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Quasar Host Galaxies of GEMS, First Results: 0.5 < z < 2.75
Understanding the host galaxies (HGs) of quasars is the key to linking the evolution of galaxies and their central black holes. Within the gems... -
Brightest Cluster Galaxy Formation in the Cluster C0037-2522: Flattening of the Dark Matter Cusp
The X-ray cluster C0337-2522 at redshift z = 0.59 hosts in its core a group of five elliptical galaxies. Using N-body simulations we show that a... -
The FORS Deep Field Spectroscopic Survey of High-Redshift Galaxies
The evolution of the properties of galaxy populations with redshift provides important constraints on current models of galaxy formation and... -
The Cosmological Evolution of Quasar Black-Hole Masses
The strong correlation observed between black-hole and bulge mass in the local Universe (eg. Magorrian et al. 1998; Gebhardt et al. 2000) directly... -
Linear Spectropolarimetry of Young and Other Emission Line Stars
The aim of this article is to demonstrate the useful role that can be played by spectropolarimetric observations of young and evolved emission line... -
Tests for the Magnetospheric Accretion Model for Young Low Mass Stars
High resolution infrared spectroscopy is a very valuable tool for the study of the formation of low mass and very low mass stars. At the stage in... -
Interpreting the Hydrogen IR Lines – Impact of Improved Electron Collision Data
We evaluate the effect of variations in the electron-impact excitation cross sections on the non-LTE line formation for hydrogen in early-type stars.... -
Tracing Accretion onto Herbig Ae/Be Stars Using Near-Infrared Spectroscopy
The mass accretion rate is thought to be a key parameter in the evolution of young stellar objects (YSOs). As a function of time, the accretion rate... -
Spectroscopy of the M Supergiant α Ori in the 1–2.5 μm Region
The study of elemental abundances in cool stars via atomic lines in the optical region is made di.cult by stellar molecular absorption. At infrared... -
Post-AGB Objects and Planetary Nebulae
Planetary nebulae and post-AGB objects are luminous dust emitters in the infrared. Indeed it is by virtue of their strong dust emission that most... -
Rotation of Young Very Low Mass Objects
We present our large sample of photometric rotation periods for VLM objects in young open clusters. Based on these periods, we investigate the mass... -
Observation of Plasma Fluctuations
The diagnostics of fluctuating plasma quantities and their evaluation is an important issue in the context of plasma waves, instabilities, and... -
Magnetic Confinement
This chapter describes the basic principles of magnetic confinement. The main representatives of magnetic confinement are the mirror machine, the... -
X-rays from the First Massive Black Holes
We briefly review some recent results from Chandra and XMM-Newton studies of the highest redshift ( ) active galactic... -
Narrow Line Seyfert 1 Galaxies and the “Anti-hierarchical” Black Hole Growth
Using a complete sample of soft X-ray selected AGNs, we show that highly accreting AGNs do not follow the MBH–σ relation of normal galaxies. This... -
Measuring the Masses and Accretion Rates in Rapidly Growing Young NLS1s
We find that Narrow-Line Seyfert 1 Galaxies accrete at moderately super-Eddington rates. This was already suggested with the discovery of extreme... -
Torus Models for Obscuration in Type 2 AGN
We discuss a clumpy model of obscuring dusty tori around AGN. Cloud-cloud collisions lead to an effective viscosity and a geometrically thick... -
Narrow-Line Seyfert 1 Galaxies: Growing Black Holes at Supercritical Accretion?
The X-ray spectra of NLS1, characterized by a significant soft excess and a steep hard tail analogous to the soft-state black-hole binaries, are... -
Formation of the First Supermassive Black Holes
Understanding the emergence of the first supermassive black holes, and hence the first quasars, is a crucial ingredient for models of reionization... -
Black Hole Growth in a Cosmological Context and the Associated Cosmic Star Formation History
Based on a co-evolution scenario of massive black holes (MBH) and their host spheroids, we trace the BH growth and the joint cosmic star formation...