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  • 1
    Electronic Resource
    Electronic Resource
    Fine structure of a very bright active region at a wavelength of 2.8 cm (1974)
    Springer
    Solar physics 37 (1974), S. 395-402 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The radio structure of the active region McMath 11976 has been investigated with an east-west resolution of 16″ at a wavelength of 2.8 cm. Six bright components were found with angular sizes of the order of 20″. From the position measure of these components in two following days the heights above the solar photosphere are determined. Their positions are compared with the Hα and magnetic structure of the active region. The derived brightness temperatures reach unusual values, up to 6 × 106K for the brightest component.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00152497
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Tircam:A mid-infrared camera for ground-based astronomy (1995)
    Springer
    Experimental astronomy 6 (1995), S. 293-293 
    Details
    ISSN: 1572-9508
    Keywords: Infrared array detectors ; Infrared camera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A mid-infrared (8–22 μm) camera, equipped with a Hughes hybrid bulk Si:As array detector of 10×64 pixels was developed for the 1.5 m Italian Infrared Telescope (TIRGO). The instrument was used for narrow- band 8–14 μm high-background astronomical observations. Here we present a short description of the camera, including its fast readout electronics and its optical design. When used at TIRGO, the camera has a pixel scale of 1.23 arcsec/pix. From the observations of infrared standard stars we derived a noise equivalent flux density (NEFD) that, for all the filters, is in the range 0.5–0.7 Jy×arcsec-2×min-1/2 and a point spread function (PSF) of the order of 3 arcsec(FWHM). Mosaics of the extended sources Mars at 8.8, 9.8, and 12.5 μm, and of the star forming region Orion BN-KL Nebula at 12.5 μm, are shown. The camera performances are also illustrated on the basis of the image of the post-AGB source CRL618.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00418327
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Tircam: A mid-infrared camera for ground-based astronomy (1994)
    Springer
    Experimental astronomy 5 (1994), S. 363-374 
    Details
    ISSN: 1572-9508
    Keywords: Infrared array detectors ; Infrared camera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A mid-infrared (8 – 22 µm) camera, equipped with a Hughes hybrid bulk Si:As array detector of 10 × 64 pixels was developed for the 1.5 m Italian Infrared Telescope (TIRGO). The instrument was used for narrow-band 8–14 µm high-background astronomical observations. Here we present a short description of the camera, including its fast readout electronics and its optical design. When used at TIRGO, the camera has a pixel scale of 1.23 arcsec/pix. From the observations of infrared standard stars we derived a noise equivalent flux density (NEFD) that, for all the filters, is in the range 0.5–0.7 Jy × arcsec−2 xmin−1/2 and a point spread function (PSF) of the order of 3 arcsec(FWHM). Mosaics of the extended sources Mars at 8.8, 9.8, and 12.5 µm, and of the star forming region Orion BN-KL Nebula at 12.5 µm, are shown. The camera performances are also illustrated on the basis of the image of the post-AGB source CRL618.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01583707
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    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Solar limb brightening at 3.1 cm (1970)
    Springer
    Solar physics 13 (1970), S. 194-197 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The existence of limb brightening at the equator of the quiet Sun at 3.1 cm is derived from a statistical analysis of scans of the solar disk taken during 1968. A ratio of 0.7% is found between the flux emitted by the equatorial limb enhancements and that of a disk of uniform brightness temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00963951
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    On the nature of some active regions in the microwave range (1975)
    Springer
    Solar physics 42 (1975), S. 377-390 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The radio emission of a selected number of solar active regions has been investigated with high angular resolution at two frequencies: 10 and 17 GHz. By comparing the results of the two observations the following conclusions can be drawn: (1) The brightness temperature distribution of an active region is often composed of very bright cores of small dimension (angular extent θ≃20″) imbedded in extended halos of lower brightness. (2) The radio emission of such structures as well as the degree of polarization can be explained with a thermal process. The halos can originate by pure thermal bremsstrahlung while in the case of the very bright cores found at 10 GHz (brightness temperature T b≃1–9 × 106K) the emission at the harmonics of the gyrofrequency is needed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00149919
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    The development and structure of bright active regions at 2.8 cm (1978)
    Springer
    Solar physics 56 (1978), S. 335-350 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The development of three intense active centers during their appearance on the solar disk is examined using high resolution observations at 2.8 cm. Each region shows a very bright component with brightness temperature 〉 106 K and size smaller than 20″. The development of the bright components have been investigated on different time scales. Intensity fluctuations on a time scale of minutes are within the instrumental accuracy while the evolution over periods of days shows a variation of the flux density up to 30–40% per day. The problem of the bright cores height is discussed. Heights within 10 × 103 and 40 × 103 km are found using their apparent displacement on the disk.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00152475
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    Paper (German National Licenses)
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  • 7
    Electronic Resource
    Electronic Resource
    The impact of comet SL9 with Jupiter: IR observations at TIRGO (1994)
    Springer
    Earth, moon and planets 66 (1994), S. 83-89 
    Details
    ISSN: 1573-0794
    Keywords: Jupiter ; Comets ; Comet Shoemaker-Levy 9 ; Infrared
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Infrared images of Jupiter have been obtained on 5 nights before, during and shortly after the period of the impacts of the fragments of comet Shoemaker-Levy 9 (1993e) with the giant planet. Long lived bright spots produced by the impacts have been measured and analyzed. By measuring the intensity variation of the spots as a function of Jupiter rotation we show that these spots are likely constituted by large and thin clouds of dust located above the methane layer. The IR relative albedos has been also measured for some of these spots.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00612888
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    Paper (German National Licenses)
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