Related papers: Gravitational redshift in the NGC 4258 disk?
Mass and concentration of clusters of galaxies are related and evolving with redshift. We study the properties of a sample of 31 massive galaxy clusters at high redshift, 0.8 < z < 1.5, using weak and strong lensing observations.…
The nearby lenticular galaxy NGC 1277 is thought to host one of the largest black holes known, however the black hole mass measurement is based on low spatial resolution spectroscopy. In this paper, we present Gemini Near-infrared Integral…
(abridged) We investigate the kinematics of the central gas disk of the radio-loud elliptical galaxy NGC 4335, derived from HST/STIS long-slit spectroscopic observations of Halpha+[NII] along 3 parallel slit positions. The observed mean…
We present a deep XMM-Newton observation of the extremely massive, rapidly rotating, relativistic-jet-launching spiral galaxy 2MASX J23453268-0449256. Diffuse X-ray emission from the hot gaseous halo around the galaxy is robustly detected…
The peculiar elliptical galaxy IC 1459 (M_V = -21.19, D = 16.5 Mpc) has a fast counterrotating stellar core, stellar shells and ripples, a blue nuclear point source and strong radio core emission. We present results of a detailed HST study…
We determine the total enclosed mass profile from 0.7 to 35 kpc in the elliptical galaxy NGC 4636 based on the hot interstellar medium temperature profile measured using the Chandra X-ray Observatory, and other X-ray and optical data. The…
The proto-galaxy, cB58, was discovered in the CNOC survey of cluster redshifts. Absorption features reveal that this system is at a redshift of $z=2.72$, implying an absolute magnitude of ${\rm M_v \sim -26}$, and a star-formation rate of…
The ultra-diffuse galaxy in the NGC 5846 group (NGC 5846_UDG1) was shown to have a large number of globular cluster (GC) candidates from deep imaging as part of the VEGAS survey. Recently, Muller et al. published a velocity dispersion,…
We present an edge-on Keplerian disk model to explain the main component of the 12.2 and 6.7 GHz methanol maser emission detected toward NGC7538-IRS1 N. The brightness distribution and spectrum of the line of bright masers are successfully…
We present Space Telescope Imaging Spectrograph emission-line spectra of the central regions of the spiral galaxies NGC 1300 and NGC 2748. From the derived kinematics of the nuclear gas we have found evidence for central supermassive black…
We present a Chandra study of the hot ISM in the giant elliptical galaxy NGC4649. In common with other group-centred ellipticals, its temperature profile rises with radius in the outer parts of the galaxy, from ~0.7keV at 2kpc to ~0.9keV by…
New spectroscopic observations of 36 HII regions in NGC 4258 obtained with the Gemini telescope are combined with existing data from the literature to measure the radial oxygen abundance gradient in this galaxy. The [OIII]4363 auroral line…
We report a three year, 18 epoch, VLBI monitoring study of H2O masers in the sub-parsec, warped, accretion disk within the NGC4258 AGN. Our immediate goals are to trace the geometry of the underlying disk, track rotation via measurement of…
The discovery of hundreds of young, bright stars within a parsec from the massive black hole at the center of the Galaxy presents a challenge to star formation theories. The requisite Roche densities for the gravitational collapse of gas…
The new observational data concerning distribution, excitation, and kinematics of the ionized gas in the giant early-type disk galaxy NGC 2655 obtained at the 6m telescope of the Special Astrophysical Observatory (SAO RAS) and at the 2.5m…
Gravitational redshift is a fundamental parameter that allows us to determine the mass-to-radius ratio of compact stellar objects, such as black holes, neutron stars, and white dwarfs (WDs). In the X-ray spectra of the close binary system,…
We present an analysis of polarimetric observations at 22 GHz of the water vapor masers in NGC 4258 obtained with the VLA and the GBT. We do not detect any circular polarization in the spectrum indicative of Zeeman-induced splitting of the…
We point out that the mass of the cosmos on gigaparsec scales can be measured, owing to the unique geometric role of the maximum in the areal radius. Unlike all other points on the past null cone, this maximum has an associated mass, which…
It has been recently shown (Tsiklauri & Viollier, 1998a) that the matter concentration inferred from observed stellar motion at the galactic center (Eckart & Genzel, 1997, MNRAS, 284, 576 and Genzel et al., 1996, ApJ, 472, 153) is…
We present results of a ground-based survey for Cepheid variables in NGC 4258. This galaxy plays a key role in the Extragalactic Distance Scale due to its very precise and accurate distance determination via VLBI observations of water…