Astronomy and Astrophysics Supplement Series

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List of Papers (Total 2,129)

The density and shock characteristics of NGC 2818

We report the results of narrow band imaging of the bipolar outflow source NGC 2818 in transitions of [NII], [OIII], [SII], and HI. As a consequence, we are able to assess the overall excitation properties of the shell, and determine that line ratios towards the nebular periphery are anomalous, and characteristic of planar shocks with velocity km s-1. Pre-shock densities are...

Photographic observations of visual double stars

The photographic observations of 72 visual double stars are presented. The observations were made in the years 1992-1997 with the 60-cm double refractor of the Bosscha Observatory at Lembang.

A method to analyze adaptive optics images of binary stars

We present a fast and robust ad-hoc method to analyze a set of short exposure images of a close binary star taken by the adaptive optics system of the ESO 3.6 m telescope. At first each image is fitted, assuming as a radially symmetrical approximation of its "instantaneous” PSF, the superposition of a central Gaussian and of a Moffat torus. Owing to the coral variability and...

Atomic data from the Iron Project - XXXV. Relativistic fine structure oscillator strengths for Fe XXIV and Fe XXV

The first large-scale calculations of relativistic radiative transition probabilities from the Iron Project is reported for dipole allowed and intercombination (E1) transitions in Li-like Fe XXIV and He-like Fe XXV. The ab intio calculations are carried out in the close coupling approximation using the Breit-Pauli R-matrix method in intermediate coupling characterized by SLJ...

A list of nearby dwarf galaxies towards the Local Void in Hercules-Aquila

Based on film copies of the POSS-II we inspected a wide area of □° in the direction of the nearest cosmic void: {RA = 18h 38m, , 1500 km s-1}. As a result we present a list of 78 nearby dwarf galaxy candidates which have angular diameters and a mean surface brightness , mag/□″. Of them 22 are in the direction of the Local Void region. To measure their redshifts, a HI survey of...

Optimised polarimeter configurations for measuring the Stokes parameters of the cosmic microwave background radiation

We present configurations of polarimeters which measure the three Stokes parameters I, Q and U of the Cosmic Microwave Background Radiation with a nearly diagonal error matrix, independent of the global orientation of the polarimeters in the focal plane. These configurations also provide the smallest possible error box volume.

Radial velocities of Hipparcos southern B8-F2 type stars

Radial velocities have been determined for a sample of B8-F2 type stars observed by the Hipparcos satellite. Observations were obtained within the framework of an ESO key-program. Radial velocities have been measured using a cross-correlation method, the templates being a grid of synthetic spectra. The obtained precision depends on effective temperature and projected rotational...

The photographic observations on the components of Sirius

A series of photographic observations on the components of Sirius was carried out in the years 1976-1986 at the Bosscha Observatory. We present the analysis and the results of the measurements.

Stellar kinematic data for the central region of spiral galaxies. II.

We present a second dataset of absorption spectroscopy on the inner region of spiral galaxies. We have determined the central velocity dispersion for 42 Sa-Sc objects and, for 32 of them, stellar rotation curves and velocity-dispersion profiles. Some of these profiles are limited to the bulge, some others do reach a region dominated by the luminosity of the disk. These data are...

3D mapping of optical turbulence using an atmospheric numerical model - II. First results at Cerro Paranal

The first statistical results of simulations of optical turbulence over Cerro Paranal by an atmospheric non-hydrostatic model (Meso-Nh) are presented. Measurements from the whole PARSCA93 campaign are analyzed. Simulations are compared to optical measurements obtained by a Scidar and a DIMM working at the same time during 14 nights 13-26 May 1993 over Paranal (Chile). An...

Spectral analysis of stellar light curves by means of neural networks

Periodicity analysis of unevenly collected data is a relevant issue in several scientific fields. In astrophysics, for example, we have to find the fundamental period of light or radial velocity curves which are unevenly sampled observations of stars. Classical spectral analysis methods are unsatisfactory to solve the problem. In this paper we present a neural network based...

IC 348 proper motion study from digitised Schmidt plates

A new proper motion study for about 1400 stars with  mag in a one square degree region around the young open cluster IC 348 based on Schmidt plates is presented. With an overall accuracy of about 3 mas/yr (2.5 mas/yr, respectively for all stars with  mag) we have obtained membership probabilities dividing our sample into three groups: foreground stars, cluster stars and...

The Hamburg/SAO survey for emission–line galaxies - II. The second list of 128 galaxies

We present the second part of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAO – Special Astrophysical Observatory, Russia) which is based on the digitized objective-prism photoplates database of the Hamburg Quasar Survey (HQS). The main goal of the project is the search for emission-line galaxies (ELG) in order to create a new deep sample of blue compact/Hii...

Elemental abundance studies of CP stars - II. The silicon stars HD 133029 and HD 192913

Fine analyses of the silicon stars HD 133029 and HD 192913 are presented using ATLAS9 model atmospheres whose predictions fit the optical region spectrophotometry and Hγ profiles and have the same bulk metallicity as the deduced abundances. Both are very He poor stars. The light elements are mostly solar except for silicon, and all the heavier elements, except nickel in HD 133029...

Photometric studies of some starburst galaxies

We present the results of a detailed morphological analysis of ten starburst galaxies selected from the Markarian catalog of uv-excess objects. CCD surface photometry of these galaxies was carried out based on observations made in B, V (Johnson) and R, I (Kron-Cousins) band passes. We present the radial variations of surface brightness, ellipticity, position angle and the colour...

Young massive star clusters in nearby galaxies - II. Software tools, data reductions and cluster sizes

A detailed description is given of the data analysis leading to the discovery of young massive star clusters (YMCs) in a sample of 21 nearby galaxies. A new useful tool, ishape, for the derivation of intrinsic shape parameters of compact objects is presented, and some test results are shown. Completeness tests for the cluster samples are discussed, and ishape is used to estimate...

Stark broadening of the lower Rydberg , and lines of atomic hydrogen

This paper deals with the calculation of line widths and lineshapes of the lower Rydberg lines of atomic hydrogen () in the conditions of stellar envelopes and atmospheres - electron densities scaling from 109 to 1016 cm-3 and temperatures varying between 5000 and 40000 K. For these lines, the traditional semi-classical method breaks down, especially at low densities. Another or...

The effective temperature scale of giant stars (F0–K5) - I. The effective temperature determination by means of the IRFM

We have applied the InfraRed Flux Method (IRFM) to a sample of approximately 500 giant stars in order to derive their effective temperatures with an internal mean accuracy of about 1.5% and a maximum uncertainty in the zero point of the order of 0.9%. For the application of the IRFM, we have used a homogeneous grid of theoretical model atmosphere flux distributions developed by...

A survey of flares and current helicity in active regions

We examine the spatial and temporal relationship between chromospheric H flares and photospheric current helicities in active regions. All of the data were obtained by the vector magnetograph system at Huairou Solar Observing Station of Beijing Astronomical Observatory. We focus our analysis on NOAA Active Region 6233, which was observed on 30 August 1990. The result shows that...

Survey of bipolar outflows and methanol masers in the C32S ( and C34S (2-1) lines in the Northern sky

A survey of 158 sources (bipolar outflows and methanol masers) was carried out in the CS(2-1) and C34S(2-1) lines to measure and compare densities in a large number of bipolar outflows and in Class I and Class II methanol masers, both associated with and unrelated to bipolar outflows. The statistical characteristics of the regions, forming Class I methanol masers differ from...

Strömgren photometry of 40 Harmonia, 45 Eugenia and 52 Europa

The Asteroids 40 Harmonia, 45 Eugenia and 52 Europa have been studied photometrically. From their lightcurves synodic periods of , and , and maximum amplitudes of , and , have been deduced for 40 Harmonia, 45 Eugenia and 52 Europa, respectively. Improved solutions for the sense of rotation, sidereal period, pole orientation and shape properties are proposed.

Six years of short-spaced monitoring of the and , 28SiO maser emission in evolved stars

We present the results from a monitoring of the and , 28SiO maser emission in 21 objects, covering all types of known SiO maser emitters: 13 Mira variables, 2 long period semi regu lars (SRGs), 3 variable super giants (SGs), 2 OH/IR stars, and one young stellar object. This study has been carried out with the 13.7 meter radiotelescope of the Centro Astronómico de Yebes...

A catalog of rotational and radial velocities for evolved stars

Rotational and radial velocities have been measured for about 2000 evolved stars of luminosity classes IV, III, II and Ib covering the spectral region F, G and K. The survey was carried out with the CORAVEL spectrometer. The precision for the radial velocities is better than 0.30 km s-1, whereas for the rotational velocity measurements the uncertainties are typically 1.0 km s-1...

Starspot photometry with robotic telescopes. and by light curves of 47 active stars in 1996/97

We present continuous multicolor photometry for 47 stars from October 1996 through June 1997. Altogether, 7073 , UBV, and by data points, each the average of three individual readings, were acquired with three automatic photoelectric telescopes (APTs) at Fairborn Observatory in southern Arizona. Most of our targets are chromospherically active single and binary stars of spectral...

The luminosity function of cluster galaxies - II. Data reduction procedures applied to the cluster Abell 496

We initiated a large project aimed to estimate the Luminosity Function of galaxies in clusters and to evaluate its relation to cluster morphology. With this paper we deem necessary to outline the general procedures of the data reduction and details of the data analysis. The cluster sample includes the brightest southern ROSAT all-sky survey clusters with . These have been...