Related papers: Stellar Dynamics at the Galactic Center with an Ex…
We present the stellar dynamical mass of the central black hole in the nearby Seyfert galaxy MCG$-$06-30-15 using the Schwarzschild orbit-superposition method implemented in the open-source code FORSTAND. We obtained spatially resolved…
In this paper we develop a Markov Chain Monte Carlo code to study the dark matter properties in interpreting the recent observations of cosmic ray electron/positron excesses. We assume that the dark matter particles couple dominantly to…
In recent years, there has been increasing recognition of the potential of the galactic center as a probe of general relativity in the strong field. There is almost certainly a black hole at Sgr A* in the galactic center, and this would…
The capture and gradual inspiral of stellar mass objects by a massive black hole at the centre of a galaxy has been proposed as one of the most promising source of gravitational radiation to be detected by LISA. Unfortunately rate estimates…
Dark matter comprises the bulk of the matter in the universe but its particle nature and cosmological origin remain mysterious. Knowledge of the dark matter density distribution in the Milky Way Galaxy is crucial to both our understanding…
We investigate a mechanism for a super-massive black hole at the center of a galaxy to wander in the nucleus region. A situation is supposed in which the central black hole tends to move by the gravitational attractions from the nearby…
Adaptive Optics observations have dramatically improved the quality and versatility of high angular resolution measurements of the center of our Galaxy. In this paper, we quantify the quality of our Adaptive Optics observations and report…
The majority of massive black holes (MBHs) likely hosted gas discs during their lifetimes. These could either be long-lived active galactic nuclei (AGN) discs, or shorter-lived discs formed following singular gas infall events, as was…
We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A$^*$), the Galactic center source associated with a supermassive black hole. These observations were conducted in 2017 using a global interferometric…
A significant fraction of the stellar population in the cusp around central black holes of galaxies consists of compact remnants of evolved stars, such as white dwarfs, neutron stars and stellar mass black holes. We estimate the rate of…
We present a new analytical solution to the steady-state distribution of stars close to a central supermassive black hole of mass $M_{\bullet}$ in the center of a galaxy. Assuming a continuous mass function of the form $dN/dm \propto…
We derive the upper limit to the ejecta mass of S190814bv, a black hole-neutron star merger candidate, through the radiative transfer simulations for kilonovae with the realistic ejecta density profile as well as the detailed opacity and…
The centers of massive elliptical galaxies exhibit a wide range in density profiles, from central cusps to resolved cores with order kiloparsec sizes. The cored ellipticals have been linked to the presence of supermassive black hole…
The high precision of the latest version of the planetary ephemeris EPM2011 enables one to explore more accurately a variety of small effects in the solar system. The processing of about 678 thousand of position observations of planets and…
In order to constrain parameters in galaxy formation theories, especially those for a star formation process, we investigate cold gas in elliptical galaxies. We calculate the detection rate of cold gas in them using a semi-analytic model of…
Measurements of the dynamical environment of supermassive black holes (SMBHs) are becoming abundant and precise. We use such measurements to look for ultralight dark matter (ULDM), which is predicted to form dense cores ("solitons") in the…
Gravitational microlensing is currently the only technique that helps study the Galactic distribution of planets as a function of distance from the Galactic center. The Galactic location of a lens system can be uniquely determined only when…
Over two decades of astrometric and radial velocity data of short period stars in the Galactic center have the potential to provide unprecedented tests of General Relativity and insight into the astrophysics of supermassive black holes.…
Gravitational microlensing may detect dark stellar remnants - black holes or neutron stars - even if they are isolated. However, it is challenging to estimate masses of isolated dark stellar remnants using solely photometric data for…
Using the EGRET data and an improved point source analysis, including an energy dependent point spread function and an unbinned maximum likelihood technique, we have been able to place considerably lower limits on the gamma ray flux from…