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Related papers: Using ACT arrays as Intensity Interferometers

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A simple analysis technique is described which allows to intercalibrate the response of imaging atmospheric Cherenkov telescopes in stereoscopic telescope arrays at a level of 1-2%.

Astrophysics · Physics 2008-11-26 Werner Hofmann

The conventional approach to high-precision narrow-angle astrometry using a long baseline interferometer is to directly measure the fringe packet separation of a target and a nearby reference star. This is done by means of a technique known…

Instrumentation and Methods for Astrophysics · Physics 2014-08-25 Y. Kok , M. J. Ireland , A. C. Rizzuto , P. G. Tuthill , J. G. Robertson , B. A. Warrington , W. J. Tango

We present the successful measurement of the squared visibility of Sirius at a telescope separation of 3.3 m using small 0.25 m Newtonian-style telescopes in an urban backyard setting. The primary science goal for small-scale intensity…

Instrumentation and Methods for Astrophysics · Physics 2025-01-20 Thomas J. Mozdzen , Richard M. Scott , Ricardo R. Rodriguez , Philip D. Mauskopf

What is long-baseline optical/IR stellar interferometry? A few years ago, many astronomers might not have been able to answer that question properly. This is today hopefully not the case anymore, because mainstream facilities, such as the…

Instrumentation and Methods for Astrophysics · Physics 2016-11-26 Florentin Millour

Large Array of imaging atmospheric Cherenkov Telescope (LACT) is an array of 32 Cherenkov telescopes with 6-meter diameter mirrors to be constructed at the LHAASO site, aiming to enhance our understanding of ultra-high energy gamma ray…

High Energy Astrophysical Phenomena · Physics 2025-09-26 Zhipeng Zhang , Ruizhi Yang , Shoushan Zhang

Relative astrometric measurements with a precision far better than 1 mas (milli-arcsec) are commonly regarded as the domain of interferometry. Pioneering work by Pravdo & Shaklan (1996), made in the optical, reached a precision of 150…

Astrophysics · Physics 2015-05-13 Andreas Seifahrt , Tristan Roell , Ralph Neuhaeuser

The surface-brightness-color (SBC) relationship for Red Clump stars provides a critical foundation for precision distance ladder measurements, including the 1\% distance determination to the Large Magellanic Cloud. Current SBC calibrations…

Solar and Stellar Astrophysics · Physics 2026-04-10 Alex G. Kim , Robin Kaiser

Arrays of imaging air Cherenkov telescopes (IACTs) like VERITAS, HESS have been recently proposed as the instruments of the next generation for ground based very high energy gamma-ray astronomy invading into 50-100 GeV energy range. Here we…

Astrophysics · Physics 2009-10-31 Alexander K. Konopelko

The Cherenkov Telescope Array (CTA) will be able to perform unprecedented observations of the transient very high-energy sky. An on-line science alert generation (SAG) pipeline, with a required 30 second latency, will allow the discovery or…

Instrumentation and Methods for Astrophysics · Physics 2019-07-19 Valentina Fioretti , Deivid Ribeiro , Thomas B. Humensky , Andrea Bulgarelli , Gernot Maier , Abelardo Moralejo , Cosimo Nigro

The ASTRI project aims to develop, in the framework of the Cherenkov Telescope Array, an end-to-end prototype of the small-size telescope, devoted to the investigation of the energy range ~ 1-100 TeV. The proposed design is characterized by…

Instrumentation and Methods for Astrophysics · Physics 2017-08-23 N. La Palombara , P. Caraveo , M. Fiorini , L. Stringhetti , R. Canestrari , R. Millul , G. Pareschi , O. Catalano , M. C. Maccarone , S. Vercellone , E. Giro , G. Tosti

For several years the only experiments sensitive to astrophysical gamma rays with energies beyond the reach of EGRET but below that of the Cherenkov imaging telescopes have been the "solar tower" detectors. They use >2000 m2 mirror areas to…

Astrophysics · Physics 2007-05-23 David A. Smith

The large optical reflector (~ 100 m^2) of a H.E.S.S. Cherenkov telescope was used to search for very fast optical transients of astrophysical origin. 43 hours of observations targeting stellar-mass black holes and neutron stars were…

Astrophysics · Physics 2009-11-13 C. Deil , W. Domainko , G. Hermann , A. -C. Clapson , A. Förster , C. van Eldik , W. Hofmann

The apparent size of stars is a crucial benchmark for fundamental stellar properties such as effective temperatures, radii and surface gravities. While interferometric measurements of stellar angular diameters are the most direct method to…

Solar and Stellar Astrophysics · Physics 2014-05-23 L. Casagrande , L. Portinari , I. S. Glass , D. Laney , V. Silva Aguirre , J. Datson , J. Andersen , B. Nordström , J. Holmberg , C. Flynn , M. Asplund

We measured the angular diameters of 44 stars with the Navy Precision Optical Interferometer, obtaining uncertainties on the limb darkened diameter of 2% or less for all but four stars. We then used our diameters with Gaia or Hipparcos…

Recent dynamical studies indicate that the possibility of an Earth-like planet around $\alpha\;$Cen A or B should be taken seriously. Such a planet, if it exists, would perturb the orbital astrometry by $<10 \ {\mu}\rm as$, which is…

Instrumentation and Methods for Astrophysics · Physics 2022-09-15 Km Nitu Rai , Subrata Sarangi , Prasenjit Saha , Soumen Basak

Interferometry has been a very successful tool for measuring anisotropies in the cosmic microwave background. Interferometers provided the first constraints on CMB anisotropies on small angular scales (l~10000) in the 1980s and then in the…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-11 Clive Dickinson

We report the first use of Michelson interferometry on the Keck I telescope for diffraction-limited imaging in the near infrared JHK and L bands. By using an aperture mask located close to the f/25 secondary, the 10 m Keck primary mirror…

Astrophysics · Physics 2009-10-31 P. G. Tuthill , J. D. Monnier , W. C. Danchi , E. H. Wishnow , C. A. Haniff

Infrared interferometry has seen a revolution over the last few years. The advent of GRAVITY+ is about to enable high-contrast observations, all-sky coverage and faint science up to K=21, with the implementation on 8m-class telescope of…

Instrumentation and Methods for Astrophysics · Physics 2024-10-30 G. Bourdarot , F. Eisenhauer

After decades of efforts, optical long-baseline interferometry has become a mainstream observational technique in terms of operation robustness and user friendliness. Interferometry has opened a new observational window, enabling…

Solar and Stellar Astrophysics · Physics 2025-12-02 H. Sana E. Bordier , K. Deshmukh , A. J. Frost , A. Keskar , C. Lanthermann , R. R. Lefever , L. Mahy , A. A. C. Sander , T. Shenar , F. Tramper

The sensitivity of imaging atmospheric Cherenkov telescopes (IACTs) in TeV gamma-ray observations reachs its maximum at small zenith angles (< 30 degree) which provide the minimum attainable energy threshold of an instrument. However, for a…

Astrophysics · Physics 2008-11-26 A. Konopelko , F. Aharonian , M. Hemberger , W. Hofmann , J. Kettler , G. Puehlhofer , H. J. Voelk