The total spectrum

M 87 was observed with XMM-Newton on June 19 2000 for 60 ks and re-observed in January 2005 with an exposure time of 109 ks. The extraction regions for the RGS spectra are rotated with respect to each other by only 7.3 , which allows us to combine the spectra obtained during the two observations. The total useful exposure time of the combined dataset is 124 ks. We fit these spectra simultaneously. We model the plasma with two thermal Fig. 1. Left panel 1st order RGS spectra of M 87 obtained...

Star Formation in cD Galaxies

A small fraction of central dominant galaxies (hereafter referred to as cD galaxies) harbor star formation proceeding at rates of a few M0 yr-1, as in the disk of the Milky Way, to more than 100 M0 yr-1 1,2 , rivaling the rates in burgeoning galaxies at redshifts z 2 3. This star formation is fueled by reservoirs of molecular gas 3 and is often accompanied by spectacular nebular emission 4, Crawford and Hatch, this volume , as in NGC 1275 of the Perseus cluster. The incidence of line emission...

Results and Discussion

We present the spectra and Ha images of two of our CF cluster BCGs in Figures 1 - 4. At the distance of the clusters, 1 corresponds to 0.25 kpc and 2.80 kpc for Abell 1060 and Abell 1204, respectively (for ho 0.7). Fig. 1. Ha image of the BCG of Fig. 2. Ha image of the BCG of Fig. 1. Ha image of the BCG of Fig. 2. Ha image of the BCG of Abell 1060 The BCG shows Ha emission with nebular line ratios characteristic of star formation. The strongest Ha emission is spatially correlated with a large...

SLAQ Survey

The 2dF-SDSS LRG and QSO (2SLAQ) survey is a collaboration of over 70 UK, US and Australian astronomers focused on studying the evolution with redshift of Luminous Red Galaxies (LRGs) and faint quasars. The details of the 2SLAQ survey can be found in a series of recent papers, including Cannon et al. (2006) and Richards et al. (2005). In this paper, we focus on two recent works on the evolution of LRGs with redshift (Wake et al. 2006 Roseboom et al. 2006) from the joint SDSS and 2SLAQ surveys.

Selection of BCGs and Clusters

The basis of our cluster sample is the C4 cluster catalog 1 , which is based on the spectroscopic data of SDSS and is currently available for DR3. It identifies clusters in a parameter space of position, redshift, and color. Due to fiber collisions in the SDSS (no two fibers can be placed within 55 of each other), the true BCG is not included in the SDSS spectroscopic data for about 30 of the dense clusters and is thus missed by the C4 algorithm. Although an earlier version of the C4 catalog...

Weak Shock Heating

Weak shocks associated with AGN outbursts are generally only detected in deep X-ray observations, so that relatively few are known, e.g. 8, 9, 10, 11, 12 , although they are probably produced in most AGN outbursts. The energies required to drive the shocks are comparable to cavity enthalpies, but much of this energy will end up as potential energy in the ICM. The main requirement for stopping gas from cooling is to replace the entropy lost by radiation and, since the entropy jump, AS, varies as...

On the origin of the cavities

The constraint on the central point source (AGN) is LX < 1039 erg s-1 in 0.54 keV, much lower than the required mechanical luminosity Lmech 1.8x 1042 erg s-1. At least there is no energy input from AGN now. The radio data indicates Lradio < 9 x 1037 erg s-1 per cavity, and the equipartition condition gives Pnon-th 6 eV cm-3, nearly 1 3 of Pgas 17 eV cm-3. With K as proton to electron pressure ratio and f as filling factor, K f > 690 is required to offset the hot gas. The synchrotron life...

Suzaku Observations of A2218

Henry3, K. Mitsuda1, R. Fujimoto1, T. Tamura1, N. Y. Yamasaki1, K. Hayashida4, N. Tawa4, K. Matsushita5, M. W. Bautz6, J. P. Hughes7, G. M. Madejski8, R. L. Kelley9 and K. A. Arnaud9 1 ISAS JAXA, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan takei astro.isas.jaxa.jp 2 Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan 3 University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822, USA 4 Osaka University, Toyonaka 560-0043,...

Main open questions

The two examples described above are just two examples taken from ourown work that show how simulations have become mature enough to address the physical challenges posed by AGN feedback. However, while simulations have made significant progress, we would like to end with a list of open questions that delineate the problems that still need to be solved in this field - Why do AGN-blown cavities remain intact and appear spherical while simulations suggest that the cavities fragment - How are the...

Integral Field Spectroscopy

2D optical (and IR) spectroscopy is clearly the best way to decompose the velocity fields in these systems. 60 have used the Visible Multiobject Spectrograph on the VLT, with 1600 optical fibers to obtain velocity and line ratio maps for 4 extreme cool-core clusters, Abell 1664, Abell 1835, Abell 2204, and Zw 8193. The relative velocites of the nebular features in these systems were low, around 100-300 km sec. The biggest disturbances were in galaxies with companions. Remarkably, the NII Ha...

Morphological Signatures of AGN Feedback in the Hot Interstellar Medium of Normal Elliptical Galaxies

1 Los Alamos National Laboratory, diehl lanl.gov 2 Ohio University, statler ohio.edu Summary. We present the results of a systematic morphological analysis of the X-ray emission of the hot interstellar medium (ISM) in 54 normal elliptical galaxies observed with the Chandra satellite. We find evidence for the gas not to be resting completely in hydrostatic equilibrium. In particular, we find that optical and X-ray ellipticities are uncorrelated, contrary to expectations from hydrostatic...

Heating in CC and NCC Clusters

2.1 Analytic Models & Comparison to Observations If the heating requirements necessary to explain the observed structure of clusters could be calculated, this would yield valuable clues to the nature of the heating sources once present in these systems. Fortunately, in the absence of feedback, radiative cooling and gravity establish a unique (steady-state) distribution for the ICM in a cluster of mass M. To explain, within rcool the shapes of the ICM temperature and density profiles are...

Introduction

The radiative cooling time in the central regions of many dense clusters is less than the age of the cluster. Without any outside disturbance this gas should continue to cool to very low temperatures creating a cooling flow in the cluster center 7 . The search for cool gas through X-ray spectroscopic observations has revealed the surprising fact that the temperature drop in cluster cores seems to halt at temperatures around one-third of the maximum cluster temperature 16 . An obvious candidate...

List of Participants

Tokyo Metropolitan University akataku phys.metro-u.ac.jp KIPAC (Stanford University and SLAC) Chiba University asai astro.s.chiba-u.ac.jp University of Waterloo mbalogh uwaterloo.ca Belsole, Elena IoA Cambridge elena ast.cam.ac.uk Swietokrzyska Academy bmonika pu.kielce.pl Max-Planck-Institut fuer extraterr. Physik Dept. of Astronomy - University of Trieste ICC, University of Durham r.g.bower durham.ac.uk University of Colorado jack.burns cu.edu Universita di Roma Tor Vergata cavaliere...

Discussion

Chandra has revealed that the hot ISM in normal elliptical galaxies is not hydrostatic, and almost always disturbed to some degree. In these systems the dynamical times, sound crossing times, cooling times, and AGN cycle times are all 108 yr. This is different from the situation in clusters, where the characteristic timescales of the observable features can be much longer, and consequently the AGN can look like a steady heat source to the bulk of the intracluster medium. In normal ellipticals,...

Metal transport by AGN

The ICM has a metallicity of about 1 3 solar. However, cooling core clusters, i.e. clusters with a centrally peaked X-ray brightness, show peaked abundance profiles. A number of observations indicates that SNe Ia in the central galaxy are mainly responsible for the metal enrichment in the central part of clusters. However, the observed metallicity profiles are much broader than the light profiles of the central cluster galaxy. Hence, the difference in the light and the metal distributions are...

Springer

Peter Sch Cker Max Planck

Pratt Alexis Finoguenov Peter Schuecker Karl-Schwarzschild-Str. 2 85748 Garching Germany Library of Congress Control Number 2007931618 ISBN 978-3-540-73483-3 Springer Berlin Heidelberg New York This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in...

Physical viscosity in SPH simulations of galaxy clusters

There is growing observational evidence 2, 3, 4 that gas viscosity in massive, hot clusters might not be negligible, and that it could play an important role in dissipating energy generated by AGN-driven bubbles or during merger events. Within the framework of the entropy conserving formulation of SPH 5 in GADGET-2 6, 7 , we have implemented a treatment of physical viscosity that accounts both for the shear and bulk part, as explained in detail in 8 . In particular, we have derived novel SPH...