相关论文: Time-Domain Radio Loudness of Active Galactic Nucl…

We conducted an analysis of gamma-ray variability in a large sample of jetted active galactic nuclei (AGNs) by utilizing archival Fermi-LAT light curves and applying damped random walk modeling to obtain variability amplitude. Our primary…

Only a small fraction of observed Active Galactic Nuclei display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and…

The dichotomy between radio-loud (RL) and radio-quiet (RQ) active galactic nuclei (AGN) is thought to be intrinsically related to radio jet production. This difference may be explained by the presence of a strong magnetic field (B-field)…

A wide-frequency radio study of Active Galactic Nuclei (AGN) is crucial to evaluate the intervening radiative mechanisms responsible for the observed emission and relate them with the underlying accretion physics. We present wide frequency…

Double-double radio galaxies (DDRGs) represent a short but unique phase in the life-cycle of some of the most powerful radio-loud active galactic nuclei (RLAGN). These galaxies display large-scale remnant radio plasma in the intergalactic…

The radio-X-ray slope in the fundamental plane of radio-loud active galactic nuclei (AGNs) is found to be steeper compared with that of radio-quiet AGNs in previous works. In this work, we reinvestigate the fundamental plane in radio-loud…

Active galactic nuclei (AGNs) form two distinct sequences on the radio-loudness -- Eddington-ratio plane. The `upper' sequence contains radio selected AGNs, the `lower' sequence is composed mainly of optically selected AGNs. The sequences…

We present simultaneous, sub-arcsecond (<=50pc) resolution 5 GHz, 8.4 GHz, and 15 GHz VLA observations of a well-defined sample of sixteen low-luminosity active galactic nuclei (LLAGNs). The radio emission in most of these nuclei does not…

Diffuse radio recombination lines (RRLs) in the Galaxy are possible foregrounds for redshifted 21~cm experiments. We use EDGES drift scans centered at $-26.7^o$~declination to characterize diffuse RRLs across the southern sky. We find RRLs…

The question of radio dichotomy in the active galactic nuclei (AGNs) is still in debate even it has been proposed for more than forty years. In order to solve the old riddle, we collect a sample of AGNs with optical $B$ band and radio 6cm…

Hardness-intensity diagrams (HIDs) have been used with great success to study the accretion states and their connection to radio jets in X-ray binaries (XRBs). The analogy between XRBs and active galactic nuclei (AGN) suggests that similar…

We study the long-term ($\approx$30 years) radio variability of 43 radio bright AGNs by exploiting the data base of the University of Michigan Radio Astronomy Observatory (UMRAO) monitoring program. We model the periodograms (temporal power…

The physical origin of radio emission in Radio Quiet Active Galactic Nuclei (RQ AGN) remains unclear, whether it is a downscaled version of the relativistic jets typical of Radio Loud (RL) AGN, or whether it originates from the accretion…

We present a study of variability time scales in a large sample of Active Galactic Nuclei at several frequencies between 4.8 and 230 GHz. We investigate the differences of various AGN types and frequencies and correlate the measured time…

Radio-loud active galactic nuclei (RLAGNs) are rare among AGN populations. Lacking high-resolution and high-frequency observations, their structure and evolution stages are not well understood at high redshifts. In this work, we report ALMA…

We have studied the relationship between the nuclear (high-resolution) radio emission, at 8.4 GHz (3.6 cm) and 1.4 GHz (20 cm), the [O IV] 25.89um, [Ne III] 15.56um and [Ne II] 12.81um emission lines and the black hole mass accretion rate…

We extend our study of energetic radio loud and quiet gamma-ray bursts (GRBs), suggesting these GRBs potentially come from two separate progenitor systems. We expand the sample from our previous paper (Lloyd-Ronning & Fryer, 2017) and find…

The remnant phase of a radio galaxy is characterized by the cessation of AGN activity resulting in the stoppage of jets supplying plasma to radio lobes. In this paper, we present the search and characterization of remnant candidates in 12.5…

We present a model describing the evolution of Fanaroff-Riley type I and II radio AGN, and the transition between these classes. We quantify galaxy environments using a semi-analytic galaxy formation model, and apply our model to a…

A thorough study of radio emission in Active Galactic Nuclei (AGN) is of fundamental importance to understand the physical mechanisms responsible for the emission and the interplay between accretion and ejection processes. High frequency…