J/MNRAS/400/1413 Near-IR spectra of extremely red AGB stars (Wright+, 2009)
Near-IR spectra of IPHAS extremely red Galactic AGB stars.
Wright N.J., Barlow M.J., Greimel R., Drew J.E., Matsuura M., Unruh Y.C.,
Zijlstra A.A.
<Mon. Not. R. Astron. Soc. 400, 1413 (2009)>
=2009MNRAS.400.1413W 2009MNRAS.400.1413W
ADC_Keywords: Stars, giant ; Spectra, infrared
Keywords: techniques: spectroscopic - atlases - stars: AGB and post-AGB -
stars: carbon - stars: chemically peculiar - infrared: stars
Abstract:
We present a library of 139 near-IR spectra of cool asymptotic giant
branch stars that will be useful for comparison with theoretical model
atmosphere calculations and for modelling the integrated emission from
intermediate-age stellar populations. The source list was selected
from the 'extremely red' region of the Isaac Newton Telescope (INT)
Photometric Hα Survey (IPHAS) colour-colour plane that is
overwhelmingly dominated by very late-type stars. The spectral library
also includes a large fraction of S-type and carbon stars. We present
a number of spectral classification sequences highlighting the various
molecular features identified and discuss a number of rare features
with uncertain identifications in the literature. With its focus on
particularly cool photospheres, this catalogue serves as a companion
to recent spectroscopic atlases of MK standards in the near-IR.
Finally, the relationship between IPHAS (r'-i') and (r'-Hα)
colours and spectroscopically determined properties is discussed and a
strong correlation between the (r'-Hα) colour and the C/O
abundance index for S-type and carbon stars is noted. This relation
has the potential to separate O-rich, S-type and carbon stars in the
Galaxy based on their photometry alone.
Description:
Spectra of 139 sources were obtained using Long-Slit Intermediate
Resolution Infrared Spectrograph (LIRIS), a near-IR
camera/spectrometer on the 4.2m William Herschel Telescope (WHT) at
the Roque de Los Muchachos Observatory in La Palma, Spain.
Observations were performed on five nights in the summers of 2006 and
2007.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 122 140 Sources observed with LIRIS on the William Herschel
Telescope (139 from the sample + HIP 71819)
sp/* . 288 *Individual flux densities in zj and hk grism files
(wavelength range 880-2300nm)
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Note on sp/*: For each ERSO stars, there is one file in zj (ersoNNN_zj.txt)
and one file in hk (ersoNNN_hk.txt). For HIP71819, there are 5 files
in zj (hip71819zjN.txt) and 5 files in hk (hip71819hkN.txt).
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See also:
J/A+A/480/409 : IPHAS symbiotic stars candidates (Corradi+, 2008)
J/MNRAS/384/1277 : Hα emission line sources from IPHAS (Witham+, 2008)
J/A+A/504/291 : IPHAS candidate Planetary Nebulae (Viironen+, 2009)
J/MNRAS/397/1685 : Galactic plane IPHAS-POSSI pm survey (Deacon+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [ERSO]
6- 8 I3 --- ERSO ? ERSO sequential number (0 for HIP 71819)
10- 14 A5 --- --- [IPHAS]
16- 34 A19 --- IPHAS IPHAS name of source (JHHMMSS.ss+DDMMSS.s)
36- 37 I2 h RAh Right ascension (J2000)
39- 40 I2 min RAm Right ascension (J2000)
42- 46 F5.2 s RAs Right ascension (J2000)
48 A1 --- DE- Declination sign (J2000)
49- 50 I2 deg DEd Declination (J2000)
52- 53 I2 arcmin DEm Declination (J2000)
55- 58 F4.1 arcsec DEs Declination (J2000)
60- 65 F6.3 mag r'mag ?=- Sloan r' magnitude
67- 72 F6.3 mag i'mag ?=- Sloan i' magnitude
74- 79 F6.3 mag Hamag ?=- IPHAS Hα magnitude
81- 84 F4.1 s zJexp ?=- zJ grism exposure time
86- 90 F5.1 s HKexp ?=- HK grism exposure time
92- 97 A6 --- SpT MK spectral type (1)
100-113 A14 --- Notes Notes on object (2)
115-122 A8 --- Name Name (for HIP 71819)
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Note (1): Spectral types for all sources are also listed (only the temperature
class is listed since all sources are believed to be giants).
* for S-type stars, spectral types are listed as SX/Y, where X is
the temperature index (not available for all sources) and Y is
the abundance index.
* Carbon stars are listed as 'C', as further classification was
not possible.
* Unclassified O-rich stars are listed as 'K0-M2'
* completely unclassified stars are listed as 'U'.
* Stars with emission lines are denoted with 'e'.
Previous identifications are listed if available from the SIMBAD
astronomical data base.
Note (2): Variable stars are identified based on the presence of strong
water vapour bands. O-rich sources with high C/O ratios (C/O∼0.9-0.95)
are identified based on very strong H-band CO lines and no OH lines.
Carbon stars with the suspected C2H2 feature in their H-band
spectra are also noted.
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1- 17 F17.11 0.1nm lambda Wavelength
19- 31 E13.7 --- flux Flux density, in arbitrary units of energy
per wavelength interval
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Acknowledgements:
Nick Wright, nwright(at)head.cfa.harvard.edu
(End) Patricia Vannier [CDS] 28-Dec-2009