Dongwei Fan
A5006156667- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Advanced Computational Techniques and Applications
- Distributed and Parallel Computing Systems
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Advanced Data Storage Technologies
- Adaptive optics and wavefront sensing
- Scientific Computing and Data Management
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Spectroscopy and Chemometric Analyses
- GNSS positioning and interference
- Scientific Research and Discoveries
- Metallurgy and Material Forming
- Cloud Computing and Resource Management
- Astrophysics and Star Formation Studies
- Impact of Light on Environment and Health
- Metal Forming Simulation Techniques
- Advanced Database Systems and Queries
- Calibration and Measurement Techniques
Tianjin University
2025
National Astronomical Observatories
2015-2024
Chinese Academy of Sciences
2015-2024
University of Chinese Academy of Sciences
2013-2023
ArcelorMittal (United States)
2019-2021
Johns Hopkins University
2013-2020
ArcelorMittal (Luxembourg)
2018
Beijing University of Technology
2015
Soochow University
2010
The Large sky Area Multi-Object Spectroscopic Telescope (LAMOST) General Survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra stars, galaxies QSOs. Objects both in pilot first year general are included LAMOST First Data Release (DR1). started October 2011 ended June 2012, data have been released to public as Pilot August 2012. September completed its operation 2013. DR1 includes total 1202 plates containing...
The Jiangmen Underground Neutrino Observatory (JUNO) is proposed to determine the neutrino mass hierarchy using an underground liquid scintillator detector. It located 53 km away from both Yangjiang and Taishan Nuclear Power Plants in Guangdong, China. experimental hall, spanning more than 50 meters, under a granite mountain of over 700 m overburden. Within six years running, detection reactor antineutrinos can resolve at confidence level 3-4$\sigma$, oscillation parameters...
The Beijing–Arizona Sky Survey (BASS) is a wide-field two-band photometric survey of the northern Galactic Cap using 90Prime imager on 2.3 m Bok telescope at Kitt Peak. It four-year collaboration between National Astronomical Observatory China and Steward Observatory, University Arizona, serving as one three imaging surveys to provide input catalogs for target selection Dark Energy Spectroscopic Instrument (DESI) project. BASS will take up 240 dark/gray nights cover an area about 5400 deg2...
We present new three-dimensional (3D) interstellar dust reddening maps of the Galactic plane in three colours, E(G-Ks), E(Bp-Rp) and E(H-Ks). The have a spatial angular resolution 6 arcmin covers over 7000 deg$^2$ for longitude 0 deg $<$ $l$ 360 latitude $|b|$ $10$ deg. are constructed from robust parallax estimates Gaia Data Release 2 (Gaia DR2) combined with high-quality optical photometry DR2 infrared 2MASS WISE surveys. estimate colour excesses, E(H-Ks), 56 million stars machine learning...
As a novel X-ray focusing technology, lobster eye micro-pore optics (MPO) feature both wide observing field of view and true imaging capability, promising sky monitoring with significantly improved sensitivity spatial resolution in soft X-rays. Since first proposed by Angel (1979), the have been extensively studied, developed trialed over past decades. In this Letter, we report on first-light results from flight experiment Lobster Eye Imager for Astronomy ($LEIA$), pathfinder wide-field...
The Lobster Eye Imager for Astronomy (LEIA), a pathfinder of the Wide-field X-ray Telescope Einstein Probe (EP) mission, was successfully launched onboard SATech-01 satellite Chinese Academy Sciences on 27 July 2022. In this paper, we introduce design and on-ground test results LEIA instrument. Using state-of-the-art Micro-Pore Optics (MPO), wide field-of-view (FoV) 346 square degrees (18.6 * 18.6 degrees) imager is realized. An optical assembly composed 36 MPO chips used to focus incident...
Abstract Astronomical knowledge entities, such as celestial object identifiers, are crucial for literature retrieval and graph construction, other research applications in the field of astronomy. Traditional methods extracting entities from texts face numerous challenging obstacles that difficult to overcome. Consequently, there is a pressing need improved efficiently extract them. This study explores potential pre-trained Large Language Models (LLMs) perform astronomical entity extraction...
Abstract This paper reports on the application of supervised machine-learning algorithm to stellar effective temperature regression for second Gaia data release, based combination stars in four spectroscopic surveys: Large Sky Area Multi-Object Fiber Spectroscopic Telescope, Sloan Extension Galactic Understanding and Exploration, Apache Point Observatory Evolution Experiment, Radial Velocity Extension. combination, about million stars, enables us construct one largest training samples...
We aim to select quasar candidates based on the two large survey databases, Pan-STARRS and AllWISE. Exploring distribution of quasars stars in color spaces, we find that combination infrared optical photometry is more conducive candidates. Two new criterions (yW1W2 izW1W2) are constructed distinguish from efficiently. With izW1W2, 98.30% star contamination eliminated, while 99.50% retained, at least magnitude limit our training set stars. Based features, put forward an efficient schema high...
With the development of medical imaging technology, magnetic resonance (MRI) has become an important tool for diagnosing and monitoring a variety diseases. However, traditional MRI techniques are limited in terms speed resolution. In this study, we developed efficient body mode metasurface composite enhancement system based on deep learning network training realized design control MHz band. Firstly, forward neural is used to predict electromagnetic response characteristics quickly. On basis,...
Abstract The identification of specific galaxy populations in large-scale spectroscopic surveys represents an essential yet challenging task, particularly for rare or anomalous galaxies that deviate from the typical distributions. Traditional methods based on template-fitting predefining spectral features face challenges addressing complexity and scale modern astronomical datasets. To overcome these limitations, we propose GalSpecEncoder-KB, a modular flexible framework combines deep...
Abstract We performed a statistical study of magnetic activities M-type stars by combining the spectra LAMOST DR5 with light curves from Kepler and K 2 missions. mainly want to relationship between chromospheric activity flares, their relations rotation period. have obtained maximum catalog 516,688 stellar 480,912 M calculated equivalent widths indicators (H α , H β γ δ Ca ii H&K, He i D3). Using indicator, 40,464 38,417 show activity, 1791 these 5499 repeated observations variability....
Abstract The Beijing–Arizona Sky Survey (BASS) is a wide and deep imaging survey that covers 5400 deg 2 area in the northern Galactic cap with 2.3 m Bok telescope using two filters ( g r bands). Mosaic z -band Legacy (MzLS) same band 4 Mayall telescope. These surveys will be used for spectroscopic targeting by Dark Energy Spectroscopic Instrument (DESI) northernmost portion of DESI footprint. This paper describes third data release (DR3) BASS, which contains photometric from all BASS MzLS...
The SCUSS is a deep $u$-band imaging survey in the south Galactic cap using 2.3m Bok telescope. observations were completed end of 2013, covering an area about 5000 square degrees. We release data region with 4000 deg$^2$ that mostly covered by Sloan digital sky survey. products contain calibrated single-epoch images, stacked photometric catalogs, and catalog star proper motions derived Peng et al, 2015. median seeing magnitude limit ($5\sigma$) are 2".0 23.2 mag, respectively. There 8...
Cross-matching catalogues at different wavelengths is a difficult problem in astronomy, especially when the objects are not point-like. At radio wavelengths, an object can have several components corresponding, for example, to core and lobes. Considering all detections correspond visible or infrared sources, matching these be challenging. Traditionally, this done by eye better quality, which does scale large data volumes expected from next-generation of telescopes. We present novel automated...
The Beijing-Arizona Sky Survey (BASS) Data Release 3 (DR3) catalogue was released in 2019, which contains the data from all BASS and Mosaic z-band Legacy (MzLS) observations during 2015 January 2019 March, about 200 million sources. We cross-match DR3 with spectral databases Sloan Digital (SDSS) Large Area Multi-object Fiber Spectroscopic Telescope (LAMOST) to obtain spectroscopic classes of known samples. Then, samples are cross-matched ALLWISE database. Based on optical infrared...
Correlating BASS DR3 catalogue with ALLWISE database, the data from optical and infrared information are obtained. The quasars SDSS taken as training test samples while those LAMOST considered external sample. We propose two schemes to construct redshift estimation models XGBoost, CatBoost Random forest. One scheme (namely one-step model) is predict photometric redshifts directly based on optimal created by these three algorithms; other two-step firstly classify into low- high- datasets,...
Abstract Based on previous site testing and satellite cloud data, Ali, Daocheng Muztagh-ata have been selected as candidate sites for the Large Optical/Infrared Telescope (LOT) in China. We present data collection, processing, management quality analysis our based using similar hardware. analyze meteorological seeing, background light, precipitable water vapor from 2017 March 10 to 2019 10. also investigated relative usefulness of all-sky camera comparison that TERRA a night-by-night...
Abstract LAMOST Data Release 5, covering ∼17 000 deg 2 from –10° to 80° in declination, contains 9 million co-added low-resolution spectra of celestial objects, each spectrum combined repeat exposure two tens times during Oct 2011 Jun 2017. In this paper, we present the individual exposures for all objects 5. For spectrum, equivalent width 60 lines 11 different elements are calculated with a new method combining actual line core and fitted wings. stars earlier than F type, Balmer both...
The accurate estimation of photometric redshifts plays a crucial role in accomplishing science objectives the large survey projects. template-fitting and machine learning are two main types methods applied currently. Based on training set obtained by cross-correlating DESI Legacy Imaging Surveys DR9 galaxy catalogue SDSS DR16 catalogue, kinds used optimized, such as EAZY for approach CATBOOST learning. Then created models tested cross-matched samples SurveysDR9 with LAMOST DR7, GAMA DR3...
The Beijing-Arizona Sky Survey (BASS) is a new wide-field legacy imaging survey in the northern Galactic cap using 2.3m Bok telescope. will cover about 5400 deg$^2$ $g$ and $r$ bands, expected 5$\sigma$ depths (corrected for extinction) two bands are 24.0 23.4 mag, respectively. BASS started observations January 2015, has completed 41% of whole area as July 2016. first data release contains both calibrated images photometric catalogs obtained 2015 single-epoch 22.9 full three epochs 24.1 23.5
ABSTRACT The precise estimation of the statistical errors and accurate removal systematical are two major challenges for stage IV cosmic shear surveys. We explore their impact China Space Station Telescope (CSST) with survey area ${\sim} 17\,500\deg ^2$ up to redshift ∼4. consider error contributed from Gaussian covariance, connected non-Gaussian super-sample covariance. find covariances, which is dominated by can largely reduce signal-to-noise ratio two-point statistics CSST, leading an...