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Orbit design for launching INTEGRAL on the Proton/Block-DM launcher
Clausen, K.; Eismont, N. A.; Janin, G. +6 more
This paper describes some aspects of the mission design determined by use of the Proton/Block-DM launch vehicle in the version used for injection onto a highly elliptical orbit of the international gamma-ray astrophysics laboratory INTEGRAL. Methods and results used for choosing an operational orbit for INTEGRAL are presented.
Using Multiwavelength Observations to Determine the Black Hole Mass and Accretion Rate in the Type 1 Seyfert Galaxy NGC 5548
Chiang, James; Blaes, Omer
We model the spectral energy distribution of the type 1 Seyfert galaxy NGC 5548, fitting data from simultaneous optical, UV, and X-ray monitoring observations. We assume a geometry consisting of a hot central Comptonizing region surrounded by a thin accretion disk. The properties of the disk and the hot central region are determined by the feedbac…
First INTEGRAL observations of GRS 1915+105
Belloni, T.; Charles, P. A.; Rodriguez, J. +20 more
We present data from the first of six monitoring Open Time observations of GRS 1915+105 undertaken with the orbiting INTEGRAL satellite. The source was clearly detected with all three X-ray and gamma-ray instruments on board. GRS 1915+105 was in a highly variable state, as demonstrated by the JEM X-2 and ISGRI lightcurves. These and simultaneous R…
X-ray and radio observations of the activation stages of an X-class solar flare
Hudson, H. S.; Karlický, M.; Fárník, F. +1 more
We report interesting developments prior to the impulsive phase of an X-class solar flare that occurred on September 24, 2001. Our multiwavelength study makes use of X-ray data from the Yohkoh satellite, the Ondřejov radio spectral observations in the decimetric band, and the new Hard X-Ray Spectrometer instrument (HXRS) on board the MTI satellite…
A Method for Black Hole Mass Determination in Accretion-powered X-Ray Sources
Titarchuk, Lev; Shrader, Chris R.
We describe a method for the determination of black hole masses based on information inferred from high-energy spectra. It is required that the spectral energy distribution consist of thermal and Comptonized components. One can then, in principle, infer the depth of the gravitational potential well for sources of known distance. The thermal compon…
Three-component Stäckel potentials satisfying recent estimates of Milky Way parameters
Famaey, B.; Dejonghe, H.
We present a set of three-component Stäckel potentials defined by five parameters and designed to model the Milky Way. We review the fundamental constraints that any model of the Milky Way must satisfy, including the most recent ones derived from Hipparcos data, and we study how the parameters of the presented potentials can vary in order to match…
Minor axis kinematics of 19 S0-Sbc bulges
Peletier, R. F.; Falcón-Barroso, J.; Vazdekis, A. +1 more
We present minor axis kinematic profiles for a well-studied sample of 19 early- to intermediate-type disk galaxies. We introduce, for the first time, the use of single-burst stellar population (SSP) models to obtain stellar velocities, velocity dispersions and higher order Gauss-Hermite moments (h3, h4) from galaxy spectra in…
Relative Flux Calibration of Keck HIRES Echelle Spectra
O'Meara, John M.; Tytler, David; Lubin, Dan +2 more
We describe a method to calibrate the relative flux levels in spectra from the High-Resolution Echelle Spectrograph (HIRES) on the Keck I telescope. Standard data reduction techniques that transfer the instrument response between HIRES integrations leave errors in the flux of 5%-10% because the effective response varies during the night. The flux …
Infrared Space Observatory and Ground-Based Infrared Observations of the Classical Nova V723 Cassiopeiae
Hayward, T. L.; Gehrz, R. D.; Eyres, S. P. S. +13 more
We present observations of the classical nova V723 Cassiopeiae (Nova Cas 1995), obtained both with the Infrared Space Observatory (ISO) and from the ground. The infrared spectrum was dominated in the first year by H and He recombination lines, and at later times by coronal lines. The H recombination lines imply a reddening of E(B-V)=0.78, an elect…
Star Formation and Asymmetry in the Spiral Arms of M51: Variable Star Formation Caused by More than One Spiral Density Wave
Gutermuth, Robert; Quillen, A. C.; Henry, Alaina L.
In the inner 3 kpc of M51, we find that logarithmic spirals provide good fits to the peak intensities in molecular gas observed by the Berkeley-Illinois-Maryland Association array in the CO (J=1-0) emission line along the spiral arms. However, we measure significant asymmetries between the location and density of the arms observed on one side of t…