107 datasets found

We examine the Fundamental Plane of black hole activity for correlations with redshift and radio loudness in both radio-loud and radio-quiet quasar populations. Sources are...

We present the space density evolution, from z = 1.5 up to z = 5.5, of the most massive (M => 10^9^ M_{sun}) black holes hosted in jetted active galactic nuclei (AGNs). The...

We present ground-based and Swift photometric and spectroscopic observations of the candidate tidal disruption event (TDE) ASASSN-14li, found at the centre of PGC 043234 (d~90...

The uncharted territory of the high-redshift (z>~3) universe holds the key to understanding the evolution of quasars. In an attempt to identify the most extreme members of...

We present a multiwavelength study of the active galactic nucleus in the nearby (D=14.1Mpc) low-mass galaxy IC750, which has circumnuclear 22GHz water maser emission. The masers...

We investigate whether the correlation between the hard X-ray photon index ({Gamma}) and accretion rate for super-Eddington accreting quasars is different from that for...

We analyzed the relationship between several basic parameters describing supermassive black holes such as jet power, black hole spin, accretion disk magnetic field, black hole...

We investigated the snapshots of five NICER observations of the black hole transient GX 339-4 when the source transited from the hard state into the soft state during its...

All 280 of the statistically complete Palomar sample of nearby (< 120 Mpc) galaxies {delta} > 20{deg} have been observed at 1.5 GHz as part of the LeMMINGs e-MERLIN legacy...

Most ultraluminous X-ray sources (ULXs) are thought to be powered by super- Eddington accretion on to stellar-mass compact objects. Accretors in this extreme regime are...

The majority of non-merging stellar mass black holes are discovered by observing high energy emission from accretion processes. Here, we pursue the large, but still mostly...

Our understanding of the unification of jetted AGN has evolved greatly as jet samples have increased in size. Here, based on the largest-ever sample of over 2000 well-sampled...

We estimate chemical abundances and ionization parameters in the nuclear region of a sample of 143 galaxies from the Palomar Spectroscopic Survey, composed by star-forming...

We present X-ray spectral and long-term variability analyses of an unbiased sample of 361 optically selected radio-loud quasars (RLQs) utilizing sensitive serendipitous X-ray...

Accretion states, which are universally observed in stellar mass black holes in X-ray binaries, might be expected in active galactic nuclei (AGN). This is the case at low...

X-ray observations provide a unique probe of the accretion disc corona of supermassive black holes (SMBHs). In this paper, we present a uniform Chandra X-ray data analysis of a...

Mass accretion rates in dimensionless and physical units, and efficiency factors describing the total radiant luminosity of the disc and the beam power of the outflow are...

We investigate the responsiveness of the 2798{AA} MgII broad emission line in active galactic nuclei (AGNs) on time-scales of several years. Our study is based on a sample of...

Radio-loud quasars (RLQs) are more X-ray luminous than predicted by the X-ray-optical/UV relation (i.e. L_x_{prop.to}L_uv_^{gamma}^) for radio-quiet quasars (RQQs). The excess...

The mechanisms responsible for the production of relativistic jets from supermassive black holes (SMBHs) accreting at near-Eddington rates are not well understood. Simple...