Spectral Irradiance Calibration in the Infrared. XIII. “Supertemplates” and On-Orbit Calibrators for the SIRTF Infrared Array Camera

We describe the technique that will be used to develop a set of on-orbit calibrators for the Infrared Array Camera (IRAC) and demonstrate the validity of the method for stars with spectral types either K0–M0 III or A0–A5 V. For application to SIRTF, the approach is intended to operate with all available optical, near-infrared (NIR), and mid-infrared (MIR) photometry and to yield complete absolute spectra from UV to MIR. One set of stars is picked from Landolt's extensive network of optical (UBVRI) calibrators, the other from the Carter-Meadows set of faint IR standards. Traceability to the "Cohen-Walker-Witteborn" framework of absolute photometry and stellar spectra is assured. The method is based on the use of either "supertemplates," which represent the intrinsic shapes of the spectra of K0–M0 III stars from far-UV (1150 Å) to MIR (35 μm) wavelengths, or Kurucz synthetic spectra for A0–A5 V stars. Each supertemplate or Kurucz model is reddened according to the individual star's extinction and is normalized using available characterized optical photometry. This paper tests our capability to predict NIR (JHK) magnitudes using supertemplates or models constrained by Hipparcos/Tycho or precision ground-based optical data. We provide absolutely calibrated 0.275–35.00 μm spectra of 33 Landolt and Carter-Meadows optical standard stars to demonstrate the viability of this technique, and to offer a set of IR calibrators 100–1000 times fainter than those we have previously published. As an indication of what we can expect for actual IRAC calibration stars, we have calculated the absolute uncertainties associated with predicting the IRAC magnitudes for the faintest cool giant and hot dwarf in this new set of calibration stars.

[1]  Wm. A. Wheaton,et al.  Spectral Irradiance Calibration in the Infrared. XIV. The Absolute Calibration of 2MASS , 2003, astro-ph/0304350.

[2]  Martin G. Cohen,et al.  Spectral Irradiance Calibration in the Infrared. XII. Radiometric Measurements from the Midcourse Space Experiment , 2001 .

[3]  Michael S. Bessell,et al.  The Hipparcos and Tycho Photometric System Passbands , 2000 .

[4]  M. M. Moshir,et al.  The Midcourse Space Experiment Point Source Catalog, Version 1.2 , 1999 .

[5]  Mark R. Kidger,et al.  Spectral Irradiance Calibration in the Infrared. X. A Self-Consistent Radiometric All-Sky Network of Absolutely Calibrated Stellar Spectra , 1999 .

[6]  Edward L. Fitzpatrick,et al.  Correcting for the Effects of Interstellar Extinction , 1998, astro-ph/9809387.

[7]  A. Pickles.  A Stellar Spectral Flux Library: 1150–25000 Å , 1998 .

[8]  E. L. Wright,et al.  The COBE Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background. I. Limits and Detections , 1998, astro-ph/9806167.

[9]  Martin Cohen,et al.  Spectral Irradiance Calibration in the Infrared. IX. Calibrated Stellar Spectra Using DIRBE Radiometry , 1998 .

[10]  D. Fabricant,et al.  The FAST Spectrograph for the Tillinghast Telescope , 1998 .

[11]  F. V. Leeuwen,et al.  The Hipparcos Mission , 1997 .

[12]  Martin G. Cohen,et al.  Spectral Irradiance Calibration in the Infrared.VII.New Composite Spectra, Comparison with Model Atmospheres, and Far-Infrared Extrapolations , 1996 .

[13]  Beverly J. Smith,et al.  The IRTS (Infrared Telescope in Space) Mission , 1996 .

[14]  L. Metcalfe,et al.  Spectral Irradiance Calibration in the Infrared. VI. 3-35 micron Spectra of Three Southern Standard Stars , 1996 .

[15]  B. S. Carter,et al.  Fainter southern JHK standards suitable for infrared arrays , 1995 .

[16]  Jesse D. Bregman,et al.  Spectral Irradiance Calibration in the Infrared.IV. 1.2-35 micron spectra of six standard stars , 1995 .

[17]  E. Erickson,et al.  Airborne Astronomy Symposium on the Galactic Ecosystem: from Gas to Stars to Dust, 5-8 July 1994, NASA-Ames Research Center , 1995 .

[18]  O. Manuel Uy,et al.  Midcourse Space Experiment: Introduction to the Spacecraft, Instruments, and Scientific Objectives , 1994 .

[19]  J. E. O'Donnell.  R(sub nu)-dependent optical and near-ultraviolet extinction , 1994 .

[20]  M. Cohen.  A Model of the 2-35 micron Point Source Infrared Sky , 1993 .

[21]  R. Kurucz.  ATLAS9 Stellar Atmosphere Programs and 2 km/s grid. , 1993 .

[22]  Martin G. Cohen,et al.  Spectral irradiance calibration in the infrared. II - Alpha Tau and the recalibration of the IRAS low resolution spectrometer , 1992 .

[23]  Michael J. Barlow,et al.  Spectral irradiance calibration in the infrared. I - Ground-based and IRAS broadband calibrations , 1992 .

[24]  Arlo U. Landolt,et al.  UBVRI Photometric Standard Stars in the Magnitude Range 11 , 1992 .

[25]  V. Straižys.  Multicolor Stellar Photometry , 1992 .

[26]  J. Menzies,et al.  UBV(RI)C photometry of equatorial standard stars. A direct comparison between the northern and southern systems , 1991 .

[27]  J. Mathis,et al.  The relationship between infrared, optical, and ultraviolet extinction , 1989 .

[28]  P. C. Keenan,et al.  The Perkins catalog of revised MK types for the cooler stars , 1989 .

[29]  The effect of pass-bands on broad-band optical photometry of SN1987A , 1989 .

[30]  G. Rieke,et al.  The interstellar extinction law from 1 to 13 microns. , 1985 .

[31]  Michael S. Bessell,et al.  VRI PHOTOMETRY : AN ADDENDUM. , 1983 .

[32]  J. B. Oke,et al.  Secondary standard stars for absolute spectrophotometry , 1983 .

[33]  Arlo U. Landolt,et al.  UBVRI PHOTOMETRIC STANDARD STARS AROUND THE CELESTIAL EQUATOR: UPDATES AND ADDITIONS , 2009, 0904.0638.

[34]  C. Perry,et al.  A photometric map of interstellar reddening within 300 parsecs. , 1982 .

[35]  D. Crawford,et al.  A photometric map of interstellar reddening whitin 100 pc. , 1982 .

[36]  Michael S. Bessell,et al.  UBVRI PHOTOMETRY II: THE COUSINS VRI SYSTEM, ITS TEMPERATURE AND ABSOLUTE FLUX CALIBRATION, AND RELEVANCE FOR TWO-DIMENSIONAL PHOTOMETRY. , 1979 .

[37]  A. Landolt,et al.  Spectral classifications for Landolt's celestial equatorial standard stars , 1979 .

[38]  D. W. Latham,et al.  A rediscussion of the atmospheric extinction and the absolute spectral-energy distribution of Vega. , 1975 .

[39]  Nancy Houk,et al.  Michigan catalogue of two-dimensional spectral types for the HD stars , 1975 .

[40]  A. Landolt,et al.  UBV photoelectric sequences in the celestial equatorial Selected Areas 92-115 , 1973 .