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Related papers: Identifying Galaxy Mergers in Observations and Sim…

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Dark matter (DM) halos form hierarchically in the Universe through a series of merger events. Cosmological simulations can represent this series of mergers as a graph-like ``tree'' structure. Previous work has shown these merger trees are…

Image segmentation aims to partition an image according to the objects in the scene and is a fundamental step in analysing very high spatial-resolution (VHR) remote sensing imagery. Current methods struggle to effectively consider land…

Computer Vision and Pattern Recognition · Computer Science 2024-01-08 Xianwei Lv , Claudio Persello , Wangbin Li , Xiao Huang , Dongping Ming , Alfred Stein

Detecting post-merger features of merger remnants is highly dependent on the depth of observation images. However, it has been poorly discussed how long the post-merger features are visible under different observational conditions. We…

Astrophysics of Galaxies · Physics 2014-07-02 Inchan Ji , Sebastien Peirani , Sukyoung K. Yi

In recent years, continuous latent space (CLS) and discrete latent space (DLS) deep learning models have been proposed for medical image analysis for improved performance. However, these models encounter distinct challenges. CLS models…

Computer Vision and Pattern Recognition · Computer Science 2023-10-30 Vandan Gorade , Sparsh Mittal , Debesh Jha , Ulas Bagci

Studies of cosmology, galaxy evolution, and astronomical transients with current and next-generation wide-field imaging surveys like the Rubin Observatory Legacy Survey of Space and Time (LSST) are all critically dependent on estimates of…

Instrumentation and Methods for Astrophysics · Physics 2022-08-24 Biprateep Dey , Brett H. Andrews , Jeffrey A. Newman , Yao-Yuan Mao , Markus Michael Rau , Rongpu Zhou

Optical spectra of galaxies and quasars from large cosmological surveys are used to measure redshifts and infer distances. They are also rich with information on the intrinsic properties of these astronomical objects. However, their…

Based on the DUSTGRAIN-pathfinder suite of simulations, we investigate observational degeneracies between nine models of modified gravity and massive neutrinos. Three types of machine learning techniques are tested for their ability to…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 Julian Merten , Carlo Giocoli , Marco Baldi , Massimo Meneghetti , Austin Peel , Florian Lalande , Jean-Luc Starck , Valeria Pettorino

The formation of Hoag-type galaxies with central spheroidal galaxies and outer stellar rings has yet to be understood in astronomy. We consider that these unique objects were formed from the past interaction between elliptical galaxies and…

Instrumentation and Methods for Astrophysics · Physics 2019-04-08 Eleanor Leung , Kenji Bekki , Lyndon While

Galaxies and clusters embedded in the large-scale structure of the Universe are observed to align in preferential directions. Galaxy alignment has been established as a potential probe for cosmological information, but the application of…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-02 Casper J. G. Vedder , Nora Elisa Chisari

Symmetry is a key feature observed in nature (from flowers and leaves, to butterflies and birds) and in human-made objects (from paintings and sculptures, to manufactured objects and architectural design). Rotational, translational, and…

Computer Vision and Pattern Recognition · Computer Science 2019-08-28 Felice De Luca , Md Iqbal Hossain , Stephen Kobourov

Current observational and simulated large-scale structure (LSS) catalogues often lack consistency in assigning galaxies to specific structures, due to the absence of a universally accepted classification criterion. With the aim to generate…

We demonstrate the ability of convolutional neural networks (CNNs) to mitigate systematics in the virial scaling relation and produce dynamical mass estimates of galaxy clusters with remarkably low bias and scatter. We present two models,…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-23 Matthew Ho , Markus Michael Rau , Michelle Ntampaka , Arya Farahi , Hy Trac , Barnabas Poczos

Galaxy-scale strong lenses in galaxy clusters provide a unique tool to investigate their inner mass distribution and the sub-halo density profiles in the low-mass regime, which can be compared with the predictions from cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 G. Angora , P. Rosati , M. Meneghetti , M. Brescia , A. Mercurio , C. Grillo , P. Bergamini , A. Acebron , G. Caminha , M. Nonino , L. Tortorelli , L. Bazzanini , E. Vanzella

Mergers play a complex role in galaxy formation and evolution. Continuing to improve our understanding of these systems require ever larger samples, which can be difficult (even impossible) to select from individual surveys. We use the new…

We explore the effectiveness of deep learning convolutional neural networks (CNNs) for estimating strong gravitational lens mass model parameters. We have investigated a number of practicalities faced when modelling real image data, such as…

Instrumentation and Methods for Astrophysics · Physics 2019-07-24 James Pearson , Nan Li , Simon Dye

We estimate the evolution of the galaxy-galaxy merger fraction for $M_\star>10^{10.5}M_\odot$ galaxies over $0.25<z<1$ in the $\sim$18.6 deg$^2$ deep CLAUDS+HSC-SSP surveys. We do this by training a Random Forest Classifier to identify…

Astrophysics of Galaxies · Physics 2021-06-09 Nathalie Thibert , Marcin Sawicki , Andy Goulding , Stephane Arnouts , Jean Coupon , Stephen Gwyn

The taxonomy of galaxy morphology is critical in astrophysics as the morphological properties are powerful tracers of galaxy evolution. With the upcoming Large-scale Imaging Surveys, billions of galaxy images challenge astronomers to…

Astrophysics of Galaxies · Physics 2022-05-04 Zhirui Zhang , Zhiqiang Zou , Nan Li , Yanli Chen

The amount and complexity of data delivered by modern galaxy surveys has been steadily increasing over the past years. Extracting coherent scientific information from these large and multi-modal data sets remains an open issue and data…

Instrumentation and Methods for Astrophysics · Physics 2023-01-18 Marc Huertas-Company , François Lanusse

Galaxy-scale strong gravitational lensing is not only a valuable probe of the dark matter distribution of massive galaxies, but can also provide valuable cosmological constraints, either by studying the population of strong lenses or by…

Instrumentation and Methods for Astrophysics · Physics 2017-12-06 Francois Lanusse , Quanbin Ma , Nan Li , Thomas E. Collett , Chun-Liang Li , Siamak Ravanbakhsh , Rachel Mandelbaum , Barnabas Poczos

We present predictions for the galaxy-galaxy lensing profile from the EAGLE hydrodynamical cosmological simulation at redshift z=0.18, in the spatial range 0.02 < R/(Mpc/h) < 2, and for five logarithmically equi-spaced stellar mass bins in…