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200 篇论文

SDSS J2222+2745, at z = 0.489, is one of the few currently known lens clusters with multiple images of a background (z = 2.801) quasar with measured time delays. We combine imaging from the Hubble Space Telescope (HST) with recent Multi…

Accurate and reliable energy time series prediction is of great significance for power generation planning and allocation. At present, deep learning time series prediction has become the mainstream method. However, the multi-scale time…

机器学习 · 计算机科学 2025-08-08 Wei Li , Zixin Wang , Qizheng Sun , Qixiang Gao , Fenglei Yang

The observable time delays between the multiple images of strong lensing systems with time variable sources can provide us with some valuable information to probe the expansion history of the Universe. Estimation of these time delays can be…

宇宙学与河外天体物理 · 物理学 2015-06-15 Amir Aghamousa , Arman Shafieloo

Strong gravitational lensing of time variable sources such as quasars and supernovae creates observable time delays between the multiple images. Time delays can provide a powerful cosmographic probe through the "time delay distance"…

宇宙学与河外天体物理 · 物理学 2013-06-18 Alireza Hojjati , Alex G. Kim , Eric V. Linder

Time-delay cosmography can be used to infer the Hubble parameter $H_0$ by measuring the relative time delays between multiple images of gravitationally-lensed quasars. A few of such systems have already been used to measure $H_0$: their…

天体物理仪器与方法 · 物理学 2022-08-03 L. Biggio , A. Domi , S. Tosi , G. Vernardos , D. Ricci , L. Paganin , G. Bracco

The spatial resolution of astronomical images is limited by atmospheric turbulence and diffraction in the telescope optics, resulting in blurred images. This makes it difficult to accurately measure the brightness of blended objects because…

天体物理仪器与方法 · 物理学 2023-05-31 Kevin Michalewicz , Martin Millon , Frédéric Dux , Frédéric Courbin

Astrometric calibration of images with a small field of view is often inferior to the internal accuracy of the source detections due to the small number of accessible guide stars. One important experiment with such challenges is the Hubble…

天体物理仪器与方法 · 物理学 2019-11-06 Fan Tian , Tamás Budavári , Amitabh Basu , Stephen H. Lubow , Richard L. White

Strongly lensed quasars can be used to constrain cosmological parameters through time-delay cosmography. Models of the lens masses are a necessary component of this analysis. To enable time-delay cosmography from a sample of…

A degeneracy in strong lens model is shown analytically. The observed time delays and quasar image positions might {\it not} uniquely determine the concentration and the extent of the lens galaxy halo mass distribution. Simply hardwiring…

天体物理学 · 物理学 2009-11-07 HongSheng Zhao , Bo Qin

Strong gravitational lensing and microlensing of supernovae (SNe) are emerging as a new probe of cosmology and astrophysics in recent years. We provide an overview of this nascent research field, starting with a summary of the first…

宇宙学与河外天体物理 · 物理学 2024-07-12 Sherry H. Suyu , Ariel Goobar , Thomas Collett , Anupreeta More , Giorgos Vernardos

We present a determination of the Hubble constant from the joint, free-form analysis of 8 strongly, quadruply lensing systems. In the concordance cosmology, we find $H_0 = 71.8^{+3.9}_{-3.3}\,\mathrm{km}\,\mathrm{s}^{-1}\,\mathrm{Mpc}^{-1}$…

宇宙学与河外天体物理 · 物理学 2021-02-22 Philipp Denzel , Jonathan P. Coles , Prasenjit Saha , Liliya L. R. Williams

Quantifying the parameters and corresponding uncertainties of hundreds of strongly lensed quasar systems holds the key to resolving one of the most important scientific questions: the Hubble constant ($H_{0}$) tension. The commonly used…

宇宙学与河外天体物理 · 物理学 2022-10-11 Kuan-Wei Huang , Geoff Chih-Fan Chen , Po-Wen Chang , Sheng-Chieh Lin , Chia-Jung Hsu , Vishal Thengane , Joshua Yao-Yu Lin

Challenges inherent to high-resolution and high signal-to-noise data as well as model degeneracies can cause systematic biases in analyses of strong lens systems. In the past decade, the number of lens modeling methods has significantly…

宇宙学与河外天体物理 · 物理学 2024-12-10 A. Galan , G. Vernardos , Q. Minor , D. Sluse , L. Van de Vyvere , M. Gomer

Realizing Refsdal's original idea from 1964, we present estimates of the Hubble constant that are complementary to and potentially competitive with those of other cosmological probes. We use the observed positions of 89 multiple images,…

宇宙学与河外天体物理 · 物理学 2018-06-27 C. Grillo , P. Rosati , S. H. Suyu , I. Balestra , G. B. Caminha , A. Halkola , P. L. Kelly , M. Lombardi , A. Mercurio , S. A. Rodney , T. Treu

Weak gravitational lensing is one of the most powerful tools for cosmology, while subject to challenges in quantifying subtle systematic biases. The Point Spread Function (PSF) can cause biases in weak lensing shear inference when the PSF…

天体物理仪器与方法 · 物理学 2021-12-13 Tianqing Zhang , Rachel Mandelbaum , The LSST Dark Energy Science Collaboration

The time delay measured between the images of gravitationally lensed quasars probes a combination of the angular diameter distance to the source-lens system and the mass density profile of the lens. Observational campaigns to measure such…

宇宙学与河外天体物理 · 物理学 2020-04-22 Kfir Blum , Emanuele Castorina , Marko Simonović

Time-delay cosmography leverages strongly lensed quasars to measure the Universe's current expansion rate, H_0, independently from other methods. While the latest TDCOSMO results relied mainly on quadruply lensed quasars, doubly lensed…

This work presents AstroPT, an autoregressive pretrained transformer developed with astronomical use-cases in mind. The AstroPT models presented here have been pretrained on 8.6 million $512 \times 512$ pixel $grz$-band galaxy postage stamp…

天体物理仪器与方法 · 物理学 2024-05-27 Michael J. Smith , Ryan J. Roberts , Eirini Angeloudi , Marc Huertas-Company

Time-series forecasting has gained significant attention in machine learning due to its crucial role in various domains. However, most existing forecasting models rely heavily on point-wise loss functions like Mean Square Error, which treat…

机器学习 · 计算机科学 2025-07-16 Dilfira Kudrat , Zongxia Xie , Yanru Sun , Tianyu Jia , Qinghua Hu

We introduce the STAR-MELT Python package that we developed to facilitate the analysis of time-resolved emission line spectroscopy of young stellar objects. STAR-MELT automatically extracts, identifies and fits emission lines. We summarise…