相关论文: More evidence for extinction of activity in galaxi…

There are several lines of evidence that active galactic nuclei (AGN) can be regarded as scaled-up X-ray binaries (XRB). The timescales of the evolutionary phenomena in these two classes are proportional to the black hole (BH) masses.…

X-ray binaries are composed of a normal star in orbit around a neutron star or stellar-mass black hole. Radio and X-ray observations have led to the presumption that some X-ray binaries called microquasars behave as scaled down active…

Galaxy formation is significantly modulated by energy output from supermassive black holes at the centers of galaxies which grow in highly efficient luminous quasar phases. The timescale on which black holes transition into and out of such…

In this third of a series of papers concerning active galaxies in the FIRST and Sloan Digital Sky Surveys, we analyze the spectroscopic and radio properties of a sample of narrow-line Active Galactic Nuclei (AGN), broad-line Seyfert I…

Typical blazars seem to be associated with FR I and FR II radio galaxies and radio-loud quasars. However, what happens at lower powers? Do blazars exist in low-luminosity AGN or do they exist in radio-quiet AGN? A recent detection of…

We report the detection in Chandra ACIS archival data of an elongated soft (<3 keV) X-ray feature tp the south of the Compton Thick Active Galactic Nucleus (CT AGN) galaxy IC 2497, coincident with the emission feature known as Hanny's…

We have performed a search over 3440 deg$^2$ of Epoch 1 (2017-2019) of the Very Large Array Sky Survey to identify unobscured quasars in the optical ($0.2 < z < 3.2$) and obscured active galactic nuclei (AGN) in the infrared that have…

Although radio-quiet quasars (RQQs), which constitute the majority of optically-identified quasar samples, are by no means radio silent the properties of their radio emission are only poorly understood. We present the results of a…

There is considerable evidence that powerful radio quasars and radio galaxies are orientation-dependent manifestations of the same parent population: massive spheroids containing correspondingly massive black holes. Following the…

We combine Chandra and XMM-Newton X-ray data from our previous papers with new X-ray observations and with Spitzer mid-infrared data in order to study the nature of the nuclei of radio galaxies and radio-loud quasars with z<1.0 from the…

We present a brief overview of a very extensive studies of the group of active galactic nuclei (AGNs) that transitioned to radio-loud state over the past few decades. The sample consists of twelve sources, both quasars and galaxies, showing…

We present high- and intermediate resolution radio observations of the central region in the spiral galaxy IC 2497, performed using the European VLBI Network (EVN) at 18 cm, and the Multi-Element Radio Linked Interferometer Network (MERLIN)…

To constrain the origin of the soft X-ray excess phenomenon seen in many active galactic nuclei, the intensity-correlated spectral analysis, developed by Noda et al. (2011b) for Markarian 509, was applied to wide-band (0.5-45 keV) Suzaku…

Recent work on the engines of active galactic nuclei jets suggests their power depends strongly and perhaps counter-intuitively on black hole spin. We explore the consequences of this on the radio-loud population of active galactic nuclei…

Active galactic nuclei and quasars are thought to be scaled up versions of Galactic black hole binaries, powered by accretion onto supermassive black holes with masses of 10^6-10^9 M_Sun, as opposed to the ~10 M_Sun in binaries. One example…

We present high and intermediate resolution radio observations of the central region in the spiral galaxy IC 2497, performed using the European VLBI Network (EVN) at 18 cm, and the Multi-Element Radio Linked Interferometer Network (MERLIN)…

Over the past few years, we have been collecting data with the Nordic Optical Telescope (NOT) on the galaxy environments around active galactic nuclei (AGN). Here we present some results from a sample of 21 radio-loud and 20 radio-quiet…

The recent development of unified theories of active galactic nuclei (AGN) has indicated that there are two physically distinct classes of these objects - radio-loud and radio-quiet. The primary observational distinctions between the two…

Radio observations allow us to identify a wide range of active galactic nuclei (AGN), which play a significant role in the evolution of galaxies. Amongst AGN at low radio-luminosities is the 'radio-quiet' quasar (RQQ) population, but how…

Properties of galaxies depend on their large-scale environment. As the influence of active galactic nuclei (AGN) in galaxy evolution is becoming more evident, their large scale environments may help us understand the evolutionary processes…