J/ApJ/543/1016 EUV spectrum of solar active region from SERTS-97 (Brosius+ 2000)
Analysis of a solar active region extreme-ultraviolet spectrum from SERTS-97.
Brosius J.W., Thomas R.J., Davila J.M., Landi E.
<Astrophys. J. 543, 1016 (2000)>
=2000ApJ...543.1016B 2000ApJ...543.1016B
ADC_Keywords: Sun ; Spectra, ultraviolet ; Spectroscopy
Mission_Nane: SOHO
Keywords: instrumentation: spectrographs - line: identification -
Sun: activity - Sun: corona - Sun: UV radiation
Abstract:
Goddard Space Flight Center's Solar EUV Research Telescope and
Spectrograph was flown on 1997 November 18, carrying an intensified
CCD detector and a multilayer-coated toroidal diffraction grating with
enhanced sensitivity over that of a standard gold-coated grating
throughout the instrument's 299-353Å spectral bandpass. Spectra and
spectroheliograms of NOAA Active Region 8108 (N21°, E18°) were
obtained with a spectral resolution (instrumental FWHM) of 115mÅ.
Nearly 100 emission lines were observed in the spatially averaged
active region spectrum. Spectra and spectroheliograms of quiet areas
south of the region were also obtained. An end-to-end radiometric
calibration of the rocket instrument was carried out at the
Rutherford-Appleton Laboratory in the same facility that was used to
calibrate the Coronal Diagnostic Spectrometer experiment on SOHO and
using the same EUV light source. The accuracy of this calibration is
confirmed by the excellent agreement between the measured and
theoretical values of density- and temperature-insensitive line
intensity ratios. Nine emission lines of Fe XV are identified in our
spectrum; however, large differences between wavelengths in the
CHIANTI database and some of the measured solar wavelengths, as well
as inconsistencies of various theoretical intensity ratios, suggest a
need for improvement in the Fe XV atomic physics parameters and/or the
presence of unidentified blending lines.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 68 95 SERTS-97 absolutely calibrated active region
line list
notes1.dat 80 47 Notes to table1
table2.dat 43 15 Confirmation of the SERTS-97 calibration with
density- and temperature-insensitive line
intensity ratios (insensitive ratios)
table3.dat 31 24 Emission lines used to derive active region
differential emission measure (DEM)
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See also:
J/A+AS/113/237 : Ultraviolet Spectrum of the Sun (Samain, 1995)
J/A+AS/129/41 : Fe I line shifts in the Sun (Allende Prieto+ 1998)
J/A+A/304/563 : Cool X-ray flares of Sun with GOES (Phillips+, 1995)
J/ApJS/120/409 : The SMM Atlas of Gamma-Ray flares (Vestrand+, 1999)
J/A+AS/103/57 : Ion-atom collisions in Sun atmosphere (Mihajlov+ 1994)
J/A+AS/131/431 : Accurate wavelengths in Sun spectrum (Allende Prieto+ 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 F7.3 0.1nm lambda Wavelength
9- 15 F7.1 mW/m2/sr Int Intensity
17- 22 F6.1 mW/m2/sr e_Int rms uncertainty on Int
24- 28 F5.1 0.1pm FWHM Measured width, including instrumental,
thermal, and nonthermal contributions
30- 32 F3.1 0.1pm e_FWHM rms uncertainty on FWHM
34- 41 A8 --- Ion Ion
42- 44 F3.2 0.1nm Flare ? Flare fractional portion of lambda
(Dere, 1978ApJ...221.1062D 1978ApJ...221.1062D)
46- 49 F4.3 0.1nm Active ? Active fractional portion of lambda
(Thomas & Neupert 1994, Cat. J/ApJS/91/461)
51- 54 F4.3 0.1nm Full ? Full fractional portion of lambda
(Behring et al., 1976ApJ...203..521B 1976ApJ...203..521B)
56- 59 F4.3 0.1nm Quiet ? Quiet fractional portion of lambda
(Brooks et al. 1999A&A...347..277B 1999A&A...347..277B, in which
the shortest wavelength is 308.515Å)
61- 66 A6 --- Note Notes detailed in notes1.dat file
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Byte-by-byte Description of file: notes1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Note Note number
4- 80 A77 --- Text Text of the note
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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- 7 A7 --- Ion Ion line ratio
9- 13 F5.1 0.1nm lambda1 First wavelength
14 A1 --- --- [/]
15- 19 F5.1 0.1nm lambda2 Second wavelength
21- 25 F5.3 --- RatioT Theoretical line ratio
27- 31 F5.3 --- e_RatioT ? rms uncertainty on RatioT
33- 37 F5.3 --- RatioM Measured line ratio
39- 43 F5.3 --- e_RatioM ? rms uncertainty on RatioM
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Ion Ion
10- 16 F7.3 0.1nm lambda Wavelength
18- 21 F4.2 K Teff Effective temperature (1)
23- 26 F4.2 --- lobs/ldem Ratio of the observed intensity to the
theoretical intensity derived from the
differential emission measure (DEM)
28- 31 F4.2 --- e_lobs/ldem rms uncertainty on lobs/ldem
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Note (1): Effective temperature, as defined by Landi & Landini
(1997A&A...327.1230L 1997A&A...327.1230L). This is not the same as the formation
temperature (the temperature of maximum ion abundance), for which
examples derived from the Mazzotta et al. (1998, Cat.
J/A+AS/133/403) ion fraction calculations are given in Sect. 4.2 of
the paper.
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History:
From ApJ electronic version
(End) Patricia Bauer [CDS] 12-Feb-2001