相关论文: Probing $H_0$ and resolving AGN disks with ultrafa…

We propose a new method to determine the dark matter density profile in the vicinity of distant supermassive black holes (SMBH) using reverberation mapping (RM) measurements of active galactic nuclei (AGN). The mapping of multiple emission…

In the last years we have operated two very similar ultrafast photon counting photometers (Iqueye and Aqueye+) on different telescopes. The absolute time accuracy in time tagging the detected photon with these instruments is of the order of…

The bolometric luminosity of active galactic nuclei (AGN) is difficult to determine and various approximations have been used to calibrate it against different observed properties. Here I combine theoretical calculations of optically thick,…

The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured Active Galactic Nuclei…

The origin of the tight scaling relation between the mass of supermassive black holes (SMBHs; $M_{\rm BH}$) and their host-galaxy properties remains unclear. Active galactic nuclei (AGNs) probe phases of ongoing SMBH growth and offer the…

By using the GRAVITY instrument with the near-infrared (NIR) Very Large Telescope Interferometer (VLTI), the structure of the broad (emission-)line region (BLR) in active galactic nuclei (AGNs) can be spatially resolved, allowing the…

Reverberation mapping methods have been used to measure masses in about three dozen AGNs. The consistency of the virial masses computed from line widths and time delays, the relationship between black hole mass and host-galaxy stellar bulge…

Recent models for the inner structure of active galactic nuclei (AGN) aim at connecting the outer region of the accretion disk with the broad-line region and dusty torus through a radiatively accelerated, dusty outflow. Such an outflow not…

Telescopes like Herschel and the Atacama Large Millimeter/submillimeter Array (ALMA) are creating new opportunities to study sources in the far infrared (FIR), a wavelength region dominated by cold dust emission. Probing cold dust in active…

In the 1970s, the Narrabri intensity interferometer was used to measure 32 stellar diameters; some as small as 0.4 milli-arc-seconds (mas). The interferometer consisted of a pair of 6.5m telescopes with relatively crude optics, similar to…

We present an analysis of broad emission lines observed in moderate-luminosity active galactic nuclei (AGNs), typical of those found in X-ray surveys of deep fields, with the aim to test the validity of single-epoch virial black hole mass…

Infrared interferometry is a new frontier for precision ground based observing, with new instrumentation achieving milliarcsecond (mas) spatial resolutions for faint sources, along with astrometry on the order of 10 microarcseconds. This…

Observational searches for intermediate-mass black holes (IMBHs; $10^2 - 10^6$ $M_\odot$) include relatively isolated dwarf galaxies. For those that host active galactic nuclei (AGNs), the IMBH nature may be discerned through the accretion…

Identifying active galactic nuclei (AGN) and isolating their contribution to a galaxy's energy budget is crucial for studying the co-evolution of AGN and their host galaxies. Brightness temperature ($T_b$) measurements from high-resolution…

The masses of supermassive black holes in active galactic nuclei (AGN) can be derived spectroscopically via virial mass estimators based on selected broad optical/ultraviolet emission lines. These estimates commonly use the line width as a…

Representing simultaneous black hole accretion during a merger, binary active galactic nuclei (AGNs) could provide valuable observational constraints to models of galaxy mergers and AGN triggering. High-resolution radio interferometer…

For over 60 years, the scientific community has studied actively growing central super-massive black holes (active galactic nuclei -- AGN) but fundamental questions on their genesis remain unanswered. Numerical simulations and theoretical…

We analyze an intensity interferometry measurement carried out with two point-like detectors facing a distant source (e.g., a star) that may be partially occluded by an absorptive object (e.g., a planet). Such a measurement, based on the…

The luminous electromagnetic emission from distant active galactic nuclei (AGNs) including quasars is believed to be powered by accretion onto super-massive black holes (SMBHs). In the standard unification model for AGNs a dusty torus…

Interferometric observations of gravitational microlensing events offer an opportunity for precise, efficient, and direct mass and distance measurements of lensing objects, especially those of isolated neutron stars and black holes.…