Search Publications
Hosts of type II quasars: An HST study
Krolik, J. H.; Schneider, D. P.; Heckman, T. M. +6 more
Type II quasars are luminous Active Galactic Nuclei whose centers are obscured by large amounts of gas and dust. In this contribution we present 3-band HST images of nine type II quasars with redshifts 0.25 < z < 0.4 selected from the Sloan Digital Sky Survey based on their emission line properties. The intrinsic luminosities of these quasar…
Origin of the shrapnels around the Vela SNR
Katsuda, Satoru; Tsunemi, Hiroshi
There are several shrapnels around the Vela SNR that originated from the inner layer of the progenitor star. We present here the analysis of the X-ray spectrum of the Vela shrapnel A with XMM-Newton satellite. The Vela shrapnel A is one of several protrusions identified as bullets from Vela supernova explosion. We confirmed that there was a promin…
Scientific highlights from INTEGRAL
Winkler, Christoph
The gamma-ray observatory INTEGRAL was launched in October 2002 and produces since then a wealth of discoveries and important new results. I will present a selection of scientific highlights obtained during the first 2.5 years of the mission.
Star formation in hosts of young radio galaxies
O'Dea, C. P.; Labiano, A.; Baum, S. A. +2 more
We present near ultraviolet imaging with the Hubble Space Telescope Advanced Camera for Surveys, targeting young radio galaxies (gigahertz peaked spectrum and compact steep spectrum sources), in search of star formation regions in their hosts. We find near UV light which could be the product of recent star formation in eight of the nine observed s…
Young stars in high- z QSO host galaxies
Wisotzki, Lutz; Jahnke, Knud; Sánchez, Sebastián F.
We study the stellar properties of type 1 QSO host galaxies at redshifts to z ∼ 3 using the HST within the GEMS project as well as ground based adaptive optics. The host galaxies have a tendency for younger stars than their inactive counterparts, showing the coeval evolution of Black Holes and stars in progress. Judging from 40% distorted morpholo…
Host galaxy evolution in radio-loud AGN
Urry, C. Megan; O'Dowd, Matt
We investigate the luminosity evolution of the host galaxies of radio-loud AGN through Hubble Space Telescope imaging of 72 BL Lac objects. This sample has enabled us to avoid the biases implicit in quasar studies. We find that the host galaxies of BL Lacs evolve strongly, consistent with that observed in the hosts of other radio-loud AGN, and inc…
The Type Ia Supernova rate in the local Universe
Strigari, Louis E.
Current measurements of the Type Ia Supernova (SNIa) rate, as determined by standard astronomical methods, are in reasonable agreement with measurements of the cosmic star formation rate combined with simple models for SNIa progenitors. However, systematic uncertainties still undermine a precise determination of the SNIa rate. Recent models of the…
Programs for laser-AO assisted integral-field spectrometers on ionized flows
Cecil, Gerald
An AO-assisted integral-field spectrograph is becoming the most efficient tool with which to explore ionized gas outflows. It maps faint spectral lines that diagnose cloud dust content, gas pressure, excitation mechanism, and chemical abundances. Coupled with recent improvements in photoionization models, the total mass hence flow energetics can b…
The evolution of QSO host colours
Schramm, Malte; Wisotzki, Lutz; Jahnke, Knud +1 more
We summarise the evidence that the hosts of luminous QSOs are systematically bluer than normal (inactive) galaxies of comparable morphological type. We particularly emphasize the importance of performing such studies in a comparative way, placing QSO hosts in a context of the overall galaxy population.
Near-infrared integral-field spectroscopy of violent starburst environments
de Grijs, Richard
Near-infrared (NIR) integral-field spectroscopy (IFS) of violent starburst environments at high spatial (and spectral) resolution has the potential to revolutionise our ideas regarding the local interactions between the newly formed massive stars and the interstellar medium (ISM) of their host galaxies. To illustrate this point, I present NIR IFS …