II/179 Southern Spectrophotometric Standards. I + II (Hamuy+ 1992,94)
Southern Spectrophotometric Standards. I + II
Hamuy M., Walker A.R., Suntzeff N.B., Gigoux P., Heathcote S.R.,
Phillips M.M.
<Publ. Astron. Soc. Pacific 104, 533 (1992)>
<Publ. Astron. Soc. Pacific 106, 566 (1994)>
=1992PASP..104..533H 1992PASP..104..533H
=1994PASP..106..566H 1994PASP..106..566H
ADC_Keywords: Spectrophotometry; Stars, standard
Description:
M. Hamuy, et al. have compiled their observations of secondary and
tertiary spectrophotometric standard stars for the southern
hemisphere in the wavelength range 3300-7550 Angstroms. The
observations were made using the RC spectrographs and CCD cameras
on the 1.5m and 4m telescopes at CTIO. The machine-readable files
contain monochromatic magnitudes vs. wavelength for 29 stars in
ASCII and 31 stars in FITS format.
Introduction:
The author's observations of secondary and tertiary southern
spectrophotometric standard stars have been used to generate
computer-readable files containing monochromatic magnitudes vs.
wavelength for the range 3300-7550 Angstroms. The authors modified
the monochromatic fluxes of the secondary standards according to
the calibration of Vega published in 1985 by D. S. Hayes, and
adjusted the zero point of their energy distributions by matching
their V(synthetic) magnitudes to the observed magnitudes. They have
used these adjusted secondary standards to calculate new fluxes for
the tertiary standards of Stone and Baldwin (1983MNRAS.204..347S 1983MNRAS.204..347S).
The spectrophotometric data are reported in the "sp" subdirectory,
which consist of 29 files of blue magnitudes vs. wavelength and 30
files of red magnitudes vs. wavelength for different standard stars;
30 additional files contain magnitude vs. wavelength for the entire
wavelength range. There are an additional two stars, HR 1903 and HR
2421, for which the data is only in FITS format. Information on the
contents of the FITS files is contained in the FITS headers of those
files.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
stars.dat 96 32 List of stars contained in this catalog
(from table1 and table7 of paper I)
sp/* . 89 Individual spectra
--------------------------------------------------------------------------------
Byte-by-byte Description of file: stars.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Star name
15- 16 I2 h RAh Right Ascension J2000 (hours)
18- 19 I2 min RAm Right Ascension J2000 (minutes)
21- 24 F4.1 s RAs Right Ascension J2000 (seconds)
26 A1 --- DE- Declination J2000 (sign)
27- 28 I2 deg DEd Declination J2000 (degrees)
30- 31 I2 arcmin DEm Declination J2000 (minutes)
33- 34 I2 arcsec DEs Declination J2000 (seconds)
35 A1 --- n_Name [*] Additional star, not listed in paper
(position from the SIMBAD data-base)
37- 41 F5.2 mag B-V ? B-V color index
43- 47 F5.2 mag Vmag ? V magnitude
49- 56 A8 --- SpType Spectral class
59- 70 A12 --- File1 Filename in "sp" subdirectory of spectrum
72- 83 A12 --- File2 Filename in "sp" subdirectory of blue part
85- 96 A12 --- File3 Filename in "sp" subdirectory of red part
--------------------------------------------------------------------------------
Byte-by-byte Description of file: sp/*
--------------------------------------------------------------------------------
Bytes Format Unit Label Explanations
-------------------------------------------------------------------------------
1- 5 I5 0.1nm lambda Central wavelength
7-12 F6.3 mag mag Monochromatic magnitude (see source reference)
14-15 I2 0.1nm dlam Bandpass bandwidth (in Å)
--------------------------------------------------------------------------------
FITS files:
The format of the two FITS files which are included, for HR 1903 and
HR 2421, is apparent from the headers --- note that the flux is not
expressed in monochromatic magnitudes in these files.
Remarks:
The computer-readable version of Southern Spectrophotometric
Standards. I corresponds to the contents of tables 13 and 14 in
the source reference (Hamuy et al. 1992). The HR stars are
secondary standards. The data provided are monochromatic
magnitudes for the ten secondary standards at steps of 16
Angstroms, which corresponds to the resolution of the authors'
1.5m spectra. The magnitudes are averages of all the observations
gathered for these stars. The published version of this data
contains error estimates and bandpasses flagged for the presence
of telluric features. This information is not part of the
computer-readable version.
The remaining files contain monochromatic magnitudes for the
tertiary standard stars calculated through 50 A bandpasses. As
with the secondary standard files, errors and telluric feature
flags which appear in the source reference are not part of the
computer-readable files. For this reason, researchers are
cautioned to review the source reference carefully before using
these data.
The only changes made to the files as received were right justify the
first column and align decimals in the second one. The FITS files,
which were also received, have been omitted if the ASCII file is
present.
Acknowledgments:
The staff of the ADC gratefully acknowledges the support of Dr. Mario
Hamuy in making the data files available for distribution. The fits
files have been included only for the records for which no ASCII data
are available. The first work on this catalog at the ADC was by James.
E. Gass who also wrote the first version of this document.
History:
* May 1995: Original version with spectrophotometry
* July 1998: the list of stars (file stars.dat) was added at CDS,
using the SIMBAD data-base.
* 12-Apr-2010: Reformatted the table (to enable plotting of spectra)
References:
Hayes, D. S. 1985, in Calibration of Fundamental Stellar
Quantities, ed. D. S.
Hayes, L. E. Pasinetti, and A. G. Davis Philip (Dordrecht,
Reidel), p. 225
Stone, R. P. S. 1977, =1977ApJ...218..767S 1977ApJ...218..767S
Stone, R. P. S., and Baldwin, J. A. 1983, =1983MNRAS.204..347S 1983MNRAS.204..347S
(End) Nancy G. Roman [NASA/ADC/SSDOO] 31-May-1995