J/A+A/579/A68 CANDID code for interferometric observations (Gallenne+, 2015)
Robust high-contrast companion detection from interferometric observations.
The CANDID algorithm and an application to six binary Cepheids.
Gallenne A., Merand A., Kervella P., Monnier J.D., Schaefer G.H., Baron F.,
Breitfelder J., Le Bouquin J.B., Roettenbacher R.M., Gieren W.,
PietrzyNski G., McAlister H., ten Brummelaar T., Sturmann J., Sturmann L.,
Turner N., Ridgway S., Kraus S.
<Astron. Astrophys. 579, A68 (2015)>
=2015A&A...579A..68G 2015A&A...579A..68G
ADC_Keywords: Models ; Interferometry
Keywords: stars: variables: Cepheids - binaries: close -
techniques: high angular resolution - techniques: interferometric
Abstract:
Long-baseline interferometry is an important technique to spatially
resolve binary or multiple systems in close orbits. By combining
several telescopes together and spectrally dispersing the light, it is
possible to detect faint components around bright stars in a few hours
of observations.
We provide a rigorous and detailed method to search for high-contrast
companions around stars, determine the detection level, and estimate
the dynamic range from interferometric observations.
We developed the code CANDID (Companion Analysis and Non-Detection in
Interferometric Data), a set of Python tools that allows us to search
systematically for point-source, high-contrast companions and estimate
the detection limit using all interferometric observables, i.e., the
squared visibilities, closure phases and bispectrum amplitudes. The
search procedure is made on a NxN grid of fit, whose minimum needed
resolution is estimated a posteriori. It includes a tool to estimate
the detection level of the companion in the number of sigmas. The code
CANDID also incorporates a robust method to set a 3σ detection
limit on the flux ratio, which is based on an analytical injection of
a fake companion at each point in the grid. Our injection method also
allows us to analytically remove a detected component to 1) search for
a second companion; and 2) set an unbiased detection limit.
Description:
This is a suite of Python2.7 tools to find faint companion around star
in interferometric data in the OIFITS format. This tool allows to
systematically search for faint companions in OIFITS data, and if not
found, estimates the detection limit.
All files are also available at https://github.com/amerand/CANDID .
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
candid.py 186 2368 CANDID Python program
readme.txt 693 209 ReadMe file to the use the program
AXCir.oifits 2880 41 Example of OIFITS file
--------------------------------------------------------------------------------
Acknowledgements:
Alexandre Gallenne, agallenne(at)astro-udec.cl
References:
Gallenne et al., Paper I 2013A&A...552A..21G 2013A&A...552A..21G
Gallenne et al., Paper II 2014A&A...561L...3G 2014A&A...561L...3G
Gallenne et al., Paper IV 2019A&A...622A.164G 2019A&A...622A.164G, Cat. J/A+A/622/A164
(End) Patricia Vannier [CDS] 01-Jul-2015