Fantastic Fits with fantasy of Active Galactic Nuclei Spectra -- Exploring the Fe II emission near the H$\alpha$ line

Abstract

In this study, a refined approach for multicomponent fitting of active galactic nuclei (AGN) spectra is presented utilizing the newly developed Python code $fantasy$ (fully automated python tool for AGN spectra analysis). AGN spectra are modeled by simultaneously considering the underlying broken power-law continuum, predefined emission line lists, and an Fe II model, which is here extended to cover the wavelength range 3700 - 11000 A. The Fe II model, founded solely on atomic data, effectively describes the extensive emission of the complex iron ion in the vicinity of the H$\gamma$ and H$\beta$ lines, as well as near the H$\alpha$ line, which was previously rarely studied. The proposed spectral fitting approach is tested on a sample of high-quality AGN spectra from the Sloan Digital Sky Survey (SDSS) Data Release 17. The results indicate that when Fe II emission is present near H$\beta$, it is also detected redward from H$\alpha$, potentially contaminating the broad H$\alpha$ line wings and thus affecting the measurements of its flux and width. The production of Fe II emission is found to be strongly correlated with Eddington luminosity and appears to be controlled by the similar mechanism as the hydrogen Balmer lines. The study highlights the benefits of fitting AGN type 1 spectra with the $fantasy$ code, pointing that it may be used as a robust tool for analyzing a large number of AGN spectra in the coming spectral surveys.

arXiv commentAccepted in ApJS

References in corpus (74)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• A Catalog of Quasar Properties from SDSS DR7
• The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars
• The Multi-Object, Fiber-Fed Spectrographs for SDSS and the Baryon Oscillation Spectroscopic Survey
• Estimating Black Hole Masses in Active Galaxies Using the Halpha Emission Line
• Active Galactic Nuclei: what's in a name?
• An Empirical Ultraviolet Template for Iron Emission in Quasars as Derived from I Zw 1
• Tidal Disruption Events
• The diversity of quasars unified by accretion and orientation
• The Zwicky Transient Facility: Surveys and Scheduler
• PESSTO : survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient Objects
• The unusual emission line spectrum of IZw1
• Spectral Classification of Quasars in the Sloan Digital Sky Survey: Eigenspectra; Redshift and Luminosity Effects
• Fe II Emission in 14 Low-Redshift Quasars: I - Observations
• Spectral properties of quasars from Sloan Digital Sky Survey data release 14: The catalog
• Analysis of optical Fe II emission in a sample of AGN spectra
• Distributions of Galaxy Spectral Types in the Sloan Digital Sky Survey
• Broad-line Balmer Decrements in Blue Active Galactic Nuclei
• 4MOST - 4-metre Multi-Object Spectroscopic Telescope
• The Sloan Digital Sky Survey Reverberation Mapping Project: Sample Characterization
• Exploring the Low-Mass End of The M-Sigma Relation with Active Galaxies
• Parsec-scale dust emission from the polar region in the type 2 nucleus of NGC 424
• A Catalog of Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey Data Release 12
• The Lick AGN Monitoring Project 2011: Fe II Reverberation from the Outer Broad-Line Region
• Average Quasar Spectra in the Context of Eigenvector 1
• The Origin of Fe II Emission in AGN
• Spectral Decomposition of Broad-Line AGNs and Host Galaxies
• The flux ratio of the [OIII] 5007,4959 lines in AGN: Comparison with theoretical calculations
• The Near-Infrared Broad Emission Line Region of Active Galactic Nuclei -- I. The Observations
• Contribution of the Disk Emission to the Broad Emission Lines in AGNs: Two-component model
• The Sloan Digital Sky Survey Reverberation Mapping Project: Estimating Masses of Black Holes in Quasars with Single-Epoch Spectroscopy
• Predicted FeII Emission-Line Strengths from Active Galactic Nuclei
• The Quasar Main Sequence explained by the combination of Eddington ratio, metallicity and orientation
• Spectral Optical Monitoring of the Narrow Line Seyfert 1 galaxy Ark 564
• Dissecting the active galactic nucleus in Circinus -- I. Peculiar mid-IR morphology explained by a dusty hollow cone
• A comprehensive and uniform sample of broad-line active galactic nuclei from the SDSS DR7
• Constraining Sub-Parsec Binary Supermassive Black Holes in Quasars with Multi-Epoch Spectroscopy. III. Candidates from Continued Radial Velocity Tests
• What controls the Fe II strength in active galactic nuclei?
• QSFit: Automatic analysis of optical AGN spectra
• The case for cases B and C: intrinsic hydrogen line ratios of the broad-line region of active galactic nuclei, reddenings, and accretion disc sizes
• Solar coronal lines in the visible and infrared. A rough guide
• The Fe II problem in NLS1s
• The Fundamental Plane of the Broad-line Region in Active Galactic Nuclei
• Lyman Alpha Fluorescent Excitation of FeII in Active Galactic Nuclei
• Testing broad line region models with Reverberation Mapping
• The structure of the Mg II broad line emitting region in Type 1 AGNs
• The UV and optical Fe II emission lines in type 1 AGNs
• Variability of Fe II Emission Features in the Seyfert 1 Galaxy NGC 5548
• Balmer Lines as Diagnostics of Physical Conditions in AGN Broad Emission Line Regions
• Evidence that most type 1 AGN are reddened by dust in the host ISM
• Improved Fe II emission line models for AGN using new atomic datasets
• On the size of the Fe II emitting region in the AGN Akn 120
• A New Iron Emission Template for Active Galactic Nuclei. I. Optical Template for the H$\beta$ region
• The flux ratio of the [N II]$\lambda \lambda$ 6548, 6583 Å lines in sample of Active Galactic Nuclei Type 2
• The rise and fall of the iron-strong nuclear transient PS16dtm
• Theoretical FeI/II/III Emission-Line Strengths from Active Galactic Nuclei with Broad-Line Regions
• Reddening of the BLR and NLR in AGN From a Systematic Analysis of Balmer Decrement
• The analysis of the hydrogen broad Balmer line ratios: possible implications to the physical properties of the BLR of AGN
• A flare in the optical spotted in the changing-look Seyfert NGC 3516
• Variability of Optical \ion{Fe}{ii} Complex in Narrow-Line Seyfert 1 Galaxy NGC 4051
• Panchromatic Properties of the Extreme FeII Emitter PHL 1092
• Fe II emission in active galactic nuclei
• A Near-Infrared Template Derived from I Zw 1 for the FeII Emission in Active Galaxies
• Tracing the outflow kinematics in Type 2 Active Galactic Nuclei
• Long-term monitoring of the broad-line region properties in a selected sample of AGN
• Kinematics of the H$\alpha$ and H$\beta$ broad line region in an SDSS sample of type 1 AGNs
• Dusty plasma in active galactic nuclei

Cited by in corpus (3)

• [OIII] emission in z=2 quasars with and without Broad Absorption Lines
• Searching for signatures of Fe II atomic processes in spectra of active galactic nuclei
• Time Evolution of Mg II in SDSS J2320+0024: Implications for a Subparsec Binary Supermassive Black Hole System