A5022017895- Adaptive optics and wavefront sensing
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Impact of Light on Environment and Health
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Plant Water Relations and Carbon Dynamics
- Atmospheric aerosols and clouds
- Relativity and Gravitational Theory
- Distributed and Parallel Computing Systems
- Infrared Target Detection Methodologies
- Cryospheric studies and observations
- Polar Research and Ecology
- CCD and CMOS Imaging Sensors
- Advanced Data Storage Technologies
- Optical Systems and Laser Technology
- Optical Wireless Communication Technologies
- Advanced optical system design
Chinese Academy of Sciences
1999-2023
National Astronomical Observatories
2012-2023
Tianjin Normal University
2013-2022
Chinese Arctic and Antarctic Administration
2010-2018
Purple Mountain Observatory
1996-2017
UNSW Sydney
2008-2014
Polar Research Institute of China
2014
Nanjing Institute of Astronomical Optics & Technology
2014
Texas A&M University
2014
University of Wyoming
2005-2013
Bolometric corrections are used in quasar studies to quantify total energy output based on a measurement of monochromatic luminosity. First, we enumerate and discuss the practical difficulties determining such corrections, then present bolometric luminosities between 1 \mu m 8 keV rest frame derived from detailed spectral distributions 63 bright quasars low moderate redshift (z = 0.03-1.4). Exploring several mathematical fittings, provide forms L_iso=\zeta \lambda L_{\lambda} log(L_iso)=A+B...
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in new era multi-messenger astronomy. In this paper, we present event GW170817 and its SSS17a/DLT17ck (IAU label AT2017gfo) 14 Australian telescopes partner observatories as part Australian-based Australian-led research programs. We report early- late-time multi-wavelength observations, including optical imaging spectroscopy,...
We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating work Elvis et al. (1994) by using high-quality data obtained with several space and ground-based telescopes, including NASA's Great Observatories. present an atlas SEDs 85 optically bright, non-blazar quasars over electromagnetic spectrum from radio to X-rays. The heterogeneous sample includes 27 radio-quiet 58 radio-loud quasars. Most objects quasi-simultaneous ultraviolet-optical...
We investigate the ultraviolet-to-optical spectral energy distributions of 17 active galactic nuclei (AGNs) using quasi-simultaneous spectrophotometry spanning 900-9000 Å (rest frame). employ data from Far Ultraviolet Spectroscopic Explorer, Hubble Space Telescope, and 2.1 m telescope at Kitt Peak National Observatory. Taking advantage short-wavelength coverage, we are able to study so-called big blue bump, region in which output peaks, detail. Most objects exhibit a break around 1100 Å....
We have investigated a sample of 5088 quasars from the SDSS DR2 in order to determine how frequency and properties BALs depend on black hole mass, bolometric luminosity, Eddington fraction (L/LEdd), spectral slope. focus only high-ionization find number significant results. While accreting near limit are more likely show than lower L/LEdd systems, present at few percent Eddington. stronger effect with such that most luminous BALs. There is an additional effect, previously known, BAL redder...
The edge-on, nearby spiral galaxy NGC 5907 has long been used as the prototype of a "noninteracting" warped galaxy. We report here discovery two interactions with companion dwarf galaxies that substantially change this picture. First, faint ring structure is discovered around likely due to tidal disruption spheroidal elliptical in shape center close one ring's foci. This suggests material orbit 5907. No gaseous component detected either deep Hα images or Very Large Array H I 21 cm line maps....
Intrigued by the initial report of an extended luminosity distribution perpendicular to disk edge-on Sc galaxy NGC 5907, we have obtained very deep exposures this with a Schmidt telescope, large-format CCD, and intermediate-band filters centered at 6660 Å 8020 Å. These two filters, part 15-filter set, are custom designed avoid brightest (and most variable) night skylines. As result, our images able go deeper lower sky noise than those taken broadband similar effective wavelengths: e.g., 0.6...
The domes, or local elevation maxima, on the Antarctic plateau provide a unique opportunity for ground-based astronomy in that turbulent boundary layer is so thin telescope small tower can be free atmosphere, i.e., portion of atmosphere which turbulence decoupled from effect Earth's surface. There, it enjoy itself appears to offer superior conditions temperate sites. This breaks problem characterizing at sites into two separate tasks: determining variability, distribution and thickness...
Abstract The SiTian project, designed to utilize 60 telescopes distributed across multiple sites in China, is a next-generation time-domain survey initiative. As pathfinder of the mini (MST) has been proposed and implemented test brain, data pipeline, evaluate feasibility its technology science cases. Mounted at Xinglong Observatory, MST project comprised three 30 cm operated since Nov. 2022. Each telescope possesses large field view, covering 2.29° × 1.53° FOV, mounted g', r', i' filters,...
Abstract The mini-SiTian Array serves as a pathfinder for the SiTian project, which aims to survey entire sky in $gri$ bands every 30 minutes, reaching limiting magnitude of 21. This special issue features 11 papers covering design, operation, data reduction, and early scientific results from two years Mini-SiTian observations. insights gained these experiments represent significant milestone toward full realization project.
Two sets of relationships relate QSO UV to soft X-ray continua with the broad-line region. These are (i) Baldwin relationships, which inverse between equivalent width and continuum luminosity, (ii) Boroson & Green's optical "Principal Component 1" linking steeper spectra narrower Hβ emission, stronger blue wings, Fe II weaker [O III] λ5007 lines. In order understand these we extended into for 22 QSOs high-quality spectra. from complete sample Bright Quasar Survey Laor et al. demonstrated...
In order to investigate the dependence of quasar variability on fundamental physical parameters like black hole mass, we have matched quasars from Quasar Equatorial Survey Team, Phase 1 (QUEST1) survey with broad-lined objects Sloan Digital Sky Survey. The sample contains ≈100 quasars, and spectra are used estimate masses bolometric luminosities. Variability amplitudes measured QUEST1 light curves. We find that mass correlates several measures amplitude at 99 per cent significance level or...
We have obtained quasi-simultaneous ultraviolet-optical spectra for 22 out of 23 quasars in the complete Palomar-Green X-ray sample with redshift z < 0.4 and MB -23. The cover rest-frame wavelengths from at least Lyα to Hα. Here we provide a detailed description data, including careful spectrophotometry determination. also present direct measurements continua, strong emission lines, features, Lyα, Si IV+O IV] λ1400, C IV, III], Mg II, Hβ, [O He I λ5876+Na λλ5890,5896, Hα, blended iron UV...
Currently, the ability to produce black hole mass estimates using CIV 1549 line that are consistent with Hb is uncertain, due in large part disagreement between velocity width measurements for two lines. This discrepancy and arises from fact both profiles treated same way single-epoch scaling relationships based on assumption broad-line region virialized, even though a non-virialized emission component often significant absent or weak line. Using quasi-simultaneous optical ultra-violet...
SiTian is an ambitious ground-based all-sky optical monitoring project, developed by the Chinese Academy of Sciences. The concept integrated network dozens 1-m-class telescopes deployed partly in China and at various other sites around world. main science goals are detection, identification transients (such as gravitational wave events, fast radio bursts, supernovae) on largely unknown timescales less than 1 day; will also provide a treasure trove data for studies AGN, quasars, variable...
We have performed a spectral principal component analysis (SPCA) for an essentially complete sample of 22 low-redshift QSOs with data from Lyα to Hα. SPCA yields set independent spectra, each which represents relationships among QSO continuum and line properties. find three significant components, account ~78% the total intrinsic variance. The first component, carrying ~41% variance, Baldwin relationships: anticorrelations between equivalent widths broad emission lines luminosity....
In this paper we present a multicolor photometric study of the nearby spiral galaxy M81, using images obtained with Beijing Astronomical Observatory 60/90 cm Schmidt telescope in 13 intermediate-band filters from 3800 to 10000 Å. The observations cover whole area total integration 51 hr 1995 1997 February. This provides map M81 pixels 17 × 17. Using theoretical stellar population synthesis models, demonstrate that some BATC (Beijing-Arizona-Taiwan-Connecticut Multicolor Sky Survey) colors...
We present a deep, 42.79 hr image of the nearby, edge-on galaxy NGC 4565 in Beijing-Arizona-Taipei-Connecticut 6660 Å band using large-format CCD system on 0.6 m Schmidt telescope at Xinglong Station National Astronomical Observatories China. Following procedures previously developed by our team for analysis deep images galaxies, we obtain final that is calibrated to an accuracy 0.02 mag zero point and which can measure surface brightness 0.25 27.5 arcsec-2 Å, corresponding distance 22 kpc...
The PLATeau Observatory (PLATO) is an automated self-powered astrophysical observatory that was deployed to Dome A, the highest point on Antarctic plateau, in 2008 January. PLATO consists of a suite site-testing instruments designed quantify benefits A site for astronomy, and science take advantage unique observing conditions. Instruments include CSTAR, array optical telescopes transient astronomy; Gattini, instrument measure sky brightness cloud cover statistics; DASLE, experiment...
ABSTRACT The i -band observing conditions at Dome A on the Antarctic plateau have been investigated using data acquired during 2008 with Chinese Small Telescope Array. sky brightness, variations in atmospheric transparency, cloud cover, and presence of aurorae are obtained from these images. median brightness moonless clear nights is 20.5 mag arcsec −2 SDSS band south celestial pole (which includes a contribution about 0.06 diffuse Galactic light). over all Moon phases winter 19.8 . There...
We present infrared bolometric luminosity corrections derived from the detailed spectral energy distributions of 62 bright quasars low- to moderate-redshift (z=0.03-1.4). At 1.5, 2, 3, 7, 12, 15, and 24 microns we provide mathematical forms L_iso=\zeta \lambda L_\lambda log(L_iso)=A+B log(\lambda L_\lambda). Bolometric for radio-loud radio-quiet objects are consistent within 95% confidence intervals, so do not separate them. luminosities estimated using these typically smaller than those...