International Workshop jointly organized by:
ESO/Chile, FONDAP-Chile and Universidad de Chile    

Physics of Active Galactic Nuclei at all Scales
at ESO/Santiago Headquarters, Chile - December 3 to 6, 2003


Please make sure that all posters fit onto a panel 1m x 1m in size. We advise you bring copies of your posters, or of highlights therein, on single "take-away" sheets of paper to be placed next to your poster. Posters will be displayed next to the coffee area in a tent on the ESO grounds.


Spectroscopic Properties of Quasars from the Calan-Tololo Survey

The Very Long Baseline Array (VLBA) has been used to obtain radio images of the compact steep-spectrum quasars 3C119, 3C216, 3C147 and
3C454 at 1.4, 2.7 and 5 GHz. The Faraday rotation is determined along the jets and appear to be of external origin according to models of depolarization of the radio radiation and range from 400 to 1600 rad m-2. We discuss the morphological aspects of individual sources and conclude that these sources show evidence for strong deceleration for the radio compontentes. We overrrule the hypothesis that free adiabatic expansion is responsible for the deceleration, which can be explained by strong jet-environmental interactions.

Spectral Sequence & Luminosity function of low luminosity blazars
The knowledge on blazars has been built on the properties of the most powerful objects, yet they may not be representative of the population as a whole. Here we present the results from a study that aims to probe the red end of the spectral sequence of blazars, and the low luminosity tail of the luminosity function (LF). The objects under consideration are a set of low luminosity radio selected sources, all having core-jet structures and flat spectra from the radio to the mm/submillimetre bands. Their Spectral Energy Distributions show a range of peak frequencies, from log v_peak ~ 12 to 16 Hz. By comparing the radio luminosity range and peak frequency distribution of these objects with those of the SLEW and 1 Jy samples, we conclude that our objects do not follow the spectral sequence proposed by Fossati et al and Ghisellini et al. The less luminous objects are one order of magnitude fainter than 1 Jy sample. The low luminosity points suggest that the LF does not flatten at luminosities lower than 1.0E+25 WHz-1, rather has a slope consistent with that of the 1 Jy sample.


Possible analytical solutions to the equations hydrodynamics that are in "outflows"
The structure and evolution of jet-like structures under a variety of physical conditions is a problem that generally requires numerical modeling. However, in certain cases valuable insight can be gained from purely analytical hydrodynamical solutions, which exhibit outflows of varying characteristics. We will show several solutions of this type, applicable to various accretion scenarios.

In this paper, we present results of an HI line and radio continuum survey of selected southern Active galaxies made with the Very Large Array and the Australia Telescope Compact Array. Radio images are presented and rotation curves for individual galaxies were obtained. The radio continuum can be explained by enhanced star-formation models.The HI content in seyfert galaxies is larger than those seen in starburst galaxies. Our trends confirm that the infrared luminosity correlates well with the total neutral gas content which supports the scenario that star formation in the bulges of seyfert galaxies are considerably higher than in regular late-type galaxies. We also find a trend between various observational quantities which are commented in
this work.

Clustering and light profiles of galaxies in the environment of 20 USS Radio sources
We have analyzed galaxy properties in the neighborhood of 20 Ultra-Steep Spectrum Radio sources (USS) taken from the WISH catalog of De Breuck et al. (2002). Galaxies in these USS fields were identified in deep observations that were carried out in the K'-band using the OSIRIS imager at the CTIO 4m telescope. We find a statistically significant signal of clustering around our sample of USS.
The angular extension of the detected USS-galaxy clustering is $\theta_c\sim 20\arcsec$ corresponding to a spatial scale $\sim 120 h^{-1}{\rm kpc}$, assuming the sources are at z $\sim 1$ in a $\Omega_m=0.3$, $\Omega_{\Lambda}=0.7$ model universe. These results are in agreement with those obtained by Best (2000) for radio galaxy-galaxy correlation, and Best et al. (2003) for radio-loud AGN-galaxy correlation. We have also analyzed the light distribution of the galaxies by fitting S\'ersic's law profiles. Our results show no significant dependence of the galaxy shape parameters on the projected distance to the USS.


Star Forming Galaxies in Galaxy Groups in the SDSS.
We present an study of the environments of galaxies with a high star formation activy, that resides in galaxy groups identified in the SDSS first release. Besides the strong star formation supression in groups of galaxies, we found several AGN galaxies in such environments and describes its physical characteristics.

Multiwavelength simultaneous observations of PKS 2155-304 at several time scales
PKS 2155-304 is one of the brightest BL Lacs at X-rays, UV and optical wavelengths and it is the only southern hemisphere AGN detected at TeV energies. Although it has been a common target for variability studies, few conclusions and effective constrains were obtained up to now to explain the origin of the observed activity. In this work we present the results of optical and near infrared observations of this source, most of them obtained simultaneously, covering time scales of less than 10 minutes to some months. At the longest time scales we found a linear correlation between the optical spectral index and magnitude, with the spectrum becoming harder as the brightness increases. At very short timescales we detected variability both at infrared and optical wavelengths, without time lags and we did not detected the correlation between spectral index and magnitude found at larger time scales, suggesting that the two types of variability may originate in different regions. Some physical scenarios are proposed to explain these differences. Based on observations made at the Laboratório Nacional de Astrofísica (MCT/CNPq)

We present detailed BVI photometry and H$\alpha$+N[II] images for a sample of eleven minor mergers selected from the Catalogue of Arp-Madore. Total magnitudes, luminosity profiles, isophote and color maps are presented for each galaxy of the sample. Despite most galaxies of the sample are strongly disturbed we could recongnize a wide range in morphological types going from early ellipticals to late spirals. However, most profiles do not follow a simple bulge + disk model and show a strong excess respect to this law. We found a correlation between the ratio of the major diameters of the members of each pair and their corresponding differences in luminosities.
Basic photometric parameters, H$\alpha$+[NII] luminosity, metallicity and age of HII regions in these galaxies are also presented in this paper, as well as its sizes and positions respect to the galaxy nucleus. We have also investigated for a possible dependence of the HII regions luminosities to the distance to the (kinematic) and (optical) centers of the galaxies.

A Kinematical Study of Nuclear Stellar Populations in Seyfert Galaxies
Recent studies in the optical and in the UV have detected circumnuclear starbursts in 40\% of nearby Seyfert 2; about half of the remaining 60\% present an UV excess whose nature is not well known, mainly because of the limitations of stellar populations analysis techniques in the optical and UV. A possible way to circumvent these difficulties is to use a determination of the Mass to Light ratio (M/L), obtained with the combination of velocity dispersions with photometric information; M/L is a powerful discriminant between different stellar populations, and can thus be used to check the nature of the UV excess in optically ambiguous Seyfert 2s. In this work we present the first results of a spectroscopic survey of a sample of 35 Seyfert nuclei, being 27 Seyfert 2s and 8 Seyfert 1s; for all of them we have complementary data, like HST images, optical and (in some cases) UV spectroscopy. The data were collected on the ESO 1.52m telescope in La Silla, in two runs in 2002; long slit spectroscopy was performed around the infrared triplet lines of ionized Calcium at $\lambda\lambda$ 8498, 8542, 8662 \AA. Here we describe the analysis steps and present the first results concerning velocity dispersions measures and equivalent widths of the Ca II lines, at different distances from the nuclei. These data will allow us to investigate the ambiguos Seyfert 2 nuclei nature, thus contributing to a better understanding of the Starburst-AGN scenario. This work is supported by CAPES and CNPq.

Low lyman alpha using Drawin and Emard escape probality formulation.

VLA and MERLIN observations of selected quasar jets (3C208, 3C352, 3C434, 3C9 and 3C14) between 1,4 and 15 GHz are used to derive astrophysical properties in the jets of this FR-II radio sources. We interpret the results as giving support for unifying schemes of radiogalaxies and quasars.
We also have determined the Faraday rotation for jets and counter-jet sides. Rotation measeures are used to constrain the internal density and mach numbers in the jets, obtaining similar values for quasar jets. The radio brightness can be explained by doppler boosting of the synchrotron radiation giving evidence for orientation effects as a origin for the Laing-Garrington effect.


Tracing the coronal line region in AGN with VLT/NACO

Are Quasars Associated with Dark Matter Overdensities?
Hierarchical models of galaxy evolution have been successful in explaining the observed properties of galaxies and clusters over a large range in redshift. Recently, Kauffmann and Haehnelt (2002) have also incorporated the formation and evolution of quasars in these models. They assume that quasars are created when massive dark matter halos (M = 1e12) merge to form black holes, which are fed by cool gas in galaxies resulting in the quasar phenomenon. Although there may also be other triggers of quasar activity in some galaxies, e.g. Seyferts, the overall agreement with properties of the quasar population suggests that quasar formation through hierarchical growth of large scale structures is important in explaining the formation of a majority of quasars. Turning the argument around implies that most quasars are luminous markers of merging (or merged) massive dark halos.
Members of the Deep Lens Survey (DLS) team have discovered dark matter overdensities through shear mapping of background galaxies (e.g. Wittman 2003). Here we present the data, methods and preliminary results from a search for quasars associated with two of these matter overdensities. A wider search for associations of dark matter mass overdensities and quasars will allow us to test the validity of models in which quasars are formed as a result of hierarchical structure formation.


Spectral Energy Distribution of Three-dimensional Magnetohydrodynamic Accretion Flows
We investigate the SED and its time variability of the accretion flows whose structure is calculated by the global three-dimensional magnetohydrodynamic (3D-MHD) simulations. Here, the radiation transfer equation, in which Comptonization is taken into consideration, is solved by the Monte Carlo simulations.
The optically-thin high-temperature accretion flows is thought to reproduce the SED of the low-luminosity AGN. Indeed, it is known that the ADAF model can successfully reproduce the actual SED. However, the non-steady irregular flow structure, which does not accurately agree with ADAF solution, is revealed by the global 3D-MHD simulations. Thus, it is necessary to solve radiation transfer in the 3D-MHD accretion flows for investigating the actual, self-consistent SED.
We investigate the SED and its variability of the accretion flows through Monte Carlo simulations with taking into account the emission/absorption due to synchrotron and free-free as well as Compton scattering. It is found that the resultant SED of 3D-MHD flows well agrees with the observed data of
Sgr A* and vary in wide range of wavelength.

Geometric model for the OH megamaser in IIIZw35
We present a thin disk model to match the low and high resolution observations of the OH megamaser in IIIZw35. A simple mathematical argumentation is presented to constrain the parameter space and fit the spectrum and the brightness distribution. Observations suggest that the IR and radio activity in IIIZw35 is powered by a very compact nuclear starburst rather than an AGN component. These observationsseem to be consistent with the paradigm that OH megamasers unlike H2O megamsers are associated with circumnuclear starbursts rather than an AGN accretion disk.

In this paper, we interpret C and X-band radio continuum observations of a sample of Markarian galaxies. The results are briefly discussed. Seyfert 2 galaxies show sistematically higher HI mass-to-blue magnitude than Seyfert 1 galaxies, as well as higher radio to far-infrared luminosities. The observational properties are interpreted in terms of simple non-thermal and dust emission. Radio brightness temperatures, equipartition magnetic fields and total magnetic densities for the disk are obtained. Upper limits for thermal densities are derived from simple free-free emission. Star formation rates and mean supernova rates are estimated for individual Markarian galaxies. The SFR values for the most luminous Markarian galaxies are considerably higher than those found for compact blue dwarf galaxies and also for early-type spirals.

Serote Roos
Stellar populations of the members of a distant galaxy cluster CL0048-2942

Predicting BLR Spectra with Models Incorporating Exact Radiative Transfer

Extended emission-line regions in Seyfert galaxies: 3D-spectroscopy and kinematical modelling with N-body gas velocity fields   
We model morphology and kinematics of extended narrow-line regions in Seyfert galaxies taking into account gas distribution and motion in N-body barred potentials as well as various orientations of the ionization cone with respect to the host galaxy disk. At the same time, we present new preliminary 3D-spectroscopy data on nearby Seyfert galaxies.

Obscured and non-obscured AGN in the GOODS fields

Faraday Rotation Studies OF 3C33.1: another naked-jet radio source ?
In this paper we present results of a detailed morphological and radio polarization studies of the nearby radio galaxy 3C33.1 (4C72.01, 0106+729, z=0.18) made with the Very Large Array at 18 and 21 cm. Recently it has been classified within a sample of large core-dominated radio sources. The jet show little Faraday rotation with rotation measures RM<10 rad m2 whereas the hotspots exhibit higher values. The low rotation measures indicate that this radio source has a visible jet which can be a naked jet or stripped from a dense environment. We also interpret these results as the radio component is expanding through the intergalactic medium with a expected mean particle density less than 6X10-2 cm-3 at the hotspots and external magnetic fields less than 20 microgauss. A spectral ageing analysis based on syncrotrong power losses arguments of the integrated spectra suggest that the radio structure is younger than 10 Myears. Further beaming parameters of the jet flow are derived based on analytical jet flow models. General aspects of this source are also discussed.

Rapid Growth of Super-massive Black holes: "Hidden" Super-Critical Accretion
We investigate the effects of viewing angle on the SED of super-critical accretion flows, by which the seed black hole can grow into super massive black hole in a short period. We conjecture that the self-occultation of the disk and Doppler effect is able to change the spectral shape at various viewing angles. Although the Doppler boosting effect monotonically increase as $i$ increasing in the case of low inclination angle ($i~\lesssim 40$), they are suppressed by self-occultation for high inclination angle ($i \gtrsim 50$), since the super-critical accretion flow (mdot >> 1) is geometrically thick due to the radiation pressure. That is, the self-occultation effects terminated the Doppler factor increasing in super-critical accretion flow, and then we cannot expect highly beamed radiation.
Thus, we could propose that {\it hidden super-critical accretion} are existing in already observed AGNs or quasars, and super massive black hole grow up within several 10^6 yr by super-critical accretion. Using these effects, we also find that how to discriminate black hole rotation from the shape of UV/optical spectra. We also propose the method in the poster.