Related papers: Multiple Emission States in Active Galactic Nuclei
One percent of redshift z~0.1 Active Galactic Nuclei (AGNs) show velocity splitting of a few hundred km/s in the narrow emission lines in spatially integrated spectra. Such line profiles have been found to arise from the bulk motion of…
Under the unified model for active galactic nuclei (AGNs), narrow-line (Type 2) AGNs are, in fact, broad-line (Type 1) AGNs but each with a heavily obscured accretion disk. We would therefore expect the optical continuum emission from Type…
In a series of papers based on the FIRST and Sloan Digital Sky Surveys (SDSS), we investigate the local population of star-forming galaxies and Active Galactic Nuclei (AGN) in order to clarify the link between these two types of activity,…
Active Galactic Nuclei (AGN) are highly energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, which present unique observational signatures covering the full electromagnetic spectrum (and more) over…
We predict the observational signatures of galaxy scale outflows powered by active galactic nuclei (AGN). Most of the emission is produced by the forward shock driven into the ambient interstellar medium (ISM) rather than by the reverse…
Active Galactic Nuclei (AGN) are ideal sources for multi-wavelength studies as their emission can cover almost 20 orders of magnitude in frequency from the radio to the gamma-ray band. After reviewing their basic properties, I will assess…
We consider the emission of high energy to very high energy $\gamma$-rays in radio-quiet active galactic nuclei (AGN) or the central regions of radio-loud AGN. We use our results to estimate the $\gamma$-ray flux from the central regions of…
There has been a growing body of evidence to suggest that AGN activity, which is powered by mass accretion on to a supermasive black hole, could be episodic, although the range of time scales involved needs to be explored further. The…
We present ongoing work on the spectral energy distributions (SEDs) of active galactic nuclei (AGNs), derived from X-ray, ultraviolet, optical, infrared and radio photometry and spectroscopy. Our work is motivated by new wide-field imaging…
Continuum and emission-line variability of active galactic nuclei provides a powerful probe of microarcsecond scale structures in the central regions of these sources. In this contribution, we review basic concepts and methodologies used in…
To investigate the effect of feedback from active galactic nuclei (AGN) on their surrounding medium, we study the diffuse X-ray emission from galaxy groups and clusters by coupling the Astrophysical Plasma Emission Code (APEC) with the…
Active Galactic Nuclei (AGN) are multiwavelength emitters. To have any hope of understanding them, or even to determine their energy output, we must observe them with many telescopes. I will review what we have learned from broad-band…
Active galactic nucleus (AGN)-driven gas outflows are one of the best tracers of AGN feedback in action, as these powerful outflows expel/heat or compress the surrounding interstellar medium (ISM), thus quenching or enhancing star-forming…
Accreting supermassive black holes at the centres of galaxies are the engine of active galactic nuclei (AGN). X-ray light curves of unabsorbed AGN show dramatic random variability on timescales ranging from seconds to years. The power…
We apply an analytic Markov Chain Monte Carlo model to a sample of 18 AGN-driven biconical outflows that we identified from a sample of active galaxies with double-peaked narrow emission lines at z < 0.1 in the Sloan Digital Sky Survey. We…
Double-peaked narrow emission lines in active galactic nucleus (AGN) spectra can be produced by AGN outflows, rotation, or dual AGNs, which are AGN pairs in ongoing galaxy mergers. Consequently, double-peaked narrow AGN emission lines are…
We investigate the effect of embedded active galactic nuclei (AGN) in galaxy mergers on the CO molecular line emission by combining non-local thermodynamic equilibrium (LTE) radiative transfer calculations with hydrodynamic simulations. We…
In this study, we demonstrate some of the caveats in common statistical methods used for analysing astronomical variability timescales. We consider these issues specifically in the context of active galactic nuclei (AGNs) and use a more…
The abundance of active galactic nuclei (AGN) in cosmic voids is relatively unexplored in the literature, but can potentially provide new constraints on the environmental dependence of AGN activity and the AGN-host co-evolution. We…
Active galactic nuclei (AGN) are believed to be promising candidates of extragalactic cosmic-ray accelerators and sources, and associated high-energy neutrino and hadronic gamma-ray emission has been studied for many years. We review models…