Search Publications
NGC 1275: Baryonic cycling in the Perseus cluster of galaxies
Gallagher, J. S.
NGC 1275, the central galaxy of the Perseus cluster, contains a remarkable cool ISM. This gas is arrayed in a series of filaments extending over 30 kpc with an extension of 70 kpc to the north. These emit substantial cooling line radiation from H II, a hot H_2 zone, and CO in a cool molecular region which contains most of the gas mass. This contri…
The symbiotic system CH Cygni: An analysis of the shocked nebulae at different epochs
Rafanelli, P.; Angeloni, R.; Contini, M.
We analyse the line and continuum spectra of the symbiotic system CH Cygni. We adopt the colliding-wind model to explain the symbiotic system at different phases. Peculiar observed features such as flickering, radio variation, X-ray emission, as well as the distribution of the nebulae and shells throughout the system are investigated by modelling …
The chromospherically active binary star EI Eridani: I. Absolute dimensions
Strassmeier, K. G.; Weber, M.; Granzer, T. +2 more
We present a detailed determination of the astrophysical parameters of the chromospherically active binary star EI Eridani. Our new radial velocities allow to improve the set of orbital elements and reveal long-term variations of the barycentric velocity. A possible third-body orbit with a period of {≈ 19} years is presented. Absolute parameters a…
Orbits of Comets C/1845 L1 (Great June Comet) and C/1846 D1 (de Vico)
Branham, R. L., Jr.
Orbits are calculated for Comet C/1845 L1 (the Great June Comet) and C/1846 D1 (de Vico), the former based on 157 observations in right ascension and 152 in declination and the latter on 10 and 9, respectively. Both orbits are hyperbolic and statistically distinguishable from parabolas. Statistical tests indicate that the residuals are random and …
Smooth, undisturbed dwarf spheroidal galaxies in the Perseus cluster core: Implications for dark matter content
Held, E. V.; Conselice, C. J.; De Rijcke, S. +1 more
Using deep HST/ACS observations of the core of the Perseus Cluster, we identify a large population of dwarf elliptical galaxies down to MV = -12. All these dwarfs are remarkably smooth in appearance, showing no evidence for internal features that could be the result of tidal processes or star formation induced by the cluster potential. …
High energy emission from AGN cocoons in clusters of galaxies
Nagai, H.; Kawakatu, N.; Kino, M. +1 more
Gamma-ray emission from cocoons of young radio galaxies is predicted. Considering the process of adiabatic injection of the shock dissipation energy and mass of the relativistic jet into the cocoon, we find that the thermal electron temperature of the cocoon is typically predicted to be of the order of ∼MeV, and is determined only by the bulk Lore…
The evolution of spheroidal galaxies in different environments
Ziegler, B. L.; Fritz, A.
We analyse the kinematic and chemical evolution of 203 distant spheroidal (elliptical and S0) galaxies at 0.2<z<0.8 which are located in different environments (rich clusters, low-mass clusters and in the field). VLT/FORS and CAHA/MOSCA spectra with intermediate-resolution have been acquired to measure the internal kinematics and stellar pop…
Field optimization and CCD data simulation for the antarctic International Concordia Explorer Telescope (ICE-T)
Strassmeier, K. G.; Fügner, D.; Fuhrmann, C.
We performed extensive data simulations for the planned ultra-wide-field, high-precision photometric telescope ICE-T (International Concordia Explorer Telescope). ICE-T consists of two 60 cm-aperture Schmidt telescopes with a joint field of view simultaneously in two photometric bandpasses. Two CCD cameras, each with a single 10.3k×10.3k thinned b…
The evolution of cluster dwarfs
Harsono, D.; De Propris, R.
We summarize the results from analyzing six clusters of galaxies at 0.14 < z < 0.40 observed with the Hubble Space Telescope Advanced Camera for Surveys. We derive deep composite luminosity functions in B, g, V, r, i, and z down to absolute magnitude of ∼ -14 + 5 log h mag. The luminosity functions are fitted by a single Schechter function w…
A multi-wavelength view of the archetypical CSS radio galaxy 3C303.1: Evidence for shocks and induced star formation
O'Dea, C. P.
I discuss multi-wavelength data on the archetypal CSS radio galaxy 3C303.1. The radio source is sub-galactic in scale where it can directly affect the ISM of the host galaxy. The emission line kinematics and ionization diagnostics are consistent with energy input from shocks driven by the radio source. The Spitzer IRS spectrum indicates that star …