854 research outputs found
Der Sonnenwirt -- Fakt, Fiktion, Held und Verbrecher
Die Zwecken dieser BA-Arbeit sind drei verschiedene Analysenarten aus der Literaturtheorie am Beispiel Verbrecher aus verlorener Ehre (1786) von Friedrich Schiller anzuwenden: Hermeneutik, Strukturalismus, Dekonstruktion. Ich interpretiere den Text Lebensgeschichte Fridrich Schwans (1787) von Jakob Friedrich Abel als Vorläufer von Verbrecher und erstelle dabei einem möglichst anschaulichen Überblick der wandelnden Verhältnisse des Krimibegriffs. Unter diesem Krimibegriff werden sowohl Texte als auch TV-Serien und Filme als Krimi verstanden
High Resolution Near-Infrared Imaging Observations of the Galactic Centre
Ziel der vorliegenden Doktorarbeit war es, neue Erkenntnisse über die Struktur, Zusammensetzung
und Dynamik des zentralen Sternhaufens unserer Milchstraße zu gewinnen. Im
Mittelpunkt unserer Analysen stand dabei vor allem die Natur der Konzentration einiger Millionen
Sonnenmassen dunkler Materie im Zentrum dieses Haufens, bei welcher es sich vermutlich
um ein supermassives Schwarzes Loch handelt. Schon seit Jahrzehnten wurde vermutet,
dass die kompakte, nicht-thermische Radioquelle Sagittarius A* (Sgr A*), welche 1974 entdeckt
wurde, mit einem solchen Objekt assoziiert ist. In großen Teilen basiert diese Arbeit
auf Beobachtungen des galaktischen Zentrums mit der neuartigen Nahinfrarotkamera CONICA
und dem dazugehörigen System für adaptive Optik, NAOS, am Very Large Telescope der
Europäischen Südsternwarte. Dieses kombinierte System wurde Ende 2001/Anfang 2002 in
Betrieb genommen und bietet ideale Voraussetzungen für tiefe, hochaufgelöste Nahinfrarot-
Beobachtungen des galaktischen Zentrums.
Ein grundliegendes Problem, welches es zu lösen galt, war die Astrometrie der Aufnahmen
des Sternfeldes im galaktischen Zentrum. Ein akkurates astrometrisches System ist eine
essentielle Voraussetzung dafür, Sgr A* auf Infrarotbildern zu identifizieren und die relativen
Positionen und Bewegungen der Sterne in seiner Umgebung zu messen. Mit Hilfe von SiO
Maser Sternen, deren Position durch Radiointerferometrie zu < 1 Millibogensekunde bestimmt
werden kann, gelang es uns, die Position der nicht-thermischen Radioquelle Sagittarius
A* (Sgr A*), welche mit dem vermuteten schwarzen Loch assoziiert ist, relativ zu den
Sternen in seiner Umgebung mit einer Genauigkeit von < 10 mas zu bestimmen.
Durch Sternzählungen in tiefen, hochauflösenden Bildern konnten wir zeigen, dass die
Sterndichte zu Sgr A* hin mit einem Potenzgesetz ansteigt, dass der Sternhaufen also einen
sogenannten Cusp in einem Radius von ca. 100 oder 40 mpc um das vermutete schwarze Loch
aufzeigt. In einer Distanz < 4 mpc von Sgr A* steigt die Massendichte des Haufens auf über
108 M an. Die Sternpopulation im Cusp zeigt einen Mangel an Riesensternen und an Sternen
auf dem horizontalen Ast relativ zum umgebenden Haufen. Hierfür könnten Sternkollisionen
und/oder Massensegregation verantwortlich sein
Peering through the veil: near-infrared photometry and extinction for the Galactic nuclear star cluster
The aims of this work are to provide accurate photometry in multiple
near-infrared broadband filters, to determine the power-law index of the
extinction-law toward the central parsec of the Galaxy, to provide measurements
of the absolute extinction toward the Galactic center, and finally to measure
the spatial variability of extinction on arcsecond scales.We use adaptive
optics observations of the central parsec of the Milky Way. Absolute values for
the extinction in the H, Ks, and L'-bands as well as of the power-law indices
of the H to Ks and Ks to L' extinction-laws are measured based on the
well-known properties of red clump stars. Extinction maps are derived based on
H-Ks and Ks-L' colors. We present Ks-band photometry for ~7700 stars (H and L'
photometry for a subset). From a number of recently published values we compute
a mean distance of the Galactic center of R_0=8.03+-0.15 kpc, which has an
uncertainty of just 2%. Based on this R_0 and on the RC method, we derive
absolute mean extinction values toward the central parsec of the Galaxy of
A_H=4.48+-0.13 mag, A_Ks=2.54+-0.12$ mag, and A_L'=1.27+-0.18 mag. We estimate
values of the power-law indices of the extinction-law of
alpha_{H-Ks}=2.21+-0.24 and alpha_{Ks-L'}=1.34+-0.29. A Ks-band extinction map
for the Galactic center is computed based on this extinction law and on stellar
H-Ks colors. Mean extinction values in a circular region with 0.5" radius
centered on Sagittarius A* are A_{H, SgrA*}=4.35+-0.12, A_{Ks,
SgrA*}=2.46+-0.03, and A_{L', SgrA*}=1.23+-0.08.Comment: accepted for publication by Astronomy & Astrophysics; please contact
RS for higher quality figure
Lutheran Youth Groups in Action
The purpose of this study is to collect, analyze, and interpret information regarding the Young People\u27s program in a limited number of congregations of the Lutheran Church-Missouri Synod. Although this is not a nation wide survey, the amount of material obtained is sufficient to present a bird\u27s eye view of\u27 what is happening in the Youth Program or the Church
Ks- and Lp-band polarimetry on stellar and bow-shock sources in the Galactic center
Infrared observations of the Galactic center (GC) provide a unique
opportunity to study stellar and bow-shock polarization effects in a dusty
environment. The goals of this work are to present new Ks- and Lp-band
polarimetry on an unprecedented number of sources in the central parsec of the
GC, thereby expanding our previous results in the H- and Ks-bands. We use
AO-assisted Ks- and Lp-band observations, obtained at the ESO VLT. High
precision photometry and the new polarimetric calibration method for NACO allow
us to map the polarization in a region of 8" x 25" (Ks) resp. 26" x 28" (Lp).
These are the first polarimetric observations of the GC in the Lp-band in 30
years, with vastly improved spatial resolution compared to previous results.
This allows resolved polarimetry on bright bow-shock sources in this area for
the first time at this wavelength. We find foreground polarization to be
largely parallel to the Galactic plane (Ks-band: 6.1% at 20 degrees, Lp-band:
4.5% at 20 degrees, in good agreement with our previous findings and with older
results. The previously described Lp-band excess in the foregound polarization
towards the GC could be confirmed here for a much larger number of sources. The
bow-shock sources contained in the FOV seem to show a different relation
between the polarization in the observed wavelength bands than what was
determined for the foreground. This points to the different relevant
polarization mechanisms. The resolved polarization patterns of IRS 5 and 10W
match the findings we presented earlier for IRS~1W. Additionally, intrinsic
Lp-band polarization was measured for IRS 1W and 21, as well as for other, less
prominent MIR-excess sources (IRS 2S, 2L, 5NE). The new data offer support for
the presumed bow-shock nature of several of these sources (1W, 5, 5NE, 10W, 21)
and for the model of bow-shock polarization presented in our last work.Comment: 19 pages, 18 figure
The Siren\u27s Song of a Trickle-Down Bureaucracy: The Transport Rule, the Problem of Air Contamination Crossing State Lines, and the EPA Crossing Its Line
The significance of religious training in relation to personality development
Religion has played a vital role in the development of American culture. The church has been an integral part of the lives of the early settlers and of the foundations of American government. In the early days the church even maintained and controlled the entire educational system. The church has played an entire part in the development of communities throughout the nation
Parables in the Gospel of Thomas
Dr. Schoedel provides important light on a burning contemporary question concerning the authority of the Scripture. He does this by studying the attitude of an important early group of Christians to the sayings of Jesus. He concludes that the Gnostic Christians who produced the Gospel of Thomas did not hesitate to edit and change the sayings of Jesus to suit their own theological viewpoints
Morse v. Frederick: Tinkering with School Speech: Can Five Years of Inconsistent Interpretation Yield a Hybrid Content—Effects-Based Approach to School Speech as a Tool for the Prevention of School Violence?
- …