Imaging the asymmetric dust shell around CI Cam with long baseline optical interferometry
Abstract
We present the first high angular resolution observation of the B[e] star/X-ray transient object CI Cam, performed with the two-telescope Infrared Optical Telescope Array (IOTA), its upgraded three-telescope version (IOTA3T) and the Palomar Testbed Interferometer (PTI). Visibilities and closure phases were obtained using the IONIC-3 integrated optics beam combiner. CI Cam was observed in the near-infrared H and K spectral bands, wavelengths well suited to measure the size and study the geometry of the hot dust surrounding CI Cam. The analysis of the visibility data over an 8 yr period from soon after the 1998 outburst to 2006 shows that the dust visibility has not changed over the years. The visibility data show that CI Cam is elongated which confirms the disc-shape of the circumstellar environment and totally rules out the hypothesis of a spherical dust shell. Closure phase measurements show direct evidence of asymmetries in the circumstellar environment of CI Cam and we conclude that the dust surrounding CI Cam lies in an inhomogeneous disc seen at an angle. The near-infrared dust emission appears as an elliptical skewed Gaussian ring with a major axis a= 7.58 ± 0.24 mas , an axis ratio r= 0.39 ± 0.03 and a position angle θ= 35°± 2°.
Additional Information
© 2009 RAS. Accepted 2009 April 20; received 2009 April 16; in original form 2008 October 7. N. Thureau has received research funding from the European Community's Sixth Framework Programme through an International Outgoing Marie-Curie fellowship OIF - 002990. We thank our IOTA colleagues for their invaluable contribution to the CI Cam observation program. The IONIC3 instrument has been developed by the Laboratoire d'Astrophysique de Grenoble (LAOG) and LETI in the context of the IONIC collaboration (LAOG, IMEP, LETI) with funding from the Centre National de Recherche Scientifique (CNRS, France) and Centre National d'Etudes Spatiales (CNES, France). We acknowledge our PTI colleagues for their assistance in planning and carrying out the CI Cam observing program at PTI. PTI was developed by Jet Propulsion Laboratory and is operated by the Michelson Science Center on behalf of the PTI collaboration. This research has made use of: NASA's Astrophysics Data System Bibliographic Services, SIMBAD data base operated at CDS, Strasbourg, France, MSC resources, CHARM2 and 2MASS catalogues through the VizieR service at CDS, Strasbourg, France. TIFKAM was funded by the Ohio State University, the MDM consortium, MIT and NSF grant AST-9605012. NOAO and USNO paid for the development of the ALADDIN arrays and contributed the array currently in use in TIFKAM. This research was made possible thanks to a Michelson Postdoctoral Fellowship and a Scottish Universities Physics Association (SUPA) advanced fellowship awarded to E. Pedretti. Part of the research described in this paperwas carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. M.R. Garcia acknowledges partial support from NASA Contract NAS8-03060 to the Chandra X-ray Center.Attached Files
Published - Thureau2009p5970Mon_Not_R_Astron_Soc.pdf
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Additional details
- Eprint ID
- 16153
- Resolver ID
- CaltechAUTHORS:20091001-121850085
- OIF-002990
- Marie Curie Fellowship
- Ohio State University
- MDM Consortium
- Massachusetts Institute of Technology (MIT)
- AST-9605012
- NSF
- NASA Postdoctoral Program
- Scottish Universities Physics Alliance
- NAS8-03060
- NASA
- Created
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2009-10-05Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field