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Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract The non‐linear correlation between the UV and X‐ray emission observed in active galactic nuclei remains a puzzling question that challenges accretion models. While the UV emission originates from the cold disk, the X‐ray emission is emitted by a hot corona whose physical characteristics and geometry are still highly debated.
S. Barnier +3 more
wiley +1 more source
Relation between AGN type and host galaxy properties [PDF]
Astronomy & Astrophysics, 2021 We use 3213 active galactic nuclei (AGNs) from the XMM-XXL northern field to investigate the relation of AGN type with host galaxy properties. Applying a Bayesian method, we derive the hardness ratios, and through these the hydrogen column density (NH) for each source. We consider those with NH > 1021.5 cm−2 as absorbed sources (type 2).
Masoura, V. A. +3 more
openaire +5 more sources
Overmassive Black Holes in Dwarf Galaxies Out to z ∼ 0.9 in the VIPERS Survey
The Astrophysical Journal Letters, 2023 Supermassive black holes (SMBHs) are thought to originate from early universe seed black holes of mass M _BH ∼ 10 ^2 –10 ^5 M _⊙ and grown through cosmic time. Such seeds could be powering the active galactic nuclei (AGN) found in today’s dwarf galaxies.
Mar Mezcua +5 more
doaj +1 more source
The hyperluminous X‐ray source population
Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract We have recently published a catalog of 1843 candidate ultraluminous X‐ray sources (ULXs). This is the largest catalog of ULXs to date and was built by cross‐correlating recent serendipitous source catalogs from the XMM‐Newton, Swift, and Chandra observatories with a large sample of galaxies, primarily from HyperLEDA.
A. D. A. MacKenzie +2 more
wiley +1 more source
Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract Radiation‐magnetohydrodynamic simulation of the active galactic nuclei predicts the presence of the strong accretion disk wind, which gets unstable far from the central region and turns into gas clumps. These inner wind and outer clumps may be actually observed as the ultrafast outflows (UFOs) and the clumpy absorbers, respectively.
Takuya Midooka +2 more
wiley +1 more source
CLEAR: Spatially Resolved Emission Lines and Active Galactic Nuclei at 0.6 < z < 1.3
The Astrophysical Journal, 2023 We investigate spatially resolved emission-line ratios in a sample of 219 galaxies (0.6 < z < 1.3) detected using the G102 grism on the Hubble Space Telescope Wide Field Camera 3 taken as part of the CANDELS Ly α Emission at Reionization survey to ...
Bren E. Backhaus +10 more
doaj +1 more source
Black hole masses from emission‐line widths
Astronomische Nachrichten, Volume 343, Issue 1-2, January-February 2022., 2022 Abstract Reverberation mapping and scaling relationships based on reverberation results provide the underpinning of all estimates of quasar black hole masses. When applying these scaling relationships, there are potential pitfalls that are widely unappreciated and can result in biases that can, in turn, lead to systematic errors in the black hole mass ...
Elena Dalla Bontà, Bradley M. Peterson
wiley +1 more source
High‐Energy Neutrinos from the Cosmos
Annalen der Physik, Volume 533, Issue 11, November 2021., 2021 The IceCube Neutrino Observatory is the first detector of its kind, designed to observe the cosmos from deep within the South Pole ice. It consists of a cubic kilometer of instrumented transparent ice transformed into a Cherenkov detector. IceCube's first decade of operations has yielded breakthrough results, including the discovery of very high energy
Francis Halzen
wiley +1 more source
Peaked sources and narrow‐line Seyfert 1s: A love story
Astronomische Nachrichten, Volume 342, Issue 9-10, Page 1066-1070, November-December 2021., 2021 Abstract The first similarities between peaked sources (PS) and narrow‐line Seyfert 1 (NLS1) galaxies were noticed already 20 years ago. Nowadays, it is known that several sources can share both classifications, and that part of the parent population of γ‐ray emitting NLS1s could be hiding among PS.
Marco Berton, Emilia Järvelä
wiley +1 more source
AGN in dusty hosts: implications for galaxy evolution [PDF]
Monthly Notices of the Royal Astronomical Society, 2013 We present strong empirical evidence for a physical connection between the occurrence of a starburst (SB) and a luminous AGN phase. Drawing infrared (IR), X-ray, and optically selected samples from COSMOS, we find that the locus of type-2 AGN hosts in the optical colour-magnitude (U-V/V) and colour-colour (U-V/V-J) space significantly overlaps with ...
Symeonidis, M. +8 more
openaire +6 more sources