Constraints on the masses of dark matter haloes associated with galaxies in the field and in clusters have been successfully obtained used galaxy-galaxy lensing techniques. Weak lensing thus provides important information on the mass distribution in galaxies at large radii in a statistical fashion. Current work suggests that all galaxies possess extended dark matter haloes, however those that host galaxies in clusters are less extended and less massive.

We present the distribution of Galactic bulge globular clusters and a method based on simultaneous detection of field and cluster horizontal branches to derive the cluster distances. This method has the advantage of being independent of both reddening and the reddening law, RV = AV/E(B−V). The vast majority of clusters projected in the direction of the Galactic bulge are located on the near side of the Galactic Center. Deviations from the reddening law do not seem to be responsible for this peculiarity. We need to introduce a peculiar, steep dependence of the absolute horizontal-branch magnitude with metallicity in the metal-rich regime if we want to reproduce a symmetrical distribution. Instead, if the observed distribution is correct, we expect a rather large number of bulge globular clusters are still to be discovered.

By means of a simple non-gravitational force model of the cometary nucleus, which relies on the observed light curves assumed to be a good representation of the water sublimation rate, we estimate the masses of a sample of long-period comets (LPCs).

A critical issue of our method is the assumption of a correlation between visual heliocentric magnitudes and water production rates. This is a necessary assumption because of the sparse observational data of gas production rates (with the exception of very few comets like Hale-Bopp or Hyakutake). In this regard we present here a new correlation for LPCs. We also present the preliminary results for the masses of comets Hale-Bopp and Hyakutake.

The rapid neutron-capture process (r-process), which produces some of the heaviest elements, is not well understood. Obtaining accurate abundances of these heavy elements (Z > 38) is important, both in the context of the chemical evolution of the Galaxy and for understanding the site(s) and process(es) of formation of those elements. We have determined elemental abundances for several r-process elements, notably silver, from high resolution VLT/UVES spectra. Silver was chosen because it is predominantly a light r-process element (38 < Z < 50), and little is known about its formation and evolution in the Galaxy. Here, we present our preliminary results.

We present measurements of the EUV spectral irradiance we have obtained from radiance measurements with the SOHO Coronal Diagnostic Spectrometer, from 1997 to date. We discuss the contribution of the various regions of the Sun to the total EUV irradiance, and how they varied dramatically between the last two solar minima. These observations allow us to interpret spectral irradiance measurements in the EUV which have been available since 2002 with the TIMED mission. We also briefly discuss how changes in various activity indices compare with the EUV spectral variability, and the limitations of spectral modelling.

We present a review on the determination of the primordial helium abundance Yp, based on the study of hydrogen and helium recombination lines in extragalactic H ii regions. We also discuss the observational determinations of the increase of helium to the increase of oxygen by mass ΔY/ΔO, and compare them with predictions based on models of galactic chemical evolution.

One of the reasons for which this symposium has been organised is to seek answers to several questions, one of which being: Can Astronomy help reducing the waning interest that the younger generations of students feel about science studies? My personal opinion is that it is indeed the case. In fact, I claim that astronomy can be very effective for this aim. The present situation of pupil shortages in scientific studies is a complex problem because there are multiple and diverse variables influencing this situation. One of them is that the contents are not introduced in the most appropriate form, because the methods used in teaching scientific disciplines are not appropriate. This paper relates my personal experience; first as a teacher and then as a student at the Faculty of Sciences in the University of Alicante.

Today's time and frequency standards range from the most sophisticated reference standards to the smallest oscillator for handheld radios. The technical requirements and technologies needed are different for the various applications but they derive from similar physical concepts. These different technologies can be categorized into four major areas, reference standards, mobile systems, man-portable (handheld) and space systems. These areas are the core areas of time and frequency standard applications and different areas of technology are needed to address them. This presentation discusses the time and frequency standards used or available for these areas.

We present a simple, largely empirical but physically motivated model, which is designed to interpret consistently multi-wavelength observations from large samples of galaxies in terms of physical parameters, such as star formation rate, stellar mass and dust content. Our model is both simple and versatile enough to allow the derivation of statistical constraints on the star formation histories and dust contents of large samples of galaxies using a wide range of ultraviolet, optical and infrared observations. We illustrate this by deriving median-likelihood estimates of a set of physical parameters describing the stellar and dust contents of local star-forming galaxies from the Spitzer Infrared Nearby Galaxy Sample (SINGS) and from a newly-matched sample of SDSS galaxies observed with GALEX, 2MASS, and IRAS. The model reproduces well the observed spectral energy distributions of these galaxies across the entire wavelength range from the far-ultraviolet to the far-infrared. We find important correlations between the physical parameters of galaxies which are useful to investigate the star formation activity and dust properties of galaxies. Our model can be straightforwardly applied to interpret observed ultraviolet-to-infrared spectral energy distributions (SEDs) from any galaxy sample.

We are conducting long-term monitoring of several AGN with the aim of understanding the interplay between the emitting regions around the central black hole as well as the physics of the accreting flow. Here we present results for two of our sources, NGC 3783 and MR 2251–178, with strong evidence for disk-driven variability and the existence of cold accretion disks, where near-IR emission can be clearly detected from a region close to the black hole.

A full understanding of the physical properties of integrated stellar systems demands a multiwavelength approach since each spectral window shows us the contribution of different types of stars. However, most of the observational effort in stellar population studies has been focused on the optical range. Now, the new generation of instruments allow us to explore the K band, where RGB and AGB stars dominate the light of the integrated spectra. Here we present a K-band spectroscopic analysis of early-type galaxies in different environments. Our sample comprises 12 field early-type galaxies observed with ISAAC at VLT with medium resolution, and they are compared with 11 Fornax cluster galaxies previously reported by Silva et al. (2008). The clear differences found in the infrared DCO and NaI indices between field and Fornax galaxies are discussed, trying to solve the puzzle formed by the near-infrared and optical measurements.

Large optical surveys provide an unprecedsCeented census of galaxies in the local Universe, forming an invaluable framework into which more detailed studies of objects can be placed. But how useful are optical surveys for understanding the co-evolution of black holes and galaxies, given their limited wavelength coverage, selection criteria, and depth? Here we present work-in-progress comparing optical and mid-IR diagnostics of three “unusual” low-z populations (luminous Seyferts, dusty Balmer-strong AGN, ULIRGs) with a set of ordinary star-forming galaxies from the SDSS. We address the questions “how well do the mid-IR and optical diagnostics of star formation and AGN strength agree?” and “to what extent do optical surveys allow us to include extreme, dusty, morphologically disturbed galaxies in our ‘complete’ census of BH-galaxy co-evolution?

I analyze the stochastic effects introduced by sampling the stellar initial mass function (SIMF) in the derivation of the individual masses and the cluster mass function (CMF) from broad-band visible/near-infrared unresolved photometry. The classical method of using unweighted U BV photometry to simultaneously establish ages and extinctions of stellar clusters is found to be unreliable for clusters older than ≈30 Myr, even for relatively large cluster masses. On the other hand, augmenting the filter set to include longer-wavelength filters and using weights for each filter increases the range of masses and ages that can be measured accurately with unresolved photometry. Nevertheless, a relatively large range of masses and ages is found to be dominated by SIMF sampling effects that render the observed masses useless, even when using U BV RI JHK photometry.

We present the analysis of the narrowband solar radio spike emissions observed by the Brazilian Solar Spectroscope (BSS) on 24 June, 1999, at 16:53:55–16:56:48 UT. The data were recorded with temporal resolution of 50 ms and frequency resolution of 5 MHz. The dynamic spectra of clusters of spikes were recorded in 100 channels in the 1.2-1.7 GHz frequency band. The groups of radio spikes observed clearly show spectral semi-harmonic structures and an intermittent temporal patter. The observational parameters were determined from the dynamic spectra analysis. The wavelet analysis technique able us to determine the temporal cadence for the clusters. The frequency ratio between two clusters of spikes recorded at same time were inferred. The preliminary results show average cadence of clusters of spikes occurrence of about 32 seconds and a semi-harmonic average frequency ratio of the order of 1:1.2.

Time ephemeris is the location-independent part of the transformation formula relating two time coordinates such as TCB and TCG (Fukushima 1995). It is computed from the corresponding (space) ephemerides providing the relative motion of two spatial coordinate origins such as the motion of geocenter relative to the solar system barycenter. The time ephemerides are inevitably needed in conducting precise four dimensional coordinate transformations among various spacetime coordinate systems such as the GCRS and BCRS (Soffel et al. 2003). Also, by means of the time average operation, they are used in determining the information on scale conversion between the pair of coordinate systems, especially the difference of the general relativistic scale factor from unity such as LC. In 1995, we presented the first numerically-integrated time ephemeris, TE245, from JPL's planetary ephemeris DE245 (Fukushima 1995). It gave an estimate of LC as 1.4808268457(10) × 10−8, which was incorrect by around 2 × 10−16. This was caused by taking the wrong sign of the post-Newtonian contribution in the final summation. Four years later, we updated TE245 to TE405 associated with DE405 (Irwin and Fukushima 1999). This time the renewed vale of LC is 1.48082686741(200) × 10−8 Another four years later, by using a precise technique of time average, we improved the estimate of Newtonian part of LC for TE405 as 1.4808268559(6) × 10−8 (Harada and Fukushima 2003). This leads to the value of LC as LC = 1.48082686732(110) × 10−8. If we combine this with the constant defining the mean rate of TCG-TT, LG = 6.969290134 × 10−10 (IAU 2001), we estimate the numerical value of another general relativistic scale factor LB = 1.55051976763(110) × 10−8, which has the meaning of the mean rate of TCB-TT. The main reasons of the uncertainties are the truncation effect in time average and the uncertainty of asteroids' perturbation. The former is a natural limitation caused by the finite length of numerical planetary ephemerides and the latter is due to the uncertainty of masses of some heavy asteroids. As a compact realization of the time ephemeris, we prepared HF2002, a Fortran routine to compute approximate harmonic series of TE405 with the RMS error of 0.446 ns for the period 1600 to 2200 (Harada and Fukushima 2003). It is included in the IERS Convention 2003 (McCarthy and Petit 2003) and available from the IERS web site; http://tai.bipm.org/iers/conv2003/conv2003_c10.html.

Strong gravitational lensing and stellar dynamics provide two complementary methods in the study of the mass distribution of dark matter in galaxies out to redshift of unity. They are particularly powerful in the determination of the total mass and the density profile of mass early-type galaxies on kpc to tens of kpc scales, and also reveal the presence of mass-substructure on sub-kpc scale. I will shortly discuss these topics in this review.

We present a study of the dynamical evolution of plutinos recently escaped from the resonance through numerical simulations. It was shown in previous works the existence of weakly chaotic orbits in the plutino population that diffuse very slowly finally diving into a strong chaotic region. These orbits correspond to long-term plutino escapers and then represent the plutinos that are escaping from the resonance at present. Then, we divided the numerical simulation in two parts. First, we develop a numerical simulation of 20,000 test particles in the resonance in order to detect the long-term escapers. We set the initial orbital elements such that cover the present observational range of orbital elements of plutinos. Second, we perform a numerical simulation of the selected escaped plutinos in order to study their dynamical post escaped behavior. We describe and characterize the routes of escape of plutinos and their evolution in the Centaur zone. Also, we obtain that Centaurs coming from plutinos would represent a fraction of less than 6% of the total Centaur population.

Accurate measurements of the 4He/H abundance ratio are important in constraining Big Bang nucleosynthesis, models of stellar and Galactic evolution, and H ii region physics. We discuss observations of radio recombination lines using the Green Bank Telescope toward a small sample of H ii regions and planetary nebulae. We report 4He/H abundance ratio differences as high as 15–20% between optical and ratio data that are difficult to reconcile. Using the H ii regions S206 and M17 we determine 4He production in the Galaxy to be dY/dZ = 1.71 ± 0.86.

Although the first stars were likely very hot and luminous, their low or zero metallicity implies that any mass loss through winds driven by line-scattering of radiation in metal ions was likely small or non-existent. Here we examine the potential role of another possible mechanism for mass loss in these first stars, namely via decretion disks associated with near-critical rotation induced from evolution of the stellar interior. In this case the mass loss is set by the angular momentum needed to keep the stellar rotation at or below the critical rate. In present evolutionary models, that mass loss is estimated by assuming effective release from a spherical shell at the surface. Here we examine the potentially important role of viscous coupling of the decretion disk in outward angular momentum transport, emphasizing that the specific angular momentum at the outer edge of the disk can be much larger than at the stellar surface. The net result is that, for a given stellar interior angular momentum excess, the mass loss required from a decretion disk can be significantly less than invoked in previous models assuming a direct, near-surface release.

Astronomy is a science devoted to the study of what existed, exists and will exist, from the most elemental particle to the most massive and powerful galaxy one observes. The study of the universe is not only meant to be to achieve an important understanding about it, but also in other fields of science and technology. The most important contribution from astronomy is perhaps social: it fascinates millions of people along the globe. The history of astronomy carries along the very history of humankind.