J/ApJS/210/12 Solar photoionization rates (Bochsler+, 2014)
Solar photoionization rates for interstellar neutrals in the inner heliosphere:
H, He, O, and Ne.
Bochsler P., Kucharek H., Mobius E., Bzowski M., Sokol J.M., Didkovsky L.,
Wieman S.
<Astrophys. J. Suppl. Ser., 210, 12 (2014)>
=2014ApJS..210...12B 2014ApJS..210...12B
ADC_Keywords: Atomic physics ; Interstellar medium ; Sun ; Ultraviolet
Keywords: atomic processes; ISM: atoms; Sun: heliosphere; Sun: UV radiation
Abstract:
Extreme UV (EUV) spectra from the Thermosphere Ionosphere Mesosphere
Energetics and Dynamics (TIMED)/Solar EUV Experiment are used to infer
photoionization rates in the inner heliosphere. Relating these rates
to various proxies describing the solar EUV radiation, we construct a
multi-linear model which allows us to extrapolate ionization rates
back to periods when no routine measurements of the solar EUV spectral
distribution have been available. Such information is important, e.g.,
for comparing conditions of the interstellar neutral particles in the
inner heliosphere at the time of Ulysses/GAS observations with
conditions during the more recent observations of the Interstellar
Boundary Explorer. From a period of 11 yr when detailed spectra from
both TIMED and three proxies -- Solar and Heliospheric
Observatory/CELIAS/SEM-rates, F10.7 radio flux, and Mg II core-to-wing
indices -- have been available, we conclude that the simple model is
able to reproduce the photoionization rates with an uncertainty of
typically 5%.
Description:
Using the spectral data for solar extreme UV (EUV) routinely available
from Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Solar
EUV Experiment (TIMED/SEE), we have derived the photoionization rates
of H, He, O, and Ne at the location of the Earth for the period from
the launch of TIMED in 2002 up through the end of 2012. We compared
these rates with a set of three proxies, count rates from the Solar
Extreme Ultraviolet Monitor (SEM) on the Charge, ELement, and Isotope
Analysis System (CELIAS) of the Solar and Heliospheric Observatory
(SOHO) spacecraft, the F10.7 cm radio flux, and the MgII core-to-wing
index.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 51978 Photoionization rates for H, He, O, and Ne at the
location of the Earth
table2.dat 49 12210 Adjusted radio-flux rates
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See also:
J/ApJ/717/674 : Ionization energies of CnN(n=4-12) (Kostko+, 2010)
J/ApJ/707/482 : Models of the solar atmosphere. III. (Fontenla+, 2009)
J/ApJ/667/1119 : Photoionization of H in strong magnetic fields (Zhao+, 2007)
J/A+A/439/387 : Absolute photoionization cross sections (Bizau+, 2005)
J/A+A/432/1063 : Analysis of inner solar corona in EUV (Lanzafame+, 2005)
J/A+A/422/337 : Solar EUV Post-Eruptive Arcades (Tripathi+, 2004)
J/ApJ/543/1016 : EUV spectrum of solar active region (Brosius+ 2000)
J/A+AS/113/237 : Ultraviolet Spectrum of the Sun (Samain, 1995)
J/ApJS/91/461 : EUV spectrum of solar active region (Thomas+, 1994)
http://www.usc.edu/dept/space_science/sem_data/downloadSEM.html : SEM data
http://lasp.colorado.edu/see/see_data.html : TIMED/SEE web site
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Num [1/255] Spectrum index number
5- 8 I4 yr Obs.Y [2002/2012] Year of the observation
10- 12 I3 d Obs.D [1/366] Day of the year of the observation
14- 20 F7.1 s Start Start time
22- 28 F7.1 s End End time
30- 39 F10.5 yr Year [2002/2013] Fractional year time
41- 51 E11.5 s-1 HRate [5.4e-8/1.9e-7] H photoionization rate
53- 63 E11.5 s-1 HeRate [4.1e-8/1.9e-7] He photoionization rate
65- 75 E11.5 s-1 ORate [1.8e-7/7.1e-7] O photoionization rate
77- 87 E11.5 s-1 NeRate [1.2e-7/7.1e-7] Ne photoionization rate
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 yr Obs.Y [1978/2012] Year of the observation
6- 8 I3 d Obs.D [1/366] Day of the year of the observation
10- 17 F8.3 yr Year [1978/2013] Fractional year time
19- 25 F7.5 10-7/s HRate [0.73/1.2] H photoionization rate
27- 33 F7.5 10-7/s HeRate [0.77/1.6] He photoionization rate
35- 41 F7.5 10-7/s ORate [0.79/1.4] O photoionization rate
43- 49 F7.5 10-7/s NeRate [0.78/1.8] Ne photoionization rate
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-Jan-2014