J/A+AS/129/541 Spectroscopy of IRC +10420 (Oudmaijer 1998)
High resolution spectroscopy of the post-red supergiant IRC +10420. I: The data.
Oudmaijer R.D.
<Astron. Astrophys. Suppl. Ser. 129, 541 (1998)>
=1998A&AS..129..541O 1998A&AS..129..541O (SIMBAD/NED BibCode)
ADC_Keywords: Stars, supergiant ; Spectroscopy ; Spectra, infrared
Keywords: stars: circumstellar matter - stars: emission-line, Be -
stars: individual: IRC +10420 - stars: AGB and post-AGB -
stars: supergiants
Abstract:
A high resolution optical spectrum of the post-red supergiant
candidate IRC +10420 is presented. The Utrecht Echelle Spectrograph
observations, with a total integration time of more than 9 hours
provide a spectral coverage from 3850 A to 1micron, and a spectral
resolution of 9km/s. The spectrum is shown, and an identification list
of lines in the spectrum is provided. From a preliminary analysis of
the spectrum we find that the spectral type of IRC+10420 has changed
from F8I+ in 1973 to mid- to early A type now, confirming the results
of Oudmaijer et al. (1996MNRAS.280.1062O 1996MNRAS.280.1062O), who claimed a change in
temperature based on photometric changes. It is shown that most of the
emission lines in the spectrum of IRC +10420 are blue-shifted with
respect to the systemic velocity traced by circumstellar rotational CO
emission, while the (few) absorption lines - with the exception of
some high excitation lines - are red-shifted by 25km/s, which may
suggest infall of material onto the star. Finally, it is found that
the interstellar extinction towards IRC +10420, as traced by the
Diffuse Interstellar Bands is very large, with an inferred E(B-V) of
1.4±0.5 compared to a total E(B-V) of 2.4.
This table provides the line identifications for the measured spectral
lines from atomic species. Listed in the table are respectively the
laboratory wavelength (in air) taken from Moore (1945, in A multiplet
table of astrophysical interest, Contribution from the Princeton
University Observatory No. 20.), the line identification (ion and
multiplet), the energies of the lower levels of the transitions in eV,
and the log(gf). The latter two values are taken from Wiese et al.
(1966, Nat. Stand. Ref. Data Ser. 20 and 1969, Nat. Stand. Ref. Data
Ser. 22), Martin et al. (1988, Cat. VI/72) and Fuhr et al. (1988,
Cat. VI/72). The spectral lines that are marked `UN' were not
identified, the wavelength given for these lines is the observed
wavelength. Then next entries in the table are the velocity shift of
the centres of spectral lines (in LSR), the equivalent width in
milli-Angstrom, and the full-width-at-half maximum of the fit in
Angstrom. The velocity shifts have been measured by fitting Gaussian
profiles through the lines, the equivalent widths have been measured
by integrating the line over the continuum. In the case of overlapping
lines, the lines were de-composed by fitting multiple Gaussian
components to the profiles. In these cases (marked with `deb.' in the
table) the equivalent widths are the areas under the Gaussian fits.
Equivalent widths for lines that could not be deblended, are given
between brackets. These values represent the total equivalent width of
the lines concerned.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
19 24 26.7 +11 15 11 IRC+10420
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 77 583 Spectroscopy of IRC +10420, line identifications
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 0.1nm W Air wavelength
12- 18 A7 -- El Ion (UN = unidentified lines)
19- 23 A5 -- Mult Multiplet
25- 29 F5.2 eV Chil ? Lower level excitation energy
31- 36 F6.3 -- loggf ? log(gf)
38- 40 I3 km/s Vlsr ? Velocity shift of the centre of spectral
lines (in Local Standard of Rest) (1)
42- 46 I5 10-4nm EW ? Equivalent Width (2)
47 A1 --- n_EW [:)ae] Note on EW (4)
49- 51 F3.1 0.1nm FWHM ? Full-Width-Half-Maximum (3)
53- 76 A24 -- Rem Remarks (5)
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Note (1): Estimated accuracy of central velocities is 5km/s
Note (2): Error in EW is mostly 10%
Note (3): Error FWHM is 10%
Note (4): ':' : EW especially uncertain
')' : lines that could not be deblended. The value represents the
total equivalent width of the lines concerned
'a' : absorption
'e' : emission
Note (5): Users should take special care interpreting line EW and FWHM in
cases where these were measured through a de-blending routine. The
lines are marked with `deb'
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Acknowledgements: Rene Oudmaijer
References:
Fuhr J.R., Martin G.A., Wiese W.L. 1988, J. Phys. Chem. Ref. Data, Vol.
17, Suppl. 4 (Fe - Ni)
Martin G.A., Fuhr J.R., Wiese W.L 1988, J. Phys. Chem. Ref. Data, Vol.
17, Suppl. 3 (Sc - Mn)
Moore C.E. 1945 "A multiplet table of astrophysical interest",
Contribution from the Princeton University Observatory No. 20.
Oudmaijer R.D., Groenewegen M.A.T., Matthews H.E.M., Blommaert J.A.D.L.,
Sahu K.C. 1996MNRAS..280.1062O
Wiese W.L., Smith M.W., Glennon B.M. 1966, "Atomic Transition Probabilities,
Vol. II Hydrogen through Neon", Nat. Stand. Ref. Data Ser. 20
Wiese W.L., Smith M.W., Miles B.M. 1969, "Atomic Transition Probabilities,
Vol. II Sodium through Calcium", Nat. Stand. Ref. Data Ser. 22
(End) Patricia Bauer [CDS] 19-Dec-1997