Results 21 to 30 of about 166,156 (289)
Decomposition of the central structure of NGC 2273 in the NIR: A case study
Astronomische Nachrichten, Volume 344, Issue 10, December 2023., 2023 Abstract The Seyfert 2 galaxy NGC 2273 is a prime target to explore how active nuclei can be fed. It has a star‐forming innermost nuclear ring with a radius of 0.33kpc from where material may be funneled to the supermassive black hole in its center. In this article, we discuss high‐resolution adaptive optics aided JHKs images of NGC 2273 taken with the
L. Schey +13 more
wiley +1 more source
Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023 The Potsdam Arrayed Waveguide Spectrograph (PAWS) is based on an integrated photonic spectrograph designed and developed by innoFSPEC to work in the astronomical H‐band. PAWS demonstrates how a traditional bulk optics spectrograph can be miniaturized and additionally serves as a tool for testing in‐house developed astrophotonical devices.
Eloy Hernandez +6 more
wiley +1 more source
A Global Inventory of Feedback
Galaxies, 2023 Feedback from both supermassive black holes and massive stars plays a fundamental role in the evolution of galaxies and the inter-galactic medium. In this paper, we use available data to estimate the total amount of kinetic energy and momentum created ...
Timothy M. Heckman, Philip N. Best
doaj +1 more source
PAWS and POCO: NIR Astrophotonic Instruments for Astronomy
Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023 Abstract For near‐infrared ground and space‐based astronomy, compact photonic devices can replace the large bulk optical components in spectrographs, frequency combs, beam combiners, and sky subtraction filters, thus saving cost, reducing volume, weight, and power requirements.
Kalaga Madhav +8 more
wiley +1 more source
Epicyclic Oscillations around Simpson–Visser Regular Black Holes and Wormholes
Universe, 2021 We study epicyclic oscillatory motion along circular geodesics of the Simpson–Visser meta-geometry describing in a unique way regular black-bounce black holes and reflection-symmetric wormholes by using a length parameter l.
Zdeněk Stuchlík, Jaroslav Vrba
doaj +1 more source
Local supermassive black holes, relics of active galactic nuclei and the X-ray background [PDF]
, 2003 We quantify the importance of mass accretion during AGN phases in the growth of supermassive black holes (BH) by comparing the mass function of black holes in the local universe with that expected from AGN relics, which are black holes grown entirely ...
A. Marconi +5 more
semanticscholar +1 more source
Characterization of a C‐RED One camera for astrophotonical applications
Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023 Abstract To better understand the impact of the avalanche gain applied in the detector technology and apply this technology in our in‐house astrophotonic projects, we have characterized a C‐RED One camera and produced a stable and reliable method for calculating the system gain at any desired avalanche gain setting.
Stella Vješnica +3 more
wiley +1 more source
Fortschritte der Physik, Volume 71, Issue 8-9, September 2023., 2023 Abstract The momentum and Hamiltonian constraints of vacuum Einstein equations, within the Bowen‐York formalism, for two interacting black holes in close separation, with anti‐parallel spins and anti‐parallel linear momenta is studied. An analytical solution using perturbation theory is given.
Emel Altas, Emine Ertugrul, Bayram Tekin
wiley +1 more source
Investigation of some galactic and extragalactic gravitational phenomena [PDF]
Serbian Astronomical Journal, 2012 Here we present a short overview of the most important results of our investigations of the following galactic and extragalactic gravitational phenomena: supermassive black holes in centers of galaxies and quasars, supermassive black hole ...
Jovanović P.
doaj +1 more source
A tool to understand emission mechanisms of blazars through their high‐energy gamma‐ray emission
Astronomische Nachrichten, Volume 344, Issue 6, August 2023., 2023 The blazar SED is characterized by two energy components. Evidence suggests that the low‐energy component is generated by the synchrotron mechanism, but for the high‐energy component, the mechanism is still uncertain. Two main models have been proposed to explain this emission. According to the leptonic model, a correlation between the emission of both
Mabel Osorio +3 more
wiley +1 more source