Search

Your search keyword '"Keck M"' showing total 755 results
Start Over Author "Keck M" Publication Year Range Last 50 years
755 results on '"Keck M"'

1. A Suzaku, NuSTAR, and XMM-Newton view on variable absorption and relativistic reflection in NGC 4151

Author

Beuchert, T., Markowitz, A. G., Dauser, T., García, J. A., Keck, M. L., Wilms, J., Kadler, M., Brenneman, L. W., and Zdziarski, A. A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

We disentangle X-ray disk reflection from complex line-of-sight absorption in the nearby Seyfert NGC 4151, using a suite of Suzaku, NuSTAR, and XMM-Newton observations. Extending upon earlier published work, we pursue a physically motivated model using the latest angle-resolved version of the lamp-post geometry reflection model relxillCp_lp together with a Comptonization continuum. We use the long-look simultaneous Suzaku/NuSTAR observation to develop a baseline model wherein we model reflected emission as a combination of lamp-post components at the heights of 1.2 and 15.0 gravitational radii. We argue for a vertically extended corona as opposed to two compact and distinct primary sources. We find two neutral absorbers (one full-covering and one partial-covering), an ionized absorber ($\log \xi = 2.8$), and a highly-ionized ultra-fast outflow, which have all been reported previously. All analyzed spectra are well described by this baseline model. The bulk of the spectral variability between 1 keV and 6 keV can be accounted for by changes in the column density of both neutral absorbers, which appear to be degenerate and inversely correlated with the variable hard continuum component flux. We track variability in absorption on both short (2 d) and long ($\sim$1 yr) timescales; the observed evolution is either consistent with changes in the absorber structure (clumpy absorber at distances ranging from the broad line region (BLR) to the inner torus or a dusty radiatively driven wind) or a geometrically stable neutral absorber that becomes increasingly ionized at a rising flux level. The soft X-rays below 1 keV are dominated by photoionized emission from extended gas that may act as a warm mirror for the nuclear radiation., Comment: 21 pages, 19 figures, 8 tables, accepted for publication by A&A

Published
2017
Full Text
View/download PDF

3. Aspects of transition cow metabolomics—Part I: Effects of a metaphylactic butaphosphan and cyanocobalamin treatment on the metabolome in liver, blood, and urine in cows with different liver metabotypes

Author

Schären, M., Snedec, T., Riefke, B., Slopianka, M., Keck, M., Gruendemann, S., Wichard, J., Brunner, N., Klein, S., Theinert, K.B., Pietsch, F., Leonhardt, A., Theile, S., Rachidi, F., Kaiser, A., Köller, G., Bannert, E., Spilke, J., and Starke, A.

Published
2021
Full Text
View/download PDF

6. NuSTAR and Suzaku X-ray Spectroscopy of NGC 4151: Evidence for Reflection from the Inner Accretion Disk

Author

Keck, M. L., Brenneman, L. W., Ballantyne, D. R., Bauer, F., Boggs, S. E., Christensen, F. E., Craig, W. W., Dauser, T., Elvis, M., Fabian, A. C., Fuerst, F., García, J., Grefenstette, B. W., Hailey, C. J., Harrison, F. A., Madejski, G., Marinucci, A., Matt, G., Reynolds, C. S., Stern, D., Walton, D. J., and Zoghbi, A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present X-ray timing and spectral analyses of simultaneous 150 ks Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku X-ray observations of the Seyfert 1.5 galaxy NGC 4151. We disentangle the continuum emission, absorption, and reflection properties of the active galactic nucleus (AGN) by applying inner accretion disk reflection and absorption-dominated models. With a time-averaged spectral analysis, we find strong evidence for relativistic reflection from the inner accretion disk. We find that relativistic emission arises from a highly ionized inner accretion disk with a steep emissivity profile, which suggests an intense, compact illuminating source. We find a preliminary, near-maximal black hole spin a>0.9 accounting for statistical and systematic modeling errors. We find a relatively moderate reflection fraction with respect to predictions for the lamp post geometry, in which the illuminating corona is modeled as a point source. Through a time-resolved spectral analysis, we find that modest coronal and inner disk reflection flux variation drives the spectral variability during the observations. We discuss various physical scenarios for the inner disk reflection model, and we find that a compact corona is consistent with the observed features., Comment: 20 pages, 12 figures, accepted for publication in ApJ

Published
2015

26. TMEM132D, a new candidate for anxiety phenotypes: evidence from human and mouse studies

Author

Erhardt, A, Czibere, L, Roeske, D, Lucae, S, Unschuld, P G, Ripke, S, Specht, M, Kohli, M A, Kloiber, S, Ising, M, Heck, A, Pfister, H, Zimmermann, P, Lieb, R, Pütz, B, Uhr, M, Weber, P, Deussing, J M, Gonik, M, Bunck, M, Keßler, M S, Frank, E, Hohoff, C, Domschke, K, Krakowitzky, P, Maier, W, Bandelow, B, Jacob, C, Deckert, J, Schreiber, S, Strohmaier, J, Nöthen, M, Cichon, S, Rietschel, M, Bettecken, T, Keck, M E, Landgraf, R, Müller-Myhsok, B, Holsboer, F, and Binder, E B

Published
2011
Full Text
View/download PDF

43. Two-dimensional Josephson junction network architectures for maximum microwave radiation emission

Author

Oppenlander, J., Guttinger, W., Traueble, T., Keck, M., Doderer,T., and Huebener, R.P.

Subjects
Electromagnetic radiation -- Measurement, High temperature superconductors -- Research, Josephson junction -- Research, Network architecture -- Research, Business, Electronics, Electronics and electrical industries
Abstract

Research was conducted to examine a novel type of self-synchronizing two-dimensional Josephson junction arrays based on special symmetry breaking network architectures. The calculations prove that the Josephson oscillators mutually synchronize into a coherent in-phase state and that such arrays can emit maximum coherent microwave power in the entire theoretically expected frequency range. Experimental results indicate that the symmetry breaking array architecture will be applicable for an implementation with Josephson junctions made from high critical temperature superconductors.

Published
1999

46. Wie gut werden Frauen in Deutschland auf Internetseiten der universitären Brustzentren über Brustrekonstruktionsmöglichkeiten informiert?

Author

Keck, M, Wittig, K, and Lohmeyer, J

Subjects
ddc: 610, 610 Medical sciences, Medicine
Abstract

Einleitung: Das Internet hat sich in den letzten Jahrzehnten zu einer der wichtigsten Informationsquellen für Patienten entwickelt. Wie gut sind die Möglichkeiten sich im Internet über eine Brustrekonstruktion zu informieren? Wie präsent ist die Plastische Chirurgie mit ihrem[zum vollständigen Text gelangen Sie über die oben angegebene URL], 50. Jahrestagung der Deutschen Gesellschaft der Plastischen, Rekonstruktiven und Ästhetischen Chirurgen (DGPRÄC), 24. Jahrestagung der Vereinigung der Deutschen Ästhetisch-Plastischen Chirurgen (VDÄPC)

Published
2019
Full Text
View/download PDF

47. Infektionen nach Mammaaugmentation und Implantatrekonstruktion – Untersuchung zur passenden Antibiotikatherapie und -prophylaxe

Author

Lohmeyer, J, Jakob, V, Keck, M, and Wittig, K

Subjects
ddc: 610, 610 Medical sciences, Medicine
Abstract

Hintergrund: Die perioperative Antibiotikaprophylaxe sollte sich wie die Therapie der manifesten Infektion am Erreger- und Resistenzspektrum der zu erwartenden Keimflora orientieren. Ziel dieser Arbeit ist die Aufarbeitung der positiven Bakterienkulturen aus Abstrichen und Gewebeproben der Implantatlager.[zum vollständigen Text gelangen Sie über die oben angegebene URL], 50. Jahrestagung der Deutschen Gesellschaft der Plastischen, Rekonstruktiven und Ästhetischen Chirurgen (DGPRÄC), 24. Jahrestagung der Vereinigung der Deutschen Ästhetisch-Plastischen Chirurgen (VDÄPC)

Published
2019
Full Text
View/download PDF

48. Die Wahl des ICR bei der Rekonstruktion der Brust durch DIEP Lappenplastik

Author

Bergmann, PA, Shahmiri-Zimmermann, S, Lohmeyer, JA, Keck, M, and Wittig, K

Subjects
ddc: 610, 610 Medical sciences, Medicine
Abstract

Einleitung: Bei elektiven Brustrekonstruktionen mittels DIEP Lappenplastiken stellen wir die A. thoracia interna sowie ihre Begleitvene(n) im Bereich des 2. , 3. bzw. 4. Intercostalraumes (ICR) dar. Erscheint der ICR subjektiv zu eng, entfernen wir die angrenzende Rippe partiell oder auch vollständig.[zum vollständigen Text gelangen Sie über die oben angegebene URL], 50. Jahrestagung der Deutschen Gesellschaft der Plastischen, Rekonstruktiven und Ästhetischen Chirurgen (DGPRÄC), 24. Jahrestagung der Vereinigung der Deutschen Ästhetisch-Plastischen Chirurgen (VDÄPC)

Published
2019
Full Text
View/download PDF

49. The influence of the critical current spread on the frequency locking of Josephson junctions in two-dimensional arrays

Author

Laub, A., Keck, M., Doderer, T., Huebener, R.P., Traeuble, T., Dolata, R., Weimann, T., and Nemeyer, J.

Subjects
Josephson junction -- Research, Semiconductors -- Junctions, Physics
Abstract

A study was conducted to examine the two-dimensional arrays of overdamped Josephson junctions under microwave irradiation. Arrays of 10 Josephson junctions were utilized in the study while the electron beam was determined at a frequency of 20 kHz. Results indicated that the critical current spread influences the arrays' behavior under microwave irradiation. They also indicated a close association between the dynamic resistance and frequency locked junctions.

Published
1998

50. Detailed investigation of two-dimensional Josephson junction array circuits

Author

Keck, M., Doderer, T., Mueller, R., Pfeifer, R., Laub, A., Huebener, R.P., Traeuble, T., Dolata R., Weimann, T., and Niemeyer, J.

Subjects
Josephson junction -- Research, Microwave circuits -- Research, Damping (Mechanics) -- Research, Business, Electronics, Electronics and electrical industries
Abstract

A detailed study was conducted on two-dimensional arrays of overdamped Josephson junctions based in Nb/Al2O3/Nb-technology. Microwave-coupled on-chip detectors reveal that the arrays emit coherent microwave radiation. The coupling of microwave radiation to an on-chip load was examined using low-temperature scanning electron microscopy. A method for deriving the margins of the critical current spread of the junctions for coherent oscillation is described.

Published
1997

Catalog

Books, media, physical & digital resources
See catalog results