Article
Astronomy & Astrophysics
Uddipan Banik, Frank C. van den Bosch
Summary: The study focuses on impulsive encounters between astrophysical objects, finding that the distant tide approximation method often overpredicts the energy change caused by impulses when the impact parameter is small, and is not suitable for the most interesting close encounters. To address these issues, a comprehensive, non-perturbative treatment of impulsive encounters is proposed, which is valid for any impact parameter and not hampered by divergence issues.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Qingyang Li, Jiaxin Han, Wenting Wang, Weiguang Cui, Zhaozhou Li, Xiaohu Yang
Summary: Using hydrodynamical simulations, researchers studied the dynamic modeling of the underlying gravitational potential of a galaxy cluster with different types of tracers. They found that the halo mass and concentration can be recovered in an ensemble unbiased way, but with stochastic bias reflecting deviations from steady state. Different types of tracers lead to systematic uncertainties in mass and concentration, with intracluster gas showing comparable results to dark matter as tracers.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Duncan A. Forbes, Jonah S. Gannon, Aaron J. Romanowsky, Adebusola Alabi, Jean P. Brodie, Warrick J. Couch, Anna Ferre-Mateu
Summary: The ultra diffuse galaxy NGC 5846 UDG1 in the NGC 5846 group shows high dark matter contribution within its effective radius and is likely pressure supported, with a dynamic mass indicating a similarly high total dark matter mass inferred from the stellar velocity dispersion. The enclosed mass derived from the positions and motions of globular clusters suggests a cored mass profile and a total halo mass of around 2 x 10^11 M-circle dot. With a stellar mass of 1.1 x 10^8 M-circle dot, NGC 5846 UDG1 appears to be an ultra diffuse galaxy with an overly massive halo.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Qingyang Li, Jiaxin Han, Wenting Wang, Weiguang Cui, Federico De Luca, Xiaohu Yang, Yanrui Zhou, Rui Shi
Summary: This study investigates the importance of various dynamical features in predicting the dynamical state of galaxy clusters using the Random Forest machine-learning approach. The research found that the virial ratio eta is the most important single feature, and features related to the centroid positions are more important. A combination of up to three features of different types can already saturate the prediction score.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Rahul Ramesh, Dylan Nelson, Annalisa Pillepich
Summary: We analysed the physical properties of gas in the circumgalactic medium (CGM) of 132 Milky Way-like galaxies at z=0 and found diverse properties and abundance of CGM gas across the sample, with considerable variations in the fractional budgets of different phases and in neutral H I mass and metal mass. The CGM exhibits great structural complexity, both within individual galaxies and across different galaxies. The physical properties of the CGM are tightly connected to the galactic star formation rate, which is dependent on feedback from supermassive black holes (SMBHs).
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Valeria Coenda, Martin de los Rios, Hernan Muriel, Sofia A. Cora, Hector J. Martinez, Andres N. Ruiz, Cristian A. Vega-Martinez
Summary: By analyzing galaxy properties based on their orbital classification, we found distinct differences in characteristics among different types of galaxies, such as cluster galaxies with lowest sSFR, reddest and oldest properties, and backsplash galaxies with intermediate properties between cluster and recent infaller galaxies. We also discovered the importance of separating galaxy populations by color to achieve more accurate analysis of the 2D data, with reliable results found for recent infallers, infalling galaxies, and interloper galaxies in the blue population.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Matthew Frosst, Stephane Courteau, Nikhil Arora, Connor Stone, Andrea Maccio, Marvin Blank
Summary: An analysis of observed and simulated galaxy data reveals diversity in galaxy structural parameters, rotation curve shapes, and stellar mass profiles. Two distinct populations are identified, one consisting of low-mass blue spirals with constant rotation curve slopes, and the other consisting of redder, more massive, and more diverse spirals with increasing slopes. The study also shows that the diversity increases mildly with mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Nabeel Rehemtulla, Monica Valluri, Eugene Vasiliev
Summary: Spherical Jeans modelling is commonly used for estimating mass profiles of various systems, ranging from star clusters to galactic stellar haloes and clusters of galaxies, by deriving cumulative mass distributions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Enrico M. Di Teodoro, Lorenzo Posti, Patrick M. Ogle, S. Michael Fall, Thomas Jarrett
Summary: We studied the kinematics and scaling relations of 43 giant spiral galaxies and found that most of them conform to the standards set by low-mass galaxies. It is speculated that these rare giant galaxies are scaled up versions of smaller discs, indicating that spiral galaxies exhibit self-similarity at the high-mass end.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Dhayaa Anbajagane, Han Aung, August E. Evrard, Arya Farahi, Daisuke Nagai, David J. Barnes, Weiguang Cui, Klaus Dolag, Ian G. McCarthy, Elena Rasia, Gustavo Yepes
Summary: Researchers have calibrated the velocity bias by comparing galaxy and dark matter velocity dispersions from different simulations, and found that it varies with host halo mass, redshift, and galaxy stellar mass threshold. They demonstrate that dynamical mass estimation is comparable to weak lensing mass estimation in terms of accuracy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. Khelashvili, A. Rudakovskyi, S. Hossenfelder
Summary: The kinematics of galaxies can provide valuable insights into the distribution of dark matter. This study uses a Bayesian framework to analyze the stellar kinematics of galaxies and compares different dark matter halo models. The results indicate a preference for fuzzy dark matter models in more than half of the galaxies, but it is also found that there is no universal particle mass value that fits all galaxies well.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Shi Shao, Marius Cautun, Alis Deason, Carlos S. Frenk
Summary: The study identifies that the minor axis of the Galactic DM halo roughly points towards the plane of the stellar disc, but its flattening and orientation vary with radius. The inner parts of the halo are rounder and aligned with the stellar disc, while further out the halo twists and the minor axis changes direction by 90 degrees.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ivan de Martino, Antonaldo Diaferio, Luisa Ostorero
Summary: We use kinematic data of stars in eight dwarf spheroidal galaxies to investigate if f(R) gravity can explain their observed velocity dispersion profiles without dark matter. Our model assumes spherical symmetry, constant velocity anisotropy parameter beta, and constant mass-to-light ratio. The f(R) velocity dispersion profiles depend on two parameters: the scale length xi(-1) and the gravitational field boost delta. While the xi(-1) values are consistent for the entire sample, the delta values show a bimodal distribution indicating tension for f(R) gravity. Further studies or additional constraints from astrometric space missions are needed to resolve this tension.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Enrico M. Di Teodoro, Lorenzo Posti, S. Michael Fall, Patrick M. Ogle, Thomas Jarrett, Philip N. Appleton, Michelle E. Cluver, Martha P. Haynes, Ute Lisenfeld
Summary: This study presents new and archival observations of atomic hydrogen in 15 massive spiral galaxies, deriving extended rotation curves and estimating the masses of dark matter halos and specific angular momenta of discs. The results confirm that the massive spiral galaxies align with power laws in the Tully-Fisher relation and Fall relation, indicating self-similar populations closely linked to their dark halos.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Emily J. E. Charles, Michelle L. M. Collins, R. Michael Rich, Justin Read, Stacy Y. Kim, Rodrigo A. Ibata, Nicolas F. Martin, Scott C. Chapman, Eduardo Balbinot, Daniel R. Weisz
Summary: In this study, we find that And XXV is a dwarf spheroidal galaxy dominated by dark matter, with a relatively high mass and significant differences compared to other galaxies of similar mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Haowen Zhang, Peter Behroozi, Marta Volonteri, Joseph Silk, Xiaohui Fan, Philip F. Hopkins, Jinyi Yang, James Aird
Summary: Trinity is a flexible empirical model that can infer the statistical connection between dark matter haloes, galaxies, and supermassive black holes. It calculates the average SMBH mass, SMBH accretion rate, merger rate, and Eddington ratio distribution as functions of halo mass, galaxy stellar mass, and redshift.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Emma Aycoberry, Virginia Ajani, Axel Guinot, Martin Kilbinger, Valeria Pettorino, Samuel Farrens, Jean-Luc Starck, Raphael Gavazzi, Michael J. Hudson
Summary: This study assesses the impact of systematic effects on weak lensing peak counts and cosmological parameters for the UNIONS survey. The results show that calibration, shear bias, baryonic feedback, redshift estimate, intrinsic alignment, and cluster member dilution can affect cosmological constraints. The constraints are expected to become more reliable with larger future data catalogs.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Dennis Zaritsky, Peter Behroozi
Summary: We propose a technique for estimating the mass of dark matter halos in local galaxies based on photometric measurements, allowing us to establish the relationship between stellar mass and halo mass down to stellar masses of 10^(5) M. We find no significant differences among the relationships in four local galaxy clusters or between the clusters and field galaxies, and our results agree with previous studies using abundance matching methods. By fitting a power law to our empirical relationship, we determine that for stellar masses less than 10^(9) M, the halo mass is M_h = 10^(10.35 +/- 0.02)(M_* / 10^(8) M)(0.63 +/- 0.02). However, this relationship is susceptible to systematic modeling errors and the uncertainties quoted refer to the uncertainties in the median relationship. The scatter about the fit in halo mass, including uncertainties from our methodology, is 0.3 dex for galaxies that meet our selection criteria and have stellar masses less than 10^(9) M. Additionally, we apply the same technique to lower luminosity galaxies in the Local Group and find evidence for additional mass beyond the effective radius that is not accounted for by the standard dark matter profile. If this mass is in the form of a central black hole, their masses are in the range of intermediate mass black holes, around 10^((5.7 +/- 0.6)) M, corresponding to a few percent of the halo mass and higher than extrapolated values for more massive galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Han Aung, Daisuke Nagai, Anatoly Klypin, Peter Behroozi, Mohamed H. Abdullah, Tomoaki Ishiyama, Francisco Prada, Enrique Perez, Javier Lopez Cacheiro, Jose Ruedas
Summary: We release the Uchuu-UM galaxy catalogues, which are obtained by applying the UniverseMachine algorithm to assign galaxies to dark matter haloes in the Uchuu N-body cosmological simulation. This catalogue provides various baryonic properties for galaxies down to a mass of 5 x 10(8) M-circle dot, covering a mass range of 10(10) < M-halo/M-circle dot < 5 x 10(15) up to redshift z = 10. It reproduces observed stellar mass functions, galaxy quenched fractions, and clustering statistics at low redshifts, and includes more massive galaxies hosted by large-mass dark matter haloes compared to previous catalogues.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Yuchen Guo, Shardha Jogee, Steven L. Finkelstein, Zilei Chen, Eden Wise, Micaela B. Bagley, Guillermo Barro, Stijn Wuyts, Dale D. Kocevski, Jeyhan S. Kartaltepe, Elizabeth J. McGrath, Henry C. Ferguson, Bahram Mobasher, Mauro Giavalisco, Ray A. Lucas, Jorge A. Zavala, Jennifer M. Lotz, Norman A. Grogin, Marc Huertas-Company, Jesus Vega-Ferrero, Nimish P. Hathi, Pablo Arrabal Haro, Mark Dickinson, Anton M. Koekemoer, Casey Papovich, Nor Pirzkal, L. Y. Aaron Yung, Bren E. Backhaus, Eric F. Bell, Antonello Calabro, Nikko J. Cleri, Rosemary T. Coogan, M. C. Cooper, Luca Costantin, Darren Croton, Kelcey Davis, Avishai Dekel, Maximilien Franco, Jonathan P. Gardner, Benne W. Holwerda, Taylor A. Hutchison, Viraj Pandya, Pablo G. Perez-Gonzalez, Swara Ravindranath, Caitlin Rose, Jonathan R. Trump, Alexander de la Vega, Weichen Wang
Summary: This study presents the first quantitative identification and characterization of stellar bars at z > 1 using JWST CEERS NIRCam images. The results reveal the early onset and persistence of stellar bars, suggesting their significant impact on galaxies over long periods of time.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Steven L. Finkelstein, Micaela B. Bagley, Henry C. Ferguson, Stephen M. Wilkins, Jeyhan S. Kartaltepe, Casey Papovich, L. Y. Aaron Yung, Pablo Arrabal Haro, Peter Behroozi, Mark Dickinson, Dale D. Kocevski, Anton M. Koekemoer, Rebecca L. Larson, Aurelien Le Bail, Alexa M. Morales, Pablo G. Perez-Gonzalez, Denis Burgarella, Romeel Dave, Michaela Hirschmann, Rachel S. Somerville, Stijn Wuyts, Volker Bromm, Caitlin M. Casey, Adriano Fontana, Seiji Fujimoto, Jonathan P. Gardner, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Nimish P. Hathi, Taylor A. Hutchison, Saurabh W. Jha, Shardha Jogee, Lisa J. Kewley, Allison Kirkpatrick, Arianna S. Long, Jennifer M. Lotz, Laura Pentericci, Justin D. R. Pierel, Nor Pirzkal, Swara Ravindranath, Russell E. Ryan, Jonathan R. Trump, Guang Yang, Rachana Bhatawdekar, Laura Bisigello, Veronique Buat, Antonello Calabro, Marco Castellano, Nikko J. Cleri, M. C. Cooper, Darren Croton, Emanuele Daddi, Avishai Dekel, David Elbaz, Maximilien Franco, Eric Gawiser, Benne W. Holwerda, Marc Huertas-Company, Anne E. Jaskot, Gene C. K. Leung, Ray A. Lucas, Bahram Mobasher, Viraj Pandya, Sandro Tacchella, Benjamin J. Weiner, Jorge A. Zavala
Summary: We conducted an investigation into the first 500 million years of galaxy evolution using the CEERS survey. By analyzing the CEERS NIRCam imaging data, we identified a sample of 26 galaxy candidates at z similar to 9-16, suggesting that the number density of galaxies at this redshift range remains relatively constant. These findings highlight the potential of JWST to discover more ultrahigh-redshift galaxies in the future.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
G. Yang, K. I. Caputi, C. Papovich, P. Arrabal Haro, M. B. Bagley, P. Behroozi, E. F. Bell, L. Bisigello, V. Buat, D. Burgarella, Y. Cheng, N. J. Cleri, R. Dave, M. Dickinson, D. Elbaz, H. C. Ferguson, S. L. Finkelstein, N. A. Grogin, N. P. Hathi, M. Hirschmann, B. W. Holwerda, M. Huertas-Company, T. A. Hutchison, E. Iani, J. S. Kartaltepe, A. Kirkpatrick, D. D. Kocevski, A. M. Koekemoer, V. Kokorev, R. L. Larson, R. A. Lucas, P. G. Perez-Gonzalez, P. Rinaldi, L. Shen, J. R. Trump, A. de la Vega, L. Y. A. Yung, J. A. Zavala
Summary: Mid-infrared (mid-IR) observations are used to identify heavily obscured active galactic nuclei (AGN) that are difficult to detect in other wavelengths. The Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope provides data for such studies. Utilizing MIRI imaging data, researchers investigated the AGN population in the distant universe and classified them into different types based on their spectral energy distribution (SED). The study shows that MIRI can identify a large population of heavily obscured AGN missed by X-ray surveys at high redshifts.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Bailey Robison, Michael J. Hudson, Jean-Charles Cuillandre, Thomas Erben, Sebastien Fabbro, Raphael Gavazzi, Axel Guinot, Stephen Gwyn, Hendrik Hildebrandt, Martin Kilbinger, Alan McConnachie, Lance Miller, Isaac Spitzer, Ludovic van Waerbeke
Summary: Using weak gravitational lensing, the ellipticity of dark matter haloes around Luminous Red Galaxies (LRGs) was measured. The results showed that for LRGs in the Sloan Digital Sky Survey Data Release 7 (DR7) with mass M~ 2.7 x 10^13 M_sun h^-1, the halo ellipticity was found to be e = 0.46 +/- 0.10, with f(h) = 2.2 +/- 0.6 as a fraction of the galaxy's ellipticity. For BOSS LRGs, the detection was marginally significant: e = 0.20 +/- 0.10 and f(h) = 0.7 +/- 0.7. These findings are consistent with previous measurements and suggest an increase in halo ellipticity of 0.10 +/- 0.06 per decade in halo mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Finn A. Roper, Kyle A. Oman, Carlos S. Frenk, Alejandro Benitez-Llambay, Julio F. Navarro, Isabel M. E. Santos-Santos
Summary: We use cosmological hydrodynamical simulations to study the kinematics of gaseous discs in late-type dwarf galaxies. By creating high-resolution 'observations' of simulated dwarfs, we investigate the effect of different galaxy formation models on the rotation curves. We find that systematic discrepancies between the recovered rotation curve and the actual circular velocity curve arise due to non-circular gas orbits, finite thickness of gaseous discs, and departures from dynamical equilibrium.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Richard A. N. Brooks, Kyle A. Oman, Carlos S. Frenk
Summary: The number density of extragalactic 21-cm radio sources has been measured in the northern and southern Galactic fields, and it was found that the number density is systematically higher in the north, which contradicts theoretical predictions. The discrepancy is found to be due to differences in survey sensitivity between the two fields and inadequacies in the completeness correction algorithm used. After accounting for these systematic effects, updated measurements of the HIWF were obtained.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Andrew M. M. Reeves, Michael J. Hudson, Kyle A. Oman
Summary: We use data from the Sloan Digital Sky Survey to forward-model mass-weighted stellar ages and quiescent fractions in projected phase space, aiming to constrain an infall quenching model for galaxies in massive clusters at z similar to 0. We find that the deviation in mass-weighted stellar ages depends on the position in projected phase space, with the greatest difference between inner cluster and infalling interloper galaxies being approximately 1 Gyr. Our model incorporates infall information from N-body simulations and stochastic star-formation histories from the UNIVERSEMACHINE model. Our results suggest that quenching starts close to or just after pericentre, but the time-scale for full quenching to occur is much longer, indicating that ram-pressure stripping is not completed on first pericentric passage.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Eleanor R. Downing, Kyle A. Oman
Summary: By studying 33 low-mass galaxies, we found that the assumption of galaxy rotation curves being equal to their circular velocity curves is often incorrect. Only 3 galaxies satisfy this assumption and the rest are affected by various dynamical perturbations. These perturbations lead to an underestimation of the low-velocity slope of the mass-rotation relation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Simon E. T. Smith, Jaclyn Jensen, Joel Roediger, Federico Sestito, Christian R. R. Hayes, Alan W. W. McConnachie, Jean-Charles Cuillandre, Stephen Gwyn, Eugene Magnier, Ken Chambers, Francois Hammer, Mike J. J. Hudson, Nicolas Martin, Julio Navarro, Douglas Scott
Summary: We have discovered a new ultra-faint dwarf galaxy candidate called Bootes V. It was detected as a resolved overdensity of stars during an ongoing search for new Local Group dwarf galaxy candidates in the UNIONS photometric data set. Bootes V has a physical half-light radius of 26.9(-5.4)(+7.5) pc, a V-band magnitude of -4.5 +/- 0.4 mag, and is located at a heliocentric distance of approximately 100 kpc. Using Gaia DR3 astrometry, we have identified member stars, characterized the systemic proper motion, and confirmed the reality of this faint stellar system. The spectroscopic analysis shows that Bootes V is larger, more distant, and more metal-poor than most globular clusters, suggesting that it is an ultra-faint dwarf galaxy but further studies are needed for definitive classification.
ASTRONOMICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Annagrazia Puglisi, Ugne Dudzeviciute, Mark Swinbank, Steven Gillman, Alfred L. Tiley, Richard G. Bower, Michele Cirasuolo, Luca Cortese, Karl Glazebrook, Chris Harrison, Edo Ibar, Juan Molina, Danail Obreschkow, Kyle A. Oman, Matthieu Schaller, Francesco Shankar, Ray M. Sharples
Summary: We present the first results from the KMOS Ultra-deep Rotation Velocity Survey (KURVS), which examines the outer rotation curves and dark matter content of 22 star-forming galaxies at z similar to 1.5. Using Hα emission, we analyze individual rotation curves to a radius of 4 times the effective radius, finding that most curves are flat or rising between three and six disc scale radii. Our measurements suggest a declining dark matter fraction with increasing stellar mass and stellar mass surface density. The tension with high stellar mass surface density observations indicates a need to reassess baryonic processes in the most massive galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)