Article
Astronomy & Astrophysics
Elizabeth J. Gonzalez, Kai Hoffmann, Enrique Gaztanaga, Diego R. Garcia Lambas, Pablo Fosalba, Martin Crocce, Francisco J. Castander, Martin Makler
Summary: This study tests the recovery of halo cluster shapes and masses using weak-lensing stacking techniques. The results show that when considering the relaxation state of haloes, the lensing semi-axial ratio estimates are consistent within 5% with the mean shapes of the projected dark-matter particle distribution of the stacked haloes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Alessandro Sonnenfeld, Crescenzo Tortora, Henk Hoekstra, Marika Asgari, Maciej Bilicki, Catherine Heymans, Hendrik Hildebrandt, Konrad Kuijken, Nicola R. Napolitano, Nivya Roy, Edwin Valentijn, Angus H. Wright
Summary: Using weak gravitational lensing observations, this study investigates the relationship between the dark matter halo mass and the properties of massive elliptical galaxies. The results show that there is no significant correlation between the halo mass and the half-light radius or colour of the galaxies, indicating that the average star formation efficiency of these galaxies is not dependent on their final size or colour. This suggests that the diversity in the size and colour distribution of massive elliptical galaxies may be attributed to other factors.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Tim Schrabback, Henk Hoekstra, Ludovic Van Waerbeke, Edo van Uitert, Christos Georgiou, Marika Asgari, Patrick Cote, Jean-Charles Cuillandre, Thomas Erben, Laura Ferrarese, Stephen D. J. Gwyn, Catherine Heymans, Hendrik Hildebrandt, Arun Kannawadi, Konrad Kuijken, Alexie Leauthaud, Martin Makler, Simona Mei, Lance Miller, Anand Raichoor, Peter Schneider, Angus Wright
Summary: By combining data from five weak lensing surveys, the observational constraints on galaxy-scale halo ellipticity have been tightened, leading to a significant detection of the halo flattening signature at the mass scale of galaxies with corrected systematics.
ASTRONOMY & ASTROPHYSICS
(2021)
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
Martin W. Sommer, Tim Schrabback, Douglas E. Applegate, Stefan Hilbert, Behzad Ansarinejad, Benjamin Floyd, Sebastian Grandis
Summary: Parametric modeling of galaxy cluster density profiles from weak lensing observations can lead to a mass bias, which is important for accurate mass-observable relations in cosmological models. A robust framework for calculating this mass bias in one-parameter fits to simulations of dark matter haloes has been developed. The approach is independent of noise level and the accuracy of bias estimation depends on the number and representativeness of haloes in simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Richard E. Griffiths, Mitchell Rudisel, Jenny Wagner, Timothy Hamilton, Po-Chieh Huang, Carolin Villforth
Summary: We reported the discovery of a 'folded' gravitationally lensed image, 'Hamilton's Object', found near an active galactic nucleus, which showed unique surface brightness features and stretched properties. The lensed images are sourced by a galaxy at a spectroscopic redshift and form a fold configuration on a caustic caused by a foreground galaxy cluster. The analysis suggests a mass density that hardly varies on an arcsecond scale over the areas covered by the multiple images.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Calum Murray, James G. Bartlett, Emmanuel Artis, Jean-Baptiste Melin
Summary: In this study, weak lensing mass estimates were presented for 458 galaxy clusters using weak lensing data. The mass-richness relation and the correlation between cluster richness and weak lensing masses were explored. The results showed some discrepancies compared to other studies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Niemiec, M. Jauzac, D. Eckert, D. Lagattuta, K. Sharon, A. M. Koekemoer, K. Umetsu, A. Acebron, J. M. Diego, D. Harvey, E. Jullo, V Kokorev, M. Limousin, G. Mahler, P. Natarajan, M. Nonino, C. Steinhardt, S- Tam, A. Zitrin
Summary: The study presents a combined strong and weak lensing analysis of the Abell 370 cluster using the HST BUFFALO program. Seven candidate substructures were identified and evaluated for their physical significance. Five of these candidates were found to be reliable, and the mass distribution in Abell 370 was observed to extend along the north-west and south-east directions. This research provides new insights into the complex mass distribution of clusters at large cluster-centric radii.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. Vega-Ferrero, J. M. Dana, J. M. Diego, G. Yepes, W. Cui, M. Meneghetti
Summary: The study compares the statistics and morphology of giant arcs in galaxy clusters using different models, finding that self-interacting dark matter produces fewer but more magnified arcs. The probability of interaction is higher in colliding clusters and in denser regions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Daniel A. Torres-Ballesteros, Leonardo Castaneda
Summary: In this work, we introduce a software package called RELENSING, which models galaxy clusters through gravitational lensing. The package provides a free-form approach to compute the gravitational deflection potential and constrain strong lensing. Our results show that by smoothing the deflection potential, the method can better recover the mass profile of galaxy clusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Daniel A. Torres-Ballesteros, Leonardo Castaneda
Summary: In this work, the software package RELENSING is introduced, which aims to model galaxy clusters through gravitational lensing. This package expands the available software options and provides a variety of models for the scientific community to compare and validate physical results. The approach implemented in RELENSING calculates the gravitational deflection potential on an adaptive irregular grid, allowing for characterization of the cluster as a gravitational lens. By applying a smoothing technique, the capability of the approach to recover the mass profile, magnification map, and critical and caustic curves of galaxy clusters is improved.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jack Sayers, Mauro Sereno, Stefano Ettori, Elena Rasia, Weiguang Cui, Sunil Golwala, Keiichi Umetsu, Gustavo Yepes
Summary: The study analyzed 16 galaxy clusters in the CLASH sample and found significant variations in non-thermal pressure fractions at different radial ranges, indicating different dynamical states within the same cluster.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Quinn Minor, Manoj Kaplinghat, Tony H. Chan, Emily Simon
Summary: The perturbations of strongly lensed images by low-mass dark matter subhaloes are significantly impacted by the concentration of the perturbing subhalo. Constraints on the concentration can be obtained at Hubble Space Telescope (HST) resolution for subhaloes with masses larger than about 10^10M(circle dot). The study also highlights the critical role of subhalo concentration in the detectability of perturbations, with implications for the mass-concentration relation at low masses and the probe of dark matter physics.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
David J. Lagattuta, Johan Richard, Harald Ebeling, Quentin Basto, Catherine Cerny, Alastair Edge, Mathilde Jauzac, Guillaume Mahler, Richard Massey
Summary: This study presents the first strong gravitational lensing analysis of the galaxy cluster RXJ0437. By using deep MUSE observations, near-infrared spectroscopy, and Hubble Space Telescope imaging, the researchers discovered 13 multiply imaged background galaxies, including three in hyperbolic umbilic (H-U) lensing configurations. They were able to use these systems to determine the inner slope of the mass distribution and investigate the nature of dark matter.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Matthew Fong, Jiaxin Han, Jun Zhang, Xiaohu Yang, Hongyu Gao, Jiaqi Wang, Hekun Li, Antonios Katsianis, Pedro Alonso
Summary: We used weak lensing observations to measure the characteristic depletion radius and studied the impact of mass and concentration on the depletion radius. Our results showed consistency with the simulation predictions for most cases, except for the lowest mass bins.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Anton T. Jaelani, Cristian E. Rusu, Issha Kayo, Anupreeta More, Alessandro Sonnenfeld, John D. Silverman, Malte Schramm, Timo Anguita, Naohisa Inada, Daichi Kondo, Paul L. Schechter, Khee-Gan Lee, Masamune Oguri, James H. H. Chan, Kenneth C. Wong, Kaiki T. Inoue
Summary: This study presents spectroscopic confirmation of three new two-image gravitationally lensed quasars, providing information on redshifts and various point sources for different systems. The data from different systems demonstrate the capability of the HSC-SSP project in discovering multiple-image quasars lensed by foreground galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Anowar J. Shajib, Tommaso Treu, Simon Birrer, Alessandro Sonnenfeld
Summary: By utilizing a joint lensing-dynamics analysis, the study investigates the internal structure of elliptical galaxies at a redshift of z≈0.2, revealing that dark matter haloes are well described by a standard Navarro-Frenk-White halo. Additionally, comparison of inferred stellar masses with those obtained from the stellar population synthesis method supports a heavy initial mass function (IMF) such as the Salpeter IMF.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Alessandro Sonnenfeld, Marius Cautun
Summary: The increasing number of strong gravitational lenses will allow for improved calibration of stellar mass measurements and better constraints on the dark matter density profile of galaxies.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. Bilicki, A. Dvornik, H. Hoekstra, A. H. Wright, N. E. Chisari, M. Vakili, M. Asgari, B. Giblin, C. Heymans, H. Hildebrandt, B. W. Holwerda, A. Hopkins, H. Johnston, A. Kannawadi, K. Kuijken, S. J. Nakoneczny, H. Y. Shan, A. Sonnenfeld, E. Valentijn
Summary: The study presents a bright galaxy sample selected using accurate photometric redshifts from the Kilo-Degree Survey Data Release 4, with precise photo-zs determined through a supervised machine learning neural network algorithm. The data shows low mean errors and scatter, allowing for estimation of robust absolute magnitudes and stellar masses. Analysis of the data reveals that red galaxies at high stellar mass occupy dark matter halos that are significantly more massive than those occupied by blue galaxies at the same stellar mass.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Benedetta Veronesi, Teresa Paneque-Carreno, Giuseppe Lodato, Leonardo Testi, Laura M. Perez, Giuseppe Bertin, Cassandra Hall
Summary: Recent ALMA observations of the protoplanetary disk around Elias 2-27 revealed a two-armed spiral structure, making it an ideal laboratory to investigate the role of self-gravity in early star formation. The dynamical estimate suggests that the disk mass is 17% of the star mass, indicating that the disk could be prone to gravitational instabilities.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
Alessandro Sonnenfeld
Summary: This study finds that spiral arms can introduce biases in the photometry of galaxies fitted with a Sersic profile, with the extent of the bias depending on the underlying surface brightness profile, arm location, and depth of photometric data. For galaxies dominated by bulges with contributions from spiral arms, the biases can lead to overestimation of the total flux and half-light radius by approximately 15% and 30%, respectively.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Alessandro Sonnenfeld
Summary: Time-delay lensing is a powerful tool for measuring the Hubble constant H-0, but breaking the degeneracy between H-0 and the lens model parameters from lensing data alone requires a large sample of time-delay lenses or prior knowledge of the structural parameter distribution of the lens population from a separate sample.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Alessandro Sonnenfeld
Summary: This study examines whether it is possible to break the degeneracy between H-0 and the lens model parameters by solely relying on strong lensing data. Results show that a sample of 100 lenses provides a 3% precision measurement of H-0, but with a -4% bias. However, combining prior information on lens structural parameters allows for a 1% level inference.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Alessandro Sonnenfeld
Summary: By statistically analyzing a large sample of time-delay lenses, it is possible to break the degeneracy between the Hubble constant and lens model parameters without considering stellar kinematics information. However, to achieve more accurate measurements of the Hubble constant, a larger sample of time-delay lenses or knowledge of the structural parameter distribution from another lens sample is required.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Alessandro Sonnenfeld, Crescenzo Tortora, Henk Hoekstra, Marika Asgari, Maciej Bilicki, Catherine Heymans, Hendrik Hildebrandt, Konrad Kuijken, Nicola R. Napolitano, Nivya Roy, Edwin Valentijn, Angus H. Wright
Summary: Using weak gravitational lensing observations, this study investigates the relationship between the dark matter halo mass and the properties of massive elliptical galaxies. The results show that there is no significant correlation between the halo mass and the half-light radius or colour of the galaxies, indicating that the average star formation efficiency of these galaxies is not dependent on their final size or colour. This suggests that the diversity in the size and colour distribution of massive elliptical galaxies may be attributed to other factors.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
R. Li, N. R. Napolitano, N. Roy, C. Tortora, F. La Barbera, A. Sonnenfeld, C. Qiu, S. Liu
Summary: This study developed a family of convolutional neural networks (CNNs) to analyze the surface brightness of galaxies quickly and accurately. Two different CNNs were trained to derive Sersic profile parameters, and they showed faster computational speed and comparable accuracy to standard tools in certain cases.
ASTROPHYSICAL JOURNAL
(2022)
Article
Physics, Multidisciplinary
Giuseppe Bertin, Francesco Pegoraro
Summary: We revisit the problem of the isothermal slab in self-gravitating stellar systems and investigate the role of weak collisionality in this context. By considering a system of heavy and light stars, we derive the properties of the final state from the assumed initial conditions using mass and energy conservation. We find that when the heavy stars are exactly twice as massive as the light stars, a simple analytic solution is possible. Our formulation and results pave the way for future studies on the evolution induced by weak collisionality using standard collision operators or numerical simulations.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Astronomy & Astrophysics
Carlo Cannarozzo, Alexie Leauthaud, Grecco A. Oyarzun, Carlo Nipoti, Benedikt Diemer, Song Huang, Vicente Rodriguez-Gomez, Alessandro Sonnenfeld, Kevin Bundy
Summary: We compare the properties of massive early-type galaxies from the MaNGA survey with simulated galaxies from the TNG100 simulation. There is an excellent agreement between their stellar mass surface density profiles, as well as the profiles of stellar metallicity, age, and velocity dispersion. However, the velocity dispersion profiles of very massive central galaxies in TNG100 are significantly higher than in MaNGA. This study supports the idea that high-mass early-type galaxies in the present-day Universe are formed through mergers that homogenize the stellar populations of their progenitors.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Danial Langeroodi, Alessandro Sonnenfeld, Henk Hoekstra, Adriano Agnello
Summary: With upcoming wide-field surveys, it is difficult to obtain spectroscopic source redshifts for large samples of strong lenses. Therefore, studying the possibility of obtaining source photometric redshifts (photo-zs) and addressing the issue of blending between the lens and the source light is necessary.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Cristiano Longarini, Giuseppe Lodato, Giuseppe Bertin, Philip J. Armitage
Summary: Recent observations indicate that planet formation occurs in young systems, even when the protostar is still embedded in the molecular cloud and the accretion disc is massive. The dynamical evolution of the disc in such environments is determined by the crucial role of self-gravity and gravitational instability. This study investigates the role of drag force in self-gravitating discs for the formation of planetesimals during early protoplanetary stages, finding that the stability threshold depends on the local dust-to-gas density ratio, dust relative temperature, and relevant Stokes number.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)