Jeffrey W. Brosius

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Fully relativistic calculations of radiative rates and electron impact excitation cross sections for Fex are used to derive theoretical emission-line ratios involving transitions in the 174–366Å wavelength range. A comparison of these with solar active region observations obtained during the 1989 and 1995 flights of the Solar Extreme-ultraviolet Research(More)
We observed NOAA region 7563 simultaneously with Goddard Space Flight CenterÏs Solar EUV Rocket Telescope and Spectrogaph (SERTS) and with the Very Large Array (VLA) on 1993 August 17. SERTS obtained spectra in the 280È420 wavelength range, and images in the lines of Mg IX j368.1, Ó Fe XV j284.1, and Fe XVI j335.4. The VLA obtained microwave images at 20(More)
Recent fully relativistic calculations of radiative rates and electron impact excitation cross sections for Fexiii are used to generate emission-line ratios involving 3s3p– 3s3p and 3s3p–3s3p3d transitions in the 170–225Å and 235–450Å wavelength ranges covered by the Solar Extreme-Ultraviolet Research Telescope and Spectrograph (SERTS). A comparison of(More)
Context. Coordinated observations of a GOES B4.8 microflare with SDO’s Atmospheric Imaging Assembly (AIA) and the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) on 2010 July 31 show that emission in all seven of AIA’s EUV channels brightened simultaneously nearly 6 min before RHESSI or GOES detected emission from plasma at temperatures around 10 MK.(More)
We obtained coordinated observations of the large sunspot in NOAA Region 8539 on 1999 May 9 and 13 with the Very Large Array and three instruments (CDS, EIT, MDI) aboard the Solar and Heliospheric Observatory satellite. The EUVobservations reveal a plume in the sunspot umbra on both observing dates. The plume appears brightest in emission lines formed at(More)
This paper presents a completely new method for the calculation of expectations (and thus joint probability distributions) of structure factors or phase invariants. As an example, a first approximation of the expectation of the triplet invariant (up to a constant) is given and a complex number is obtained. Instead of considering the atomic vector positions(More)
Using an unbiased and very general joint density of the atomic position vectors we are able to calculate different probabilities for the sign of the quartet given its second neighborhood. One already knows that additional chemical information alters the joint probability distribution (j.p.d.) of structure factors. That is, they can and will give different(More)
It is shown that the formula for the positivity of the triplet invariant in P 1bar changes drastically if one uses a different statistical method by imposing acceptable and unbiased additional structural information. We obtain a much lower probability for the strength (almost (1/2)) of the triplet formula than the classical one.
We present a method that we call symbolic asymptotic development (SAD) to obtain joint probability distributions (j.p.d.'s) of phases of structure factors for general even densities of the atomic position vectors. The formula for the triplet and quartet invariant that we obtain in this way reduces to the well known classical formula for the case of a(More)