Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 0708.0550

On The Mass and Energy Loading of EUV Brightpoints

Scott W. McIntosh
View original source ↗Read source document ↗Export metadata ↓

Abstract

We discuss the appearance of EUV brightpoints (BPs) in the analysis of long-duration observations in the He II 304 Angstrom passband of the Solar and Heliospheric Observatory (SOHO) Extreme-ultraviolet Imaging Telescope (EIT). The signature of the observed 304 Angstrom passband intensity fluctuations around the BPs suggest that the primary source of the mass and energy supplied to the magnetic structure is facilitated by relentless magnetoconvection-driven reconnection, forced by the magnetic evolution of the surrounding supergranules. Further, we observe that if the magnetic conditions in the supergranules surrounding the footpoints of the cool 304 Angstrom BPs are sufficient (large net imbalance with a magnetic field that closes beyond the boundaries of the cell it originates in) the magnetic topology comprising the BP will begin to reconnect with the overlying corona, increasing its visibility to hotter EUV passbands and possibly Soft X-Rays.

Explore related subjects

astro-ph

Keep this discovery

BibTeXRIS

Scott W. McIntosh. 2007-08-03. On The Mass and Energy Loading of EUV Brightpoints. https://doi.org/10.1086/521948

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2010

Circumstellar water vapour in M-type AGB stars: Radiative transfer models, abundances and predictions for HIFI

Aims: By performing a detailed radiative transfer analysis, we determine fractional abundances of circumstellar H2O in the envelopes around six M-type asymptotic giant branch stars. The models are also used to predict H2O spectral line emission for the upcoming Herschel/HIFI mission. Methods: We use Infrared space observatory long wavelength spectrometer spectra to constrain the circumstellar fractional abundance distribution of ortho-H2O, using a non-local thermal equilibrium, and non-local, radiative transfer code based on the accelerated lambda iteration formalism. The mass-loss rates and kinetic temperature structures for the sample stars are determined through radiative transfer modelling of CO line emission based on the Monte-Carlo method. The density and temperature profiles of the circumstellar dust grains are determined through spectral energy distribution modelling using the publicly available code Dusty. Results: The determined ortho-H2O abundances lie between 1e-4 and 1.5e-3 relative to H2, with the exception of WX Psc, which has a much lower estimated ortho-H2O abundance of only 2e-6, possibly indicating H_2O adsorption onto dust grains or recent mass-loss-rate modulations. The estimated abundances are uncertain by, at best, a factor of a few. Conclusions: The high water abundance found for the majority of the sources suggests that either the `normal' chemical processes are very effective in producing H2O, or else non-local thermal equilibrium atmospheric chemistry, grain surface reactions, or a release of H_2O (e.g. from icy bodies like Kuiper belt objects) play a role. We provide predictions for ortho-H2O lines in the spectral window of Herschel/HIFI.

astro-ph↗
arXiv2010

CMB Anisotropies and Inflation from Non-Standard Spinors

The apparent alignment of the cosmic microwave background multipoles on large scales challenges the standard cosmological model. Scalar field inflation is isotropic and cannot account for the observed alignment. We explore the imprints, a non-standard spinor driven inflation would leave on the cosmic microwave background anisotropies. We show it is natural to expect an anisotropic inflationary expansion of the Universe which has the effect of suppressing the low multipole amplitude of the primordial power spectrum, while at the same time to provide the usual inflationary features.

astro-ph↗