Recent high resolution images of spiral galaxies show wide varieties of features including nuclear spirals in the central parts. Some of the galaxies show grand-design nuclear spirals. The morphology of grand-design spirals can be further divided by the openness of the arms: tightly wound ones with winding angle of around 3π radian and open spirals with winding angle of around π radian. Based o...

While many observed ultra-luminous X-ray sources (ULXs, LX ≥ 1039 erg s−1) could be extragalactic X-ray binaries (XRBs) emitting close to the Eddington limit, the highest-luminosity ULXs (LX > 3× 1039 erg s−1) exceed the isotropic Eddington luminosity for even high-stellar-mass accreting black hole XRBs. It has been suggested that these highest-luminosity ULXs may contain accreting intermediate...

We study the properties of infrared-selected QSOs (IR QSOs), opticallyselected QSOs (PG QSOs) and Narrow Line Seyfert 1 galaxies (NLS1s). We compare their properties from the infrared to the optical and examine various correlations among the black hole mass, accretion rate, star formation rate and optical and infrared luminosities. We find that the infrared excess in IR QSOs is mostly in the fa...

Cooling flows in galaxy clusters and isolated elliptical galaxies are a source of mass for fueling accretion onto a central supermassive black hole. We calculate the dynamics of accreting matter in the combined gravitational potential of a host galaxy and a central black hole assuming a steady state, spherically symmetric flow (i.e., no angular momentum). The global dynamics depends primarily o...

The on-chip detection of a weak optical signal in biological experiments can easily be complicated by the presence of an overwhelming background signal, and as such, pre-detection background suppression is substantively important for weak signal detection. In this paper, we report a structure that can be directly incorporated onto optical sensors to accomplish background suppression prior to de...

I very briefly discuss the ages and kinematics of spheroids as well as the black hole relations, via a few recent and illustrative studies, which include results on the downsizing, scaling laws, angular momentum and central massive objects.

Asymptotic symmetry of the Euclidean 3D gravity with torsion is described by two independent Virasoro algebras with different central charges. Elements of this boundary conformal structure are combined with Cardy’s formula to calculate the black hole entropy.

Recent observations of Galactic Black Hole Candidates (BHCs) suggest that those that are superluminal jet sources have more rapid black hole spin rates than otherwise normal BHCs. This provides observational support for models of relativistic jet formation that extract rotational energy of the central black hole. To investigate this mechanism, we have developed a new general relativistic magnet...

We study the structure and properties of hot MHD accretion onto a Kerr black hole. In such a system, the hole is magnetically coupled to the inflowing gas and exerts a torque onto the accretion flow. A hot settling flow can form around the hole and transport the angular momentum outward, to the outer edge of the flow. Unlike other hot flows, such as advectionand convection-dominated flows and i...