Xiaohui Fan
A5025532100- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Cosmology and Gravitation Theories
- Iron and Steelmaking Processes
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Scientific Research and Discoveries
- Mineral Processing and Grinding
- Recycling and utilization of industrial and municipal waste in materials production
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- CCD and CMOS Imaging Sensors
- Concrete and Cement Materials Research
- Relativity and Gravitational Theory
- Black Holes and Theoretical Physics
- Metal Extraction and Bioleaching
- Mining and Gasification Technologies
- Metallurgical Processes and Thermodynamics
- Thermochemical Biomass Conversion Processes
University of Arizona
2016-2025
Zhejiang University of Technology
2024-2025
Central South University
2015-2024
Astronomy and Space
2006-2021
Tsinghua University
2018-2021
Tianjin Municipal Engineering Design and Research Institute
2020
Max Planck Institute for Astronomy
2009-2019
U.S. National Science Foundation
2004-2019
Max Planck Society
2019
Peking University
2015-2018
The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of distribution luminous and nonluminous matter in universe: a photometrically astrometrically calibrated digital imaging survey π sr above about Galactic latitude 30° five broad optical bands depth g' ∼ 23 mag, spectroscopic approximately 106 brightest galaxies 105 quasars found photometric object catalog produced by survey. This paper summarizes observational parameters products SDSS serves as an...
This paper describes the Seventh Data Release of Sloan Digital Sky Survey (SDSS), marking completion original goals SDSS and end phase known as SDSS-II. It includes 11,663 deg2 imaging data, with most ∼2000 increment over previous data release lying in regions low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. survey also repeat on a 120° long, 25 wide stripe along celestial equator Southern Cap, some covered by many 90 individual runs. We...
The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere collect spectra ≈106 galaxies, 100,000 quasars, 30,000 stars, serendipity targets. In 2001 June, SDSS released to general astronomical community its early data release, roughly 462 deg2 including almost 14 million detected objects 54,008 follow-up spectra. were collected in drift-scan mode five bandpasses (u, g, r, i, z); our 95% completeness...
Building on the legacy of Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program four spectroscopic surveys three scientific themes: dark energy cosmological parameters, history structure Milky Way, population giant planets around other stars. In keeping with SDSS tradition, will provide regular public releases all its data, beginning Data Release 8 (DR8), which was made in 2011 January includes SDSS-I SDSS-II images spectra reprocessed latest pipelines calibrations produced for...
We have created a variety of composite quasar spectra using homogeneous data set over 2200 from the Sloan Digital Sky Survey (SDSS). The sample spans redshift range 0.044 ≤ z 4.789 and an absolute r' magnitude -18.0 to -26.5. input cover observed wavelength 3800–9200 Å at resolution 1800. median covers rest-wavelength 800 8555 reaches peak signal-to-noise ratio 300 per 1 element in rest frame. identified 80 emission-line features spectrum. Emission-line shifts relative nominal laboratory...
The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using original SDSS wide-field imager, and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution novel interferometer. All SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all acquired through 2013 July, 12 (DR12) adding July (including included in previous releases), marking end observing. Relative our public...
We present a new compilation of Type Ia supernovae (SNe Ia), dataset low-redshift nearby-Hubble-flow SNe and analysis procedures to work with these heterogeneous compilations. This ``Union'' 414 SN Ia, which reduces 307 after selection cuts, includes the recent large samples from Supernova Legacy Survey ESSENCE Survey, older datasets, as well recently extended distant observed HST. A single, consistent blind procedure is used for all various subsamples, implemented that consistently weights...
Abstract We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands Milky Way stars at high resolution and signal-to-noise ratios in near-infrared. Mapping Nearby Galaxies (MaNGA) survey obtaining spatially resolved spectroscopy for nearby galaxies (median <?CDATA $z\sim 0.03$?> ). extended Baryon Oscillation Spectroscopic (eBOSS)...
ABSTRACT The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from Baryon Oscillation Spectroscopic (BOSS). This ninth release (DR9) of SDSS project includes 535,995 new galaxy spectra (median z ∼ 0.52), 102,100 quasar 2.32), and 90,897 stellar spectra, along with presented in previous releases. These were obtained BOSS spectrograph taken between 2009 December 2011 July. In addition, parameters pipeline, which determines radial velocities, surface temperatures,...
The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with instrumentation and surveys focused on Galactic structure chemical evolution, measurements of the baryon oscillation feature clustering galaxies quasar Ly alpha forest, radial velocity search for planets around ~8000 stars. This paper describes first data release SDSS-III (and eighth counting from beginning SDSS). includes five-band imaging roughly 5200 deg^2 Southern Cap, bringing total footprint SDSS to 14,555...
The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in clustering matter over a larger volume than combined efforts all previous spectroscopic surveys large-scale structure. BOSS uses 1.5 million luminous galaxies as faint i = 19.9 10,000 deg2 BAO redshifts z < 0.7. Observations neutral hydrogen Lyα forest more 150,000 quasar spectra (g 22) will constrain redshift range 2.15 3.5. Early results from include first detection...
We study the evolution of ionization state IGM at end reionization epoch using spectra a sample nineteen quasars 5.745.7: optical depth changes from tau ~ (1+z)^{4.3} to (1+z)^{>11}, and average length dark gaps with tau>3.5 increases <10 >80 comoving Mpc. The dispersion properties along different lines sight also rapidly, implying fluctuations by factor >4 in UV background z>6, when mean free path photons is comparable correlation galaxies. shows most dramatic increase...
Abstract The DESI Legacy Imaging Surveys ( http://legacysurvey.org/ ) are a combination of three public projects (the Dark Energy Camera Survey, the Beijing–Arizona Sky and Mayall z -band Survey) that will jointly image ≈14,000 deg 2 extragalactic sky visible from northern hemisphere in optical bands g , r using telescopes at Kitt Peak National Observatory Cerro Tololo Inter-American Observatory. combined survey footprint is split into two contiguous areas by Galactic plane. imaging...
This paper describes the Sixth Data Release of Sloan Digital Sky Survey. With this data release, imaging northern Galactic cap is now complete. The survey contains images and parameters roughly 287 million objects over 9583 deg2, including scans a large range latitudes longitudes. also includes 1.27 spectra stars, galaxies, quasars, blank sky (for subtraction) selected 7425 deg2. release much more stellar spectroscopy than was available in previous releases detailed estimates temperatures,...
A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of exciting science opportunities next decade. The Large Synoptic Survey Telescope (LSST) have an effective aperture 6.7 meters and imaging camera field view 9.6 deg^2, be devoted ten-year 20,000 deg^2 south +15 deg. Each pointing imaged 2000 times fifteen second exposures six broad from 0.35 1.1 microns, total point-source depth r~27.5. LSST Science Book describes basic...
We present an analysis of the mid-infrared (MIR) and optical properties type 1 (broad-line) quasars detected by Spitzer Space Telescope. The MIR color-redshift relation is characterized to z ~ 3, with predictions = 7. demonstrate how combining colors can yield even more efficient selection active galactic nuclei (AGNs) than or alone. Composite spectral energy distributions (SEDs) are constructed for 259 both Sloan Digital Sky Survey photometry, supplemented near-IR, GALEX, VLA, ROSAT data,...
The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its Second Data Release. This data release consists of 3324 deg2 five-band (ugriz) imaging with photometry for over 88 million unique objects, 367,360 spectra galaxies, quasars, stars, calibrating blank sky patches selected 2627 this area, tables measured parameters from these data. reach a depth r ≈ 22.2 (95% completeness limit point sources) are photometrically astrometrically calibrated to 2% rms 100 mas per...
This paper describes the Fourth Data Release of Sloan Digital Sky Survey (SDSS), including all survey-quality data taken through 2004 June. The release includes five-band photometric for 180 million objects selected over 6670 deg2 and 673,280 spectra galaxies, quasars, stars from 4783 those imaging using standard SDSS target selection algorithms. These numbers represent a roughly 27% increment Third Release; previous releases are included in present release. also an additional 131,840...
We describe the algorithm for selecting quasar candidates optical spectroscopy in Sloan Digital Sky Survey. Quasar are selected via their non-stellar colors "ugriz" broad-band photometry, and by matching unresolved sources to FIRST radio catalogs. The automated is sensitive quasars at all redshifts lower than z=5.8. Extended also targeted as low-redshift order investigate evolution of Active Galactic Nuclei (AGN) faint end luminosity function. Nearly 95% previously known recovered (based on...
We present the fifth edition of Sloan Digital Sky Survey (SDSS) Quasar Catalog, which is based upon SDSS Seventh Data Release. The catalog, contains 105,783 spectroscopically confirmed quasars, represents conclusion SDSS-I and SDSS-II quasar survey. catalog consists objects that have luminosities larger than M_i = -22.0 (in a cosmology with H_0 70 km/s/Mpc Omega_M 0.3, Omega_Lambda 0.7) at least one emission line FWHM 1000 km/s or interesting/complex absorption features, are fainter i > 15.0...
The Sloan Digital Sky Survey has validated and made publicly available its First Data Release. This consists of 2099 square degrees five-band (u, g, r, i, z) imaging data, 186,240 spectra galaxies, quasars, stars calibrating blank sky patches selected over 1360 this area, tables measured parameters from these data. data go to a depth r ~ 22.6 are photometrically astrometrically calibrated 2% rms 100 milli-arcsec per coordinate, respectively. cover the range 3800--9200 A, with resolution...
We present the results from a survey of i-dropout objects selected ∼1550 deg2 multicolor imaging data Sloan Digital Sky Survey to search for luminous quasars at z ≳ 5.8. Objects with i*-z* > 2.2 and z* < 20.2 are selected, follow-up J-band photometry is used separate L- T-type cool dwarfs high-redshift quasars. describe discovery three new quasars, SDSSp J083643.85+005453.3 (z = 5.82), J130608.26+035626.3 5.99), J103027.10+052455.0 6.28). The quasar radio source flux 1.1 mJy 20 cm. spectra...
We present moderate-resolution Keck spectroscopy of quasars at z = 5.82, 5.99, and 6.28, discovered by the Sloan Digital Sky Survey (SDSS). find that Lyα absorption in spectra these evolves strongly with redshift. To ∼ 5.7, as expected from an extrapolation lower redshifts. However, highest-redshift object, SDSSp J103027.10+052455.0 (z 6.28), average transmitted flux is 0.0038 ± 0.0026 times continuum level over 8450 Å < λ 8710 (5.95 zabs 6.16), consistent zero flux. Thus drops a factor...