118 datasets found

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...

We present the Global Rapid Advanced Network Devoted to the Multi-messenger Addicts (GRANDMA). The network consists of 21 telescopes with both photometric and spectroscopic...

The gigahertz peaked spectrum (GPS) sources, compact steep spectrum (CSS) radio sources, and high-frequency peaker (HFP) radio sources are thought to be young radio active...

We present the results of a systematic search for quasars in the Catalina Real-time Transient Survey exhibiting both strong photometric variability and spectroscopic variability...

Using a sample of 208 broad-line active galactic nuclei (AGNs) from the Swift/BAT AGN Spectroscopic Survey in the ultra-hard X-ray band (14-195keV), the hot corona properties...

Machine learning is a powerful technique, becoming increasingly popular in astrophysics. In this paper, we apply machine learning to more than a thousand globular cluster (GC)...

We perform a systematic study of the evolution of the waveform of black hole X-ray binary low-frequency QPOs, by measuring the phase difference between their fundamental and...

Narrow-line regions excited by active galactic nuclei (AGNs) are important for studying AGN photoionization and feedback. Their strong [OIII] lines can be detected with...

It is well known that environment affects galaxy evolution, which is broadly related to supermassive black hole (SMBH) growth. We investigate whether SMBH evolution also depends...

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...

We present the third catalog release of the wide-area (31.3deg^2^) Stripe 82 X-ray survey. This catalog combines previously published X-ray source properties with...

We collect a large sample with a reliable redshift detected by the Fermi satellite after 10yr of data (4FGL-DR2), including blazars, gamma-ray narrow-line Seyfert 1 galaxies...

Tidal disruption events (TDEs) offer a unique way to study dormant black holes. While the number of observed TDEs has grown thanks to the emergence of wide-field surveys in the...

We continue to explore the relationship between the total number of globular clusters (GCs), N_GC_, and the central black hole mass, M_BH_, in spiral galaxies. We present here...

The high-ionization mid-IR lines, excited in the narrow-line regions of active galactic nuclei (AGN), barely affected by stellar excitation and dust extinction, trace the AGN...

We present measurements of black hole masses and Eddington ratios ({lambda}Edd) for a sample of 38 bright (M_1450_<-24.4mag) quasars at 5.8<~z<~7.5, derived from Very...

We perform a systematic survey of active galactic nuclei (AGNs) continuum lags using ~3days cadence gri-band light curves from the Zwicky Transient Facility. We select a sample...

The dense central regions of tidally disrupted galaxies can survive as ultracompact dwarfs (UCDs) that hide among the luminous globular clusters (GCs) in the halo of massive...