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Related papers: QUEST (Quasar Unsupervised Encoder and Synthesis T…

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The wide survey of the Chinese Space Station Telescope (CSST) will observe a large field of 17,500 $\text{deg}^2$. The GU, GV, and GI grism observations of CSST will cover a wavelength range from 2550 to 10000\r{A} at a resolution of $R\sim…

Astrophysics of Galaxies · Physics 2025-01-23 Yuxuan Pang , Xue-Bing Wu , Yuming Fu , Rui Zhu , Bing Lyu , Huimei Wang , Xiaotong Feng

As spectroscopic surveys continue to grow in size, the problem of classifying spectra targeted as quasars (QSOs) will need to move beyond its historical reliance on human experts. Instead, automatic classifiers will increasingly become the…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-09 James Farr , Andreu Font-Ribera , Andrew Pontzen

The identification of physically associated kiloparsec-scale quasar pairs is important for understanding galaxy evolution, the growth of supermassive black holes, and their co-evolution with host galaxies. However, their rarity and the high…

Astrophysics of Galaxies · Physics 2026-05-12 Xingyu Zhu , Qihang Chen , Liang Jing , Zhuojun Deng , Jun-Qing Xia , Yanxia Zhang , Jianghua Wu

There has been tremendous progress in the physical realization of quantum computing hardware in recent times, bringing us closer than ever before to realizing the promise of quantum computing. However, noise continues to pose a crucial…

Quasars can be used to measure baryon acoustic oscillations at high redshift, which are considered as direct tracers of the most distant large-scale structures in the Universe. It is fundamental to select quasars from observations before…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 Zizhao He , Nan Li

Multiple color selection techniques have been successful in identifying quasars from wide-field broad-band imaging survey data. Among the quasars that have been discovered so far, however, there is a redshift gap at $5 \lesssim {\rm z}…

Astrophysics of Galaxies · Physics 2017-01-18 Yiseul Jeon , Myungshin Im , Soojong Pak , Minhee Hyun , Sanghyuk Kim , Yongjung Kim , Hye-In Lee , Woojin Park

Supermassive black hole formation remains an unsolved problem. Quasi-stars have been suggested as a viable heavy-seeding mechanism. In this work, we implement methods for modeling quasi-stars previously used with the Cambridge STARS code…

High Energy Astrophysical Phenomena · Physics 2025-07-18 Claire B. Campbell , Andrew D. Santarelli , Matthew E. Caplan

Quasars experiencing strong lensing offer unique viewpoints on subjects related to the cosmic expansion rate, the dark matter profile within the foreground deflectors, and the quasar host galaxies. Unfortunately, identifying them in…

We present a list of quasar candidates including photometric redshift estimates from the miniJPAS Data Release constructed using SQUEzE. This work is based on machine-learning classification of photometric data of quasar candidates using…

The field of Astronomy requires the collection and assimilation of vast volumes of data. The data handling and processing problem has become severe as the sheer volume of data produced by scientific instruments each night grows…

Machine Learning · Computer Science 2020-10-05 Aniruddh Herle , Janamejaya Channegowda , Dinakar Prabhu

We present SQUEzE, a software package to classify quasar spectra and estimate their redshifts. SQUEzE is a random forest classifier operating on the parameters of candidate emission peaks identified in the spectra. We test the performance…

Astrophysics of Galaxies · Physics 2020-07-01 Ignasi Pérez-Ràfols , Matthew M. Pieri , Michael Blomqvist , Sean Morrison , Debopam Som

We describe the algorithm for selecting quasar candidates for optical spectroscopy in the Sloan Digital Sky Survey. Quasar candidates are selected via their non-stellar colors in "ugriz" broad-band photometry, and by matching unresolved…

Quasar photometric redshifts are essential for studying cosmology and large-scale structures. However, their complex spectral energy distributions cause significant redshift-color degeneracy, limiting the accuracy of traditional methods. To…

Astrophysics of Galaxies · Physics 2025-12-19 Jianzhen Chen , Zhijian Luo , Liping Fu , Zhu Chen , Hubing Xiao , Shaohua Zhang , Chenggang Shu

Studies of the most luminous quasars at high redshift directly probe the evolution of the most massive black holes in the early Universe and their connection to massive galaxy formation. However, extremely luminous quasars at high redshift…

Astrophysics of Galaxies · Physics 2017-12-20 Jan-Torge Schindler , Xiaohui Fan , Ian. D. McGreer , Qian Yang , Jin Wu , Linhua Jiang , Richard Green

Enhanced modeling of microlensing variations in light curves of strongly lensed quasars improves measurements of cosmological time delays, the Hubble Constant, and quasar structure. Traditional methods for modeling extra-galactic…

Instrumentation and Methods for Astrophysics · Physics 2025-01-03 Somayeh Khakpash , Federica Bianco , Georgios Vernardos , Gregory Dobler , Charles Keeton

Quantum architecture search (QAS) represents a fundamental challenge in quantum machine learning. Unlike previous methods that treat it as a static search process, from a perspective on QAS as an item retrieval task in vast search space, we…

Quantum Physics · Physics 2024-11-12 Lian-Hui Yu , Xiao-Yu Li , Geng Chen , Qin-Sheng Zhu , Hui Li , Guo-Wu Yang

Three-dimensional wide-field galaxy surveys are fundamental for cosmological studies. For higher redshifts (z > 1.0), where galaxies are too faint, quasars still trace the large-scale structure of the Universe. Since available telescope…

Instrumentation and Methods for Astrophysics · Physics 2022-09-21 Sándor Kunsági-Máté , Róbert Beck , István Szapudi , István Csabai

Machine learning techniques, specifically the k-nearest neighbour algorithm applied to optical band colours, have had some success in predicting photometric redshifts of quasi-stellar objects (QSOs): Although the mean of differences between…

Instrumentation and Methods for Astrophysics · Physics 2020-01-29 S. J. Curran

Resolving transient atomic configurations in non-crystalline or dynamic environments remains a fundamental bottleneck in the physical sciences. While X-ray absorption spectroscopy (XAS) is a premier probe of local structure, inverting…

Materials Science · Physics 2026-03-31 Suyang Zhong , Boying Huang , Pengwei Xu , Fanjie Xu , Yuhao Zhao , Jun Cheng , Fujie Tang , Weinan E , Zhong-Qun Tian