A5042278685- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Computational Physics and Python Applications
- Statistical and numerical algorithms
- Astrophysics and Star Formation Studies
- Landslides and related hazards
- Image and Object Detection Techniques
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Spectroscopy and Chemometric Analyses
- Remote Sensing in Agriculture
- Advanced Statistical Methods and Models
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
Tsinghua University
2022-2024
Abstract We present a study of the mass–metallicity relation (MZR) 51 dwarf galaxies ( M ⋆ ≈ 10 6.5 –10 9.5 ⊙ ) at z = 2–3 from A2744 and SMACS J0723-3732 galaxy cluster fields. These are identified confirmed by deep JWST/NIRISS imaging slitless grism spectroscopic observations. By taking advantage superior performance JWST gravitational lensing effect, we extend previous MZR to much lower-mass regime down ≈2.5 orders magnitude as compared with studies. find that has shallower slope low-mass...
Abstract We have updated and applied a convolutional neural network (CNN) machine-learning model to discover characterize damped Ly α systems (DLAs) based on Dark Energy Spectroscopic Instrument (DESI) mock spectra. optimized the training process constructed CNN that yields DLA classification accuracy above 99% for spectra signal-to-noise ratios (S/N) 5 per pixel. The is rate of correct classifications. This remains 97% lower S/N ≈1 provides estimations redshift H i column density with...
Abstract The mean free path of ionizing photons in the intergalactic medium (IGM; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mi>λ</mml:mi> </mml:mrow> <mml:mi mathvariant="normal">mfp</mml:mi> <mml:mn>912</mml:mn> </mml:msubsup> </mml:math> ) is a crucial quantity modeling ionization state IGM and extragalactic ultraviolet background, it widely used hydrodynamical simulations galaxies reionization. We construct largest quasar...
The current generation of large galaxy surveys will test the cosmological model by combining multiple types observational probes. Realising statistical promise these new datasets requires rigorous attention to all aspects analysis including measurements, modelling, covariance and parameter likelihood. In this paper we present results an end-to-end simulation study designed pipeline for combination Dark Energy Spectroscopic Instrument (DESI) Year 1 redshift dataset separate weak gravitational...
Abstract Since their first discovery, quasars have been essential probes of the distant Universe. However, due to our limited knowledge its nature, predicting intrinsic quasar continua has bottlenecked usage. Existing methods continuum recovery often rely on a number high-quality spectra, which might not capture full diversity population. In this study, we propose an unsupervised probabilistic model, factor analysis (QFA), combines with physical priors intergalactic medium overcome these...
Abstract We present the first result in exploring gaseous halo and galaxy correlation using Dark Energy Spectroscopic Instrument survey validation data Cosmic Evolution Survey (COSMOS) Hyper Suprime-Cam field. obtain multiphase properties circumgalactic medium by 115 quasar spectra (signal-to-noise ratio > 3). detect Mg ii absorption at redshift 0.6 < z 2.5, C iv 1.6 3.6, H i associated with . By crossmatching COSMOS2020 catalog, we identify host galaxies 10 fields 0.9< 3.1. find...
We present a study of the mass-metallicity relation (MZR) 51 dwarf galaxies ($M_\star\approx 10^{6.5} - 10^{9.5}~M_\odot$) at $z = 2-3$ from Abell 2744 and SMACS J0723-3732 galaxy cluster fields. These are identified confirmed by deep JWST/NIRISS imaging slitless grism spectroscopic observations. By taking advantage superior performance JWST gravitational lensing effect, we extend previous MZR $z=2-3$ to much lower mass regime down $\approx$ 2.5 orders magnitude as compared with studies....
Modeling quasar spectra is a fundamental task in astrophysics as quasars are the tell-tale sign of cosmic evolution. We introduce novel unsupervised learning algorithm, Quasar Factor Analysis (QFA), for recovering intrinsic continua from noisy spectra. QFA assumes that Ly$\alpha$ forest can be approximated Gaussian process, and continuum well described latent factor model. show learn, through directly spectra, simultaneously. Compared to previous methods, achieves state-of-the-art...