Effective collision strengths for electron impact excitation of Si VIII

Effective collision strengths for electron-impact excitation of the nitrogen-like ion Si VIII are presented over the wide range of electron temperatures log T(K) = 4.0-6.5. All 231 fine- structure transitions among the 22 fine-structure levels arising from the lowest 11 LS target states (2s(2)2p(3), 2s2p(4), 2p(5), and 2s(2)2p(2)3s) are considered in the tabulation. The collision strengths are evaluated in a multi- channel R-matrix approach, and the corresponding effective collision strengths are obtained by averaging these over a Maxwellian distribution of electron velocities. Comparisons are made with recent distorted-wave results at high incident electron energies. Differences of up to 20% are found, particularly for some allowed transitions. (C) 2003 Elsevier Inc. All rights reserved.

Electron impact excitation of Mg VIII: Collision strengths, transition probabilities and theoretical EUV and soft X-ray line intensities for Mg VIII

Context: Mg VIII emission lines are observed in a range of astronomical objects such as the Sun, other cool stars and in the coronal line region of Seyfert galaxies. Under coronal conditions Mg VIII emits strongly in the extreme ultraviolet (EUV) and soft X-ray spectral regions which makes it an ideal ion for plasma diagnostics.

Aims. Two theoretical atomic models, consisting of 125 fine structure levels, are developed for the Mg VIII ion. The 125 levels arise from the 2s(2)2p, 2s(2)p2, 2p(3), 2s(2)3s, 2s(2)3p, 2s(2)3d, 2s2p3s, 2s2p3p, 2s2p3d, 2p(2)3s, 2p(2)3p and 2p(2)3d configurations. Electron impact excitation collision strengths and radiative transition probabilities are calculated for both Mg VIII models, compared with existing data, and the best model selected to generate a set of theoretical emission line intensities. The EUV lines, covering 312-790 angstrom, are compared with existing solar spectra (SERTS-89 and SUMER), while the soft X-ray transitions (69-97 angstrom) are examined for potential density diagnostic line ratios and also compared with the limited available solar and stellar observational data.

Methods. The R-matrix codes Breit-Pauli RMATRXI and RMATRXII are utilised, along with the PSTGF code, to calculate the collision strengths for two Mg VIII models. Collision strengths are averaged over a Maxwellian distribution to produce the corresponding effective collision strengths for use in astrophysical applications. Transition probabilities are also calculated using the CIV3 atomic structure code. The best data are then incorporated into the modelling code CLOUDY and line intensities generated for a range of electron temperatures and densities appropriate to solar and stellar coronal plasmas.

Results. The present effective collision strengths are compared with two previous calculations. Good levels of agreement are found with the most recent, but there are large differences with the other for forbidden transitions. The resulting line intensities compare favourably with the observed values from the SERTS-89 and SUMER spectra. Theoretical soft X-ray emission lines are presented and several density diagnostic line ratios examined, which are in reasonable agreement with the limited observational data available.

Receipt from the Estate of Henry Carlisle, St. Catharines for payment on account

Receipt from the Estate of Henry Carlisle, St. Catharines for payment on account, Dec. 31, 1887.

Appointment of Phyn Ellices and Inglis to be the lawful attorneys of Henry W. Nelles

Appointment of Phyn Ellices and Inglis to be the lawful attorneys of Henry W. Nelles, June 20, 1788.

Examination of Henry Nelles (2 double-sided pages, handwritten)

Examination of Henry Nelles (2 double-sided pages, handwritten). The pages are stained and contain some holes. This affects some of the text. [These are copies of the answers from the previous document], 1830.

Will of Henry Pellatt

A certified copy of the Will of Henry Pellatt received by Joseph Tait, Registrar, 1905.

The golden lion of granpere : A novel

UANL

Henry VIII and his court : Catharine Parr ; an historical novel

UANL

Care of Henry.

La madre de Hugo debe ir al hospital para tener un bebe y él tiene que decidir con quien se queda los días que su mamá este ausente. Se quedará con la abuela, con la señora Mariposa, con el tío Jack. La clave esta en su perro Henry.

Care of Henry.

La madre de Hugo debe ir al hospital para tener un bebe y él tiene que decidir con quien se queda los días que su mamá este ausente. Se quedará con la abuela, con la señora Mariposa, con el tío Jack. La clave está en su perro Henry. Edición idónea para la lectura compartida.

Henry VIII to Mary I : government and religion, 1509-58.

Su contenido se adapta a las especificaciones AS de 2008 para AQA, Edexcel y OCR. Analiza la evolución política y religiosa de este período, se examina la personalidad de Enrique VIII y la ascensión y caída de Wosley, la reforma religiosa, la ruptura con Roma y la disolución de los monasterios. También, evalúa la efectividad del reinado de Enrique y de sus sucesores, Eduardo y María, así como proporciona una visión general de los cambios en la Iglesia y en el Estado en este período. Incluye fechas clave, términos y temas, perfiles biográficos, resúmenes esquemáticos, fuentes literarias y síntesis de los principales debates historiográficos.