Hannah, I. , Hudson, H. , Hurford, G. and Lin, R.P. (2010) Constraining the hard X-ray properties of the quiet sun with new RHESSI observations. Astrophysical Journal, 724(1), pp. 487-492. (doi: 10.1088/0004-637X/724/1/487)
Full text not currently available from Enlighten.
Abstract
We present new RHESSI upper limits in the 3-200 keV energy range for solar hard X-ray emission in the absence of flares and active regions, i.e., the quiet Sun, using data obtained between 2005 July and 2009 April. These new limits, substantially deeper than any previous ones, constrain several physical processes that could produce hard X-ray emission. These include cosmic-ray effects and the generation of axions within the solar core. The data also limit the properties of ''nanoflares,'' a leading candidate to explain coronal heating. We find it unlikely for nanoflares involving nonthermal effects to heat the corona because such events would require a steep electron spectrum E -δ with index δ\gt5 extending to very low energies (łt1 keV), into the thermal energy range. We also use the limits to constrain the parameter space of an isothermal model and coronal thin-target emission models (power-law and kappa distributions).
Item Type: | Articles |
---|---|
Keywords: | elementary particles, Sun: activity, Sun: corona, Sun: X-rays, gamma rays |
Status: | Published |
Refereed: | Yes |
Glasgow Author(s) Enlighten ID: | Hannah, Dr Iain and Hudson, Dr Hugh |
Authors: | Hannah, I., Hudson, H., Hurford, G., and Lin, R.P. |
Subjects: | Q Science > QB Astronomy |
College/School: | College of Science and Engineering > School of Physics and Astronomy |
Journal Name: | Astrophysical Journal |
ISSN: | 0004-637X |
ISSN (Online): | 1538-4357 |
University Staff: Request a correction | Enlighten Editors: Update this record