III/136 Optical spectrophotometry of WR C and O Stars (Torres+ 1987)
An Atlas of Optical Spectrophotometry of Wolf-Rayet Carbon and Oxygen Stars
Torres A.V., Massey P.
<Astrophys. Journ. Suppl. 65, 459 (1987)>
=1987ApJS...65..459T 1987ApJS...65..459T
ADC_Keywords: Spectrophotometry; Stars, Wolf-Rayet
Description:
The catalog contains a homogeneous set of optical spectrophotometric
observations (3300-7300 angstroms) at moderate resolution (about 10
angstroms) of 86 Wolf-Rayet carbon and oxygen stars in this galaxy,
the Large Magellanic Cloud, and the Small Magellanic Cloud. The
observations were made with the Intensified Reticon Scanner on the
white spectrograph of the 0.9 m telescope at Kitt Peak and with the
SIT-Vidicon detector on the Cassegrain spectrograph of the 1.5-m
telescope at Cerro Tololo Inter-American Observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
adc_doc.txt 80 294 Original catalog documentation
summary.dat 113 86 *Infprmation of spectra
sp/* . 88 *Individual spectra (3-column tables)
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Note on summary.dat:
Before the reformatting to make the catalog more readily accessible
under the standard documentation, all data were in one file separated
by headers. A header record for each set of spectrophotometric data
contained identification(s), type, instrument, number of data points,
and comments. Following each header, data records contained the
wavelength, flux, and magnitude for five data points. The data were
separated out in one file for each spectrum. The headers with summary
information were kept as a separate file.
Note on sp/*:
Torres and Massey have chosen not to normalize the data, nor give any
equivalent widths, line widths, or intensities above the continuum in order
to avoid any errors that can be introduced by picking the continuum level.
All these quantities can be found in Torres' Ph. D. Thesis, 1985,
Univ. of Colorado
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Byte-by-byte Description of file: summary.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Star Identification (1)
9- 28 A20 --- Alt Other name(s)
29- 31 A3 --- Sp Spectral type from Torres; Conti and Massey
(1986ApJ...300..379T 1986ApJ...300..379T)
32 A1 --- abs [+] Absorption line(s) flag
34- 36 A3 --- Instr [IRS SIT] Instrument code (2)
37- 42 I6 --- Np [477/2961] Number of data points (3)
44-113 A70 --- rem Comments (4)
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Note (1):
* WR numbers are from van der Hucht et al. (1981SSRv...28..227V 1981SSRv...28..227V, III/85).
* BR numbers are from the compilation of W-R stars in the LMC by
Breysacher 1981A&AS...43..203B 1981A&AS...43..203B).
* Sk 188 is in the SMC (Azzopardi and Breysacher 1979A&A....75..120A 1979A&A....75..120A).
Note (2): instruments are:
* IRS: Intensified Reticon Scanner on the white spectrograph at the No.1
0.9-m telescope at Kitt Peak. The IRS detector package consists of an
ITT proximity-focused image tube followed by a micro-channel inverter
image intensifier and a dual Reticon array of 936 pixels with a fiber
optic window. Only 820 pixels are usable because of distortion and
vignetting at the edge of the image tube field. The slit of the
spectrograph is replaced by a pair of circular apertures oriented in
the east-west direction so that the star and the sky can be observed
simultaneously.
* SIT: the majority of the southern hemisphere WC stars were observed by
Massey at Cerro Tololo Inter-American Observatory between November
1981 and February 1985. The SIT-Vidicon detector was used on the
Cassegrain spectrograph of The 1.5-m telescope. The SIT-Vidicon
system has a poor dynamic range, and since WC stars have very strong
emission lines, two exposures were in general necessary: one to get
good signal to noise on the continuum and weak lines, with the strongest
lines usually saturated, and one to get the strong lines unsaturated.
The unsaturated lines were inserted in the final reduction.
Note (3):
The number of valid entries to be found in the data file for this
observation. The number of data points varies from 477 to 2961.
Note (4):
If separate blue and red observations have been made, this is noted in
the comments. All other comments should be self-explanatory.
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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- 6 F6.1 0.1nm Wave [3099/7347] Wavelength λ (1)
7- 19 E13.5 cW/m2/nm Flux Flux (erg/s/cm2/Å) (2)
21- 26 E6.5 mag mag Magnitude at λ (3)
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Note (1):
Wavelength (Angstroemi) of the observed data point in Angstroms.
Wavelength scale calibration for the IRS observations was determined
by exposing a He-Ne-Ar comparison source every night. Wavelength scale
calibration for the SIT-Vidicon detector was determined by taking
exposures of a He-Ar and a Hg lamp.
Note (2):
In units of erg.s-1.cm-2.Å-1.
Several spectrophotometric standard stars were observed each night to
determine the spectrophotometric calibrations. The user is referred to
the original paper for detailed discussion of the data reduction.
Note (3):
The fluxes (Fλ) were converted to magnitude units using the
calibration of Vega by Hayes and Latham (1975ApJ...197..593H 1975ApJ...197..593H), that is,
m(ν)=-2.51og(Fν)-48.594, where νFν=λFλ.
By plotting the data in magnitudes instead of flux units the relative
strengths of the lines can be readily compared from the plots, and
approximate colors at any given wavelength can be read directly.
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History:
* 10-Jan-1997, from N. Paul Kuin & C.-H. Joseph Lyu [Hughes STX/NASA ADC]:
An Atlas of Optical Spectrophotometry of Wolf-Rayet Carbon and Oxygen
Stars (WRCOS) was received by the Astronomical Data Center (ADC), NASA
Goddard Space Flight Center, from A. V. Torres in April 1987. The
original data came in the form of 87 separate files: one file
containing Table 1 from Torres and Massey (1987) and 86 files each
containing the observed data for one star. These files were resident
on the Interactive Astronomical Data Analysis Facility (IADAF) VAX
11/750. A Forth program was run to concatenate all the data files,
while merging in the records from Table 1 and copying the results to
tape. This tape file was copied to disk on the NASA Space and Earth
Sciences Computing Center (NSESCC) IBM 3081. This data format was
judged to be less desirable for the automatic conversion of the data
to FITS using standard documentation. Therefore the data were all
separated out once more in 1996 which resulted in the current catalog.
* 15-Aug-2016, from Francois Ochsenbein [CDS]:
moved the spectra to the sub-directory "sp",
Misalognments in the spectra of WR188 fixed.
Acknowledgments:
The original ADC documentation by L.E. Brotzman (1989) was used to
create this ReadMe file.
References:
Azzopardi, M. and Breysacher, J. 1979, A. & A., 75, 120.
Breysacher, J. 1981, A. & A. Suppl., 43, 203.
Hayes, D. S. and Latham, D. W. 1975, Ap. J., 197, 593.
Torres, A. V. 1985, Ph. D. Thesis, Univ. of Colorado.
Torres, A. V., Conti, P. S., and Massey, P. 1986, Ap. J., 300, 379.
Torres, A. V. and Massey, P. 1987, An Atlas of Optical Spectrophotometry
of Wolf-Rayet Carbon and Oxygen Stars, Ap.J. Suppl., 65, 459.
van der Hucht, K. A., Conti, P. S., Lundstrom, I., and Stenholm, B. 1981,
Space Sci. Rev., 28, 227.
(End) N. Paul Kuin & C.-H. Joseph Lyu [Hughes STX/NASA ADC] 10-Jan-1997