First Keck Interferometer measurements in self-phase referencing mode: spatially resolving circum-stellar line emission of 48 Lib
| Autor: | Rachel Akeson, James R. Graham, Rafael Millan-Gabet, C. Felizardo, J.-U. Pott, J. Herstein, Julien Woillez, Andrea M. Ghez, E. Appleby, K. Summers, M. Hrynevych, A. Cooper, B. Berkey, K. Tsubota, Sam Ragland, C. Tyau, D. Medeiros, T. Panteleeva, D. Morrison, M. Mark Colavita, Josh A. Eisner, John D. Monnier, B. Smith, P. L. Wizinowich, Lynne A. Hillenbrand, E. Wetherell |
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| Přispěvatelé: | Danchi, William C., Delplancke, Françoise, Rajagopal, Jayadev K. |
| Rok vydání: | 2010 |
| Předmět: |
Physics
Be star business.industry Near-infrared spectroscopy Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Interferometry Stars Optics Astronomical interferometer Astrophysics::Solar and Stellar Astrophysics Hydrogen line Astrophysics::Earth and Planetary Astrophysics Emission spectrum Spectral resolution business Astrophysics::Galaxy Astrophysics |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.856922 |
| Popis: | Recently, the Keck interferometer was upgraded to do self-phase-referencing (SPR) assisted K-band spectroscopy at R 2000. This means, combining a spectral resolution of 150 km /s with an angular resolution of 2.7 mas, while maintaininghigh sensitiviy. This SPR mode operates two fringe trackers in parallel, and explores several infrastructural requirementsfor o -axis phase-referencing, as currently being implemented as the KI-ASTRA project. The technology of self-phase-referencing opens the way to reach very high spectral resolution in near-infrared interferometry. We present the scienti ccapabilities oftheKI-SPRmode indetail, attheexample ofobservations ofthe Be-star48 Lib. Several spectrallinesofthecirumstellar disk are resolved. We describe the rst detection of Pfund-lines in an interferometric spectrum of a Be star, inaddition to Br . The di erential phase signal can be used to (i) distinguish circum-stellar line emission from the star, (ii)to directly measure line asymmetries tracing an asymetric gas density distribution, (iii) to reach a di erential, astrometricprecision beyond single-telescope limits su cient for studying the radial disk structure. Our data support the existence ofa radius-dependent disk density perturbation, typically used to explain slow variations of Be-disk hydrogen line pro les.Keywords: stars: emission-line, Be circumstellar matter stars: individual (48 Lib) techniques: interferometric tech-niques: spectroscopic infrared: stars |
| Databáze: | OpenAIRE |
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