Paudel, S., Lisker, T., Kuntschner, H., Grebel, E., Glatt, K.
[Abridged] Using VLT/FORS2 spectroscopy, we have studied the properties of the central stellar populations of a sample of 38 nucleated early-type dwarf (dE) galaxies in the Virgo Cluster. We find...
The First Generation of Virgo Cluster Dwarf Elliptical Galaxies? (2009)
Lisker, T., Janz, J., Hensler, G., Kim, S., Rey, S. -C., Weinmann, S., ...
In the light of the question whether most early-type dwarf (dE) galaxies in clusters formed through infall and transformation of late-type progenitors, we search for an imprint of such an infall...
Stellar populations of seven early-type dwarf galaxies and their nuclei (2009)
Dwarf galaxies are the numerically dominating population in the dense regions of the universe. Although they seem to be simple systems at first view, the stellar populations of dwarf elliptical...
Koester, D., Voss, B., Napiwotzki, R., Christlieb, N., Homeier, D., Lisker, T., ...
The ESO Supernova Ia Progenitor Survey (SPY) took high-resolution spectra of more than 1000 white dwarfs and pre-white dwarfs. About two thirds of the stars observed are hydrogen-dominated DA white...
Koester, D., Voss, B., Napiwotzki, R., Christlieb, N., Homeier, D., Lisker, T., ...
Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO) DOI: 10.1051/0004-6361/200912531
The first generation of Virgo cluster dwarf elliptical galaxies? (2009)
Lisker, T., Janz, J., Hensler, G., Kim, S., Rey, S.C., Weinmann, S., ...
Original article can be found at: http://www.iop.org/EJ/journal/apjl Copyright American Astronomical Society DOI: 10.1088/0004-637X/706/1/L124 [Full text of this article is not available in the UHRA]
Stroeer, A., Heber, U., Lisker, T., Napiwotzki, R., Dreizler, S., Christlieb, N., ...
We address the origin and evolutionary status of hot subdwarf stars by studying the optical spectral properties of 58 subdwarf O (sdO) stars. Combining them with the results of our previously studied...
Evolution of field early‐type galaxies: the view from GOODS CDFS (2005)
Ferreras, I., Lisker, T., Carollo, C.M., Lilly, S.J.
We explore the evolution of field early-type galaxies in a sample extracted from the ACS images of the southern GOODS field. The galaxies are selected by means of a nonparametric analysis, followed...
GOODS, UDF, and the evolution of early-type galaxies (2005)
Ferreras, I., Lisker, T., Pasquali, A., Carollo, C. M., Lilly, S. J., Mobasher, B.
The HST/ACS images of GOODS-South have been used to select a sample of early-type galaxies, based on morphology and on the Kormendy relation. The classification scheme does not use galaxy colours,...
High resolution spectroscopy of bright subdwarf B stars - I. Radial velocity variables (2005)
Edelmann, H., Heber, U., Altmann, M., Karl, C., Lisker, T.
Radial velocity curves for 15 bright subdwarf B binary systems have been measured using high precision radial velocity measurements from high S/N optical high-resolution spectra. In addition, two...
Evolution of field early-type galaxies: The view from GOODS/CDFS (2005)
Ferreras, I., Lisker, T., Carollo, C. M., Lilly, S. J., Mobasher, B., .
(Abridged) We explore the evolution of field early-type galaxies on a sample extracted from GOODS/CDFS. The galaxies are selected by means of a non-parametric analysis followed by visual inspection....
Subluminous O Stars from the ESO Supernova Progenitor Survey - Observation versus Theory. (2005)
Stroeer, A., Heber, U., Lisker, T., Napiwotzki, R., Dreizler, S.
Subdwarf B Stars from the ESO Supernova Ia Progenitor Survey -- Observation versus Theory. (2005)
Lisker, T., Heber, U., Napiwotzki, R., Christlieb, N., Han, Z., Homeier, D., ...
Subluminous O stars from the ESO Supernova Progenitor Survey - Observation versus Theory (2004)
Stroeer, A., Heber, U., Lisker, T., Napiwotzki, R., Dreizler, S.
The ESO Supernova Progenitor Survey (SPY) has identified 58 (mostly helium-rich) subluminous O stars. We use the Balmer line strength to distinguish sdO from He-sdO (no Balmer lines) and present the...
Lisker, T., Heber, U., Napiwotzki, R., Christlieb, N., Han, Z., Homeier, D., ...
We present the analysis of a high-resolution, high-quality sample of optical spectra for 76 subdwarf B (sdB) stars from the ESO Supernova Ia Progenitor Survey (SPY). Effective temperature, surface...
Close binary EHB stars from SPY (2004)
Napiwotzki, R., Karl, C., Lisker, T., Heber, U., Christlieb, N., Reimers, D., ...
Close binary EHB stars from SPY (2004)
Napiwotzki, R., Karl, C. A., Lisker, T., Heber, U., Christlieb, N., Reimers, D., ...
We present the results of a radial velocity (RV) survey of 46 subdwarf B (sdB) and 23 helium-rich subdwarf O (He-sdO) stars. We detected 18 (39%) new sdB binary systems, but only one (4%) He-sdO...
Spectroscopic analysis of sdB stars from the ESO Supernova Ia Progenitor Survey (2004)
Lisker, T., Heber, U., Napiwotzki, R., Christlieb, N., Han, Z., Homeier, D., ...
Spectroscopic analysis of sdB stars from the ESO Supernova Ia Progenitor Survey (2003)
Lisker, T., Heber, U., Napiwotzki, R., Christlieb, N., Reimers, D., Homeier, D.
We report on the analysis of high-resolution optical spectra for 77 subdwarf B (sdB) stars from the ESO Supernova Ia Progenitor Survey. Effective temperature, surface gravity, and photospheric helium...
Double degenerates from the supernova Ia progenitor survey (SPY) (2002)
Karl, C., Napiwotzki, R., Heber, U., Lisker, T., Nelemans, G., Christlieb, N., ...
We report on follow-up observations of double degenerate (DD) white dwarfs from the Supernovae Ia Progenitor Survey (SPY). Orbital parameters of four systems, including a massive short period system,...