A comparison of spectroscopic versus imaging techniques for detecting close companions to Kepler objects of interest
Article
Article Title | A comparison of spectroscopic versus imaging techniques for detecting close companions to Kepler objects of interest |
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ERA Journal ID | 1048 |
Article Category | Article |
Authors | Teske, Johanna K. (Author), Everett, Mark E. (Author), Hirsch, Lea (Author), Furlan, Elise (Author), Horch, Elliott P. (Author), Howell, Steve B. (Author), Ciardi, David R. (Author), Gonzales, Erica (Author) and Crepp, Justin R. (Author) |
Journal Title | The Astronomical Journal |
Journal Citation | 150 (5), pp. 144-164 |
Article Number | 144 |
Number of Pages | 21 |
Year | 2015 |
Publisher | IOP Publishing |
Place of Publication | United States |
ISSN | 0004-6256 |
1538-3881 | |
Digital Object Identifier (DOI) | https://doi.org/10.1088/0004-6256/150/5/144 |
Web Address (URL) | http://iopscience.iop.org/article/10.1088/0004-6256/150/5/144 |
Abstract | Kepler planet candidates require both spectroscopic and imaging follow-up observations to rule out false positives and detect blended stars. Traditionally, spectroscopy and high-resolution imaging have probed different host star companion parameter spaces, the former detecting tight binaries and the latter detecting wider bound companions as well as chance background stars. In this paper, we examine a sample of 11 Kepler host stars with companions detected by two techniques - near-infrared adaptive optics and/or optical speckle interferometry imaging, and a new spectroscopic deblending method. We compare the companion effective temperatures (Teff) and flux ratios (FB/FA, where A is the primary and B is the companion) derived from each technique and find no cases where both companion parameters agree within 1σ errors. In 3/11 cases the companion Teff values agree within 1σ errors, and in 2/11 cases the companion FB/FA values agree within 1σ errors. Examining each Kepler system individually considering multiple avenues (isochrone mapping, contrast curves, probability of being bound), we suggest two cases for which the techniques most likely agree in their companion detections (detect the same companion star). Overall, our results support the advantage that the spectroscopic deblending technique has for finding very close-in companions (θ ≲ 0.″02-0.″05) that are not easily detectable with imaging. However, we also specifically show how high-contrast AO and speckle imaging observations detect companions at larger separations (θ ≥ 0.″02-0.″05) that are missed by the spectroscopic technique, provide additional information for characterizing the companion and its potential contamination (e.g., position angle, separation, magnitude differences), and cover a wider range of primary star effective temperatures. The investigation presented here illustrates the utility of combining the two techniques to reveal higher-order multiples in known planet-hosting systems. |
Keywords | binaries: general; planetary systems; techniques: high angular resolution techniques: interferometric techniques: photometric techniques; spectroscopic |
Contains Sensitive Content | Does not contain sensitive content |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
519999. Other physical sciences not elsewhere classified | |
Public Notes | For access to this article, please click on the URL link provided. |
Byline Affiliations | Carnegie Institution of Washington, United States |
National Optical Astronomy Observatory, United States | |
University of California, United States | |
California Institute of Technology (Caltech), United States | |
Southern Connecticut State University, United States | |
National Aeronautics and Space Administration (NASA), United States | |
University of Notre Dame, United States | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q42zw/a-comparison-of-spectroscopic-versus-imaging-techniques-for-detecting-close-companions-to-kepler-objects-of-interest
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