Related papers: M87 as a Galaxy
We calculate the effect of dark matter on the ringdown waveform and shadow of supermassive black holes at the core of galaxies. Our main focus is on the supermassive black hole at the core of M87, which is large enough to allow for viable…
We explore how the co-evolution of massive black holes (MBHs) and galaxies is affected by environmental effects, addressing in particular MBHs hosted in the central galaxies of clusters (we will refer to these galaxies in general as 'CGs').…
Visual, NIR, and H_alpha surface photometry of the oval disk galaxy M94 (NGC 4736) was performed to study the distribution of mass in old stars and the distribution of the warm emission line gas. The radial profile of the inner stellar disk…
The origin of high velocity stars observed in the halo of our Galaxy is still unclear. In this work we test the hypothesis, raised by results of recent high precision $N$-body simulations, of strong acceleration of stars belonging to a…
The X-ray data obtained with XMM-Newton is used to investigate the complex structure of the gas in the atmosphere of the Virgo cluster around M87. We construct a simple model for the temperature and density distribution. This model implies…
When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the…
We draw a quantitative comparison of the distribution of the galaxies and the intra-cluster gas in the Virgo cluster by extending the morphological analysis by Binggeli et al. (1987) to the intra-cluster gas. We use the Virgo Cluster…
The robustness of stellar-dynamical black hole (BH) mass measurements is illustrated using 7 galaxies that have results from independent groups. Derived masses have remained constant to a factor of about 2 as spatial resolution has improved…
The observed radial and transverse velocities of individual stars in M15 are implemented as inputs to a fully non-parametric code (CHASSIS) in order to estimate the equilibrium stellar distribution function and the three-dimensional mass…
Globular star clusters contain thousands to millions of old stars packed within a region only tens of light years across. Their high stellar densities make it very probable that their member stars will interact or collide. There has been…
Stellar photometry in nine fields around the giant elliptical galaxy M87 in the Virgo cluster is obtained from archival images of the Hubble Space Telescope. The resulting Hertzsprung--Russell diagrams show populated red-giant and AGB…
We performed 12CO(1-0), 13CO(1-0), and HCN(1-0) interferometric observations of the central region (about 450 pc in radius) of M82 with the Nobeyama Millimeter Array, and have successfully imaged a molecular superbubble and spurs. The…
Growing evidence indicate supermassive black holes (SMBHs) in the mass range of $M_{\rm BH}$$\sim 10^6-10^{10}M_{\odot}$ lurking in central bulges of many galaxies. Extensive observations reveal fairly tight power laws of $M_{\rm BH}$…
Using the spectral energy distribution of M87, a nearby radio galaxy in the Virgo cluster, and assuming a supermassive black hole induced spike in the dark matter halo profile, we exclude any dark matter candidate with a…
We investigate where brightest cluster galaxies (BCGs) sit on the fundamental plane of black hole (BH) activity, an established relation between the X-ray luminosity, the radio luminosity and the mass of a BH. Our sample mostly consists of…
A fundamental role is attributed to supermassive black holes (SMBH), and the feedback they generate, in the evolution of galaxies. But theoretical models trying to reproduce the relation between the SMBH mass and stellar velocity dispersion…
Models of superdense star clusters at the center of galaxies are investigated to see whether such objects can be stable and long-lived based on evaporation and collision time-scales and stability criteria. We find that physically reasonable…
Hypervelocity stars have been recently discovered in the outskirts of galaxies, such as the unbound star in the Milky Way halo, or the three anomalously fast intracluster planetary nebulae (ICPNe) in the Virgo Cluster. These may have been…
We review the motivation and search for supermassive black holes (BHs) in galaxies. Energetic nuclear activity provides indirect but compelling evidence for BH engines. Ground-based dynamical searches for central dark objects are reviewed…
Globular clusters are an excellent laboratory for stellar population and dynamical research. Recent studies have shown that these stellar systems are not as simple as previously assumed. With multiple stellar populations as well as outer…