559 citations · 9.7k across the 192 of their papers we have counts for
17 papers · 1 filter
Globular Cluster Systems in Nearby Dwarf Galaxies: I. HST/ACS Observations and Dynamical Properties of Globular Clusters at Low Environmental Density
Iskren Y. Georgiev, Thomas H. Puzia, Michael Hilker +1
We investigate the old globular cluster (GC) population of 68 faint (Mv>-16 mag) dwarf galaxies located in the halo regions of nearby (<12 Mpc) loose galaxy groups and in the field…
High M/L ratios of UCDs: a variation of the IMF?
S. Mieske, J. Dabringhausen, P. Kroupa +2
Various studies have established that the dynamical M/L ratios of ultra-compact dwarf galaxies (UCDs) tend to be at the limit or beyond the range explicable by standard stellar pop…
Compact stellar systems in the Fornax cluster: a UV perspective
Steffen Mieske, Michael Hilker, Dominik J. Bomans +4
In recent years, increasing evidence for chemical complexity and multiple stellar populations in massive globular clusters (GCs) has emerged, including extreme horizontal branches…
The Nature of UCDs: Internal Dynamics from an Expanded Sample and Homogeneous Database
Steffen Mieske, Michael Hilker, Andres Jordan +9
We have obtained high-resolution spectra of 23 ultra-compact dwarf galaxies (UCDs) in the Fornax cluster with -10.4>M_V>-13.5 mag (10^6<M/M_*<10^8), using FLAMES/Giraffe at the VLT…
The early-type dwarf galaxy population of the Hydra I cluster
I. Misgeld, S. Mieske, M. Hilker
We analyse the properties of the early-type dwarf galaxy population in the Hydra I cluster. We investigate the galaxy luminosity function (LF), the colour-magnitude relation (CMR),…
A Network Protection Framework through Artificial Immunity
Michael Hilker, Christoph Schommer
Current network protection systems use a collection of intelligent components - e.g. classifiers or rule-based firewall systems to detect intrusions and anomalies and to secure a n…
Next Challenges in Bringing Artificial Immune Systems to Production in Network Security
Michael Hilker
The human immune system protects the human body against various pathogens like e.g. biological viruses and bacteria. Artificial immune systems reuse the architecture, organization,…
Distributed Self Management for Distributed Security Systems
Michael Hilker
Distributed system as e.g. artificial immune systems, complex adaptive systems, or multi-agent systems are widely used in Computer Science, e.g. for network security, optimisations…
Comparing CN and CH Line Strengths in a Homogeneous Spectroscopic Sample of 8 Galactic Globular Clusters
Andrea Kayser, Michael Hilker, Eva K. Grebel +1
Our work focuses on the understanding of the origin of CNO-anomalies, which have been detected in several Galactic globular clusters (GCs). This study is based on a homogeneous dat…
SANA - Security Analysis in Internet Traffic through Artificial Immune Systems
Michael Hilker, Christoph Schommer
The Attacks done by Viruses, Worms, Hackers, etc. are a Network Security-Problem in many Organisations. Current Intrusion Detection Systems have significant Disadvantages, e.g. the…
Service Oriented Architecture in Network Security - a novel Organisation in Security Systems
Michael Hilker, Christoph Schommer
Current network security systems are a collection of various security components, which are directly installed in the operating system. These check the whole node for suspicious be…
SANA - Network Protection through artificial Immunity
Michael Hilker, Christoph Schommer
Current network protection systems use a collection of intelligent components - e.g. classifiers or rule-based firewall systems to detect intrusions and anomalies and to secure a n…
AGNOSCO - Identification of Infected Nodes with artificial Ant Colonies
Michael Hilker, Christoph Schommer
If a computer node is infected by a virus, worm or a backdoor, then this is a security risk for the complete network structure where the node is associated. Existing Network Intrus…
A new queueing strategy for the Adversarial Queueing Theory
Michael Hilker, Christoph Schommer
In the today's Internet and TCP/IP-networks, the queueing of packets is commonly implemented using the protocol FIFO (First In First Out). Unfortunately, FIFO performs poorly in th…
Structural Properties of Ultra-Compact Dwarf Galaxies in the Fornax and Virgo Clusters
E. A. Evstigneeva, M. J. Drinkwater, C. Y. Peng +6
We present a detailed analysis of two-band HST/ACS imaging of 21 ultra-compact dwarf (UCD) galaxies in the Virgo and Fornax Clusters. The aim of this work is to test two formation…
Old globular clusters in magellanic-type dwarf irregular galaxies
Iskren Y. Georgiev, Paul Goudfrooij, Thomas H. Puzia +1
We present a study of the old globular clusters (GC) using archival F606W and F814W HST/ACS images of 19 Magellanic-type dwarf Irregular (dIrr) galaxies found in nearby (2 - 8 Mpc)…
From star clusters to dwarf galaxies: The properties of dynamically hot stellar systems
J. Dabringhausen, M. Hilker, P. Kroupa
(Abridged) Objects with radii of 10 to 100 pc and masses in the range from 10^6 to 10^8 M_sun have been discovered during the past decade. These so-called ultra compact dwarf galax…