J/A+A/508/1403 Oxygen lines in solar granulation. II. (Pereira+, 2009)
Oxygen lines in solar granulation.
II. Centre-to-limb variation, NLTE line formation, blends, and the solar oxygen
abundance.
Pereira T.M.D., Asplund M., Kiselman D.
<Astron. Astrophys. 508, 1403 (2009)>
=2009A&A...508.1403P 2009A&A...508.1403P
ADC_Keywords: Sun ; Spectroscopy
Keywords: line: formation - Sun: photosphere - Sun: granulation -
Sun: abundances - convection
Abstract:
There is a lively debate about the solar oxygen abundance and the role
of 3D models in its recent downward revision. These models have been
tested using high-resolution solar atlases of flux and disk-centre
intensity. Further testing can be done using centre-to-limb
variations.
Using high-resolution and high S/N observations of neutral oxygen
lines across the solar surface, we seek to test that the 3D and 1D
models reproduce their observed centre-to-limb variation. In
particular we seek to assess whether the latest generation of 3D
hydrodynamical solar model atmospheres and NLTE line formation
calculations are appropriate to derive the solar oxygen abundance.
Description:
We obtained solar observations of several lines at several positions
of the solar disk. Data were obtained in May 2007 with the TRIPPEL
spectrograph at the Swedish 1-m Solar Telescope (SST). The spectra
were obtained for three distinct wavelength windows at ∼615, 630
and 777nm. Each window covers approx. 1nm. Here we provide the
spatially and temporally averaged spectra. Each spectrum was the
average of 50 frames (mu=1.0) or 25 frames (other positions). The
frames were selected by the highest continuum contrast, and thus are
not regularly spaced in time between the start and end Julian dates.
The observations are given for five positions in the solar disk,
ordered by mu, the cosine of the heliocentric angle. The objective was
to study the centre-to-limb variation of the lines. Active sun regions
were avoided.
Important note: the wavelength scales have NOT been corrected for
solar rotation or gravitational redshift.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 93 15 Observations
sp615/* . 5 Individual spectra for the 615nm camera,
(615mu_xx.dat, xx denotes mu times 10)
sp630/* . 5 Individual spectra for the 630nm camera,
(630mu_xx.dat, xx denotes mu times 10)
sp777/* . 5 Individual spectra for the 777nm camera,
(777mu_xx.dat, xx denotes mu times 10)
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See also:
J/A+A/507/417 : Oxygen lines in solar granulation (Pereira+, 2009)
J/A+A/274/555 : Asymmetry of FeI lines in solar spectrum (Stathopoulou+ 1993)
J/A+A/304/563 : Cool X-ray flares of Sun with GOES (Phillips+, 1995)
J/A+AS/113/71 : Lines in the infrared solar spectrum (Ramsauer+, 1995)
J/A+AS/113/237 : Ultraviolet Spectrum of the Sun (Samain, 1995)
J/A+A/309/655 : Solar chromospheric activity (HeI 10830A) (Shcherbakov+, 1996)
J/A+A/313/949 : Solar chromospheric structures. II. (Bocchialini+, 1996)
J/A+AS/126/281 : Solar disk spectrum (660-1175A) (Curdt+ 1997)
J/A+AS/129/41 : Fe I line shifts in the Sun (Allende Prieto+ 1998)
J/A+AS/131/431 : Accurate wavelengths in Sun spectrum (Allende Prieto+ 1998)
J/A+A/375/591 : SUMER Spectral Atlas of Solar Disk Features (Curdt+, 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 nm lambda Approximate central wavelength of filter
6- 20 F15.7 d JDstart Julian date (start of observations)
23- 37 F15.7 d JDend Julian date (end of observations)
40- 45 F6.2 deg HLAT Heliographic latitude in the Stony-Hurst
coordinate system
48- 53 F6.2 deg HLON Heliographic longitude in the Stony-Hurst
coordinate system
56- 60 F5.3 --- mu Cosine of the heliocentric angle
63- 67 F5.3 --- e_mu Error in mu
70- 73 F4.2 % S Amount of straylight removed from the
spectra. Expressed as a percentage of
the pseudo-continuum intensity.
76- 93 A18 --- FileName Path and filename of each spectrum
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Byte-by-byte Description of file: sp630/* sp615/* sp777/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 nm lambda Wavelength
13- 20 F8.6 --- Flux Normalized flux
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Acknowledgements:
Tiago M.D. Pereira, tiago(at)mso.anu.edu.au
(End) Patricia Vannier [CDS] 30-Oct-2009