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Generative adversarial networks (GANs) learn a latent space whose samples can be mapped to real-world images. Such latent spaces are difficult to interpret. Some earlier supervised methods aim to create an interpretable latent space or…

Computer Vision and Pattern Recognition · Computer Science 2025-07-03 Mohammad Hassan Vali , Tom Bäckström

We assemble the largest CIV absorption line catalogue to date, leveraging machine learning, specifically Gaussian processes, to remove the need for visual inspection for detecting CIV absorbers. The catalogue contains probabilities…

Astrophysics of Galaxies · Physics 2023-09-26 Reza Monadi , Ming-Feng Ho , Kathy L. Cooksey , Simeon Bird

A new generation of sensitive X-ray measurements are indicating that the existence of X-ray attenuation column densities, $N_{H}>10^{24}\mathrm{cm}^{-2}$ is quite common amongst broad absorption line quasars (BALQSOs). This is significant…

Astrophysics · Physics 2007-05-23 Brian Punsly , Sebastian Lipari

We present preliminary results from an investigation into broad absorption line (BAL) variability within a sample of 41 radio-loud quasars (RLQs). Using 28 new Hobby-Eberly Telescope (HET) spectra along with earlier Sloan Digital Sky Survey…

High Energy Astrophysical Phenomena · Physics 2012-01-13 B. P. Miller , C. A. Welling , W. N. Brandt , R. R. Gibson

Optimization of high-dimensional black-box functions is an extremely challenging problem. While Bayesian optimization has emerged as a popular approach for optimizing black-box functions, its applicability has been limited to…

Machine Learning · Statistics 2018-08-06 Zi Wang , Chengtao Li , Stefanie Jegelka , Pushmeet Kohli

Bayesian quadrature (BQ) is a sample-efficient probabilistic numerical method to solve integrals of expensive-to-evaluate black-box functions, yet so far,active BQ learning schemes focus merely on the integrand itself as information source,…

Machine Learning · Computer Science 2021-02-15 Alexandra Gessner , Javier Gonzalez , Maren Mahsereci

We report the discovery of five broad-absorption-line (BAL) QSOs in a complete sample of 111 ultraviolet excess (UVX) QSO candidates also detected in the NRAO VLA Sky Survey. All five BAL QSOs, which include two high-ionization BAL QSOs and…

Variational quantum algorithms (VQAs) are widely speculated to deliver quantum advantages for practical problems under the quantum-classical hybrid computational paradigm in the near term. Both theoretical and practical developments of VQAs…

Quantum Physics · Physics 2021-12-17 Shi-Xin Zhang , Chang-Yu Hsieh , Shengyu Zhang , Hong Yao

Broad absorption line (BAL) quasars are often considered X-ray weak relative to their optical/UV luminosity, whether intrinsically (i.e., the coronal emission is fainter) or due to large column densities of absorbing material. The SDSS-V is…

Variational Quantum Algorithms (VQAs) have emerged as promising methods for tackling complex problems on near-term quantum devices. Among these algorithms, the Variational Quantum Linear Solver (VQLS) addresses linear systems of the form…

Quantum Physics · Physics 2024-09-11 Gloria Turati , Alessia Marruzzo , Maurizio Ferrari Dacrema , Paolo Cremonesi

There is evidence from radio-loud quasars to suggest that the distribution of the H$\beta$ broad emission line (BEL) gas is arranged in a predominantly planar orientation, and this result may well also apply to radio-quiet quasars. This…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Brian Punsly , Shaohua Zhang

Sparse Bayesian Learning (SBL) constructs an extremely sparse probabilistic model with very competitive generalization. However, SBL needs to invert a big covariance matrix with complexity $O(M^3)$ (M: feature size) for updating the…

Machine Learning · Computer Science 2023-09-12 Jiahua Luo , Chi-Man Wong , Chi-Man Vong

Quasar absorption line analysis is critical for studying gas and dust components and their physical and chemical properties as well as the evolution and formation of galaxies in the early universe. Ca II absorbers, which are one of the…

Astrophysics of Galaxies · Physics 2022-10-18 Iona Xia , Jian Ge , Kevin Willis , Yinan Zhao

We investigate C IV broad absorption line (BAL) variability within a sample of 46 radio-loud quasars (RLQs), selected from SDSS/FIRST data to include both core-dominated (39) and lobe-dominated (7) objects. The sample consists primarily of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 C. A. Welling , B. P. Miller , W. N. Brandt , D. M. Capellupo , R. R. Gibson

A new broad absorption line quasar (BAL) sample is derived from the first data released by the Sloan Digital Sky Survey. With 116 objects, it is the largest BAL sample yet assembled. Over the redshift range 1.8 < z < 3.8, the crude fraction…

Astrophysics · Physics 2009-11-07 Alin Tolea , Julian H. Krolik , Zlatan Tsvetanov

Neural network-based algorithms have garnered considerable attention in condensed matter physics for their ability to learn complex patterns from very high dimensional data sets towards classifying complex long-range patterns of…

Quantum Physics · Physics 2021-01-01 Ian MacCormack , Conor Delaney , Alexey Galda , Nidhi Aggarwal , Prineha Narang

Super-resolution fluorescence microscopy, with a resolution beyond the diffraction limit of light, has become an indispensable tool to directly visualize biological structures in living cells at a nanometer-scale resolution. Despite…

Computer Vision and Pattern Recognition · Computer Science 2018-09-05 Yu Li , Fan Xu , Fa Zhang , Pingyong Xu , Mingshu Zhang , Ming Fan , Lihua Li , Xin Gao , Renmin Han

This paper discusses the detection of P V 1118,1128 and other broad absorption lines (BALs) in archival HST spectra of the low-redshift BALQSO, PG 1254+047. The P V identification is secured by excellent redshift and profile coincidences…

Astrophysics · Physics 2014-10-13 Fred Hamann

Motivated by the problem of effectively executing clustering algorithms on very large data sets, we address a model for large scale distributed clustering methods. To this end, we briefly recall some standards on the quantization problem…

Statistics Theory · Mathematics 2011-11-30 Benoît Patra

Lensed quasars are key to many areas of study in astronomy, offering a unique probe into the intermediate and far universe. However, finding lensed quasars has proved difficult despite significant efforts from large collaborations. These…