explanation blue bibcodes open ADS page with paths to full text
Author name code: vannieuwkoop
ADS astronomy entries on 2022-09-14
author:van Nieuwkoop, Jaap year:1960-2000
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Title: Book reviews
Authors: Humphreys, R. M.; Kemp, S.; Savonije, G.; van der Hucht,
K. A.; van der Kruit, P. C.; Miley, G.; Bumba, V.; van Nieuwkoop,
J.; van Hoolst, T.; Cox, A.; Rutten, R. J.; Kleczek, J.; de Jager,
Cornelis; Jerzykiewicz, M.; Zwaan, C.; Poedts, S.; Sakai, Jun-Ichi;
Pecker, J. -C.; Heikkila, W.; de Jong, T.; Wilson, P. R.; Müller,
E. A.; Hoyng, P.; Icke, V.; Shore, S. N.; Achterberg, A.; Lucchin, F.;
Butcher, H.; Ne'Eman, Y.; Heidmann, J.; Belton, M. J. S.; de Graauw,
Th.; Waters, L. B. F. M.; Pacini, F.; Hultqvist, B.; Akasofu, S. -I.;
Vial, J. -C.; Schatzman, E.; van der Laan, H.; Cole, K. D.; Vanbeveren,
D.; Southwood, D.; van der Klis, M.; Katgert, Peter
1996SSRv...76..339H Altcode:
No abstract at ADS
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Title: Fine Structure in Solar Microwave Bursts
Authors: Allaart, M. A. F.; van Nieuwkoop, J.; Slottje, C.; Sondaar,
L. H.
1990SoPh..130..183A Altcode:
We have designed and constructed a new multi-channel radio spectrograph
for the study of short-lived structures in solar microwave bursts. It
measured the integrated flux over the whole solar disc in two circular
polarizations at 36 frequencies between 4 and 8 GHz, with a time
constant of 0.5 ms. We have analyzed all 119 recorded bursts observed
in 1981 and 1983. We focused our attention on events with a lifetime
of less than 1 s. Fine structure occurs in about 30% of the observed
bursts, and can be as rich in detail as in bursts observed at lower
frequencies. We found at least four different classes of events. In one
event neither bandwidth nor time resolution of the receiver appear to
be sufficient to resolve the fine structure. The bulk of the drifts
is found to be towards higher frequencies. Periodic flux variations
were found in two cases.
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Title: Positional Drift Within Groups of Type-I Solar Radio Bursts
Authors: van Nieuwkoop, J.
1986SoPh..103..129V Altcode:
In the dynamic spectrograms of the 60-channel solar radiospectrograph at
Dwingeloo coherent groups of Type I bursts have been selected. At 243
MHz the positions of the bursts were measured. Within many groups the
bursts showed a systematic angular displacement with time. Movements
with apparent velocities up to 15000 km s<SUP>−1</SUP> have been
observed. The burst positions have been obtained with a two-element
interferometer. A special data reduction method used the amplitude
variation of the Type I bursts as a parameter for selection against
the background radiation.
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Title: VLBI of solar flares
Authors: Tapping, K. F.; Kuijpers, J.; Kaastra, J. S.; van Nieuwkoop,
J.; Graham, D.; Slottje, C.
1983A&A...122..177T Altcode:
From April 28 to May 3, 1981, a VLBI experiment was carried out
to observe small spatial scales in the initial energy release
in solar flares. The 25 m radio telescope at Onsala (Sweden) and
Dwingeloo (Netherlands) were used; the observing wavelength was 18
cm. Simultaneous observations were made using the Westerbork Synthesis
Radio Telescope at a wavelength of 6 cm. The VLBI baseline was 619
km. During the observing period, three weak outbursts were observed,
none yielding any strong correlated signals. However, the statistical
behaviour of the correlator output over the range of delay channels
shows significant indications of a correlated signal having a signal
to noise ratio of order unity, during the impulsive spikes preceding
the main phase of the event.
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Title: Digitally recorded type I bursts and some theoretical aspects
of continuum and burst generation
Authors: Kattenberg, A.; van Hees, R. M.; van Nieuwkoop, J.
1980IAUS...86..259K Altcode:
An analysis of digitally recorded type-I bursts is presented. The
reduction procedure is described and some typical examples and results
are presented. A model for type-I emission, compatible with low magnetic
field strengths, is proposed. Incoherent Langmuir waves, spontaneously
emitted by trapped fast electrons, are converted to transverse radiation
by coalescence with low-frequency whistlers. Recurrent upper hybrid
instability in strong MHD pulses explains the bursts in this model.
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Title: Radioastronomische waarneemtechnieken: 1950 - 1980.
Authors: van Nieuwkoop, J.
1980Zenit...7..416V Altcode:
No abstract at ADS
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Title: A model of type I emission compatible with low magnetic
field strengths
Authors: van Hees, R. M.; van Nieuwkoop, J.
1978cesra...7...44V Altcode:
No abstract at ADS
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Title: Book reviews
Authors: Nieuwenhuijzen, H.; van den Heuvel, E. P. J.; Heintze,
J. R. W.; Hultqvist, Bengt; van Nieuwkoop, J.; 't Hooft, G.; Raadu,
M. A.; Zealey, W. J.; Verhulst, Ferdinand; Boström, Rolf; Schindler,
K.
1976SSRv...19..273N Altcode:
No abstract at ADS
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Title: De nijmeegse radio-interferometer.
Authors: Atanasijevic, I.; Bluyssen, H.; Dongen, L. V.; ten Horn,
L.; Maas, L.; van Nieuwkoop, J.
1975dnr..book.....A Altcode:
No abstract at ADS
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Title: Some preliminary results of multi-channel radiospectrography
Authors: De Groot, T.; Van Nieuwkoop, J.
1968SoPh....4..332D Altcode:
No abstract at ADS
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Title: A Radio Spectrograph with High Sensitivity and High Time
Resolution
Authors: van Nieuwkoop, J.
1964Natur.201..380V Altcode:
WORK has recently been done on the fine structure in time of solar
radio emission. This fine structure is characterized by short-lived
variations of the intensity; they may have either small or large
intensities<SUP>1</SUP>.
