Article
Astronomy & Astrophysics
Aaron D. Ludlow, S. Michael Fall, Matthew J. Wilkinson, Joop Schaye, Danail Obreschkow
Summary: This study uses cosmological simulations to investigate the impact of spurious heating of stellar motions within simulated galaxies by dark matter particles. The results show that spurious heating affects the distribution and kinematics of stellar and DM particles, but has little effect on galaxy properties such as mass and star formation histories.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Sasha R. Brownsberger, Lisa Randall
Summary: This study introduces a method to measure the correspondence between dark matter models and observations of stellar populations in dwarf galaxies without assuming a parametric stellar distribution. Through this method, researchers found the consistency of different shapes and distributions of dark matter models with stellar data, as well as their consistency with stellar positions and velocities. Interestingly, the Fornax dwarf spheroidal galaxy shows no evidence of a disc-like structure and exhibits some features that are inconsistent with predictions from Lambda cold dark matter with baryon simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Andrea Maccio, Daniel Huterer Prats, Keri L. Dixon, Tobias Buck, Stefan Waterval, Nikhil Arora, Stephane Courteau, Xi Kang
Summary: Through simulations, it has been shown that dwarf galaxies can lose up to 80% of their dark matter content and see a significant change in the dark matter-to-stellar mass ratio after interactions with central galaxies. These findings align with observations of NGC 1052-DF2 and NGC 1054-DF4.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
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
Adriana Bariego-Quintana, Felipe J. Llanes-Estrada, Oliver Manzanilla Carretero
Summary: The flattening rotation velocity v(r) -> constant discovered by Rubin and collaborators in the SPARC galaxy-rotation data is in line with Kepler's law in one less dimension. Elongated dark matter distributions, with their axis of prolateness perpendicular to the galactic plane, naturally reproduce this phenomenon. Detailed fits to the rotation data also support this theoretical understanding, showing that elongated distributions provide a better fit than purely spherical ones.
Article
Astronomy & Astrophysics
Arya Farahi, Daisuke Nagai, Dhayaa Anbajagane
Summary: In this work, the coupling between dark matter, hot gas, and stellar mass is studied using cosmological simulations. The researchers find that the strength of this coupling depends on the scale at which halo profiles are measured. They also observe a radius-dependent additive bias when halos are selected based on properties other than their mass, which has implications for cluster abundance and cross-correlation cosmology.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Moritz Haslbauer, Pavel Kroupa, Akram Hasani Zonoozi, Hosein Haghi
Summary: The James Webb Space Telescope has discovered luminous high-redshift galaxy candidates, and by comparing them with the lambda CDM model, it is found that the stellar mass buildup in the early universe is more efficient than predicted.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Francesco Montanari, Juan Garcia-Bellido
Summary: This study presents two methodologies for inferring properties of perturbers from stellar streams formed by tidal stripping, using the non-Gaussian density distribution of stellar streams. The Bayesian model selection and likelihood-free gradient boosting classifier aim to discern the PBH CDM hypothesis from standard particle dark matter. Model selection based on the PDF analysis shows varying degrees of evidence, while the gradient boosting model is highly efficient with 99% accuracy for all mass ranges considered. Further tests dividing the largest mass range into smaller intervals provide similar conclusions.
PHYSICS OF THE DARK UNIVERSE
(2022)
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
Nilanjan Banik, Jo Bovy, Gianfranco Bertone, Denis Erkale, T. J. L. de Boer
Summary: This paper provides constraints on alternative dark matter scenarios based on tidal streams analysis, deriving lower limits for warm dark matter and ultra-light dark matter masses using data from streams and dwarf satellite counts.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Aaron D. Ludlow, S. Michael Fall, Joop Schaye, Danail Obreschkow
Summary: In this study, idealized N-body simulations were used to analyze the impact of spurious collisional heating on the structure and kinematics of stellar discs. It was found that collisional heating can artificially increase the velocity dispersions of disc stars and affect the thickness and size of discs. The effects of collisional heating are influenced by the mass of DM halo particles, their local density, and characteristic velocity dispersion, while being largely insensitive to the stellar particle mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Hyungjin Kim, Alessandro Lenoci
Summary: This study investigates the local overdensity of dark matter caused by massive astrophysical objects and the effects of gravitational focusing on dark matter signals. It provides insights into the similarities and differences between wave dark matter and particle dark matter, and examines the impact of wave properties on density contrast and spectrum.
Article
Astronomy & Astrophysics
Pavel E. Mancera Pina, Filippo Fraternali, Tom Oosterloo, Elizabeth A. K. Adams, Kyle A. Oman, Lukas Leisman
Summary: This study presents new H i interferometric observations of AGC 114905, finding that the rotation curve can be explained by the baryonic mass distribution alone, while standard cold dark matter halos and modified Newtonian dynamics fail to reproduce the data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Sarah Pearson, Adrian M. Price-Whelan, David W. Hogg, Anil C. Seth, David J. Sand, Jason A. S. Hunt, Denija Crnojevic
Summary: In the coming decade, thousands of stellar streams in the halos of external galaxies will be observed. By modeling the Centaurus A dwarf companion and its associated stellar stream, researchers have found that radial-velocity measurements along the stream are crucial to break degeneracies and study dark matter in extragalactic stellar streams.
ASTROPHYSICAL JOURNAL
(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
Jens Stucker, Go Ogiya, Simon D. M. White, Raul E. Angulo
Summary: Prompt cusps are dense objects of quasi-equilibrium dark matter that form at the instant of collapse within isolated peaks of the initial cosmological density field. They have power-law density profiles and contribute significantly to the annihilation luminosity of dark matter. Individual stellar encounters, rather than the mean galactic tide, are the primary disruptors of prompt cusps within galaxies. Stellar encounters suppress their mean annihilation luminosity, but this does not affect the Galactic center gamma-ray excess.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Monica Barrera, Volker Springel, Simon D. M. White, Cesar Hernandez-Aguayo, Lars Hernquist, Carlos Frenk, Ruediger Pakmor, Fulvio Ferlito, Boryana Hadzhiyska, Ana Maria Delgado, Rahul Kannan, Sownak Bose
Summary: Upcoming large galaxy surveys will test the standard cosmological model, ΛCDM, with the help of theoretical models of galaxy formation. The semi-analytic L-Galaxies code has been updated to be applied to simulations of the new MillenniumTNG project, providing more accurate predictions for galaxy clustering signals. This methodology is an important step towards better modeling of observational data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Rudiger Pakmor, Volker Springel, Jonathan P. Coles, Thomas Guillet, Christoph Pfrommer, Sownak Bose, Monica Barrera, Ana Maria Delgado, Fulvio Ferlito, Carlos Frenk, Boryana Hadzhiyska, Cesar Hernandez-Aguayo, Lars Hernquist, Rahul Kannan, Simon D. M. White
Summary: In this study, the MillenniumTNG (MTNG) project is introduced, which provides high-resolution, large-volume simulations of cosmic structure formation. The focus is on the MTNG740 simulation, which produces galaxy clusters consistent with observational constraints. It is found that the mass estimates of Planck clusters may be underestimated.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Cesar Hernandez-Aguayo, Volker Springel, Rudiger Pakmor, Monica Barrera, Fulvio Ferlito, Simon D. M. White, Lars Hernquist, Boryana Hadzhiyska, Ana Maria Delgado, Rahul Kannan, Sownak Bose, Carlos Frenk
Summary: Cosmological inference with large galaxy surveys requires efficient and accurate theoretical models that can incorporate precise predictions for large-scale structure and flexible galaxy formation modeling. The MILLENNIUMTNG project combines hydrodynamical galaxy formation models with large-scale simulations, allowing for the construction and calibration of semi-analytic models. These simulations also provide insights into non-linear clustering, matter and halo statistics, and the impact of baryonic physics.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Sownak Bose, Boryana Hadzhiyska, Monica Barrera, Ana Maria Delgado, Fulvio Ferlito, Carlos Frenk, Cesar Hernandez-Aguayo, Lars Hernquist, Rahul Kannan, Ruediger Pakmor, Volker Springel, Simon D. M. White
Summary: Modern redshift surveys are mapping the distribution of galaxies on enormous distance scales. However, current hydrodynamical simulations cannot reach the volumes needed for upcoming surveys. A new, large volume hydrodynamical simulation called MillenniumTNG (MTNG) is able to accurately reproduce the observed clustering of galaxies, but there are discrepancies when separated by color. This is due to the quenching of satellite galaxies in the model.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Boryana Hadzhiyska, Daniel Eisenstein, Lars Hernquist, Ruediger Pakmor, Sownak Bose, Ana Maria Delgado, Sergio Contreras, Rahul Kannan, Simon D. M. White, Volker Springel, Carlos Frenk, Cesar Hernandez-Aguayo, Fulvio Ferlito, Monica Barrera
Summary: This study investigates the assembly bias of two galaxy populations using a large-volume, high-resolution hydrodynamical simulation. The results show that incorporating external halo properties, such as "shear," is crucial for modeling the clustering of emission-line galaxies (ELGs). Low-mass halo centrals dominate the assembly bias signal of both luminous red galaxies (LRGs) and ELGs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Simon May, Volker Springel
Summary: Fuzzy dark matter (FDM) is a candidate for dark matter consisting of ultralight scalar particles. The authors conducted large numerical simulations to study the formation of cosmic structure with FDM. By comparing the results with cold dark matter simulations, they aimed to validate previous approximate methods used in FDM studies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Matthew D. A. Orkney, Chervin F. P. Laporte, Robert J. J. Grand, Facundo A. Gomez, Freeke van de Voort, Azadeh Fattahi, Federico Marinacci, Ruediger Pakmor, Francesca Fragkoudi, Volker Springel
Summary: We investigate the properties of mergers comparable to the Gaia-Sausage-Enceladus (GSE) using cosmological hydrodynamical simulations of Milky Way-like galaxies. The merger progenitors span an order of magnitude in their peak stellar mass and include both rotation and pressure-supported galaxies. In a minority of cases, the GSE-like debris is comprised of stars from more than one merger progenitor. However, there is a close similarity in their chemodynamical properties and the triaxial shapes of their debris, and so it is not always possible to distinguish them.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Rahul Kannan, Volker Springel, Lars Hernquist, Ruediger Pakmor, Ana Maria Delgado, Boryana Hadzhiyska, Cesar Hernandez-Aguayo, Monica Barrera, Fulvio Ferlito, Sownak Bose, Simon D. M. White, Carlos Frenk, Aaron Smith, Enrico Garaldi
Summary: The early release science results from JWST indicate a large abundance of high-redshift luminous galaxies, challenging current theories of galaxy formation. However, the lack of spectroscopic confirmation limits definitive conclusions. This study uses a large-volume hydrodynamic simulation to make predictions for the high-redshift galaxy population and finds that the simulations are consistent with observations until z≈10, but underestimate the abundance of luminous galaxies and star-formation rates beyond z≥12, indicating a need for more sophisticated galaxy formation models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Fulvio Ferlito, Volker Springel, Christopher T. Davies, Cesar Hernandez-Aguayo, Ruediger Pakmor, Monica Barrera, Simon D. M. White, Ana Maria Delgado, Boryana Hadzhiyska, Lars Hernquist, Rahul Kannan, Sownak Bose, Carlos Frenk
Summary: We study weak gravitational lensing convergence maps produced from the MillenniumTNG simulations to assess numerical convergence and the impact of baryonic physics and massive neutrinos on weak lensing statistics. By comparing with dark-matter-only runs, we find substantial effects from both baryonic physics and neutrinos, with the latter dominating on large angular scales. The 'fixed & paired' variance suppression technique improves the statistical robustness of the simulation predictions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Sergio Contreras, Raul E. Angulo, Volker Springel, Simon D. M. White, Boryana Hadzhiyska, Lars Hernquist, Ruediger Pakmor, Rahul Kannan, Cesar Hernandez-Aguayo, Monica Barrera, Fulvio Ferlito, Ana Maria Delgado, Sownak Bose, Carlos Frenk
Summary: We propose a novel approach to constrain cosmological parameters and galaxy assembly bias using non-linear redshift space clustering of galaxies. By inserting galaxies into cosmological N-body simulations with the SHAMe empirical model, we generate over 175,000 clustering measurements covering a wide range of cosmological and SHAMe parameter values. We build an emulator capable of reproducing the projected galaxy correlation function at different levels for various separations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Boryana Hadzhiyska, Lars Hernquist, Daniel Eisenstein, Ana Maria Delgado, Sownak Bose, Rahul Kannan, Rudiger Pakmor, Volker Springel, Sergio Contreras, Monica Barrera, Fulvio Ferlito, Cesar Hernandez-Aguayo, Simon D. M. White, Carlos Frenk
Summary: In this work, we propose a new phenomenological approach using a large hydrodynamical simulation to obtain an accurate and flexible galaxy-halo model on small scales. We study LRGs and ELGs at two epochs and recover their clustering down to very small scales. The occupation statistics of ELGs inform us about the satellite distribution in halos and provide evidence for cooperative galaxy formation. Our refined galaxy-halo model can improve the analysis tools and increase the constraining power of large-scale structure surveys.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)