... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Risks Comparable to NEOs . ... The Increasing Rate of Discovery of Asteroids . ... Comet and Asteroid Collision Probabilities . ... Extreme albedo comets and the impact hazard (PDF Format) . ... Asteroid Impact Animations . ... Workshop on Scientific Requirements for Mitigation of Hazardous Comets and Asteroids - 2002 . ... The Spaceguard Survey Report, 1992 (PDF) . Tsunami from Asteroid/Comet Impacts . ...

... The measured Mg2 index corresponds to a certain defined region of the object and, after systematic corrections applied to series of measurements, it is reduced to a common standard aperture (for galaxies only). The compilation of Mg2 measurements may be accessed in HyperLeda. mg2 is the Mg2 index in mag. The Mg2, as well as velocity dispersions, are standardized to an aperture r norm of 0.595 h -1 kpc, which is equivalent to an angular diameter of 3.4 arcsec at the distance of Coma. ...

... User Guide ] Task: imfit Purpose: Fit models to a given image dataset Categories: image analysis IMFIT is a Miriad task that fits model components to an image. ... Key: clip Clip level. ... Possible objects are: level An offset (DC) level gaussian An elliptical or circular gaussian. disk An elliptical or circular disk. point This is a short-hand for a gaussian with the width of the point-spread-function. beam This is a short-hand for a gaussian with a peak value of 1 and located at the image centre....

... The BL Lac objects found within DXRBS fall mostly in the range . ... A large fraction of the BL Lacs so far in our sample are at L X / L R < 10 -6.5 , the region of Figure 6 populated by LBLs. In this region of parameter space (to the left of the left-most dashed line in Figure 6), DXRBS includes objects up to two orders of magnitude fainter than the 1 Jy survey. ... For comparison, we have plotted the values for members of these three ROSAT-based surveys (DXRBS, HQS/RASS and RC) in Figure 7. ...

slitless -- Extract a spectrum from a direct/GRISM image pair slitless image grism output PARAMETERS . ... A two dimensional direct image to be used to select an object. grism . A two dimensional GRISM image containing slitless spectra of objects present in the direct image. output . ... Toggle whether or not a background estimate is subtracted from the extracted object spectrum. mingood = INDEF . Pixels of the grism image with values smaller than this are ignored. maxgood = INDEF . ...

... The project assumes creation of an international space observatory - the interferometer "Earth - Space - Space" in order to perform of astronomical investigations in millimeter, submillimeter and infrared regions with extremely high sensitivity (to a few nanoJanskies units of flux density in continuum spectrum) and extremely high angular resolution (to a parts of microsecond of arc or, possibly, nanosecond). ... radio-interferometric channels of the system "Space - Space", region 0.2 - 3 mm; . ...

... Next: Object Detection Using Up: Object Detection and Previous: Automated Classification of . ... A status report of the The GSC Object Classifier (GOC) project is presented. ... The GSC contains multiple entries for some objects due to plate overlap. It classifies objects as stars, non-stars, galaxies, blends and potential artifacts; the latter three classifications are rare, and only exist in GSC version 1.1, to which they were added manually. ... star, . ... non-star, . ...

... This effect is visible in Figure 4.3 which shows a logarithmic stretch of the image resulting from a 100s exposure on a star of V magnitude 2.6 through filter F502N in the PC. Extreme overexposure of the Loral CCDs is not believed to cause any permanent effects, and therefore the WFPC2 does not have a bright object limit. ... Several other artifacts that are common in saturated stellar images are also obvious in Figure 4.3 . ... Figure 4.3: Saturated Stellar Image Showing Horizontal Smearing. ...

... The spectrograph is designed for detailed studies of extended objects - galaxies and HII regions with a moderate spectral resolution. ... The updated Universal Astronomical Grating Spectrograph (UAGS, Carl Zeiss Jena) with a fast Schmidt camera is a base of the Long Slit Spectrograph (LSS). A cryostated Charge Coupled Device (CCD) detector is built inside the Schmidt camera. ... It was realized in the Laboratory of Spectroscopy and Photometry of Extragalactic Objects of SAO RAS. ... Camera . ...

... This section will deal with obtaining photons within specified regions of an image. Available regions are: Annulus Box Circle Ellipse Field -- entire field Irregular region based on intensity of map... i.e. region defined by contour levels. ... The imcnts task in the xray-spatial package sums the source and background counts in specified regions, and subtracts one from the other properly normalized. ... imcnts* - Find counts in an extended region, after removing an embedded point source . ...

Subject, Problems and Objects of Theoretical Astrophysics. ... Stellar Photospheres, Their Features. ... Physics of Continuous Radiation Absorption in Stellar Photospheres. ... Continuous Radiation Absorption in Stellar Photospheres of Various Spectral Classes. Solar Type Photospheres. ... Characterisics of Absorption Lines. ... Interstellar Absorption Lines, Their Features. ... Physical and Dynamic Features of Interstellar Medium, Which Follows from Observations of Interstellar Absorption Lines. ...