Local HII galaxies present a Fundamental Plane of [L–σ] where either the equivalent width of Hβ or the oxygen abundance O/H act as a second parameter. These relations are powerful cosmological distance indicators since emission line galaxies may be found to high redshifts, though some caution must be taken till systematic effects are better understood.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present spectroscopic observations of the peculiar system AM1003-435, which is composed of two strong interacting galaxies, and numerical simulations of the encounter between the galaxies, following the dynamical evolution of the stellar and gaseous components.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present results from an imaging and spectroscopic study of the dust properties of Seyfert galaxies in the 1-10 μm range. The data are compared to state of the art models of torus emission to constrain geometrical and physical properties of the obscuring medium.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Wide-angle, moderately deep redshift surveys such as that conducted as part of the Sloan Digital Sky Survey (SDSS) allow study of the relationship between the structural elements of the large-scale distribution of galaxies – including groups, cluster, superclusters, and voids – and the dependence of galaxy formation and evolution on these enviroments. We present a progress report on mapping efforts with the SDSS and discuss recently constructed catalogs of clusters, voids, and void galaxies, and evidence for a $420h^{-1}$Mpc supercluster or “Great Wall.” Analysis of multi-band photometry and moderate-resolution spectroscopy from the SDSS reveals environmental dependence of the star formation history of galaxies that extends over more than a factor of 100 in density, from clusters all the way to the deep interiors of voids. On average, galaxies in the rarified environments of voids exhibit bluer colors, higher specific star formation rates, lower dust content, and more disk-like morphology than objects in denser regions. This trend persists in comparisons of samples in low vs. high-density regions with similar luminosity and morphology, thus this dependence is not simply an extension of the morphology-density relation. Large-scale modulation of the halo mass function and the temperature of the intergalactic medium might explain this dependence of galaxy evolution on the large-scale environment.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Wide field imaging is key to understanding the build-up of distant clusters and their galaxy population. By focusing on the so far unexplored outskirts of clusters, where infalling galaxies first hit the cluster potential and the hot intracluster medium, we can help separate cosmological field galaxy evolution from that driven by environment. I present a selection of recent advancements in this area, with particular emphasis on Hubble Space Telescope wide field imaging, for its superior capability to deliver galaxy morphologies and precise shear maps of distant clusters.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

MRC B1221–423 is a powerful, nearby (z = 0.17) compact radio source, which lies within the envelope of a galaxy which is undergoing a tidal interaction with a companion. Broad-band optical/NIR colours show evidence of several distinct episodes of star formation. The evidence points to this being a radio source “caught in the act” of its first ignition.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We study AGN jet formation by means of exact solutions of the relativistic magnetohydrodynamic equations. This is an original extension in Schwarzchild's metric of previous meridionally self-similar models. The outflow is mainly thermally driven to high asymptotic speeds from the central region where the escape speed is also high. The jet solutions are magnetically collimated on the sub-parsec scale.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present the preliminary result of our project, consisting in studying the properties of a large sample of galaxy clusters. The Münster Red Sky Survey, which is a large galaxy catalogue covering an area of about 5000 square degrees on the southern hemisphere, serves as our observational basis. It is complete up to $r_F=18^m.3$. Creation of a cluster catalogue is the first step of our investigation. We propose to use the 2D Voronoi tessellation technique for identifying galaxy clusters in this 2D catalogue. Points with high values of the inverse Voronoi tessel area will be regarded as galaxy cluster centroids. We show that this approach works correctly.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

VLT and NTT spectra are used to examine the nuclear and extended coronal line emission in a sample of well-known Seyfert 1 and 2 galaxies. The excellent spatial resolution obtained with VLT allowed us to map [Si VI] 1.963μm and [Si VII] 2.48μm on scales of up to 20 pc. Coronal line emission, extended to distances of ∼102 pc, is detected in some of the lines analyzed, particularly in [Fe X] 6374Å, [Fe XI] 7891Å, and [Si VII] 2.48μm. Most coronal lines are strongly asymmetric towards the blue and broader than low-ionization lines. This result is particularly important for Circinus, where previous observations have failed to detect larger widths for high-ionization lines. Photoionization models are used to investigate the physical conditions and continuum luminosities necessary to produced the observed coronal emission. We found that an ionization parameter U>0.10 is necessary to reproduce the observations, although the clouds should be located at a distance <30 pc from the central engine.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We provide the first direct lifting of the mass/anisotropy degeneracy for a cluster of galaxies, by jointly fitting the line of sight velocity dispersion and kurtosis profiles of the Coma cluster, assuming an NFW tracer density profile, a generalized-NFW dark matter profile and a constant anisotropy profile. We find that the orbits in Coma must be quasi-isotropic, and find a mass consistent with previous analyses, but a concentration parameter 50% higher than expected in cosmological $N$-body simulations. We then test the accuracy of our method on realistic non-spherical systems with substructure and streaming motions, by applying it to the ten most massive structures in a cosmological $N$-body simulation. We find that our method yields fairly accurate results on average (within 20%), although with a wide variation (factor 1.7 at 1$\sigma$) for the concentration parameter, with decreased accuracy and efficiency when the projected mean velocity is not constant with radius.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We have studied how the active nucleus of the Seyfert 2 galaxy NGC 1068 influences the chemistry of its 200 pc circumnuclear disk of molecular gas (CND). Results from new observations made with the IRAM 30m telescope have served for deriving abundances of molecular species such as SiO, CN, HCO+, HOC+, H13CO+ and HCO. These estimates are complemented with a re-evaluation of abundances of HCN, CS and CO, based on previously published observations. We report on the first detection of significant SiO emission in the CND of NGC 1068. We also report on the first extragalactic detection of the reactive ion HOC+. Our conclusions favour an overall scenario where the CND of NGC 1068 has become a giant X-ray Dominated Region (XDR).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

This paper describes some useful results that can be obtained through long-term infrared photometric monitoring of Seyfert galaxies.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We have embarked in an HST program to determine the masses of black holes in spiral galaxies directly by measuring the line emission arising from an extended accretion disk. For each of the galaxies in our sample we have measured the rotation curve and determined the mass distribution within the inner 5–50 pc. We have modeled the stellar mass component using the photometric data from existing HST images and using both data sets we have derived the masses of the black holes in each galaxy. These results will be very important in clarifying the role of the black hole in powering the AGN, will shed light into the effectiveness of the accretion mechanisms and finally will be important in addressing the fundamental issue of unification for Seyfert 1 and Seyfert 2 galaxies.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

I will discuss a few select aspects of the most common and best understood galactic-scale outflow – starburst-driven superwinds, focusing on winds from nuclear starburst galaxies. I will show that modern observations, in particular in the soft and hard X-ray bands, complement and reinforce the existing paradigm of superwinds as flows collectively driven by multiple SNe. The properties of the diffuse X-ray emission from dwarf starburst galaxies, LBOL∼L[sstarf] starburst in spiral galaxies, and ULIRGS, are all consistent with superwind activity. Where appropriate, I contrast the physics of starburst-driven winds with poorly collimated winds from AGN, and discuss what we know of the role of LLAGN and Seyfert nuclei in starburst superwind galaxies.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

I review recent results of cosmological hydrodynamic simulations for clusters of galaxies. Such simulations have developed into an increasingly powerful tool to make theoretical predictions for clusters, and to confront them with observations. I focus, in particular, on the continuing challenge to reproduce the observed cluster X-ray scaling relations in CDM simulations. Self-consistent simulations that include radiative cooling, star formation and supernova feedback generally overpredict the X-ray luminosity on group scales and exhibit overly strong cooling flows. Solving these problems may require the consideration of more physics in cluster simulations, for example thermal conduction or heating by a central AGN.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present a dynamical analysis of the central $\sim$ 1.3 square degrees of the galaxy cluster Abell 1367, based on 272 redshift (of which 118 are new measurements). From the analysis of the 146 confirmed cluster members Abell 1367 appears as a young cluster currently forming at the intersection of two filaments.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Brightness variations across the entire electromagnetic spectrum, occurring at several time scales, are known properties of blazars. The variability of the continuum emission may be related to the formation and propagation of shock waves in the relativistic jet. In this case we may expect variations also in the degree of polarization and its position angle. In order to effectively constrain such models, we begun in 2003 a program to monitor the optical polarimetry of a sample of blazars, of which we present here the first results.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The interplay between stellar populations and gas in local starburst galaxies is analyzed using images from the Hubble Space Telescope to map the ages of the young stellar components and to isolate the contribution of shocks on spatial scales ranging from a few tens of pc to ∼1 kpc. The shocked gas represents a small fraction of the total ionized gas in these objects, yet it can have profound effects on the long–term evolution of the starburst, which may include the triggering of new star formation.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We used the near-infrared [Fe II] emission line signature of shock-heating to detect supernova remnants (SNRs) in nearby starburst galaxies. The near-IR narrow-band imaging program has led to the detection of SNR candidates in NGC 1569 and NGC 5253, both host to super-star clusters. A spatially extended component to the [Fe II] line emission dominates the integrated [Fe II] luminosity in the two galaxies. Despite the starburst environment, the [Fe II] luminosity of the individual SNRs is two orders of magnitude lower than the luminosities observed for SNRs in M82. We find that the density and the structure of the interstellar medium is a more important factor than the starburst nature of a galaxy in determining the average [Fe II] luminosity of a SNR. The observations suggest that a significant fraction of the ISM in NGC 1569 and NGC 5253 is under the influence of SNRs. This does not appear to be the case in M82 where the impact of the SNRs is limited to high density knots.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Ellipticals in very low density environments are extremely rare but hold important clues about galaxy formation and evolution. We present results of an investigation of their internal dynamics. We observe a dichotomy in kinematic properties similar to that in normal ellipticals. We compare the positions of isolated ellipticals with respect to the Fundamental Plane of normal ellipticals and find that they fall onto it, with the exception of NGC 2865. This shows that isolated ellipticals are structurally similar to normal ellipticals, and do not have very young ages, although some have signs of past mergers or interactions.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html