Annika Kreikenbohm

Annika Kreikenbohm
University of Wuerzburg | JMU · Department of Theoretical and Astrophysics

PhD
Development of immersive environments and data visualization for visual analysis and higher education of science

About

40
Publications
3,552
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673
Citations
Introduction
I am interested in innovative methods to improve knowledge discovery from big data. I use interactive and immersive data visualisation to develop a cooperation between human perception and automatic data-mining algorithms.

Publications

Publications (40)
Article
By studying the variability of blazars across the electromagnetic spectrum, it is possible to resolve the underlying processes responsible for rapid flux increases, so-called flares. We report on an extremely bright X-ray flare in the high-peaked BL Lacertae object Mrk 421 that occurred simultaneously with enhanced γ-ray activity detected at very h...
Conference Paper
Full-text available
Die Sekundarstufe I bietet zum Thema der Elektrizitätslehre viele Experimente zur Anwendung einer augmentierten Lernumgebung. Die in dem Projekt PhysikUnterricht mit Augmentierung (PUMA) entwickelte Applikation PUMA : Magnetlabor soll hauptsächlich die Modelle der magnetischen Felder sichtbar machen. Die Applikation ermöglicht einen Einblick in die...
Conference Paper
Full-text available
Durch Augmented Reality (AR) können Realobjekte mit zusätzlichen digitalen Informationen überlagert werden, was neue Arten des Lernens ermöglicht. Internationale Studien beschreiben verschiedene Vorteile von AR-gestützten Lernumgebungen. Die professionelle Entwicklung und Evaluation von AR-Applikationen für den physikalischen Schulunterricht ist da...
Poster
Full-text available
Durch *Augmented Reality* (AR) können Realobjekte mit zusätzlichen digitalen Informationen überlagert werden, was neue Arten des Lernens ermöglicht. Internationale Studien beschreiben verschiedene Vorteile von AR-gestützten Lernumgebungen. Die professionelle Entwicklung und Evaluation von AR-Applikationen für den physikalischen Schulunterricht ist...
Conference Paper
Full-text available
Im Beitrag werden zunächst Herausforderungen kognitiver, affektiver und interpersoneller Natur in der naturwissenschaftlichen Lehre im Bereich Elektrizität vorgestellt. Gestützt auf die Cognitive Load Theory, die Cognitive Theory of Multimedia Learning und die Selbstbestimmungstheorie wird die Entwicklung von Augmented Reality (AR) Anwendungen für...
Article
Full-text available
Narrow-line Seyfert 1 (NLS1) galaxies are a class of active galactic nuclei (AGN) that, in some cases, can harbor powerful relativistic jets. One of them, PKS 2004-447, shows γ -ray emission, and underwent its first recorded multifrequency flare in 2019. However, past studies revealed that in radio this source can be classified as a compact steep-s...
Preprint
Full-text available
The blazar Mrk 421 shows frequent, short flares in the TeV energy regime. Due to the fast nature of such episodes, we often fail to obtain sufficient simultaneous information about flux variations in several energy bands. To overcome this lack of multi-wavelength (MWL) coverage, especially for the pre- and post-flare periods, we have set up a monit...
Preprint
Full-text available
Narrow-line Seyfert 1 (NLS1) galaxies are a class of active galactic nuclei (AGN) that, in some cases, can harbor powerful relativistic jets. One of them, PKS 2004-447, shows gamma-ray emission, and underwent its first recorded multifrequency flare in 2019. However, past studies revealed that in radio this source can be classified as a compact stee...
Preprint
Full-text available
Temporal variability in flux and spectral shape is ubiquitous in the X-ray sky and carries crucial information about the nature and emission physics of the sources. The EPIC instrument on board the XMM-Newton observatory is the most powerful tool for studying variability even in faint sources. Each day, it collects a large amount of information abo...
Conference Paper
Full-text available
In dem vorgestellten Promotionsvorhaben wird der Einsatz von Augmented-Reality (AR)-Applikationen in der Schule als Ergänzung zum Realexperiment untersucht. Ziel ist es herauszufinden, wie sich Cognitive Load, Motivation, Interesse, Selbstkonzept und Fachwissen im Vergleich zu klassisch durchgeführten oder mit Simulationen angereicherten Experiment...
Preprint
Full-text available
Where do cosmic X-rays come from? Every new unidentified X-ray source could potentially revolutionize our understanding of the universe. The international collaborative astronomy project EXTraS aimed at automatically classifying new sources of X-ray emission (e.g., stars or galaxies) in the large observation database of the X-ray satellite XMM-Newt...
Thesis
Full-text available
Active galactic nuclei (AGN) are among the brightest and most frequent sources on the extragalactic X-ray and gamma-ray sky. Their central supermassive blackhole generates an enormous luminostiy through accretion of the surrounding gas. A few AGN harbor highly collimated, powerful jets in which are observed across the entire electromagnetic spectru...
Article
Full-text available
We present a three-dimensional map of the hydrogen density distribution in the Galactic interstellar medium. The hydrogen-equivalent column densities were obtained from the Exploring the X-ray Transient and variable Sky project (EXTRAS) which provides equivalent N_H values from X-ray spectral fits of observations within the XMM-Newton Data Release....
Preprint
Full-text available
We present a three-dimensional map of the hydrogen density distribution in the Galactic interstellar medium. The hydrogen equivalent column densities were obtained from the Exploring the X-ray Transient and variable Sky project ({\sc EXTraS}) which provides equivalent $N_{\rm H}$ values from X-ray spectral fits of observations within the {\it XMM-N...
Article
PKS 1718-649 is one of the closest and most comprehensively studied candidates of a young active galactic nucleus (AGN) that is still embedded in its optical host galaxy. The compact radio structure, with a maximal extent of a few parsecs, makes it a member of the group of compact symmetric objects (CSO). Its environment imposes a turnover of the r...
Article
PKS 1718$-$649 is one of the closest and most comprehensively studied candidates of a young active galactic nucleus (AGN) that is still embedded in its optical host galaxy. The compact radio structure, with a maximal extent of a few parsecs, makes it a member of the group of compact symmetric objects (CSO). Its environment imposes a turnover of the...
Article
PMN J1603$-$4904 is a likely member of the rare class of $\gamma$-ray emitting young radio galaxies. Only one other source, PKS 1718$-$649, has been confirmed so far. These objects, which may transition into larger radio galaxies, are a stepping stone to understanding AGN evolution. It is not completely clear how these young galaxies, seen edge-on,...
Preprint
PMN J1603$-$4904 is a likely member of the rare class of $\gamma$-ray emitting young radio galaxies. Only one other source, PKS 1718$-$649, has been confirmed so far. These objects, which may transition into larger radio galaxies, are a stepping stone to understanding AGN evolution. It is not completely clear how these young galaxies, seen edge-on,...
Article
We have compiled the X-ray characteristic properties for a unique and homogeneous sample of Type 2 AGN with water megamaser activity observed by XMM-Newton and for a control sample of non-maser galaxies, both analyzed in a uniform way. A comparison of the luminosity distributions confirms previous results (from smaller and/or less systematic studie...
Article
Near-Eddington accretion rates onto low-mass black holes are thought to be a prime driver of the multi-wavelength properties of the narrow-line Seyfert 1 (NLS1) population of active galactic nuclei (AGN). Orientation effects have repeatedly been considered as another important factor involved, but detailed studies have been hampered by the lack of...
Preprint
Near-Eddington accretion rates onto low-mass black holes are thought to be a prime driver of the multi-wavelength properties of the narrow-line Seyfert 1 (NLS1) population of active galactic nuclei (AGN). Orientation effects have repeatedly been considered as another important factor involved, but detailed studies have been hampered by the lack of...
Article
Full-text available
Simultaneous broadband spectral and temporal studies of blazars are an important tool for investigating active galactic nuclei (AGN) jet physics. We study the spectral evolution between quiescent and flaring periods of 22 radio-loud AGN through multi-epoch, quasi-simultaneous broadband spectra. For many of these sources these are the first broadban...
Article
The discovery of extraterrestrial very-high-energy neutrinos by the IceCube collaboration has launched a quest for the identification of their astrophysical sources. Gamma-ray blazars have been predicted to yield a cumulative neutrino signal exceeding the atmospheric background above energies of 100 TeV, assuming that both the neutrinos and the gam...
Preprint
The discovery of extraterrestrial very-high-energy neutrinos by the IceCube collaboration has launched a quest for the identification of their astrophysical sources. Gamma-ray blazars have been predicted to yield a cumulative neutrino signal exceeding the atmospheric background above energies of 100 TeV, assuming that both the neutrinos and the gam...
Article
Gamma-ray detected radio-loud narrow-line Seyfert 1 (g-NLS1) galaxies constitute a small but interesting sample of the gamma-ray loud AGN. The radio-loudest g-NLS1 known, PKS 2004-447, is located in the southern hemisphere and is monitored in the radio regime by the multiwavelength monitoring program TANAMI. We aim for the first detailed study of t...
Article
Full-text available
As part of the TANAMI multiwavelength progam, we discuss new X-ray observations of the $\gamma$-ray and radio-loud Narrow Line Seyfert galaxy ($\gamma$-NLS1) PKS 2004-447. The active galaxy is a member of a small sample of radio-loud NLS1s detected in $\gamma$-rays by the Fermi Large Area Telescope. It is the radio-loudest and only southern-hemisph...
Article
Full-text available
The morphology of the circumnuclear gas accreting onto supermassive black holes in Seyfert galaxies remains a topic of much debate. As the innermost regions of Active Galactic Nuclei (AGN) are spatially unresolved, X-ray spectroscopy, and in particular line-of-sight absorption variability, is a key diagnostic to map out the distribution of gas. Obs...
Article
Full-text available
The source(s) of the neutrino excess reported by the IceCube Collaboration is unknown. The TANAMI Collaboration recently reported on the multiwavelength emission of six bright, variable blazars which are positionally coincident with two of the most energetic IceCube events. Such objects are prime candidates to be the source of the highest-energy co...
Article
Context. Multiwavel ngth observations have revealed the highly unusual properties of the gamma-ray source PIYIN J1603-4904, which are difficult to reconcile with any other well established gamma-ray source class. The object either a very atypical blazar or a compact jet source seen at a larger angle to the line of sight. Aims. To determine the phys...
Article
Multiwavelength observations have revealed the highly unusual properties of the gamma-ray source PMN J1603-4904, which are difficult to reconcile with any other well established gamma-ray source class. The object is either a very atypical blazar or compact jet source seen at a larger angle to the line of sight. In order to determine the physical or...
Article
Full-text available
Centaurus A is the closest radio-loud active galaxy. Very Long Baseline Interferometry (VLBI) enables us to study the jet-counterjet system on milliarcsecond (mas) scales, providing essential information for jet emission and propagation models. We study the evolution of the central parsec jet structure of Cen A over 3.5 years. The proper motion ana...
Article
Full-text available
Very long baseline interferometry at millimetre/submillimetre wavelengths (mmVLBI) offers the highest achievable spatial resolution at any wavelength in astronomy. The anticipated inclusion of ALMA as a phased array into a global VLBI network will bring unprecedented sensitivity and a transformational leap in capabilities for mmVLBI. Building on ye...
Article
Full-text available
The IceCube Collaboration has announced the discovery of a neutrino flux in excess of the atmospheric background. Due to the steeply falling atmospheric background spectrum, events at PeV energies are most likely of extraterrestrial origin. We present the multiwavelength properties of the six radio brightest blazars positionally coincident with the...
Article
Full-text available
We investigate the nature and classification of PMNJ1603-4904, a bright radio source close to the Galactic plane, which is associated with one of the brightest hard-spectrum gamma-ray sources detected by Fermi/LAT. It has previously been classified as a low-peaked BL Lac object based on its broadband emission and the absence of optical emission lin...
Article
Full-text available
We present preliminary results of the X-ray analysis of XMM-Newton and Swift observations as part of a multi-wavelength monitoring campaign in 2012 of the radio-loud narrow line Seyfert 1 galaxy PKS 2004-447. The source was recently detected in gamma-rays by Fermi/LAT among only four other galaxies of that type. The 0.5-10 keV X-ray spectrum is wel...
Conference Paper
Full-text available
Narrow-Line Seyfert 1 galaxies have been established as a new class of gamma-ray emitting AGN with relatively low black hole masses, but near-Eddington accretion rates. Other extragalactic gamma-ray sources observed so far such as Flat Spectrum Radio Quasars, Radio Galaxies, and BL Lacertae Objects generally exhibit much higher black hole masses an...

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