New Theoretical Fe II Templates for Bright Quasars
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F25%3A00144322" target="_blank" >RIV/00216224:14310/25:00144322 - isvavai.cz</a>
Result on the web
<a href="https://iopscience.iop.org/article/10.3847/1538-4365/adb427" target="_blank" >https://iopscience.iop.org/article/10.3847/1538-4365/adb427</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.3847/1538-4365/adb427" target="_blank" >10.3847/1538-4365/adb427</a>
Alternative languages
Result language
angličtina
Original language name
New Theoretical Fe II Templates for Bright Quasars
Original language description
We present a set of new theoretical Fe II templates for bright quasars covering a wavelength range of 1000-10000 Å based on the recent atomic database available in the C23.00 version of the photoionization code CLOUDY. We compute a grid of models for a range of incident photon flux, gas density, and multiple microturbulence velocities. We examine the equivalent widths and the ratios of Fe II emission over various wave bands and compare them with observations. Our key results are as follows: (1) The flux generated from the shielded side of the cloud is insufficient to describe the measured Fe II emission. (2) Despite using the newest atomic data, we still confirm the long-standing problem that the predicted Fe II UV/optical ratio is significantly larger than that observed in the active galactic nuclei spectra. (3) The Fe II UV/optical ratio is not significantly affected by the variations in the microturbulence and the metallicity. (4) The microturbulence can create an additional apparent velocity shift of up to 1000 km s-1 in the spectra. (5) There is no Fe II template based on a single set of physical parameters that can fit the observed UV to optical Fe II emission spectra. We shortly discuss the most likely effects responsible for the Fe II UV/optical mismatch problem: the assumption of the constant density clouds and the heating mechanism for Fe II emitting clouds.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
<a href="/en/project/GF23-04053L" target="_blank" >GF23-04053L: Weather effects in using disk continuum time delays in active galactic nuclei to measure the expansion rate of the Universe</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astrophysical Journal, Supplement Series
ISSN
0067-0049
e-ISSN
1538-4365
Volume of the periodical
277
Issue of the periodical within the volume
2
Country of publishing house
GB - UNITED KINGDOM
Number of pages
27
Pages from-to
36
UT code for WoS article
001447325700001
EID of the result in the Scopus database
2-s2.0-105000294302