C. T. Yan

Large-scale sidereal anisotropy of Galactic cosmic-ray intensity observed by the Tibet air shower array

We present the large-scale sidereal anisotropy of Galactic cosmic-ray intensity in the multi-TeV region observed with the Tibet-III air shower array during the period from 1999 through 2003. The sidereal daily variation of cosmic rays observed in this experiment shows an excess of relative intensity around 4-7 hr local sidereal time as well as a deficit around 12 hr local sidereal time. While the amplitude of the excess is not significant when averaged over all declinations, the excess in individual declination bands becomes larger and clearer as the viewing direction moves toward the south. The maximum phase of the excess intensity changes from ~7 hr at the Northern Hemisphere to ~4 hr at the equatorial region. We also show that both the amplitude and the phase of the first harmonic vector of the daily variation are remarkably independent of primary energy in the multi-TeV region. This is the first result determining the energy and declination dependences of the full 24 hr profiles of the sidereal daily variation in the multi-TeV region with a single air shower experiment.

Episodic random accretion and the cosmological evolution of supermassive black hole spins

The growth of supermassive black holes (BHs) located at the centers of their host galaxies comes mainly from accretion of gas, but how to fuel them remains an outstanding unsolved problem in quasar evolution. This issue can be elucidated by quantifying the radiative efficiency parameter (

A Northern Sky Survey for Steady Tera-Electron Volt Gamma-Ray Point Sources Using the Tibet Air Shower Array

\eta

On temporal variations of the multi-tev cosmic ray anisotropy using the tibet iii air shower array

) as a function of redshift, which also provides constraints on the average spin of the BHs and its possible evolution with time. We derive a formalism to link

THE STARBURST-ACTIVE GALACTIC NUCLEUS CONNECTION: THE ROLE OF YOUNG STELLAR POPULATIONS IN FUELING SUPERMASSIVE BLACK HOLES

\eta

Observation by an air-shower array in tibet of the multi-tev cosmic-ray anisotropy due to terrestrial orbital motion around the sun

with the luminosity density, BH mass density, and duty cycle of quasars, quantities we can estimate from existing quasar and galaxy survey data. We find that

A Probable Milli-parsec Supermassive Binary Black Hole in the Nearest Quasar Mrk 231

\eta

Observation of TeV gamma rays from the fermi bright galactic sources with the tibet air shower array

has a strong cosmological evolution: at z~2,

STAR FORMATION IN SELF-GRAVITATING DISKS IN ACTIVE GALACTIC NUCLEI. I. METALLICITY GRADIENTS IN BROAD-LINE REGIONS

\eta \approx 0.3

Suppressed star formation in circumnuclear regions in seyfert galaxies

, and by