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Applying artificial intelligence to scientific problems (namely AI for science) is currently under hot debate. However, the scientific problems differ much from the conventional ones with images, texts, and etc., where new challenges…

机器学习 · 统计学 2022-08-09 Xiao-Han Wang , Pei Shi , Bin Xi , Jie Hu , Shi-Ju Ran

Convolutional neural networks (CNN) have emerged as a powerful tool for solving computational imaging reconstruction problems. However, CNNs are generally difficult-to-understand black-boxes. Accordingly, it is challenging to know when they…

图像与视频处理 · 电气工程与系统科学 2021-04-21 Ruangrawee Kitichotkul , Christopher A. Metzler , Frank Ong , Gordon Wetzstein

Cosmic reionization progresses as HII regions form around sources of ionizing radiation. Their average size grows continuously until they percolate and complete reionization. We demonstrate how this typical growth can be calculated around…

天体物理学 · 物理学 2009-11-13 Marcelo A. Alvarez , Tom Abel

We have developed a convolutional neural network (CNN) to reconstruct the shape of irregular rough particles from their interferometric images. The CNN is based on a UNET architecture with residual block modules. The database has been…

计算机视觉与模式识别 · 计算机科学 2024-08-08 Alexis Abad , Alexandre Poux , Alexis Boulet , Marc Brunel

We have run a new suite of simulations that solve hydrodynamics and radiative transfer simultaneously to study helium II reionization. Our suite of simulations employs various models for populating quasars inside of dark matter halos, which…

宇宙学与河外天体物理 · 物理学 2017-10-11 Paul La Plante , Hy Trac , Rupert Croft , Renyue Cen

Using a unified analytic model for quasars, galaxies, Lyman-alpha absorbers and the IGM, we obtain the redshift evolution of the temperature and the entropy of the gas and the corresponding cluster temperature - X-ray luminosity relation.…

天体物理学 · 物理学 2007-05-23 P. Valageas , J. Silk

We investigate the possibility of constraining the ionization state of the intergalactic medium (IGM) close to the end of reionization (z ~ 6) by measuring the size of the HII regions in high-z quasars spectra. We perform a combination of…

天体物理学 · 物理学 2008-11-26 A. Maselli , S. Gallerani , A. Ferrara , T. R. Choudhury

Active Galactic Nuclei (AGN) and star-forming galaxies are leading candidates for being the luminous sources that reionized our Universe. Next-generation 21cm surveys are promising to break degeneracies between a broad range of reionization…

宇宙学与河外天体物理 · 物理学 2018-12-20 Sultan Hassan , Adrian Liu , Saul Kohn , Paul La Plante

The Ice-sheet and Sea-level System Model (ISSM) provides numerical solutions for ice sheet dynamics using finite element and fine mesh adaption. However, considering ISSM is compatible only with central processing units (CPUs), it has…

机器学习 · 计算机科学 2025-01-15 Maryam Rahnemoonfar , Younghyun Koo

We investigate and demonstrate the use of convolutional neural networks (CNNs) for the task of distinguishing between merging and non-merging galaxies in simulated images, and for the first time at high redshifts (i.e. $z=2$). We extract…

星系天体物理 · 物理学 2020-04-28 A. Ćiprijanović , G. F. Snyder , B. Nord , J. E. G. Peek

The process of obtaining high-resolution images from single or multiple low-resolution images of the same scene is of great interest for real-world image and signal processing applications. This study is about exploring the potential usage…

计算机视觉与模式识别 · 计算机科学 2022-09-22 David O'Callaghan , Cian Ryan , Waseem Shariff , Muhammad Ali Farooq , Joseph Lemley , Peter Corcoran

The temperature of the low-density intergalactic medium is set by the balance between adiabatic cooling resulting from the expansion of the universe, and photo-heating by the UV-background. We have analysed the Lyman-alpha forest of eleven…

天体物理学 · 物理学 2009-11-07 Tom Theuns , Saleem Zaroubi , Tae-Sun Kim , Panayiotis Tzanavaris , Robert F. Carswell

Near-surface air temperature is a key physical property of the Earth's surface. Although weather stations offer continuous monitoring and satellites provide broad spatial coverage, no single data source offers seamless data in a…

计算机视觉与模式识别 · 计算机科学 2025-09-17 Shengjie Kris Liu , Siqin Wang , Lu Zhang

The hyperfine transition of $^3$He$^+$ at 3.5cm has been thought as a probe of the high-z IGM since it offers a unique insight into the evolution of the helium component of the gas, as well as potentially give an independent constraint on…

宇宙学与河外天体物理 · 物理学 2020-07-15 Shivan Khullar , Qingbo Ma , Philipp Busch , Benedetta Ciardi , Marius B. Eide , Koki Kakiichi

We aim to determine the most effective approach for estimating uncertainties in quasar photo-$z$ and to evaluate the ability of different models to reconstruct the true redshift distribution under varying data quality. We use photometric…

宇宙学与河外天体物理 · 物理学 2026-03-23 Kacper Drabicki , Szymon J. Nakoneczny , Maciej Bilicki

Studying the cosmological sources at their cosmological rest-frames is crucial to track the cosmic history and properties of compact objects. In view of the increasing data volume of existing and upcoming telescopes/detectors, we here…

高能天体物理现象 · 物理学 2022-01-11 F. Rastegar Nia , M. T. Mirtorabi , R. Moradi , A. Vafaei. Sadr , Y. Wang

We present a neural-network emulator for the thermal and chemical evolution in Population III star formation. The emulator accurately reproduces the thermochemical evolution over a wide density range spanning 21 orders of magnitude…

星系天体物理 · 物理学 2026-05-18 Sojun Ono , Kazuyuki Sugimura

We determine the thermal evolution of the intergalactic medium (IGM) over $3\, \mathrm{Gyr}$ of cosmic time $1.8<z<5.4$ by comparing measurements of the Ly{\alpha} forest power spectrum to a suite of $\sim70$ hydrodynamical simulations. We…

宇宙学与河外天体物理 · 物理学 2019-02-13 Michael Walther , Jose Oñorbe , Joseph F. Hennawi , Zarija Lukić

We present a study of the impact of a bright quasar on the redshifted 21cm signal during the Epoch of Reionization (EoR). Using three different cosmological radiative transfer simulations, we investigate if quasars are capable of…

宇宙学与河外天体物理 · 物理学 2015-06-04 Kanan K. Datta , Martina M. Friedrich , Garrelt Mellema , Ilian T. Iliev , Paul R. Shapiro