Over the last few years there has been considerable progress in linking the published scholarly literature with on-line data. This will greatly help with data discovery and aid the efforts to the VO.

In this review we discuss the evidence for galaxy interactions and mergers in the distant universe and the role of mergers in forming galaxies. Observations show that the fraction of massive (M>M*) galaxies involved in major mergers is roughly 5–10% at z ~ 1. The merger fraction however increases steeply for the most massive galaxies up to z ~ 3, where the merger fraction is 50± 20%. Using N-body models of the galaxy merger process at a variety of merger conditions, merger mass ratios, and viewing angles this merger fraction can be converted into a merger rate, and mass accretion rate due to mergers. A simple integration of the merger rate shows that a typical massive galaxy at z ~ 3 will undergo 4–5 major mergers between z ~ 3 and z ~ 0, with most of this activity, and resulting mass assembly, occurring at z>1.5.

Astrophysical Integrated Research Environment (AIRE), aims to integrate astrophysical data, analysis software and astrophysical knowledge into an easy-to-use Internet based environment. Therefore, astrophysicists from different institutes can constitute virtual research groups which are favorable to study some complex multi-band astrophysical phenomena. The AIRE was put into use in Center for Astrophysics, Tsinghua university in 2003. Up to now, there are 219 advanced users in this environment. Several astrophysical researches base on AIRE have generated some important published results.

The concordance cosmological model based on cold dark matter makes definitive predictions for the growth of galaxies in the Universe, which are being actively studied using numerical simulations. These predictions appear to contradict the observations of dwarf galaxies. Dwarf dark matter halos are more numerous and have steeper central density profiles than the observed galaxies. The first of these small-scale problems, the “missing satellites problem”, can be resolved by accounting for the low efficiency of gas cooling and star formation in dwarf halos. A newly-discovered class of HyperVelocity Stars will soon allow us to test another generic prediction of CDM models, the triaxial shapes of dark matter halos. Measuring the proper motions of HVS will probe the gravitational potential out to 100 kpc and will constrain the axis ratios and the orientation of the Galactic halo.

Red-sequence galaxies are known to obey well-defined scaling relations, such as the Fundamental Plane and the colour-magnitude relation, yet their star formation histories, which in part drive these relations, remain poorly understood. In this contribution, we summarize recent results from the NOAO Fundamental Plane Survey (NFPS). These results appear in more detail in Smith et al. (2006) and Nelan et al. (2005).

The Astro-Wise consortium has designed a new paradigm, ‘Awe‘, and implemented a fully scalable and distributed information system to overcome the huge information avalanche in wide-field astronomical imaging Surveys.

Based on VLT/FORS spectroscopy and HST/ACS imaging, we have constructed a sample of 125 field spiral galaxies that cover redshifts up to z = 1. By deriving the galaxies' luminosities, disk sizes, maximum rotation velocities, stellar masses, total masses, gas-phase metallicities etc., we are able to study the evolution of fundamental scaling relations like the Tully–Fisher relation as a function of cosmic time. While the evolution of most of the galaxies' fundamental parameters is in compliance with a hierarchical structure growth, the results from stellar population modelling favour a down-sizing scenario in the sense that the average stellar ages in high-mass spirals are older than in low-mass spirals.

The products of optical wide-field survey are very valuable for their own purposes like the studies of large scale structure of galaxies, evolution of galaxies, Galactic structure and so on. At the same time optical view of sky will provide basic reference for the observation at other wavelength ranges. For this reason Palomar all sky survey has been used for various astronomical studies over 50 years. Now in the era of electronic devices, digital archives, and powerful computer systems, modern observation will replace the Palomar all sky survey.

BACKGROUND: In the process of galaxy formation, super-nova driven feedback from low-mass galaxies is the process that most readily account for the galaxy mass-metallicity relation and for the shallower galaxy luminosity function (LF) compared to the halo mass function. Absorption-selected galaxies are prime candidates for the sites of starburst activity as (1) they probe the gaseous halos of galaxies up to ~50 kpc (Steidel 1995), and (2) galaxies on the faint end of the LF are likely dominating the statistics. Galaxies selected via their MgII λ2796/2803 doublet absorption against background QSOs are especially well suited as Mg is produced by type II supernova.

GOAL: Our project was to constrain the physical models of the gaseous halos by measuring the dark matter halo-mass (Mh) of the MgII host-galaxies statistically, i.e. without identifying spectroscopically the host-galaxy.

METHOD: We have used the cross-correlation w(rθ) (over co-moving scales rθ:0.05–13h−1Mpc) between our sample of 1800 z ≃ 0.5 MgII absorbers with equivalent w width W2796r−0.3 Å, and 250,000 Luminous Red Galaxies (LRGs), both selected from SDSS/DR3. The cross-correlation relies on the LRG photometric redshifts, but is not affected from contaminants such as stars or foreground and background galaxies as shown theoretically in Bouché et al. 2005 and empirically in Bouché et al. 2006.

RESULTS: From the cross-correlation analysis, we found (Bouché et al. 2006) (i) that the absorber host-halo mean mass is 〈 log Mh (M⊙)〉 = 11.94 ±0.31(stat)+0.24−0.25(sys), i.e. about 1/2 L*, and (ii) an anti-correlation between halo mass Mh and equivalent width W2796r.

INTERPRETATION: One SDSS MgII absorber (system) is made of several sub-components or clouds and the stronger the equivalent with of the absorber, the more clouds per system spread over a larger velocity range (Δv). This follows since each sub-component has a velocity width of ~ 5 kms s−1 (Churchill 1997). As result, the equivalent width W2796r is a measure of velocity width (Δv) as demonstrated by Ellison 2006. Together with our SDSS results, these relations imply a mass–velocity Mh–Δv anti-correlation. If the clouds in the host-halos were virialized, velocity and mass would have been correlated.

CONCLUSION: Therefore, our Mh–Δv anti-correlation shows that the clouds are not virialized in the gaseous halos of the hosts. This conclusion is best understood in the context of starburst driven outflows where the velocity Δv is related to bulk motion. This opens the possibility to study M82-analogs up to z ~ 2.0 using the MgII selection.

We have developed a neural network based technique for identifying quasars from the photometric database of the Sloan Digital Sky Survey (SDSS). We have queried the SDSS data release 5 (DR5) to produce a dataset of spectroscopically identified samples of unresolved objects consisting of quasars and stars which forms the training set.

VLA A-array snapshots were obtained of a complete sample of steep-spectrum radio sources from the Texas Radio Interferometer survey. Though similar in sensitivity to the FIRST Survey, our A-array snapshots have better resolution, and are complementary to FIRST. All initial A-array maps are made, and we are comparing them to FIRST.

We have demonstrated the first near-infrared multi-object spectrograph, CIRPASS, on the 4.2-m William Herschel Telescope (WHT) and the 3.9-m Anglo-Australian Telescope. We have conducted an Hα survey of 38 0.77 < z < 1 galaxies over ~100 arcmin2 of the Hubble Deep Field North and Flanking Fields, to determine star formation rates (SFRs) using CIRPASS on the WHT. This represents the first successful application of this technique to observing high redshift galaxies (Doherty et al. 2004). Stacking the spectra in the rest-frame, we find a lower limit (uncorrected for dust reddening) on the star formation rate density at redshift z = 1 of 0.04 M⊙ yr−1 Mpc−3 (Doherty et al. 2006). This implies rapid evolution in the star formation rate density from z = 0 to z = 1 which is proportional to (1 + z)3.1. We intend to extend our work with FMOS on Subaru as the evolSMURF project (the Evolution of Star-formation and Metallicity in the Universe at high Redshift with FMOS). This will represent nearly two orders-of-magnitude improvement on previous work, and for the first time will provide a sample of sufficient size to measure accurately the Hα luminosity function, and so determine the global star formation rate using the same indicator as used in local surveys. Using [O II]3727 Å, Hβ, [O III] 5007 Å and Hα redshifted into the z, J & H bands, we can chart the star formation history over 70% of the age of the Universe, affording complete coverage up to z = 1.6 with the same well-understood diagnostics. The line ratios will also allow the extinction and metallicity to be measured at z>1. This will resolve one of the long-standing puzzles in extragalactic astrophysics – the true evolution of the Madau-Lilly diagram of star formation density.

We present the first results of a targeted survey carried out with the 305m Arecibo radiotelescope to detect HI-line emission from disk galaxies at redshift z > 0.16. We are using this sample to study the evolution of the zero point of the Tully-Fisher relation (TFR) for galaxies at intermediate redshifts. Compared to optical widths, HI measurements sample a larger fraction of the disks, where the rotation curves are typically flat, and are not affected by slit smearing and misalignment or by aperture effects. Thus, in contrast to studies based on optical spectroscopy, this dataset allows for a direct comparison with the local TFR that is technique independent.

We present an analysis of the near-IR properties of galaxies and quasars detected in the mid-IR by the Spitzer Space Telescope. Using optical photometry from the Wide Field Survey and near-IR fluxes from the First Data Release of the UKIDSS (Dye et al. 2006) survey we carry out a preliminary characterization of the surface density of different samples of galaxies and their clustering properties.

The Virtual Solar Observatory (VSO) is a lightweight web service unifying twelve major solar data archives. With the VSO, users can simultaneously search for data from 50 space- and ground-based instruments covering the time period from 1915 to the present.

The growth and the evolution of the bar instability in stellar-gaseous disks embedded in a dark matter halo evolving in a cosmological framework is explored. We point out the impact of different gas fractions on the bar formation, inside disks of different disk-to-halo mass ratio.

We present the latest results of the survey searching for the nature of UV-selected galaxies in the Great Observatories Origins Deep Survey fields. By searching for UV-bright galaxies at intermediate redshifts (z ~ 1) we aim at understanding the nature of star-forming galaxies and their counterparts at higher-z, the so-called Lyman Break Galaxies.

The Virtual Solar Observatory (VSO) concept outlines a software environment for searching, obtaining and analyzing data from archives of solar data that are distributed at many different observatories around the world (Hill 2006, in this volume). The VSO, however, not only provides fast and reliable access to the existing data of Solar Active Regions, but also represents a powerful and unique tool to perform numerical simulations of the evolution and present state of solar phenomena. Two centers at UNAM, the Institute of Astronomy (IA) and the Supercomputer Center (DGSCA), along with the Sonora University, are working together to create the Mexican Virtual Solar Observatory (MVSO) that will be part of a wider national effort.

We use the workflow capabilities of the AstroGrid Virtual Observatory system (<http://www.astrogrid.org>) to analyse the relation between flare productivity and location of Active Region (AR) emergence on the Sun. Specifically, we investigate whether emergence of a new region near existing ones results in increased productivity of the new and/or pre-existing AR. To address this question, we build a series of workflows that perform queries to catalogues of regions and flares, and operations on the results of the queries. There is a strong East-West asymmetry in the location of emergence of new regions. We do not find a significant difference between the flaring rate of paired and isolated regions, when we choose a value of 12° as the cutoff between the two populations.

Samples of Extremely Red Galaxies (ERGs) have generally been seen to comprise a mix of actively star-forming galaxies with significant dust reddening and evolved, passive galaxies, at redshifts about z ≈ 1 − 2. Initial results from deep Keck spectroscopy of ERGs (Doherty et al. 2005) revealed dominant old stellar populations in 75% of our spectroscopic sample, but only 28% have spectra with no evidence of recent star formation activity, such as would be expected for a strictly passively-evolving population. This study suggests that the bulk of the ERGs are luminous, spheroidal, evolved galaxies, but undergoing intermittent activity consistent with continued growth.

Through a detailed investigation of individual galaxies in our sample we aim to address various outstanding questions. What fraction of their mass is produced in ongoing star formation? Is there a characteristic mass at which star formation is abruptly truncated? What mechanism provokes a secondary burst of star formation in evolved galaxies?

We fit Bruzual & Charlot (2003; BC03) simple stellar population models to the broad band SEDs over a wide baseline, using a reduced χ2 minimisation, to investigate ages, stellar masses and star formation histories. The fits for the early types agree well with information in the spectra and return ages of 2–3 Gyr and masses in the range 1011–1012M⊙. The objects with recent star formation episodes are more complex. Some are fit well by continuous star formation models, accounting for the effects of dust. We are now in the process of exploring multi-population fits to investigate the effects of episodic bursts.

Previous morphological studies of ERGs have revealed a diverse mix of galaxies – a combination of pure bulges, disks and a small fraction of irregular or interacting systems. We are curious to determine whether a morphological analysis produces results consistent with the spectroscopic properties of our sample. We are investigating a sub-sample of our galaxies which have HST imaging publically available. Initial results from a quantitative analysis using bulge/disk decomposition with GALFIT and GIM2D indicate that most galaxies with Early type spectra are bulge dominated. In contrast, a significant fraction of the galaxies showing spectroscopic signatures of on-going star formation on top of underlying old stellar populations appear to have a well-established classical spiral morphology, wih knots of star formation located in spiral arms around a central bulge. There is tenuous evidence (under further investigation) that at least half of the post-starbursts in our sample are barred spirals, lending support to theories relating post-starbursts to recent mergers.