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J/A+A/615/A24       Passband reconstruction from photometry      (Weiler+, 2018)

Passband reconstruction from photometry. Weiler M., Jordi C., Fabricius C., Carrasco J.M. <Astron. Astrophys. 615, A24 (2018)> =2018A&A...615A..24W (SIMBAD/NED BibCode)
ADC_Keywords: Photometry Keywords: instrumentation: photometers - techniques: photometric - techniques: spectroscopic Abstract: Based on an initial expectation from laboratory measurements or instrument simulations, photometric passbands are usually subject to refinements. These refinements use photometric observations of astronomical sources with known spectral energy distribution. This work investigates the methods for and limitations in determining passbands from photometric observations. A simple general formalism for passband determinations from photometric measurements is derived. The results are applied to the passbands of HIPPARCOS, Tycho, and Gaia DR1. The problem of passband determination is formulated in a basic functional analytic framework. For the solution of the resulting equations, functional principal component analysis is applied. We find that, given a set of calibration sources, the passband can be described with respect to the set of calibration sources as the sum of two functions, one which is uniquely determined by the set of calibration sources, and one which is entirely unconstrained. The constrained components for the HIPPARCOS, Tycho, and Gaia DR1 passbands are determined, and the unconstrained components are estimated. Description: In table2, passbands for HIPPARCOS, Tycho B and V, and Gaia DR1 are presented. Each of these passbands is divided into the parallel and the orthogonal component, the passbands being the sum of the two components, respectively. All passbands are normalised to a maximum value of One. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file passband.dat 102 8321 Passband solutions
Table 2: The mean wavelength, the pivot wavelength, the zero points in the VEGAMAG and the AB photometric systems, and the l2-norms of the parallel and the orthogonal components for the four pass-bands described in this work ------------------------------------------------------------------------------ parameter | G | Hp | BT | VT ------------------------------------------------------------------------------ lambdamean [nm] | 661.25 | 540.19 | 419.68 | 529.68 lambda_pivot [nm] | 646.78 | 532.74 | 418.91 | 528.34 zero point [VEGA] | 25.853 | 26.006 | 24.996 | 25.040 zero point [AB] | 25.974 | 25.975 | 24.905 | 25.000 l2-norm of the parallel component | 16.8179 | 13.0333 | 7.0095 | 7.8246 l2-norm of the orthogonal component | 4.3186 | 2.0731 | 1.9359 | 3.1433 ------------------------------------------------------------------------------ Byte-by-byte Description of file: passband.dat
Bytes Format Units Label Explanations
1- 6 F6.1 nm lambda Wavelength in nanometers 8- 18 F11.8 --- HPpar Parallel component of HIPPARCOS passband 20- 30 F11.8 --- HPort Orthogonal component of HIPPARCOS passband 32- 42 F11.8 --- BTpar Parallel component of Tycho B passband 44- 54 F11.8 --- BTort Orthogonal component of Tycho B passband 56- 66 F11.8 --- VTpar Parallel component of Tycho V passband 68- 78 F11.8 --- VTort Orthogonal component of Tycho V passband 80- 90 F11.8 --- Gpar Parallel component of Gaia DR1 G passband 92-102 F11.8 --- Gort Orthogonal component of Gaia DR1 G passband
Acknowledgements: Michael Weiler, mweiler(at)fqa.ub.edu
(End) Michael Weiler [Univ. Barcelona, Spain] Patricia Vannier [CDS] 12-Feb-2018
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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