Article
Astronomy & Astrophysics
F. Rastegarnia, M. T. Mirtorabi, R. Moradi, A. Vafaei Sadr, Y. Wang
Summary: Studying cosmological sources at their cosmological rest frames is crucial. In this study, a new neural network model called FNet is built to accurately estimate the redshift of quasars. FNet outperforms existing models in both accuracy and applicability.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Daniel Kynoch, Hermine Landt, Maryam Dehghanian, Martin J. Ward, Gary J. Ferland
Summary: This study presents the first detailed investigation into the variability of the near-infrared coronal lines in AGN. It is found that the coronal lines in AGN are generally broader and blueshifted compared to low-ionization forbidden lines. The variability primarily occurs in the broad wings of the coronal line profiles, while the cores show negligible changes. This suggests the presence of at least two coronal line regions in AGN.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Reza Monadi, Simeon Bird
Summary: This study analyzes the C iv line features and color parameters of core ERQs and finds that they may represent a separate population. A new criterion for selecting ERQs is developed, resulting in the identification of more quasars with C iv broad absorption line features. These selected quasars are confirmed to be extreme objects in the intersection of the WISE AGN catalog and the MILLIQUAS quasar catalog in the color-color space.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
R. Shirley, K. Duncan, M. C. Campos Varillas, P. D. Hurley, Y. Roehlly, M. W. L. Smith, H. Aussel, T. Bakx, V Buat, D. Burgarella, N. Christopher, S. Duivenvoorden, S. Eales, A. Efstathiou, E. A. Gonzalez Solares, M. Griffin, M. Jarvis, B. Lo Faro, L. Marchetti, I McCheyne, A. Papadopoulos, K. Penner, E. Pons, M. Prescott, E. Rigby, H. Rottgering, A. Saxena, J. Scudder, M. Vaccari, L. Wang, S. J. Oliver, K. Malek
Summary: The Herschel Extragalactic Legacy Project (HELP) collates and creates data products for high-quality multiwavelength extragalactic datasets, with a focus on open methodologies, reproducibility, and provenance. Their first data release includes far-infrared photometry, photometric redshifts, and derived physical properties estimated from modelling the spectral energy distributions over the full sky.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Yuzo Ishikawa, Ben Wang, Nadia L. Zakamska, Gordon T. Richards, Joseph F. Hennawi, Angelica B. Rivera
Summary: Through near-infrared spectroscopy of 24 luminous obscured quasar candidates, we have identified previously undetected red, obscured, high-redshift quasar candidates, indicating that the census of obscured quasar populations is incomplete.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Dohyeong Kim, Daye Lee, Myungshin Im
Summary: Bolometric luminosity is a key indicator of the radiative energy output of an active galactic nucleus. Dust extinction can affect estimates based on ultraviolet or optical luminosities, so using infrared hydrogen Paschen and Brackett line luminosities to estimate bolometric luminosities can help reduce this impact.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Yongjiang Wang, Wanqing Liu, Zhaohui Shang, Michael S. Brotherton
Summary: This study investigates the relationship between the equivalent width of broad emission lines and the underlying continuum luminosity in active galactic nuclei (AGNs), known as the Baldwin effect (BE), as well as the correlation with the Eddington ratio, referred to as the modified Baldwin effect (MBE). The results show that the BE is stronger than the MBE for most of the broad emission lines. Additionally, the study finds that the slope of the BE and MBE is related to the ionization energy of the lines. Furthermore, the O vi emission line is found to have a broader line width and larger blueshift compared to the C iv line, suggesting a closer proximity to the accretion disc and stronger influence from the accretion disc wind.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Xinfeng Xu, Nahum Arav, Timothy Miller, Kirk T. Korista, Chris Benn
Summary: The study of quasar Q0059-2735 revealed a variety of outflow absorption features, including wide and narrow absorption lines formed by high and low-ionization transitions. By fitting the absorption troughs, the physical conditions of the outflows and the presence of iron-peak elements were determined. The research also uncovered the distance of the outflows to the central quasar and the smallest outflow deceleration in any known quasars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. Lakicevic, J. Kovacevic-Dojcinovic, L. C. Popovic
Summary: The differences between Narrow Line Seyfert I galaxies (NLS1s) and Broad Line AGNs (BLAGNs) are not fully understood, with factors such as inclination, structure, and black hole mass potentially contributing. A dusty cone model is proposed as a possible explanation for the spectroscopic differences, indicating that the observed correlations may be influenced by AGN inclination and structure.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
XueGuang Zhang
Summary: In this paper, a potential sub-pc binary black hole (BBH) system in SDSS J1257+2023 is reported based on different properties of broad Balmer emission lines. The broad Hα line in SDSS J1257+2023 is significantly broader than the broad Hβ line, with a width ratio of 0.69, which is quite different from the normal line width ratio of 1.1 in quasars. The broader component in the broad Hα line can be confidently confirmed through the F-test technique and different model functions. The detection of optical quasi-periodic oscillations (QPOs) with a periodicity of about 1000 days in the BBH system of SDSS J1257+2023 is supported by the Zwicky Transient Facility (ZTF) light curves and the generalized Lomb-Scargle periodogram with a confidence level higher than 3σ.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
T. M. Buendia-Rios, C. A. Negrete, P. Marziani, D. Dultzin
Summary: By studying 309 quasars, we have found that Al III and C III] can be reliable virial mass estimators for Pop. A and Pop. B objects, providing consistent mass estimations.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. Singha, B. Husemann, T. Urrutia, C. P. O'Dea, J. Scharwachter, M. Gaspari, F. Combes, R. Nevin, B. A. Terrazas, M. Perez-Torres, T. Rose, T. A. Davis, G. R. Tremblay, J. Neumann, I Smirnova-Pinchukova, S. A. Baum
Summary: In this study, spatially resolved IFU spectroscopy was used to analyze the spatial location of ionized gas outflows in a sample of 39 luminous type 1 AGN. The results showed that some [O III] emission lines were unresolved, while others were extended on kiloparsec scales. The presence of both compact and extended emission lines is independent of AGN luminosity and inclination effects, suggesting other factors such as time delays and mechanical feedback may influence the properties of ionized gas outflows.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
XueGuang Zhang, Qi Zheng
Summary: In this paper, a method is proposed to test dual-core systems for double-peaked narrow emission lines. The main galaxy has a dual-core system with double-peaked narrow Balmer lines, while the companion galaxy has single-peaked narrow Balmer lines. The study of SDSS J2219-0938 reveals a different flux ratio between the emission components, disfavoring a dual-core system for the double-peaked narrow Balmer emission lines.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
X. G. Zhang
Summary: In this study, we discuss the properties of a mis-classified quasar, SDSS J1451+2709, which is classified as a H ii galaxy in the BPT diagram. By measuring its emission lines, we find that different model functions lead to different determined fluxes, but the different flux ratios of narrow emission lines classify it as a H ii galaxy. Two methods are proposed to explain the unique properties, but further research is needed to find the physical origin.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
P. Vermot, J. Palous, B. Barna, S. Ehlerova, M. R. Morris, R. Wunsch
Summary: We characterized the properties of stellar populations in the central regions of nearby galactic nuclei using spatially resolved spectroscopic observations. By simultaneously fitting various observables, including line-of-sight velocity, velocity dispersion, and spectral features, we determined the age, mass, and 3D geometry of the young and old stellar populations in the nuclear star cluster and surrounding disk. Our results are consistent with previous independent measurements.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Alice Deconto-Machado, Ascension del Olmo, Paola Marziani, Jaime Perea, Giovanna Stirpe
Summary: This study compared the spectroscopic properties of two sources, one radio-loud and one radio-quiet, showing similar optical properties but significant differences in UV data. The two sources are very close on the Main Sequence classification while presenting important variations in their UV behavior.
ASTRONOMISCHE NACHRICHTEN
(2022)
Article
Astronomy & Astrophysics
Paola Marziani, Edi Bon, Natasa Bon, Mauro D'Onofrio, Brian Punsly, Marzena Sniegowska, Bozena Czerny, Swayamtrupta Panda, Mary Loli Martnez Aldama, Ascension del Olmo, Alice Deconto-Machado, C. Alenka Negrete, Deborah Dultzin, Tania Buendia, Karla Garnica
Summary: In recent years, several trends associated with the quasar main sequence have been confirmed, revealing the relatively recent concept of a main sequence for quasars yet to be fully exploited. The main sequence drivers are discussed in terms of extreme objects, summarizing developments in constraining the viewing angle of accretion disks in specific quasar classes, inferences on the chemical composition of broad line emitting gas, and the nature of radio emission along the quasar main sequence.
ASTRONOMISCHE NACHRICHTEN
(2022)
Article
Astronomy & Astrophysics
M. Laurenti, E. Piconcelli, L. Zappacosta, F. Tombesi, C. Vignali, S. Bianchi, P. Marziani, F. Vagnetti, A. Bongiorno, M. Bischetti, A. del Olmo, G. Lanzuisi, A. Luminari, R. Middei, M. Perri, C. Ricci, G. Vietri
Summary: In this study, the X-ray spectral analysis of 14 high-Eddington-ratio AGN reveals that despite the homogeneous optical and supermassive black hole accretion properties, the X-ray properties of these AGN are quite heterogeneous. Interestingly, some sources exhibit much fainter X-ray emission compared to typical AGN.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Brian Punsly, Christian Groeneveld, Gary J. Hill, Paola Marziani, Gregory R. Zeimann, Donald P. Schneider
Summary: The research finds that the radio lobes of 3C 298 have a large jet power, but small equivalent widths of broad emission lines, indicating extraordinary jet power and weak ionizing continuum.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
K. Garnica, C. A. Negrete, P. Marziani, D. Dultzin, M. Sniegowska, S. Panda
Summary: In this study, we analyzed the UV spectra of quasars at intermediate redshifts to estimate the chemical abundances of the broad line emitting gas. Our results showed that these quasars have high metallicity and a deviation in the relative abundance of elements compared to solar values. This suggests a complex process in the formation and evolution of quasars.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Paola Marziani, Ascension del Olmo, C. Alenka Negrete, Deborah Dultzin, Enrico Piconcelli, Giustina Vietri, Mary Loli Martinez-Aldama, Mauro D'Onofrio, Edi Bon, Natasa Bon, Alice Deconto Machado, Giovanna M. Stirpe, Tania Mayte Buendia Rios
Summary: The study compares quasar line widths at different redshifts and luminosities, finding that the widths of Al III and H beta are highly correlated and in most quasars could be considered equivalent. A correction factor of approximately 1.25 for C lambda 1909 brings its FWHM in agreement with H beta. The statistical concordance between low-ionization and intermediate-ionization lines suggests they may come from the same virialized region.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
A. Deconto-Machado, A. del Olmo Orozco, P. Marziani, J. Perea, G. M. Stirpe
Summary: The 4D Eigenvector 1 empirical formalism (4DE1) and its main sequence (MS) are effective tools for understanding the diversity among quasar populations. In this study, the behavior of a sample of 22 high-redshift and high-luminosity quasars was evaluated in the context of the 4DE1. The analysis suggests that these quasars are strongly affected by powerful outflows.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. G. Jones, L. Verdes-Montenegro, J. Moldon, A. Damas Segovia, S. Borthakur, S. Luna, M. Yun, A. del Olmo, J. Perea, J. Cannon, D. Lopez Gutierrez, M. Cluver, J. Garrido, S. Sanchez
Summary: Hickson compact groups (HCGs) follow an evolutionary sequence of three phases, with gas initially confined to galaxies, then spread throughout the intra-group medium, and finally almost no gas remaining in the galaxies. This study finds that the deficiency of H I can be used as a proxy for the evolutionary phase of a compact group, and there is evidence for the existence of diffuse H I component in HCGs. Moreover, the distribution of H I deficiency in HCGs is broad, and the timescale for morphological changes is generally shorter than the timescale for the destruction or consumption of neutral gas.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. H. Naddaf, M. L. Martinez-Aldama, P. Marziani, S. Panda, M. Sniegowska, B. Czerny
Summary: This study investigates the scenario in which the BAL phenomenon in quasars is not a temporary stage and aims to understand the theoretical mechanism behind the massive outflow in BAL quasars. The findings support the interpretation of the BAL phenomenon as the result of the orientation of the source and the underlying theoretical model.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Paola Marziani, Swayamtrupta Panda, Alice Deconto Machado, Ascension Del Olmo
Summary: The optical and UV properties of radio-quiet and radio-loud active galactic nuclei (AGN) are different, but it is unclear whether the differences are due to sample selection or intrinsic differences in their emitting regions. Recent studies have shown that strong Feii emitters require high metal content. However, the chemical composition of jetted radio-loud sources is not well understood. This study presents a pilot analysis of the chemical composition of low-z radio-loud and radio-quiet quasars.
Article
Astronomy & Astrophysics
Marzena Sniegowska, Swayamtrupta Panda, Bozena Czerny, Dorge Savic, Mary Loli Martinez-Aldama, Paola Marziani, Jian-Min Wang, Pu Du, Luka C. Popovic, Chandra Shekhar Saraf
Summary: Narrow-line Seyfert 1 (NLSy1) galaxies have high Eddington ratios and relatively small black hole masses. The measurement of these black hole masses is influenced by the viewing angles inferred from spectropolarimetric measurements. The use of spectral decomposition and fitting techniques allows for modeling of the natural and polarized spectra around the H alpha region, providing insight into the physical conditions of the line-emitting gas and the scattering medium responsible for the polarization of the H alpha emission line.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Multidisciplinary Sciences
Paola Marziani
Summary: This study explains the distinct behaviors of blue- and redshifted broad emission-line shifts in active galactic nuclei (AGN) by considering the balance between radiation and gravitational forces. Blueshifts occur in high Eddington ratios and high luminosities AGN, while redshifts are observed in low Eddington ratios Balmer emission lines.
Article
Astronomy & Astrophysics
Paola Marziani, Alice Deconto-Machado, Ascension Del Olmo
Summary: Gaseous outflows are a common feature in both type-1 and type-2 active galactic nuclei, observed through the Doppler effect causing emission features to shift to higher frequencies. However, the observational characteristics of these outflows are often unclear and it is difficult to isolate their contribution in integrated spectra.
