1H 0707‐495: An AGN is dimming its X‐ray light
Astronomische Nachrichten, Volume 342, Issue 5, Page 708-714, June 2021., 2021 Abstract We report on one of the first science observations obtained during the Calibration and Verification phase of extended ROentgen Survey with an Imaging Telescope Array (eROSITA) aboard the Spectrum‐Roentgen‐Gamma (SRG) mission on the famous Narrow‐Line Seyfert 1 Galaxy 1H 0707‐495.
Thomas Boller
wiley +1 more source
A GMRT study of Seyfert galaxies NGC 4235 and NGC 4594: evidence of episodic activity? [PDF]
, 2016 Low frequency observations at 325 and 610 MHz have been carried out for two "radio-loud" Seyfert galaxies, NGC4235 and NGC4594 (Sombrero galaxy), using the Giant Meterwave Radio Telescope (GMRT). The 610 MHz total intensity and 325-610 MHz spectral index
P. Kharb +7 more
semanticscholar +1 more source
Power Spectral Density Background Estimate and Signal Detection via the Multitaper Method
Journal of Geophysical Research: Space Physics, Volume 126, Issue 2, February 2021., 2021 Abstract We present a new spectral analysis method for the identification of periodic signals in geophysical time series. We evaluate the power spectral density with the adaptive multitaper method, a nonparametric spectral analysis technique suitable for time series characterized by colored power spectral density.
S. Di Matteo, N. M. Viall, L. Kepko
wiley +1 more source
Emission Line Properties of Seyfert Galaxies in the 12 μm Sample [PDF]
, 2017 We present optical and ultraviolet spectroscopic measurements of the emission lines of 81 Seyfert 1 and 104 Seyfert 2 galaxies that comprise nearly all of the IRAS 12 μm AGN sample.
M. Malkan +4 more
semanticscholar +1 more source
Looking for Signatures of AGN Feedback in Radio-Quiet AGN
Galaxies, 2023 In this article, we discuss the state of “AGN feedback” in radio-quiet (RQ) AGN. This study involves heterogeneous samples of nearby Seyfert and LINER galaxies as well as quasi-stellar objects (QSOs) that have been observed at low radio frequencies (few ∼
Preeti Kharb, Sasikumar Silpa
doaj +1 more source
On the relation of optical obscuration and X-ray absorption in Seyfert galaxies [PDF]
, 2015 The optical classification of a Seyfert galaxy and whether it is considered X-ray absorbed are often used interchangeably. But there are many borderline cases and also numerous examples where the optical and X-ray classifications appear to be in conflict.
L. Burtscher +17 more
semanticscholar +1 more source
Constraining the contribution of Seyfert galaxies to the astrophysical diffuse neutrino flux using source population simulations [PDF]
EPJ Web of ConferencesRecently, the IceCube collaboration reported evidence for TeV neutrino emission from several nearby Seyfert galaxies that are intrinsically bright in X-rays, with the highest significance found for NGC 1068.
Saurenhaus Lena +2 more
doaj +1 more source
Are there reliable methods to estimate the nuclear orientation of Seyfert galaxies [PDF]
, 2016 Orientation, together with accretion and evolution, is one of the three main drivers in the Grand Unification of Active Galactic Nuclei (AGN). Being unresolved, determining the true inclination of those powerful sources is always difficult and indirect ...
F. Marin
semanticscholar +1 more source
Statistical Properties of Radio Emission from the Palomar Seyfert Galaxies [PDF]
, 2001 We have carried out an analysis of the radio and optical properties of a statistical sample of 45 Seyfert galaxies from the Palomar spectroscopic survey of nearby galaxies.
Antonucci R. R. J. +15 more
core +2 more sources
Warm absorbers in X-rays (WAX), a comprehensive high-resolution grating spectral study of a sample of Seyfert galaxies – I. A global view and frequency of occurrence of warm absorbers. [PDF]
, 2014 We present results from a homogeneous analysis of the broadband 0.3-10 keV CCD resolution as well as of soft X-ray high-resolution grating spectra of a hard X-ray flux-limited sample of 26 Seyfert galaxies observed with XMM-Newton.
S. Laha +4 more
semanticscholar +1 more source