Mouyuan Sun

The Chandra Deep Field-South Survey : 7 Ms Source Catalogs

We present X-ray source catalogs for the ≈7 Ms exposure of the Chandra Deep Field-South (CDF-S), which covers a total area of 484.2 arcmin2. Utilizing wavdetect for initial source detection and ACIS Extract for photometric extraction and significance assessment, we create a main source catalog containing 1008 sources that are detected in up to three X-ray bands: 0.5-7.0 keV, 0.5-2.0 keV, and 2-7 keV. A supplementary source catalog is also provided, including 47 lower-significance sources that have bright (Ks ≤ 23) near-infrared counterparts. We identify multiwavelength counterparts for 992 (98.4%) of the main-catalog sources, and we collect redshifts for 986 of these sources, including 653 spectroscopic redshifts and 333 photometric redshifts. Based on the X-ray and multiwavelength properties, we identify 711 active galactic nuclei (AGNs) from the main-catalog sources. Compared to the previous ≈4 Ms CDF-S catalogs, 291 of the main-catalog sources are new detections. We have achieved unprecedented X-ray sensitivity with average flux limits over the central ≈1 arcmin2 region of ≈1.9 ×10-17, 6.4 ×10-18, and 2.7 ×10-17 erg cm-2 s-1 in the three X-ray bands, respectively. We provide cumulative number-count measurements observing, for the first time, that normal galaxies start to dominate the X-ray source population at the faintest 0.5-2.0 keV flux levels. The highest X-ray source density reaches ≈50,500 deg-2, and 47% ± 4% of these sources are AGNs (≈23,900 deg-2). (Less)

The Sloan Digital Sky Survey reverberation mapping project : first broad-line Hβ and Mg II lags at z ≳ 0.3 from six-month spectroscopy

Support for the work of Y.S. was provided by NASA through Hubble Fellowship grant number HST-HF-51314, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. K.H. acknowledges support from UK Science and Technology Facilities Council (STFC) grant ST/M001296/1. C.J.G. and W.N.B. acknowledge support from NSF grant AST-1517113 and the V.M. Willaman Endowment. B.M.P. is grateful for support from the National Science Foundation through grant AST-1008882. K.D.D. is supported by an NSF AAPF fellowship awarded under NSF grant AST-1302093. J.R.T. acknowledges support from NASA through Hubble Fellowship grant HST-HF-51330 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA under contract NAS 5-26555. M.S. acknowledges support from the China Scholarship Council (No. [2013]3009). L.C.H. is supported by the Chinese Academy of Science through grant No. XDB09030102 (Emergence of Cosmological Structures) from the strategic Priority Research Program, and from the National Natural Science Foundation of China through grant No. 11473002. L.J. acknowledges the support from a 985 project at Peking University. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science.

Evolution in the Black Hole–galaxy Scaling Relations and the Duty Cycle of Nuclear Activity in Star-forming Galaxies

We measure the location and evolutionary vectors of 69 Herschel-detected broad-line active galactic nuclei (BLAGNs) in the M_BH-M_* plane. BLAGNs are selected from the COSMOS and CDF-S fields, and span the redshift range 0.2 1).

GRAVITATIONAL WAVES OF JET PRECESSION IN GAMMA-RAY BURSTS

The physical nature of gamma-ray bursts (GRBs) is believed to involve an ultra-relativistic jet. The observed complex structure of light curves motivates the idea of jet precession. In this work, we study the gravitational waves of jet precession based on neutrino-dominated accretion disks around black holes, which may account for the central engine of GRBs. In our model, the jet and the inner part of the disk may precess along with the black hole, which is driven by the outer part of the disk. Gravitational waves are therefore expected to be significant from this black-hole-inner-disk precession system. By comparing our numerical results with the sensitivity of some detectors, we find that it is possible for DECIGO and BBO to detect such gravitational waves, particularly for GRBs in the Local Group.

The Sloan Digital Sky Survey Reverberation Mapping Project: Post-Starburst Signatures in Quasar Host Galaxies at z < 1

Quasar host galaxies are key for understanding the relation between galaxies and the supermassive black holes (SMBHs) at their centers. We present a study of 191 broad-line quasars and their host galaxies at z < 1, using high signal-to-noise ratio (SNR) spectra produced by the Sloan Digital Sky Survey Reverberation Mapping project. Clear detection of stellar absorption lines allows a reliable decomposition of the observed spectra into nuclear and host components, using spectral models of quasar and stellar radiations as well as emission lines from the interstellar medium. We estimate age, mass (M*), and velocity dispersion (sigma*) of the host stars, the star formation rate (SFR), quasar luminosity, and SMBH mass (Mbh), for each object. The quasars are preferentially hosted by massive galaxies with M* ~ 10^{11} Msun characterized by stellar ages around a billion years, which coincides with the transition phase of normal galaxies from the blue cloud to the red sequence. The host galaxies have relatively low SFRs and fall below the main sequence of star-forming galaxies at similar redshifts. These facts suggest that the hosts have experienced an episode of major star formation sometime in the past billion years, which was subsequently quenched or suppressed. The derived Mbh - sigma* and Mbh - M* relations agree with our past measurements and are consistent with no evolution from the local Universe. The present analysis demonstrates that reliable measurements of stellar properties of quasar host galaxies are possible with high-SNR fiber spectra, which will be acquired in large numbers with future powerful instruments such as the Subaru Prime Focus Spectrograph.

Long-Term X-ray Variability of Typical Active Galactic Nuclei in the Distant Universe

We perform long-term (

Time Evolution of Flares in GRB 130925A: Jet Precession in a Black Hole Accretion System

\approx 15

Black hole growth is mainly linked to host-galaxy stellar mass rather than star formation rate.

yr, observed-frame) X-ray variability analyses of the 68 brightest radio-quiet active galactic nuclei (AGNs) in the 6 Ms

THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: ENSEMBLE SPECTROSCOPIC VARIABILITY OF QUASAR BROAD EMISSION LINES

Chandra

THICK ACCRETION DISK MODEL FOR ULTRALUMINOUS SUPERSOFT SOURCES

Deep Field-South (CDF-S) survey; the majority are in the redshift range of