Abstract
TODCOR is a new TwO-Dimensional CORrelation technique to measure radial velocities of two components of a spectroscopic binary. Assuming the spectra of the two components are known, the technique correlates an observed binary spectrum against a combination of the two spectra with different shifts. TODCOR measuressimultaneously the radial velocities of the two stars by finding the maximum correlation.
One of the advantages of TODCOR is its ability to detect a very faint companion in a combined spectrum, and to measure its radial velocity. We performed numerous tests in which we applied TODCOR to simulated spectra which were prepared as combinations of two spectra with various luminosity ratios, together with random noise. These tests show that TODCOR can detect a very faint secondary spectrum and measure correctly its velocity, even with a luminosity ratio of 1000, provided the combined spectrum has enough spectral coverage and highS / N. Measuring the radial velocity of the faint secondary will enable us to estimate the companion mass, a very useful tool in the search for brown dwarfs and giant planets around nearby stars.
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References
Henry, T.J.: 1991, Ph.D. Thesis, University of Arizona.
Kleinmann, S.G. and Hall, D.N.B.: 1986,Ap JS 62, 501.
Kurucz, R.L.: 1991, in: A.G.D. Philip, A.R. Upgren and K.A. Janes, ed(s).,Precision Photometry: Astrophysics of the Galaxy, Schenectady, New York, 27.
Latham, D.W.: 1985, in: A.G.D. Philip and D.W. Latham, ed(s).,IAU Colloquium 88, Stellar Radial Velocities, Schenectady, New York, 21.
Latham, D.W.: 1992, in: H.A. McAlister and W.I. Hartkopf, ed(s).,IAU Colloquium 135, Complementary Approaches to Double and Multiple Star Research, Astronomical Society of the Pacific Conference Series, Vol. 32, 110.
Latham, D.W., Mazeh, T., Stefanik, R.P., Mayor, M. and Burki, G.: 1989,Nature 339, 38.
Mazeh, T. and Goldberg, D.: 1992,Ap J 394, 592.
Mazeh, T., Goldberg, D., Duquennoy, A. and Mayor, M.: 1992,Ap J 401, 265.
Mazeh, T. and Zucker, S.: 1992, in: H.A. McAlister and W.I. Hartkopf, ed(s).,IAU Colloquium 135, Complementary Approaches to Double and Multiple Star Research, Astronomical Society of the Pacific Conference Series, Vol. 32, 164.
Tonry, J. and Davis, M.: 1979,A J 84, 1511.
Zucker, S. and Mazeh, T.: 1993,Astrophys. J., (in press).
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Mazeh, T., Zucker, S. Todcor: A TwO-Dimensional CORrelation technique to analyze stellar spectra in search of faint companions. Astrophys Space Sci 212, 349–356 (1994). https://doi.org/10.1007/BF00984538
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DOI: https://doi.org/10.1007/BF00984538