; (iv) No simple clearcut periods greater than one year have been found; (v) There may be a trend of decreasing amplitude of fluctuations in apparent magnitude with increasing luminosity.

We investigate the broadband optical emission of diffuse intergalactic stars in galaxy clusters at $z\sim0.25$ by means of an image stacking technique. The images of 654 clusters, selected with the max-BCG algorithm from a subsample of the SDSS-Data Release 1 (DR1), have been stacked after masking all the sources detected down to very low S/N. The resulting images in the g, r and i bands provide reliable photometric data at the level of $\gtrsim30$ mag$/\square$” (r band), out to $\gtrsim 600$ kpc from the Brightest Cluster Galaxy (BCG). Our analysis shows that: i) the IntraCluster Light (ICL) is much more concentrated than the galaxy light, contributing $\sim$30% of the total cluster optical emission at $R=100$ kpc, but less than 10% at $R > 500$ kpc; ii) the ICL contributes between 15 and 20% of the total cluster optical luminosity between the optical radius ($\mu_r=25$ mag$/\square$”) of the BCG and 500 kpc; iii) the colours of the ICL are consistent with the global colours of the cluster galaxies, with little evidence for redder g$-$r.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The existence of the Fundamental Plane of early-type galaxies implies that the M/L ratios of early-types are well behaved. It provides therefore an important tool to measure the evolution of the M/L ratio with redshift. These measurements, in combination with measurements of the evolution of the luminosity function, can be used to constrain the mass evolution of galaxies.

We present the Fundamental Plane relation measured for galaxies in the rich cluster CL 0024+16 at z=0.391. The galaxies satisfy a tight Fundamental Plane, with relatively low scatter (15 %). The M/L is 31 ± 12 % lower than the M/L measured in Coma, which is consistent with simple evolutionary models. Hence, galaxies with very similar dynamical properties existed at a z=0.4.

More, and deeper data are needed to measure the evolution of the slope and the scatter of the Fundamental Plane to higher accuracy. Furthermore, data on the richest nearby clusters would be valuable to test the hypothesis that the Fundamental Plane is independent of cluster environment.

The latest JPL planetary and lunar ephemerides, DE405, are referenced to the International Celestial Reference Frame (ICRF) with an accuracy that approaches 1 mas for the four innermost planets, the sun, and the moon. This has been accomplished mainly by 18 VLBI observations of the Magellan Spacecraft in orbit around Venus. The ephemeris of Jupiter, however, is not well-determined since the various observations are not consistent within each other. The outer four planets continue to rely almost entirely upon optical observations; their ephemeris uncertainties lie in the 100-200 mas range.

A catalog of physical parameters of about 1000 spectroscopic binary stars (SB), based on the Batten catalog, its extensions, and newly published data has been compiled. Masses of stars′ components (M1 and M2), mass ratios of components (q = M1/M2) and orbital angular momenta are computed, wherever possible. It is probable that the initial mass function of the primaries is non-monotonic and is described only approximately by a power-law. The distribution of q of double-line SB has a sharp maximum near q = 1, that of single-line SB, near q = 0.3. SB with 1.5 ≲ M1/M⊙ ≲ 10 and semiaxes of orbits a ≲ 10 R⊙ probably do not form. A number of assumed “initial” distributions of M1, q and a were transformed with the aim of obtaining “observed” distributions taking into account the observational selection due to the luminosities of the components, their radial velocities, inclinations of the orbits, and the effects of matter exchange between the components. The best agreement with the observations is obtained for the combination of a power-law initial mass function ξ(M) ≃ M−2.35, a distribution of q with a maximum near 1 and a distribution of semiaxes with dN/da ≃ 1/a.

Radio survey datasets comprise an increasing number of individual observations stored as sets of multidimensional data. In large survey projects, astronomers commonly face limitations regarding: 1) interactive visual analytics of sufficiently large subsets of data; 2) synchronous and asynchronous collaboration; and 3) documentation of the discovery workflow. To support collaborative data inquiry, we present encube, a large-scale comparative visual analytics framework. encube can utilise advanced visualization environments such as the CAVE2 (a hybrid 2D and 3D virtual reality environment powered with a 100 Tflop/s GPU-based supercomputer and 84 million pixels) for collaborative analysis of large subsets of data from radio surveys. It can also run on standard desktops, providing a capable visual analytics experience across the display ecology. encube is composed of four primary units enabling compute-intensive processing, advanced visualisation, dynamic interaction, parallel data query, along with data management. Its modularity will make it simple to incorporate astronomical analysis packages and Virtual Observatory capabilities developed within our community. We discuss how encube builds a bridge between high-end display systems (such as CAVE2) and the classical desktop, preserving all traces of the work completed on either platform – allowing the research process to continue wherever you are.

Wolf-Rayet type central stars have been analyzed with adequate model atmospheres. The obtained stellar parameters and chemical abundances allow for a discussion of their evolutionary origin.

The Martian satellites are some of the most interesting and accessible objects in the solar system, and therefore worth studying or even visiting. As small bodies, on the order of kilometers in diameter (see table I), they may have experienced no internal heating or volcanism, and could therefore be original condensations in the solar system. They may thus be the only remnants of the original planetesimals.

An additional point of interest is that they are the only satellites in the inner part of the solar system–Earth's Moon is generally assumed to be a sister planet. As such, their study could illuminate one of the important differences between the inner and outer parts of the solar system.

Traditionally, earth-based observations of the zodiacal light (ZL) require two assumptions for further analysis: (A1) the dust density (n) is a power of heliocentric distance (R), n ∝ R−ν; (A2) the nature (scattering cross section, σ) of the dust is independent of location, σ(r,h,θ)=σ(θ). Observations from Pioneer 10 do not verify these assumptions.

The ages, masses and evolutionary state of peculiar red giants are discussed on the basis of kinematic and other data.

We review the scientific objectives and the present status cosmic shear studies. We discuss the future prospects and the role cosmic shear could play in a precision cosmology era.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Recently the search for the oldest stars have started to focus on the Bulge region. The Galactic bulge hosts extremely old stars, with ages compatible with the ages of the oldest halo stars. The data coming from these recent observations present new chemical signatures and therefore provide complementary constraints to those already found in the halo. So, the study of the oldest bulge stars can improve dramatically the constraints on the nature of first stars and how they polluted the pristine ISM of our Galaxy. We present our first results regarding the light elements (CNO) and the neutron capture elements. Our findings in the oldest bulge stars support the scenario where the first stellar generations have been fast rotators.

Profiles and total intensities are computed for solar 01 resonance lines at λ1302 and λ1305 using a model atmosphere program that includes non-LTE effects in both hydrogen and oxygen and that includes microturbulence both as a line broadening mechanism and as a contribution to the gas pressure. Good agreement is obtained between computed and observed intensities. The computed profiles appear to have too much 'self-reversal.

8 station VLBI maps of the nuclear jets in 3C309.1 and 3C380 reveal complex, bent, structures which seem hard to reconcile with the concept of ballistic outflow. Together with the observation of “flaring” in the MERLIN/EVN map of the 3C309.1 jet the maps point strongly to the jets being confined fluid flows.

There appears to exist in the minds of most of the participants of this conference a highly stylized picture of how the majority of all stars evolve after reaching the asymptotic giant branch. This is a fascinating development as, just three decades ago, no one understood what an asymptotic giant branch (AGB) star is or does, either theoretically or observationally, and, just two decades ago, no one understood the nature of the transition from AGB to planetary nebula, other than that it happened. And, yet, today, the evolution from AGB to planetary nebula and to white dwarf is described by a very beguiling picture whose outlines have become substantially fixed.

In Japan, there is a plan for Large Millimeter Array proposed by Nobeyama Radio Observatory. The proposed array may consist of 50 10-m antennas distributed in a 2 − 3 km area at very high altitude. In this paper, scientific directions, planned system, and site survey for the LMA are reported.