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Galaxies in the Hubble Ultra Deep Field (UDF) larger than 10 pixels (0.3 arcsec) have been classified according to morphology. There are 884 galaxies, including spirals, ellipticals, chains, clump-clusters, doubles, and tadpoles; 399 disk galaxies in the Tadpole field were also measured. Linear structures dominate at faint magnitudes. Distributions of axial ratios are compared to nearby samples. 30% of ellipticals are clumpy, and 10-30% of spirals are barred. Radial profiles and clump properties are measured for disk galaxies. [ABSTRACT FROM AUTHOR]

We present results from our ongoing effort to understand the morphological and kinematical properties of early-type galaxies using the integral-field spectrograph SAURON. We discuss the relation between the stellar and gas morphology and kinematics in our sub-sample of 24 representative Sa spiral bulges. We focus on the frequency of kinematically decoupled components and on the presence of star formation in circumnuclear rings. [ABSTRACT FROM AUTHOR]

We have obtained high resolution two-dimensional velocity fields from integral field spectroscopy along with derived rotation curves for nine low surface brightness galaxies. This is a positive step forward in terms of both data quality and number of objects studied. We fit NFW and pseudo-isothermal halo models to the observations. We find that the pseudo-isothermal halo better represents the data in most cases than the NFW halo, as the resulting concentrations for the latter are lower than would be expected from CDM. Cusps can clearly be detected by this method when they are present and the data are of high quality. Yet only one of our six best cases is consistent with a cusp. [ABSTRACT FROM AUTHOR]

One process in the secular evolution of galaxies is the formation of pseudobulges.The formation of these pseudo-bulges requires the inflow of gas to smaller radii. If the inflow rate is faster than the rate of star formation, a central concentration of gas will form. In this paper we present radial profiles of stellar and 8 micron emission from Polycyclic Aromatic Hydrocarbons (PAHs) for 11 spiral galaxiesto investigate whether the interstellar medium in these galaxies contains a centralconcentration above that expected from the exponential disk. We find that in five of the 11 galaxies there is a central excess in the 8 micron and CO emission above the inner extrapolation of an exponential disk. In particular, all four barred galaxies in the sample have strong central excesses in both 8 micron and CO emission. This correlation suggests that the excess seen in the CO profiles is, in general, not simply due to a radial increase in the CO emissivity. [ABSTRACT FROM AUTHOR]

This has been an exciting conference covering a large range of topics on the properties of disk galaxies, much of it related to pioneering work done by Piet van der Kruit, the Jacobus C. Kapteyn Distinguished Professor of Astronomy at the University of Groningen. Let me therefore first say a few words about Piet, and then highlight some of the mainresults presented here this week. [ABSTRACT FROM AUTHOR]

Our goal is to study the effects of the UV radiation from the first stars, quasars and hypothetical Super Heavy Dark Matter (SHDM) particle decays on the formation of primordial bound objects in the Universe. We trace the evolution of a spherically symmetric density perturbation in the Lambda Cold Dark Matter and MOND model, solving the frequency-dependent radiative transfer equation, non-equilibrium chemistry, and one-dimensional gas hydrodynamics. We concentrate on the destruction and formation processes of the H2 molecule, which is the main coolant in the primordial objects. [ABSTRACT FROM AUTHOR]

We have used fully cosmological, high resolution N-body + SPH simulations to followthe formation of disk galaxies with a rotational velocity between 140 and 280 km/s in a ΛCDM universe. The simulations include gas cooling, star formation (SF), the effects of a uniform UV background and a physically motivated description of feedback from supernovae(SN). The host dark matter (DM) halos have a spin and last major merger redshift typical of galaxy sized halos as measured in recent large scale N-Body simulations. Galaxies formed rotationally supported disks with realistic exponential scale lengths and fall on the I-band and baryonic Tully-Fisher relations. The combination of UV background and SN feedback drastically reduced the number of visible satellites orbiting inside a Milky Way sizedhalo, bringing it fair agreement with observations. Feedback delays SF in small galaxies and more massive ones contain older stellar populations. The current star formation ratesas a function of galaxy stellar mass are in good agreement with those measured by the SDSS. [ABSTRACT FROM AUTHOR]

In order to explain disk galaxy formation within the hierarchical structure formation, it seems that gas rich mergers must play an important role. We review here our previous studies which have shown the importance of mergers at high redshift being gas rich, in the formation of both the stellar halo and thick disk components of disk galaxies. Regulation of star formation in the building blocks of our galaxy is required to form a low mass low metallicity stellar halo. This regulation results in high redshift, gas rich mergers during which the thick disk forms. In these proceedings, we categorise stars from our simulated disk galaxy into thin and thick disk components by using the Toomre diagram. Rotation velocity, metallicity and age histograms of the two populations are presented, along with alpha element abundances (oxygen, silicone, magnesium), age-height above the plane, age-radius, metallicity-height, and metalicity-radius gradients. [ABSTRACT FROM AUTHOR]

Extended, soft X-ray emission from the halo of a very large disk galaxy has been detected. The luminosity and surface brightness distribution is in excellent agreement with predictions by recent, cosmological galaxy formation models. Predicted Lyα emission, associated with "cold" accretion of filamentary gas onto galaxies, is discussed in relation to Lyα "blobs". Finally, the predicted evolution of the Tully-Fisher relation, going from z=0 to 1, is discussed in relation to recent observations. [ABSTRACT FROM AUTHOR]

Galaxy formation theory is a mysterious art. It is driven by phenomenology and by numerical simulations of dark matter clustering under gravity. Once the complications of star formation are incorporated, the theory becomes so complex that the brute force approach of numerical simulations needs to be supplemented by physical insights into the nature of such processes as feedback. I present here a few analytical perspectives that may shed some light on the nature and implications of global star formation for galaxy formation. [ABSTRACT FROM AUTHOR]

Using the results of a bulge-disk decomposition of 10 000 galaxies with B < 20 mag from the Millennium Galaxy Catalogue, we recover the space-density of galaxy disks as a joint function of luminosity and effective surface brightness. [ABSTRACT FROM AUTHOR]

Using HST data, disc scalelengths in the UV, optical and NIR wavelength regions are used to study age and metallicity gradients and dust extinction in disc galaxies of intermediate redshifts in the Hubble Deep Field North. The observed colour gradients are compared to model calculations of dusty disc galaxies. First results indicate that the age and metallicity gradients in the HDF galaxies differ from the age and metallicity gradients found in local spiral galaxies. [ABSTRACT FROM AUTHOR]

We describe our project to examine the evolution of distant disk galaxies, and present the results of our work based on the Tully-Fisher relation. Comparing matched cluster and field samples we find evidence that the cluster galaxies are on average 0.7 ± 0.2 mag brighter than those in the field. [ABSTRACT FROM AUTHOR]

We decompose the rotation curves of 34 local bright spiral galaxies into baryonic and dark matter components. Analysis of the resulting dark-to-luminous matter distributions shows that they are self-similar once scaled to an appropriate radius. In addition, the radius where the dark matter contribution to the rotation curves equals that of the baryons correlates with galaxy properties such that galaxies with greater values are larger, brighter, faster rotators, more massive, and of earlier Hubble type. In comparing our data to a model for the dark matter distribution in galaxies, we find that fits are generally poor in the inner parts, and all but 2 galaxies are better fit if adiabatic contraction of the halos is performed. [ABSTRACT FROM AUTHOR]

We calculate in detail the expected properties of low redshift DLAs under the assumption that they arise in the gaseous disks of galaxies like those in the z≈0 population. A sample of 355 nearby galaxies is analysed, for which high quality Hi 21-cm emission line maps are available as part of an extensive survey with theWesterbork telescope (WHISP). [ABSTRACT FROM AUTHOR]

We review the status of current observations of the fundamental parameters of intermediate redshift (0.2 < z < 1.2) spiral galaxies. Advances in instrumentation of 8-10m class telescopes have made possible detailed measurements of galaxy luminosity, morphology, kinematics and mass, in both the optical and the infrared passbands. [ABSTRACT FROM AUTHOR]

We present the evolution of the luminosity-size and stellar mass-size relations of luminous (LV > 3.4×1010h70−2L⊙) and of massive (M★ >3×1010h70−2M⊙) galaxies in the last∼11 Gyr. We use very deep near-infrared images of the Hubble Deep Field-South and the MS1054-03 field in the Js, H and Ks bands from FIRES to retrieve the sizes in the optical rest-frame for galaxies with z >1. [ABSTRACT FROM AUTHOR]

While many of the characteristics of the star-forming galaxies now being surveyed in large numbers at z = 2 - 3 are reminiscent of elliptical galaxies and bulges, the progenitors of today's spiral disks have proved more difficult to identify, probably because they were smaller and fainter at these early epochs. It will be many years yet before we can probe interstellar Hi gas in 21 cm emission at these redshifts, but the HII regions of UV-bright galaxies will soon be mapped on kpc-scale from the ground with new instrumentation designed to work with laser-guided adaptive optics. This will be our best chance to measure disk-like rotation at high redshift. [ABSTRACT FROM AUTHOR]

We present results from a study to determine how star formation contributes to galaxy growth since redshift z = 1.5. Using galaxies from the MUnich Near-Infrared Cluster Survey (MUNICS) and the FORS Deep Field (FDF), we investigate the specific star formation rate (SSFR, star formation rate [SFR] per unit galaxy stellar mass) as a function of galaxy stellar mass and redshift. We test the compatibility of our results with a sample drawn from a larger volume using the Sloan Digital Sky Survey. We find that the SSFR decreases as galaxy stellar mass increases, suggesting that star formation contributes more to the growth of low-mass galaxies than high-mass galaxies at all redshifts in this study. [ABSTRACT FROM AUTHOR]

We present a brief discussion of the evolution of disk galaxy stellar masses, sizes, rotation velocities, and star formation rates over the last eight billion years. Recent observations have failed to detect significant evolution in the stellar mass Tully-Fisher relation, stellar mass-size relation, and the stellar mass function of disk galaxies. Yet, most z < 1 star formation is in disks, and this star formation would be expected to drive a rapid growth of the total stellar mass (and therefore mass function) of disks in the last eight billion years. Such a build-up is not seen; instead, a rapid build-up in the total stellar mass in non-star-forming spheroiddominated galaxies is observed. Large numbers of disk-dominated galaxies are systematically shutting off their star formation and building up a spheroid (or losing a disk) in the epoch 0 < z < 1. [ABSTRACT FROM AUTHOR]

I review the observational evidence for massive disks at high redshifts. In an attempt to do something a little bit different, I will focus exclusively on galaxies at redshiftsz > 1, where much of the action seems to be happening, but where our ignorance is particularly acute. To keep the discussion concrete, I pay particular emphasis to seven key papers (the ‘Magnificent Seven') published in the last three years. Taken collectively, these papers do a fairly good job of describing what we see, and when we see it. I also use them as springboard to speculate about what we don't we see, and why not. [ABSTRACT FROM AUTHOR]

The properties of local star forming galaxies, in both clusters and the field, can aid understanding of the environmental dependence of galaxy formation and evolution. We present initial results from an Hα survey of all Sa-Sc CGCG galaxies, with velocities within 3σ of the cluster mean, in six local Abell clusters, down to a limiting magnitude of MB = -18.5. We also have a substantial field sample taken from the recent Hα Galaxy Survey (HαGS, James et al. 2004). [ABSTRACT FROM AUTHOR]

Galaxies do not spend their whole lives in isolation. In fact, interactions and merger events are very important in galaxy evolution, even more so at high redshift, where the number-density of galaxies was considerably higher than it is today. These encounters often trigger a burst of star formation. We use high spatial resolution mid-infrared observations of nearby starburst galaxies to develop a detailed understanding of this starburst phenomenon and the resulting stellar populations. The issues addressed are the properties of superstarclusters, the nature of extreme star formation in (Ultra) Luminous Infrared Galaxies ((U)LIGs), and the characteristics of nuclear starburst rings in barred galaxies. In this paper we present the first mid-infrared imaging and spectroscopy obtained with VISIR at the ESO Very Large Telescope. [ABSTRACT FROM AUTHOR]

Recent HST imaging surveys have revealed the presence of central star clusters in a majority of spiral galaxies. These nuclear clusters (NCs) may provide important clues to the central structure and secular evolution of disk galaxies. However, their origin and nature are not entirely understood. We therefore performed a spectroscopic survey with HST/STIS of NCs in 40 early- and late-type spiral galaxies. To study the ages and physical properties of the clusters we performed stellar population synthesis modeling using Bruzual-Charlot template spectra. The luminosity-weighted NC ages are almost always less than a Hubble time, indicating that star formation is an ongoing process in spiral galaxy centers. We find that NCs in late-type spirals are younger and less massive than those in early-type spirals. [ABSTRACT FROM AUTHOR]

We determined ages for 52 candidate star clusters with masses ≤ 106 M⊙ in the low surface brightness spiral galaxy NGC45. Four of these candidates are old globular clusters located in the bulge. The remaining ones span a large age range. The cluster ages suggest a continuous star/cluster formation history without evidence for bursts, consistent with the galaxy being located in a relatively unperturbed environment in the outskirts of the Sculptor group. [ABSTRACT FROM AUTHOR]

We introduce 11HUGS (11Mpc Hα and Ultraviolet Galaxy Survey), an outgrowth of the recently completed 11MPC Survey, a ground-based Hα and Rband imaging program of a volume-limited sample of 367 spiral and irregular galaxies within a distance of 11 Mpc. As such, the 11HUGS galaxies area complete subset of the 11MPC Survey catalog which avoid the Galactic plane (b > 30.) and are observable by GALEX. The goal of 11HUGS is to characterize the demographics and star formation properties of nearby galaxies, with an emphasis on the dwarf galaxies which dominate the sample population. The data also provide a foundation for follow-up studies of the HII region populations, star formation, chemical abundance, and ISM properties of the galaxy sample. The combination of Hα imaging, which provides snapshots of the ongoing star formation, and UV imaging, which traces star formation over a much longer timescale, will yield powerful constraints on the systematic errors in the inferred star formation related quantities. [ABSTRACT FROM AUTHOR]

We present results of our investigation into the metallicity historyof disk galaxies between redshifts 0

We present numerical simulations of the passage of clumpy gas through a galactic spiral shock and the subsequent formation of giant molecular clouds (GMCs) and the triggering of star formation. The spiral shock formsdense clouds while dissipating kinetic energy, producing regions that are locally gravitationally bound and collapse to form stars. In addition to triggering the star formation process, the clumpy gas passing through the shock naturally generates the observed velocity dispersion size relation ofmolecular clouds. In this scenario, the internal motions of GMCs need not be turbulent in nature. The coupling of the clouds' internal kinematics totheir externally triggered formation removes the need for the clouds to beself-gravitating. Globally unbound molecular clouds provides a simple explanation of the low efficiency of star formation. While dense regions in the shock become bound and collapse to form stars, the majority of the gas disperses as it leaves the spiral arm. [ABSTRACT FROM AUTHOR]

I assess the similarities and differences between the star-formationmodes in quiescent spiral galaxies versus those in violent starburst regions. As opposed to the quiescent star-formation mode in spiral galaxies, current empirical evidence on the star-formation processes in the extreme, high-pressure environments induced by galaxy encounters strongly suggests that star cluster formation is an important and perhaps even the dominant mode of star formation in such starburst events. The sizes, luminosities, and mass estimates of the young massive star clusters (YMCs) are entirely consistent with what is expected for young Milky Way-type globular clusters(GCs). Recent evidence lends support to the scenario that GCs, which were once thought to be the oldest building blocks of galaxies, are still forming today. One of the key unanswered questions in this field relates to their possible survival chances for a Hubble time, and thus to the potential wevolutionary connection between YMCs and GCs. [ABSTRACT FROM AUTHOR]

Detailed knowledge of the initial distribution of stellar masses at birth (known as the initial mass function or IMF) is necessary to predict and understand the evolution of stellar systems, such as clusters and galaxies. Unfortunately, stellar evolution theory cannot predict the form of this critical function and the origin of the stellar IMF remains one of the major unsolved problems of modern astrophysics.Stars form in the cold dense cores of interstellar molecular clouds and the detailed knowledge of the spectrum of masses of such cores is clearly a key for the understanding of the origin of the IMF. To date, observations have presented somewhat contradictory evidence relating to this issue. Here we present a new and more robust determination of the dense core mass function. We find the core mass function to be surprisingly similar to the stellar IMF, modified by a uniform star formation efficiency of about 30%. This suggests that the distribution of stellar birth masses is a direct product of the fragmentation/coalescence process in a molecular cloud. [ABSTRACT FROM AUTHOR]

We present an initial look at the far-infrared-radio correlation within the starforming disks of four nearby, nearly face-on galaxies (NGC 2403, NGC3031, NGC5194, and NGC6946). Using Spitzer MIPS imaging and WSRT radio continuum data, we are able to probe variations in the logarithmic 70 μm/22 cm (q70) flux density ratios across each disk at sub-kpc scales. [ABSTRACT FROM AUTHOR]

Our understanding of star formation in disks is in the midst of an observational revolution, with Spitzer, GALEX, and a host of groundbased surveys providing complete inventories of star formation in nearby galaxies,and the first truly multiwavelength spatially-resolved datasets. The same data provide detailed information on the structure of the cold interstellar medium on «100 pc scales, and thus offer the promise of understanding the complex interplay between the star formation rate and the ISM, down to the physical scales where star formation events are triggered. This talk will present a few highlights and insights that have emerged from the surveys. [ABSTRACT FROM AUTHOR]

The correlation between far-infrared and radio emission in galaxies is remarkably strong considering the very different emission mechanisms which are thought to be responsible for the two. We have examined this correlation in the LMC on scales ranging from 40 pc to 4 kpc, finding that the FIR-radio correlation remains extremely tight down to <100 pc, whereas correlations of either FIR or radio with Hi or CO degrade considerably below 1kpc. However, in nearby spiral galaxies the mid-infrared (MIR) and radio emission begin to decorrelate even on scales of <2 kpc. The difference in behaviour from the LMC may be due to the larger fraction of synchrotron flux in more massive galaxies. [ABSTRACT FROM AUTHOR]

We study influence of a galactic central supermassive black hole (SMBH) binary on gas dynamics and star formation activity in the galactic central region by making three-dimensional Tree+SPH simulations. Due to orbital motion of SMBHs, there are various resonances between gas motion and SMBH binary motion. We have shown that these resonances trigger gas concentrations and filaments in the galactic central region and the formation of small gaseous spiral arms around the SMBH binary. In these regions, star formation becomes very active. As the result, a nuclear star burst occurs in the galaxy. [ABSTRACT FROM AUTHOR]

SHARCII 350 μm continuum and archival HST J - H band maps are presentedof NGC3656, the brightest of our sample of six elliptical galaxies for which resolved CO gas disks have recently been detected with 7″-spatial-resolution, interferometry mapping. These gasdisks confirm the conclusions of earlier results showing optical dust lanes and unresolved CO that implied the common existence of molecular gas in ellipticals and the disk-likestructure of this gas. [ABSTRACT FROM AUTHOR]

We present results of CO observations of the barred spiral galaxy Maffei 2 with Nobeyama Millimeter Array (NMA). The distribution of the molecular gas in the central regionshows elongated structure with two peaks as shown in the previous data. We found that theelongated structure resolved into spiral arms that continue from the offset ridges along the bar to a radius of less than 50 pc. [ABSTRACT FROM AUTHOR]

We present our progress on a detailed study of M81 in the radio, ultraviolet and infrared wavelengths, in which we attempt to use Hi produced in photodissociation regions (PDRs) as a tracer for molecular hydrogen. Radio (VLA), UV (Galex) and IR (Spitzer) data are all available at about 6 arcsec resolution or better, corresponding to a linear scale of little over 100 parsec. We expect to pursue the viability of the use of Hi as a tracer for H2 across a variety of nearby galaxies, including NGC2403, M33 and M83, using VLA and GALEX data as a major extension to the existing studies of e.g. M101 and M81 in this context. [ABSTRACT FROM AUTHOR]

In order to study formation and evolution of interstellar clouds, we simulatethe multi-phase interstellar matter in a disk galaxy using an SPH code, consideringradiative cooling, cloud formation, star formation and heating by supernovae. By calculating various cases of total interstellar mass and strength of UV background radiation, we study how cloud mass function depends on theses parameters. We show that the power index, α, of the cloud mass function is small when there is a large amount of interstellar medium or strong UV radiation. Our results suggest that cloudmass function is a good indicator of these interstellar processes. [ABSTRACT FROM AUTHOR]

We investigate, through numerical hydrodynamical calculations, the behaviour of a galactic disk subject to an external spiral potential. In particular, we focus on the evolution of inter-arm structure such as spurs, the formation of molecular clouds, and the generation of velocity dispersion as gas passes through the spiral arms. [ABSTRACT FROM AUTHOR]

We report the results of our study of 436 giant molecular clouds (GMCs) in NGC5128 using dust extinction. The proposed technique allows us to probe the extinction up to 10 magnitudes in this galaxy. The clump mass spectrum, derived by a clumpfind algorithm, is consistent with a power law, dN/dM ∞ M−α, with α = 2.3. [ABSTRACT FROM AUTHOR]

We analyze and compare global line-profiles of 39 disk galaxies with Hi and Hii data. We find good agreement between the first and second moments of the profiles and recession and rotation velocities, respectively. The shapes of Hi and Hii profiles differ markedly, however, as the line profile asymmetries are not . Asymmetry in neither Hi nor Hii profiles is correlated with rotation curve asymmetry which suggests that differing distributions of gas, and not kinematic asymmetries, dominate the global profile asymmetries of normal disk galaxies. [ABSTRACT FROM AUTHOR]

We present integral-field echelle observations of the warm, ionized phase of the interstellar medium (ISM) of many, nearly face-on spiral galaxies. Luminosities and line-widths of Hα, [SII] and [NII] reveal several distinct trends in the conditions of the ionized gas. In principle these measures yield estimates for temperature, density, and energy sources of the kinematic heating. The emergent picture is complex: we find variations of the line-widths between galaxies and with galactic radius, and correlations between line-widths and emission-line luminosity and line-ratio. Two related bimodalities appear in line-ratio distributions and in the radial distribution of Hα luminosity. We briefly contrast ISM observations of nearby galaxies to the Milky Way and high-z galaxies. [ABSTRACT FROM AUTHOR]

I summarize some results from the recent CO survey of late-type, low surface brightness (LSB) spiral galaxies by Matthews et al. (2005). We have now detected COemission from six late-type, LSB spirals, demonstrating that despite their typical low metallicities and low mean gas surface densities, some LSB galaxies contain a molecular medium that is traced by CO. We find that the CO-detected LSB spirals adhere to the same MH2-FIR correlation as brighter galaxies. We also find a significantdrop-off in the detectability of CO among low-to-intermediate surface brightness galaxies with Vrot 90km s-1, pointing toward fundamental changes in the physical conditions of the ISM with decreasing disk mass. [ABSTRACT FROM AUTHOR]

Star-forming regions in galaxies consist of a number of components, the evolving young stellar clusters with their associated Hii regions, isolated OB stars embedded in compact Hii regions, older, non-ionizing stars, and the pre-existing old stellar populations. All of these are surrounded by a complex, turbulent and fractal screen of gas and obscuring dust. Here, I describe how self-consistent dynamical and radiative transfer modeling of these various components is leading to synthetic pan-spectral energy distributions ranging from the Lyman Limit up to millimetre wavelengths. These models provide excellent fits to real objects, and furnish the diagnostic tool needed to derive the fundamental parameters of star-forming galaxies in both the local and distant universe. [ABSTRACT FROM AUTHOR]

We present the results of our Hi survey of six loose groups of galaxies analogous to the Local Group. The survey was conducted using the Parkes telescope and the Australia Telescope Compact Array to produce a census of all the gas-rich galaxies and analogs to the high-velocity clouds (HVCs) within these groups down to MHI< 107 as a test of models of galaxy formation. We present the Hi mass function and halo mass function of the loose groups and show that they are consistent with those of the Local Group. We discuss the possible role of HVCs in solving the "missing satellite" problem and discuss the implications of our observations for models of galaxy formation. [ABSTRACT FROM AUTHOR]

Using the public data releases of the Sloan Digital Sky Survey (SDSS), we investigated the galaxy density around Low Surface Brightness (LSB) galaxies in comparison to High Surface Brightness (HSB) galaxies. Our results show significantly lower galaxy densities in the vicinity of LSBs compared to HSBs on scales between 2 and8 Mpc. On scales below 2 Mpc, the galaxy densities in the neighbourhood of LSBs aresystematically (but only with a slight significance) below that of HSBs. In pie slice diagrams LSBs favour the outer rims of the filaments of the Large Scale Structure (LSS). Some LSBs are even found inside voids. [ABSTRACT FROM AUTHOR]

Although it is widely accepted that galaxy interactions stimulate secular evolutionary effects (e.g. enhanced star formation), the amplitude of this effect and the processes for accomplishing them are not well quantified. The goal of the project AMIGA (Analysis of the Interstellar Medium of Isolated Galaxies) is to provide a sizable reference sample (n=1050) of the most isolated galaxies as a basis for the study of the influence of the environment on galaxy properties. Here, we present the far-infrared (FIR) properties of 1030 galaxies of the sample for which IRAS data are available. We improved the detection rate and accuracy of the IRAS data with respect to the Point Source and Faint Source Catalog by redoing the data reduction with the IPAC utility ADDSCAN/SCANPI. Comparing the FIR to the blue luminosities, we find a slightly non-linear relation. Furthermore, we find that interacting galaxies tend to have an enhanced FIR emission. [ABSTRACT FROM AUTHOR]

We analyze properties of subhalos/substructures resolved in a dark matter simulation of a Milky Way-like halo in a ΛCDM cosmology. We explore possible links between subhalos and the Galactic satellites and find: 1) The infall patterns of subhalos are slightly elongated along the major axis of the galaxy halo and are clumpy on smaller scales. 2) The Great disk defined by MW satellites (Kroupa et al. 2005) is easily reproduced in our simulations without recurring to sophisticated galaxy formation recipes and is purely due to their highly centrally concentrated distribution around the Galaxy. [ABSTRACT FROM AUTHOR]

We report on a study of a nearby minor merger, NGC2782, which is the result of a merger between two disk galaxies with a mass ratio of 0.25 occurring ~ 200 Myr ago. This merger produced an Hi-poor, optically bright Eastern tail and an Hi-rich, optically faint Western tail. Deep optical images reveal the presence of blue (B - V ~0.0) clusters along both tails, suggesting that they are young (<100 Myr) and possibly formed within the tail. The presence of young clusters in the Western tail is unexpected due to the lack of molecular gas observed in previous studies. These results suggest that star cluster formation is a common outcome of minor mergers regardless of molecular gas content in the tidal debris. [ABSTRACT FROM AUTHOR]

The origin of Hi at anomalous velocities and at large distances above the disk, detected in a few spiral galaxies, is still a puzzle. To improve on our understanding of this extra-planar gas, we have started a study of a representative sample of nearby edge-on galaxies. In this paper we present the observations and a preliminary analysis of the extra-planar gas of UGC1281 and NGC7814. These galaxies were observed with the WSRT for 4 × 12 hours. In the dwarf galaxy UGC1281, there are clear indications of a gaseous halo. A preliminary analysis of NGC7814 shows no halo; however, we have detected extra-planar gas, at velocities higher than the maximal rotational velocity, above and below the plane. The origin of this gas is unclear. [ABSTRACT FROM AUTHOR]