Related papers: An Improved Distance and Mass Estimate for Sgr A* …
A radio source at the Galactic center Sgr A* is a prime supermassive black hole candidate and therefore key to developing our understanding of them. Time variations in the 230 GHz band flux of Sgr A* have been found with the Atacama Large…
We present a measurement of the supermassive black hole (SMBH) mass of the nearby lenticular galaxy NGC 383, based on Atacama Large Millimeter/sub-millimeter Array (ALMA) observations of the $^{12}$CO(2-1) emission line with an angular…
Sgr A* at the Galactic Center is a puzzling source. It has a mass M=(2.5+/-0.4) x 10^6 solar masses which makes it an excellent black hole candidate. Observations of stellar winds and other gas flows in its vicinity suggest a mass accretion…
The Event Horizon Telescope (EHT) will soon provide the first high-resolution images of the Galactic Centre supermassive black hole (SMBH) candidate Sagittarius A* (Sgr A*), enabling us to probe gravity in the strong-field regime. Besides…
The Galactic Centre has been studied with the High Energy Stereoscopic System (H.E.S.S.) for over 10 years, revealing a bright, complex gamma-ray morphology. Besides a strong point-like very-high-energy gamma-ray source coincident with the…
Robust extragalactic distance measurements are crucial for resolving the persistent discrepancy in the value of the Hubble constant (H$_0$)). Active Galactic Nuclei (AGNs), through their compact and variable broad-line regions (BLRs),…
The region around the center of our Galaxy is very dense of stars. The kinematics of inner moving stars in the Galaxy (the so called S-stars) has been deeply studied by different research groups leading to the conclusion of the existence of…
We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A$^*$), the Galactic center source associated with a supermassive black hole. These observations were conducted in 2017 using a global interferometric…
In recent years, the evidence for the existence of an ultra-compact concentration of dark mass associated with the radio source Sgr A* in the Galactic Center has become very strong. However, an unambiguous proof that this object is indeed a…
We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5--11 campaign. The observations were carried…
NGC 6240 is a pair of colliding disk galaxies, each with a black hole in its core. We have used laser guide star adaptive optics on the Keck II telescope to obtain high-resolution ($\sim 0.06$") near-infrared integral-field spectra of the…
We present the longest, by a factor of two, near-infrared lightcurve from Sgr A* - the supermassive black hole in the Galactic center. Achieved by combining Keck and VLT data from one common night, which fortuitously had simultaneous…
High-resolution, multi-wavelength, and time-domain observations of the Galactic centre black hole candidate, Sgr A*, allow for a direct test of contemporary accretion theory. To date, all models have assumed alignment between the accretion…
We report results from a multiwavelength campaign to measure the simultaneous spectrum of the super-massive black hole candidate Sgr A* in the Galactic Center from cm to mm-wavelengths using the VLA, BIMA, the Nobeyama 45m, and the IRAM 30m…
The near-infrared emission from the black hole at the Galactic center (Sgr A*) has unique properties. The most striking feature is a suggestive periodic sub-structure that has been observed in a couple of flares so far. Using near-infrared…
In this paper, we investigate the effects of a dark matter (DM) spike on the neighborhood of Sgr A*, the black hole (BH) in the center of the Milky Way galaxy. Our main goal is to investigate whether current and future astronomical…
The interaction of a runaway supermassive black hole (SMBH) with the circumgalactic medium (CGM) can lead to the formation of a wake of shocked gas and young stars behind it. Here we report the serendipitous discovery of an extremely narrow…
We show that high quality laser guide star (LGS) adaptive optics (AO) observations of nearby early-type galaxies are possible when the tip-tilt correction is done by guiding on nuclei while the focus compensation due to the changing…
Proper motions and radial velocities of luminous infrared stars in the galactic center have provided strong evidence for a dark mass of 2.5 million solar masses in the central 0.05 pc of the galaxy. The leading hypothesis for this mass is a…
We discuss the possibility of enhancing intelligent life searches toward the Galactic center. From the clockwork orbital motions of stars around the Sgr A${}^*$ black hole, we can determine the distance to the Galactic center at an…