相关论文: Nuclear/Circumnuclear Starbursts and Active Galact…
It is now widely believed that the growth of massive black holes is closely linked to the formation of galaxies, but there have been few concrete constraints on the actual physical processes responsible for this coupling. Investigating the…
It was once common to regard Seyfert and starburst galaxies as completely different types of object, but there is growing recognition that these classifications refer to the extremes of a continuous spectrum of galaxy types. In a previous…
The existence of correlations between nuclear properties of galaxies, such as the mass of their central black holes, and larger scale features, like the bulge mass and luminosity, represent a fundamental constraint on galaxy evolution.…
The emission line luminosity function of active galactic nuclei (AGN) is measured from about 3000 AGN included in the main galaxy sample of the Sloan Digital Sky Survey within a redshift range of $0<z<0.15$. The $\Ha$ and [OIII]$\lambda…
Observations of the Seyfert 2 and starburst galaxy NGC 5135 with the Chandra X-ray Observatory demonstrate that both of these phenomena contribute significantly to its X-ray emission. We spatially isolate the active galactic nucleus (AGN)…
We present NGC 6221 as a case study of ``X-ray loud composite galaxies,'' which appear similar to starbursts at optical wavelengths and resemble traditional active galactic nuclei in X-rays. The net optical spectrum of NGC 6221 is properly…
The role of stars and starbursts in AGN has been a recurring issue for nearly as long as AGN have been recognized as hosts of interesting phenomena. The heated ``starburst X monster'' controversy of the 80's and 90's was gradually replaced…
Feedback from black hole activity is widely believed to play a key role in regulating star formation and black hole growth. A long-standing issue is the relation between the star formation and fueling the supermassive black holes in active…
A significant number of active galactic nuclei (AGNs) are observed to be hidden behind dust and gas. The distribution of material around AGNs plays an important role in modeling the cosmic X-ray background (CXB), especially the fraction of…
We have mapped the central region of NGC 4945 in the $J=2\to1$ transition of $^{12}$CO, $^{13}$CO, and C$^{18}$O, as well as the continuum at 1.3 mm, at an angular resolution of $5\farc \times 3\farc$ with the Submillimeter Array. The…
We present the results of X-ray imaging and spectroscopic analysis of a sample of Seyfert 2 galaxies that contain starbursts, based on their optical and UV characteristics. These composite galaxies exhibit extended, soft, thermal X-ray…
I discuss some recent observational results in the research of nearby active galactic nuclei (AGN). These results cover three main topics: (i) evidences for the current paradigm for AGN's, which include a nuclear supermassive blackhole…
We analyze an X-ray flux-limited, complete sample of 93 AGN at z< 0.1, selected from the ROSAT Bright Survey. Two thirds of the sample are Seyfert 1 galaxies (Sy1) and one third are Narrow-Line Seyfert 1 galaxies (NLSy1). We have obtained…
The central regions of galaxies harbouring active galactic nuclei (AGNs) can be quite complex, especially at high activity, presenting, besides variability, a variety of phenomena related, e.g. to ionization/excitation mechanisms. A…
The optical-ultraviolet continuum from active galactic nuclei (AGN) seem to originate from optically thick and/or thin disks, and occasionally from associated circumnuclear starburst regions. These different possible origins can, in…
Far-infrared flux densities are newly extracted from the IRAS database for the RSA and CfA complete samples of Seyfert galaxies. These data are used to classify the Seyfert galaxies into those where the far-infrared continuum emission is…
Galaxy interactions are studied in terms of the starburst-Seyfert connection. The starburst requires a high rate of gas supply. Since the efficiency for supplying the gas is high in a galaxy interaction, although the companion is not…
We present a follow-up study on a series of papers concerning the role of close interactions as a possible triggering mechanism of AGN activity. We have already studied the close (<100kpc/h) and the large scale (<1 Mpc/h) environment of a…
We investigate the relationship between the present day optical luminosity function of galaxies and the X-ray luminosity function of Seyfert 1s to determine the fraction of galaxies which host Seyfert 1 nuclei and their Eddington ratios.…
We present results from a study of the dense circum-nuclear molecular gas of starburst galaxies. The study aims to investigate the interplay between starbursts, active galactic nuclei and molecular gas. We characterise the dense gas traced…