In the PROJECT we are using the following peculiar . features of RATAN-600 . ... Brightness temperature sensitivity being equal to the antenna temperature sensitivity .. ... Receiver system .. ... Using aperture averaging effect. dual- beam and dual (multi-) frequency filtration, we demonstrated full filtration of the atmosphere noise down to the receiver noise at all scales of acoustics peaks ( Fig.1 , Fig 2 ). ... We select this frequency as the central one in our project. ... Antenna surface . ...

... Using a simple 2-D Gaussian Point Spread Function (PSF) on a constant (flat) sky background, I derive a theoretical photometric and astrometric performance model for analytical and digital PSF-fitting stellar photometry. ... The photometric performance is maximized when either the effective background area or the effective-background-level measurement error is minimized. ... An important, but frequently ignored, noise source is the uncertainty of the measurement of the effective background level ( )...

The new generation radio interferometer . ... 5000 km on the basis of square kilometer phased arrays. It is shown that this interferometer will have the sensitivity ~ 1 mJy at a frequency 100 MHz. ... VLBI interferometer, Active Galactic Nuclei, cosmology, effective area, sensitivity. ... Для исследований физических условий в активных ядрах галактик и космологических исследований необходимы низкочастотные наблюдения компактных радиоисточников с большой чувствительностью и разрешением. ...

Find Similar Abstracts . ... The turbulent dynamo in astrophysics . ... Astrophysics . ... ASTROPHYSICS, DYNAMO THEORY, GALACTIC STRUCTURE, INTERSTELLAR MAGNETIC FIELDS, TURBULENCE EFFECTS, COSMIC PLASMA, COSMOLOGY, MAGNETIC FIELD CONFIGURATIONS, PLASMA TURBULENCE, SOLAR MAGNETIC FIELD, VORTICES . ... Use: Authors Title Abstract Text Text Query with Keywords Return: Query Results Query Form Database: Astronomy Instrumentation Physics and Geophysics ABSTRACT QUERY USER FEEDBACK HELP ...

... We also present independent relationships between the visual surface brightness parameter FV and the colours (V \Gamma R), (V \Gamma I), (R \Gamma I) and (V \Gamma K). We find that (U \Gamma B) and (B \Gamma V ) are unsuitable as T eff indicators. The tightest relationship in each case is found for the (V \Gamma K) index. Our mean relationships agree reasonably well with similar relationships derived by other authors, where such are available. ...

... The task accepts two sources lists: the observation source list and the exposure source list. ... List of selected sources. This le contains a table, called SRCLIST, with the following columns: Name Type Description SRC NUM Integer Source ID from observation source list RA Double RA from exposure source list DEC Double Declination from expoure source list RATE Real Count rate from observation source list COUNTS Real Number of source counts, from exposure source ...

... ALMA . ... OOF software . ... Software . ... We present a framework for modelling atmospheric phase errors and their correction by both the fast-switching and water vapour radiometeric techniques. Notable features are simulating three dimensional turbulent volumes instead of flat phase screens, considering three representative configurations of ALMA and parametrisation in terms of phase fluctuations on a 300m baseline, allowing referencing to the site-testing interferometer data. ...

Next] [WFPC2 ISR Index] . ... The characteristics of charge transfer traps in the WFPC2 are examined and the effect they may have on observations are discussed. The dark tail created just above the location of the trap, as well as any bright tail created in the column above the trap when a bright source is clocked out during the readout, can be modeled as simple exponential decays. ... A portion of a WF2 image (before cosmic ray removal) showing the location of five of the seven traps on WF2. ...

ASC-FITS-2.0.1: ASC FITS File Designers' Guide (Rots and McDowell) (1999 Jun) . ASC-FITS-REGION-1.0: FITS region document (McDowell and Rots) (1998 Mar) . ... CXC-DM-001 Introduction: Data Analysis with the Chandra Data Model (2001 Oct) . ... 1998 Feb 26: SDS-1.0: Data Product List: obsolete . ... 1998 Mar 09: SDS-10.0: (ASC-FITS-REGION-1.0) FITS region document: see ASC-FITS-REGION-1.0 . 1998 Feb 09: SDS-11.0: FITS function document (superseded by ASC-FITS-FUNCTION-1.2) . ...

The parameter brief (with its actual uncertainty sbrief) is the mean effective surface brightness in B-band , i.e. the mean surface brightness inside the effective aperture (the circular aperture enclosing one-half the total flux). It is expressed in mag arcsec -2 . ... 2) from the mean surface brightness "LV" inside the effective isophote (elliptical isophote enclosing one half the total flux) measured by Launberts&Valentijn (1989) . ... Effective radius . ... HyperLeda . ...

. Diameter of circular antenna . 576 m . Number of antenna elements . 895 . Size of an element . 11.4 x 2 m . Geometrical area . 15000 m 2 . Effective area of full circle . 3500 m 2 . Wavelength range . 1 - 50 cm . Frequency range . 610 - 30000 MHz . Maximum angular resolution . 2 arcsec . Accuracy of coordinate determination . 1-10 arcsec . Flux density limit . 0.500 mJy . Absolute brightness temperature limit . 0.050 mK . Tracking time (South sector + Flat mirror) . 1-3 h . [RATAN-600 Homepage]

... The Miriad task uvgen can be used to simulate a variety of observing modes. ... Simulating a telescope approximately, let alone in some detail, requires a good many parameters. uvgen takes an appreciable number of parameters and input files to describe the telescope, correlator and source. Fortunately keyword and set-up files for some common situations exist ( e.g. simulating the ATCA and VLA). ... For example, to load typical parameters for the ATCA, use miriad% source $MIRCAT/uvgen.def.atca . ...

... We study in this paper the effect of shock excitation of leaky and surface modes by the p-polarized electromagnetic wave incident on the rapidly ionized gaseous or solid layer. ... For example, if [pic] (solid density, multiple ionized plasma), the basic frequency [pic], [pic], [pic] we find, that the wavelength of leaky wave [pic] is in soft x rays band. ... If [pic] (low density gaseous plasma), the basic frequency [pic], [pic], [pic] we find, that the wavelength of leaky wave [pic] is in THz band...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

Authors: V.A. Marsakov , Yu.G. Shevelev , . Journal: 1988, Astron Zh. ... Absolute magnitudes, metallicities, effective temperatures, surface gravities, distances, and tangential velocities are calculated for 5498 F stars with homogeneous data on uvby photometry and proper motion, and placed within 80 pc from the Sun. Components of space velocities, eccentricities of galactic orbits, perigalactic and apogalactic distances, and maximal remotness from galactic plane are presented for 1787 stars. ...

... Science . ... Science Users Information > Science Activities > PhD Thesis Topics offered by ESO Faculty Members > Thesis Topic: Next generation Fornax Cluster surveys . ... Data Handling and Products . ... Science Data Products Forum . ... An international team, with Dr. Hilker as Co-PI, has started to gather wide-field optical and infrared imaging data as well as spectroscopic data on the whole extent of the Fornax cluster, mainly based on observations with ESO telescopes (VLT, VST, VISTA). ...

... The object is remarkable because of its low estimated mass and age and because it is associated with a mid-infrared source, an indication of a surrounding dusty disk. Based on the comparison of our spectrum with similar spectra of field M-dwarfs and atmospheric models, we obtain revised estimates of the spectral type, effective temperature and luminosity of the central object. ...

Astronomy Picture of the Day . Maria Mitchell Inspires a Generation . ... 16.10.1999 . ... On October 1, 1847 Maria Mitchell swept the sky with her telescope and discovered a comet (comet Mitchell 1847VI). Honored and recognized internationally for her discovery, Mitchell , who lived from 1818 to 1889, became one of the most famous American scientists of her day . ... October 1999 . ... NASA Web Site Statements, Warnings, and Disclaimers . ... U. Based on Astronomy Picture Of the Day . ...

A1441 2000-May-31 12:43:02 Technical Page Proposal Type: Regular General Category: Astronomy Sub-Category: Spectroscopy Observation Category: Extragalactic Total Time Requested: 30 Hours Proposal Title: Search for AGN Malin Galaxies ABSTRACT: This project is to obtain H I measurements of a newly discovered sample of massive, low surface brightness (LSB) galaxies. These galaxies represent new extremes in M T =L, MHI =L, the ratio of stars to gas, total size and dynamical mass. ...

... It is found that the correlation coefficients between these two parameters calculated separately inside and outside the sunspot formation zone ±30 have cyclic variation and occur in anti-phase. This suggests different mechanisms of formation of the corona in the fields of small, medium, and large scales. ... The relationship between the coronal green line brightness (CGLB) and the magnetic field strength (MFS) has been investigated by constructing the corresponding synoptic maps for the 1977-2001. ...