Article
Astronomy & Astrophysics
Gerardo Martinez-Bautista, Hector Velazquez, Angeles Perez-Villegas, Edmundo Moreno
Summary: Test-particle simulations of a spiral late-type-like galaxy showed that radial migration affects stellar orbits; the study found that the radial scale length of spiral arms is the most important parameter in the radial migration phenomenon in the corotation region.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Eduardo O. Schmidt, Damian Mast, Gaia Gaspar, Walter Weidmann
Summary: In this paper, the stellar kinematics and rotation curves of 46 barred galaxies are analyzed in order to investigate their distributions and scaling relations. The rotation curves are obtained using the Pipe3D dataproducts, and a wide range of maximum rotation velocities is found. There are strong correlations between dynamical mass and maximum velocity, between maximum velocity and magnitude, and between stellar mass and maximum velocity. Barred galaxies exhibit similar behavior to normal spiral galaxies in terms of these relations and the distribution of their dynamical mass and maximum rotation velocity. However, the distribution of stellar masses of barred galaxies differs statistically from other samples, including non-barred galaxies. No difference is found in the rotation curves of galaxies showing nuclear activity compared to normal galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Evgeny Griv, Michael Gedalin, Przemek Mroz, De-Jian Liu, Ing-Guey Jiang
Summary: This study selected 2640 Gaia EDR3 O-B2 stars within 2.5 kpc from the Sun and 250 pc from the Galactic plane to derive Galactic differential rotation parameters and wave structure parameters in the solar neighborhood. The study revealed two scales of periodic rarefaction-compression irregularity of the velocity field in the form of a spiral wave propagating in the disc. The findings provide further evidence to support the Lin-Shu density-wave proposal.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Dhruv Bisaria, Kristine Spekkens, Shan Huang, Gregory Hallenbeck, Martha P. Haynes
Summary: The study presents H alpha velocity maps for HIghMass galaxies obtained with the SITELLE Imaging Fourier Transform Spectrometer, finding UGC 7899 as the best candidate for late gas accretion among the examined galaxies, with hints of inner radial flows or a bar present in UGC 7899 and UGC 9037. However, the constraints on hot-mode accretion models to explain the high H I content in HIghMass galaxies are weak.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
P. Sanchez-Martin, C. Garcia-Gomez, J. J. Masdemont, M. Romero-Gomez
Summary: We propose a dynamical mechanism that explains the asymmetry between the arms in some barred disc galaxies, where one arm is well defined while the other exhibits a ragged structure. By studying the invariant manifolds associated with the Lyapunov periodic orbits at the ends of the bar, we find that the dynamics are not symmetric due to the presence of an asymmetric bar or a non-centred bulge in the galaxy centre. As a result, one arm becomes weaker and more ragged compared to the other arm.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. A. Sellwood, R. G. Carlberg
Summary: This paper continues to explore different aspects of disc galaxy simulations that support spiral instabilities. The study finds a correlation between the growth rate of the mode and its limiting amplitude, and identifies the role of non-linear orbit deflections and available time in the saturation and decay of the spiral instabilities.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Shameer Abdeen, Benjamin L. Davis, Rafael Eufrasio, Daniel Kennefick, Julia Kennefick, Ryan Miller, Deanna Shields, Erik B. Monson, Calla Bassett, Harry O'Mara
Summary: The study examines evidence for age gradients using star formation history (SFH) maps and spatially resolved stellar clusters, finding secondary peaks in cluster distributions indicate the presence of an age gradient. Analysing SFH maps of 12 galaxies reveals a tightening of spiral arms with increasing age, with a probability of 69% +/- 25% that pitch angle values decrease with age, supporting the previous studies on the tightening of spiral patterns in galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Yuki Yoshida, Eiichiro Kokubo
Summary: The swing amplification is a mechanism for spiral arm formation and gravitational scattering by a high-density region in a disc galaxy. The synchronization of epicycle phases during this process has been previously shown to occur due to gravitational scattering by a softened point mass. In this study, we consider gravitational scattering by a finite-sized wake and find that phase synchronization is more effective for wakes with a pitch angle around pi/2. The wake shape also affects the phase synchronization, and even for realistic pitch angles less than or equal to pi/4, the synchronization can be more effective than that by a softened point mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Dmitry Bizyaev, Rene A. M. Walterbos, Yan-Mei Chen, Niv Drory, Richard R. Lane, Joel R. Brownstein, Rogemar A. Riffel
Summary: In this study, the largest sample of 561 edge-on galaxies observed with integral field units by the MaNGA survey is considered. It is found that 300 galaxies show a negative vertical gradient in the rotational speed of the ionized gas. Correlations are found between the lags, stop altitude, and galactic mass, stellar velocity dispersion, and overall Sersic index. No correlation is found between the lags or stop altitude and the star formation activity in the galaxies. It is concluded that low-mass galaxies with low-Sersic index and low-stellar velocity dispersion possess a wider 'zone of influence' in the extragalactic gas surrounding them compared to higher-mass galaxies that have a significant spherical component. The trend of the vertical rotational gradient with radius is found to be flat for most galaxies in the sample. A small subsample of galaxies with negative radial gradients of lag shows an enhanced fraction of objects with aged low-surface brightness structures around them, indicating the influence of noticeable accretion events in the past on the extraplanar gas kinematics and negative radial lag gradients. It is concluded that isotropic accretion of gas from the circumgalactic medium plays a significant role in the formation of rotation velocity lags.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. A. Sellwood, R. H. Sanders
Summary: Recent observations suggest that the ultradiffuse galaxy AGC 114905 has a rotating disc without the need for dark matter. This is surprising because a non-dark matter Newtonian disc would be expected to be unstable. N-body simulations confirm this expectation, raising questions about the galaxy's lack or scarcity of dark matter. It is also suggested that overestimating the inclination of the system could reconcile the observed rotation curve with the presence of a massive dark matter halo.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. A. Sellwood, Victor P. Debattista
Summary: Any misalignment between the inner and outer disc of a galaxy will lead to the excitation of a bending wave in the outer disc, driven by torque from the inner disc. This bending wave grows in amplitude over several Gyr, aligning parts of the disc with the inner disc. The mild warps observed in simulations of disc galaxies can be excited by shot noise, particularly the quadrupole component, but larger amplitude bending waves are likely caused by perturbations from halo substructure and galaxy assembly in real galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. A. Sellwood, R. G. Carlberg
Summary: This study explores the spiral responses in a stable disc galaxy model to evenly spaced perturbing masses. It reveals that the amplitudes of the responses are proportional to the masses of the perturbations, and higher mass rings can cause non-linear changes through scattering at major resonances. The net response from two rings orbiting at differing frequencies appears as a shearing spiral, demonstrating the effects of superposition on the evolution of simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
K. Bekki
Summary: The study found that U-Net can accurately predict the locations of spiral arms with symmetric pitch angles, but struggles with nonsymmetric and irregular arms. Therefore, more realistic galaxy images are needed for training to improve its applicability.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Meera Nandakumar, Chaitra Narayan, Prasun Dutta
Summary: By analyzing the residual velocity fields of H i discs, we have identified the velocity peaks induced by bending waves, suggesting that bending waves are a common phenomenon.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
P. A. Patsis, E. M. Xilouris, J. Alikakos, E. Athanassoula
Summary: The study successfully observed all structural components of the barred spiral galaxy NGC 352, measured their dimensions, and compared the findings with a GADGET N-body model. The X/peanut component was found to be unambiguously part of the bar, with features that are consistent with various theoretical models.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Erin Kara, Missagh Mehdipour, Gerard A. Kriss, Edward M. Cackett, Nahum Arav, Aaron J. Barth, Doyee Byun, Michael S. Brotherton, Gisella De Rosa, Jonathan Gelbord, Juan V. Hernandez Santisteban, Chen Hu, Jelle Kaastra, Hermine Landt, Yan-Rong Li, Jake A. Miller, John Montano, Ethan Partington, Jesus Aceituno, Jin-Ming Bai, Dongwei Bao, Misty C. Bentz, Thomas G. Brink, Doron Chelouche, Yong-Jie Chen, Encarni Romero Colmenero, Elena Dalla Bonta, Maryam Dehghanian, Pu Du, Rick Edelson, Gary J. Ferland, Laura Ferrarese, Carina Fian, Alexei V. Filippenko, Travis Fischer, Michael R. Goad, Diego H. Gonzalez Buitrago, Varoujan Gorjian, Catherine J. Grier, Wei-Jian Guo, Patrick B. Hall, Luis C. Ho, Y. Homayouni, Keith Horne, Dragana Ilic, Bo-Wei Jiang, Michael D. Joner, Shai Kaspi, Christopher S. Kochanek, Kirk T. Korista, Daniel Kynoch, Sha-Sha Li, Jun-Rong Liu, Ian M. M. cHardy, Jacob N. McLane, Jake A. J. Mitchell, Hagai Netzer, Kianna A. Olson, Richard W. Pogge, Luka C. Popovic, Daniel Proga, Thaisa Storchi-Bergmann, Erika Strasburger, Tommaso Treu, Marianne Vestergaard, Jian-Min Wang, Martin J. Ward, Tim Waters, Peter R. Williams, Sen Yang, Zhu-Heng Yao, Theodora E. Zastrocky, Shuo Zhai, Ying Zu
Summary: The study revealed significant X-ray absorption and new blueshifted, broad, and narrow UV absorption lines in the luminous Seyfert 1 galaxy Mrk 817, indicating partial coverage of the central source by a dust-free, ionized obscurer. Despite the obscuration, correlations between UV and optical continuum reverberation were observed, as well as reverberation lags associated with the optical broad-line region.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Shameer Abdeen, Benjamin L. Davis, Rafael Eufrasio, Daniel Kennefick, Julia Kennefick, Ryan Miller, Deanna Shields, Erik B. Monson, Calla Bassett, Harry O'Mara
Summary: The study examines evidence for age gradients using star formation history (SFH) maps and spatially resolved stellar clusters, finding secondary peaks in cluster distributions indicate the presence of an age gradient. Analysing SFH maps of 12 galaxies reveals a tightening of spiral arms with increasing age, with a probability of 69% +/- 25% that pitch angle values decrease with age, supporting the previous studies on the tightening of spiral patterns in galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Hengxiao Guo, Aaron J. Barth, Kirk T. Korista, Michael R. Goad, Edward M. Cackett, Misty C. Bentz, William N. Brandt, D. Gonzalez-Buitrago, Gary J. Ferland, Jonathan M. Gelbord, Luis C. Ho, Keith Horne, Michael D. Joner, Gerard A. Kriss, Ian McHardy, Missagh Mehdipour, Daeseong Park, Raymond Remigio, U. Vivian, Marianne Vestergaard
Summary: This study examines the contribution of diffuse continuum (DC) emission from the broad-line region in active galactic nuclei (AGN) using Hubble Space Telescope spectra. The Paschen jump region near 8200 angstrom is found to potentially aid in constraining the DC contribution. The fitting results suggest DC contributions ranging from about 10% to 50% at 8000 angstrom.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Nandini Sahu, Alister W. Graham, Benjamin L. Davis
Summary: This paper presents the fourth in a series of papers on the black hole mass scaling relations dependent on galaxy morphology and formation. Using a sample of 119 galaxies, the study investigates the correlations between black hole mass and various spheroid parameters. The findings reveal different trends for early- and late-type galaxies, as well as a decrease in scatter as the enclosing aperture increases. The study also provides insights for estimating tidal disruption event rates, binary black hole lifetimes, and gravitational wave characteristic strains.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Dexter S-H Hon, Alister W. Graham, Benjamin L. Davis, Alessandro Marconi
Summary: This paper investigates the presence and evolutionary pathways of compact massive quiescent galaxies in the local Universe. Through detailed decomposition and classification, it is found that some existing elliptical galaxies are actually galaxies with rotating discs. The paper also reports indicators such as the bulge-to-total flux ratio and volume number density of local galaxies. The study suggests that disc-cloaking is an important alternative for galaxy evolution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Misty C. Bentz, Peter R. Williams, Tommaso Treu
Summary: We present a reanalysis of reverberation mapping data for the Seyfert galaxy NGC 4151, supplemented with additional data from the literature, to constrain the continuum variations over a longer baseline. Our modeling suggests that the broad line region (BLR) in NGC 4151 is well described by a thick disk with specific geometric and kinematic properties. The models provide an independent and direct measurement of the black hole mass, which is consistent with other mass measurements from different modeling techniques.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Michael S. Fusco, Benjamin L. Davis, Julia Kennefick, Daniel Kennefick, Marc S. Seigar
Summary: In this study, we analyze the pitch angle distribution function (PADF) and black hole mass function (BHMF) of nearby galaxies. We find a distinct bimodal distribution of pitch angles in Sa-Sc and Scd-Sm galaxies, with tighter spiral arms in Sa-Sc types. Importantly, we uncover a bifurcation of the BHMF, with Sa-Sc galaxies hosting supermassive black holes and Scd-Sm galaxies harboring less-than-supermassive black holes. This has implications for spiral formation theories and the search for intermediate-mass black holes (IMBHs).
Article
Astronomy & Astrophysics
Deanna Shields, Benjamin Boe, Casey Pfountz, Benjamin L. Davis, Matthew Hartley, Ryan Miller, Zac Slade, M. Shameer Abdeen, Daniel Kennefick, Julia Kennefick
Summary: This study presents a novel MATLAB code, Spirality, which measures spiral arm pitch angles by fitting galaxy images to known spiral templates. The code demonstrates good performance in terms of computation time and accuracy.
Article
Astronomy & Astrophysics
Misty C. Bentz, Christopher A. Onken, Rachel Street, Monica Valluri
Summary: We measured the emission-line light curves for HO, Hy, and He II A4686 in the broad-line active galactic nucleus in IC 4329A by monitoring the optical continuum. The time delays for H beta and Hy were found to be 16.3 and 16.0 days, respectively, while the time delay for He II was 0.6 days. The time delay for H beta is consistent with the predicted value from the relationship between AGN luminosity and broad-line region radius. Additionally, the models suggest a large misalignment between the AGN structure and the edge-on galaxy disk.
ASTROPHYSICAL JOURNAL
(2023)
Review
Physics, Particles & Fields
Pau Amaro-Seoane, Jeff Andrews, Manuel Arca Sedda, Abbas. Askar, Quentin Baghi, Razvan Balasov, Imre Bartos, Simone S. Bavera, Jillian Bellovary, Christopher P. L. Berry, Emanuele Berti, Stefano Bianchi, Laura Blecha, Stephane Blondin, Tamara Bogdanovic, Samuel Boissier, Matteo Bonetti, Silvia Bonoli, Elisa Bortolas, Katelyn Breivik, Pedro R. Capelo, Laurentiu Caramete, Federico Cattorini, Maria Charisi, Sylvain Chaty, Xian Chen, Martyna Chruslinska, Alvin J. K. Chua, Ross Church, Monica Colpi, Daniel D'Orazio, Camilla Danielski, Melvyn B. Davies, Pratika Dayal, Alessandra De Rosa, Andrea Derdzinski, Kyriakos Destounis, Massimo Dotti, Ioana Dutan, Irina Dvorkin, Gaia Fabj, Thierry Foglizzo, Saavik Ford, Jean-Baptiste Fouvry, Alessia Franchini, Tassos Fragos, Chris Fryer, Massimo Gaspari, Davide Gerosa, Luca Graziani, Paul Groot, Melanie Habouzit, Daryl Haggard, Zoltan Haiman, Wen-Biao Han, Alina Istrate, Peter H. Johansson, Fazeel Mahmood Khan, Tomas Kimpson, Kostas Kokkotas, Albert Kong, Valeriya Korol, Kyle Kremer, Thomas Kupfer, Astrid Lamberts, Shane Larson, Mike Lau, Dongliang Liu, Nicole Lloyd-Ronning, Giuseppe Lodato, Alessandro Lupi, Chung-Pei Ma, Tomas Maccarone, Ilya Mandel, Alberto Mangiagli, Michela Mapelli, Stephane Mathis, Lucio Mayer, Sean McGee, Berry McKernan, M. Coleman Miller, David F. Mota, Matthew Mumpower, Syeda S. Nasim, Gijs Nelemans, Scott Noble, Fabio Pacucci, Francesca Panessa, Vasileios Paschalidis, Hugo Pfister, Delphine Porquet, John Quenby, Angelo Ricarte, Friedrich K. Roepke, John Regan, Stephan Rosswog, Ashley Ruiter, Milton Ruiz, Jessie Runnoe, Raffaella Schneider, Jeremy Schnittman, Amy Secunda, Alberto Sesana, Naoki Seto, Lijing Shao, Stuart Shapiro, Carlos Sopuerta, Nicholas C. Stone, Arthur Suvorov, Nicola Tamanini, Tomas Tamfal, Thomas Tauris, Karel Temmink, John Tomsick, Silvia Toonen, Alejandro Torres-Orjuela, Martina Toscani, Antonios Tsokaros, Caner Unal, Veronica Vazquez-Aceves, Rosa Valiante, Maurice van Putten, Jan van Roestel, Christian Vignali, Marta Volonteri, Kinwah Wu, Ziri Younsi, Shenghua Yu, Silvia Zane, Lorenz Zwick, Fabio Antonini, Vishal Baibhav, Enrico Barausse, Alexander Bonilla Rivera, Marica Branchesi, Graziella Branduardi-Raymont, Kevin Burdge, Srija Chakraborty, Jorge Cuadra, Kristen Dage, Benjamin Davis, Selma E. de Mink, Roberto Decarli, Daniela Doneva, Stephanie Escoffier, Poshak Gandhi, Francesco Haardt, Carlos O. Lousto, Samaya Nissanke, Jason Nordhaus, Richard O'Shaughnessy, Simon Portegies Zwart, Adam Pound, Fabian Schussler, Olga Sergijenko, Alessandro Spallicci, Daniele Vernieri, Alejandro Vigna-Gomez
Summary: The Laser Interferometer Space Antenna (LISA) is an innovative experiment for gravitational wave astronomy, offering unique opportunities to address key astrophysical questions in a novel way. By synergizing with ground-based and space-born instruments, LISA enables multi-messenger observations, enhancing its discovery potential. This review highlights the extensive landscape of astrophysical theory, numerical simulations, and astronomical observations necessary for modeling and interpreting LISA's upcoming datastream. It also discusses open issues, gaps in understanding, and potential research avenues that LISA can contribute to in combination with electromagnetic domain studies.
LIVING REVIEWS IN RELATIVITY
(2023)
Article
Astronomy & Astrophysics
R. A. Riffel, T. Storchi-Bergmann, R. Riffel, M. Bianchin, N. L. Zakamska, D. Ruschel-Dutra, M. C. Bentz, L. Burtscher, D. M. Crenshaw, L. G. Dahmer-Hahn, N. Z. Dametto, R. Davies, M. R. Diniz, T. C. Fischer, C. M. Harrison, V Mainieri, M. Revalski, A. Rodriguez-Ardila, D. J. Rosario, A. J. Schonell
Summary: We present the kinematics of hot molecular gas and warm ionized gas for 33 nearby X-ray selected active galaxies using the Gemini near-infrared integral field spectrograph. We find that 94% of the objects exhibit kinematically disturbed regions in the ionized gas, while 76% show such regions in the hot molecular gas. The outflows are interpreted as being produced by radiation-pressure in low-density environments, with possible contribution from shocks.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
M. Dehghanian, G. J. Ferland, B. M. Peterson, G. A. Kriss, K. T. Korista, M. R. Goad, M. Chatzikos, M. C. Bentz, F. Guzman, M. Mehdipour, G. De Rosa
Summary: The unusual behavior of the spectral lines of NGC5548 during the STORM campaign revealed a missing piece in the structure of AGNs, which may be attributed to the significant impact of disk winds on the spectral lines.
ASTROPHYSICAL JOURNAL
(2021)
