The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Dainis Dravins. Profile photo.

Dainis Dravins

Professor emeritus

Dainis Dravins. Profile photo.

Stellar intensity interferometry over kilometer baselines: Laboratory simulation of observations with the Cherenkov Telescope Array

Author

  • Dainis Dravins
  • Tiphaine Lagadec

Summary, in English

A long-held astronomical vision is to realize diffraction-limited optical aperture synthesis over kilometer baselines. This will enable imaging of stellar surfaces and their environments, show their evolution over time, and reveal interactions of stellar winds and gas flows in binary star systems. An opportunity is now opening up with the large telescope arrays primarily erected for measuring Cherenkov light in air induced by gamma rays. With suitable software, such telescopes could be electronically connected and used also for intensity interferometry. With no optical connection between the telescopes, the error budget is set by the electronic time resolution of a few nanoseconds. Corresponding light-travel distances are on the order of one meter, making the method practically insensitive to atmospheric turbulence or optical imperfections, permitting both very long baselines and observing at short optical wavelengths. Theoretical modeling has shown how stellar surface images can be retrieved from such observations and here we report on experimental simulations. In an optical laboratory, artificial stars (single and double, round and elliptic) are observed by an array of telescopes. Using high-speed photon-counting solid-state detectors and real-time electronics, intensity fluctuations are cross correlated between up to a hundred baselines between pairs of telescopes, producing maps of the second-order spatial coherence across the interferometric Fourier-transform plane. These experiments serve to verify the concepts and to optimize the instrumentation and observing procedures for future observations with (in particular) CTA, the Cherenkov Telescope Array, aiming at order-of-magnitude improvements of the angular resolution in optical astronomy.

Department/s

  • Lund Observatory

Publishing year

2014

Language

English

Pages

91460-91460

Publication/Series

Optical and Infrared Interferometry IV

Volume

9146

Document type

Conference paper

Publisher

SPIE

Topic

  • Astronomy, Astrophysics and Cosmology

Keywords

  • Intensity interferometry
  • Hanbury Brown - Twiss
  • Aperture synthesis
  • Second-order coherence
  • Stellar surface imaging
  • Exoplanet imaging
  • Cherenkov telescopes
  • Cherenkov Telescope Array

Conference name

Conference on Optical and Infrared Interferometry IV

Conference date

2014-06-23 - 2014-06-27

Conference place

Montreal, Canada

Status

Published

ISBN/ISSN/Other

  • ISSN: 1996-756X
  • ISSN: 0277-786X