This paper presents the observations of a complete sample of radio sources at the 0.97, 2.3, 3.9, 7.6, 11.1, and 21.7 GHz frequencies with the RATAN-600 radio telescope. The sample includes all sources stronger than 200 mJy from the MGB-survey at 4.85 GHz in the declination zone 10o-12o30' (J2000) and |b| > 15o. Flux densities for all sources with flat spectra at 0.97-21.7 GHz frequency range were determined. Eighty six per cent of sources with flat spectra and 59% of sources with steep spectra were identified with optical objects. The flat spectrum sources were separated into extended and compact components.
Automation of the South sector and the Periscopic reflector of RATAN-600 increased the efficiency of solar investigations with the radiotelescope and made it possible to develop a method of multiazimuth observations. In combination with the multiwave solar receiver complex, this method provides a possibility to study dynamic characteristics of solar structures in a wide range of radiowaves and to carry out two-dimensional mapping of the Sun simultaneously at many wavelengths. The time resolution of 4 minutes within 4 hours of observations is now achieved, in azimuthal range from +30o up to -30o. The methods and programmes developed for the implementation of the multiazimuth observations mode are presented in this paper.
The results of the spectral observations of the sample of barred galaxies with twists of inner isophotes usually named a "secondar bar" are described. The ionized gas and stars' velocity fields and the fields of radial velocity dispersion were constructed from integral-field spectroscopy observations at the 6 m telescope of SAO RAS. Various types of non-circular gas motions were found: radial flows in the large-scale bars, counter-rotation of the gas and stars in NGC 3945, polar gaseous disk in NGC 5850 etc. The analysis of the ground-based and the Hubble Space Telescope optical and NIR images reveals circumnuclear mini-spirals in 5 objects. It is shown that the inner (secondary) bars in galactic images do not affect the circumnuclear stellar and gaseous kinematics. Thus the secondary bar is not a dynamically decoupled structure, contrary to the common point-of-view. The Author suggests that the so-called "double-barred galaxies" are, in fact, galaxies with very different circumnuclear structure rather than distinct type galaxies.
An introduction to the problem of spectroscopic investigations of halo stars is given. A requirements to spectroscopic data suitable for studying the abundances of chemical elements in the atmospheres of the oldest objects of the Galaxy are formulated. A method is described for observations and reduction of spectral material. Characteristic properties of the method of producing an atlas of spectra and line identifications are noted. An atlas of spectra in the range 3500-5000 with the spectral resolution R=60000 is presented for four objects in the interval of metallicities -3.0 < [Fe/H] < -0.6, temperatures 4750 < Teff < 5900K, luminosities 1.6 < < 5.0. Parameters of model atmospheres and abundances of 29 chemical elements and their ions are determined. The abundance determination errors for different chemical elements are inspected.
Results of spectral and photometric observations of a sample of candidates for double-barred galaxies are presented. The fields of ionized gas and stars velocities and fields of the stellar velocity dispersion were constructed from integral-field spectroscopy observations at the 6m telescope by using the spectrograph MPFS and scanning interferometer Fabry-Perot. The optical and NIR images of galaxies were obtained from observations at the 6m telescope of SAO RAS, 2.1m telescope (Mexico) and Hubble Space Telescope. The morphological and kinematic features of all 13 objects in the sample are described. Attention is focussed on the interpretation of observed non-circular motions of gas and stars in circumnuclear (one kiloparsec-scale) regions.
The main extent of work on the creation, testing and placing in service of a complex of spectroscopic instruments is reported to have been completed. The complex incorporates present-day CCD and is located on the 6m telescope BTA. The system is in use for up to 30% of the calendar time of the telescope and primarily intended for investigations of stars and star-like objects in a wide range of stellar magnitudes (to mv=18) and spectral resolutions (R=2500-82000). Using the basic characteristics of the complex, the question of information capacity of astronomical spectrographs is discussed. The reserve of the created observing techniques is evaluated.
Results are the presented of adaptation of a CCD (2048x2048 pixels, "Uppsala CCD") to an echelle spectrograph with a large collimated beam diameter (NES), which is located on the Nasmyth focus platform of BTA. Compared to the former detector (a CCD of 1160x1140 pixels), the throughput of the spectrograph has increased by 2 stellar magnitudes; the positional instability of spectrograms has diminished, the number of spectral elements transmitted simultaneously has increased by nearly a factor of 4. Spacimens of spectra of different objects and other information that makes it possible to plan observations with the spectrograph are presented.
Based on spectroscopic (resolution R=60000) and spectropolarimetric (R=15000) observations with the 6m telescope, the details of photospheric and circumstellar origin in the optical spectrum of the bipolar proto-planetary nebula AFGL 2688 were separated for the first time. An identification of absorption feature, the photospheric spectrum (about 200 lines in the range 4650-6050 ) was performed, radial velocities were measured. The rotational structure of the heads of emission Swan bands of the C2 molecule was resolved. The P Cygni component of the line profile of the resonance sodium doublet, which forms in the optical lobes of the nebula was isolated. Linear polarization in the range 5000-6600 was measured from spectropolarimetric observations. It was established that emission in the lines of the resonance sodium doublet and Swan bands form in the envelope, resonance fluorescence being the mechanism of excitation of the bands. The published results of many observations of AFGL 2688 in the optical, infrared, submillimeter and centimeter ranges are being discussed. From the collection of earlier and new observations in the optical range kinematic structure of the nebula is proposed. The envelope lost at the AGB stage is expanding at a velocity 23km/s. Motions with a velocity of 40km/s, which are characteristic of the post-AGB stage, are observed in the nebula. The inclination angle of major axis of the nebula, which connects the optical lobes, to the picture plane is 7o. The mass of the central star is 1.2, the luminosity is 4X104L. Comparison of the results of determination of chemical composition of the central star and envelope allows to suggest that when losing matter at the post-AGB stage, the layers of the stellar envelope processed in the CN cycle become uncovered. A conclusion is drawn that the AFGL 2688 progenitor star was very massive.
Creation of a digital television system for BTA is repoted. The complex digitizes video information from the 3 foci of BTA. This allows more reliable identification of an object, guiding by its digital video image and also accumulation and processing of TV images to be performed. The digital TV complex has been designed on the basis of the video server with a frame grabber VS56/VS60. The server has inputs for 4 independent television analog signals of the BTA TV guide cameras with programme-controlled selection of one of them for subsequent digitization of the video image. The programmes of control of the video server and of the processing of TV information, including guiding by the object digital video image, are written to run under the OS Linux. This enables connection to the video server from any computer in the local network of SAO and independent processing of observed images.
General principles of organization and the methodology of constructing an automation complex to prepare and implement observations with the RATAN-600 are described. The complex USS is considered as an integrated system combining the key radio telescope subsystems and providing their qualitatively new and interconnected development and operation.
The algorithms used for reduction of data obtained with the new focal reducer of the 6m telescope SCORPIO in a Fabry-Perot mode are described. The main attention is given to the procedures of a photometry correction of channels and night sky emission subtraction, that are especially important for observations with a CCD as compared with the photon counter. The influence of various sources of errors on measurements of radial velocities in a data cube is investigated. The examples of velocity field construction with using emission and absorption lines in the galaxy NGC 6951 and globular cluster í 71, respectively, are presented.
The main results of development and adoption of the observational databank ODA-R for the radio telescope RATAN-600 are described. The created databank is the multidatabase distributed information system included into the round-the-clock observational cycle of the radio telescope. The ideology of construction of the system, the archiving technology of observational material and the access to archive information are discussed. The results of multiyear archive statistics are given.
Based on CCD spectra obtained with the echelle spectrometers of the 6 m telescope, a spectral atlas has been made for the low luminisity LBV stars HD168625 and HD160529, white hypergiants - candidates for LBV HD168607 and AS314, and the supergiant HD183143. The interval from 4800 A to 6700 A is presented in a graphical and table form with a resolution of 0.4 A. 380 lines and DIB are identified. Spectroscopic distinguishing features of the objects are described.
Testing of a spectropolarimeter made on the basis of the echelle spectrometer LYNX is reported. Characteristics of the technique that measures the four Stokes parameters in spectra recorded with a resolution R=25000-30000 are given. Specimens of observational data are presented.
It is reported on the designing of a technique for linear polarization measurement with high spectral resolution. Results of the first observations are presented. Prospects of development of the method are evaluated.