English
Related papers

Related papers: A Fourier method for the determination of focus fo…

200 papers

The Wide-Field InfraRed Space Telescope (WFIRST) will be capable of delivering precise astrometry for faint sources over the enormous field of view of its main camera, the Wide-Field Imager (WFI). This unprecedented combination will be…

To determine the precise positions of stars in CCD frames, various centering algorithms have been proposed for astrometry. The effective point spread function (ePSF) and the Gaussian centering algorithms are two representative centering…

Instrumentation and Methods for Astrophysics · Physics 2021-12-28 F. R. Lin , Q. Y. Peng , Z. J. Zheng , B. F. Guo , Y. J. Shang

A breakthrough in the sensitivity level of the hard X-/gamma-ray telescopes, which today are based on detectors that view the sky through (or not) coded masks, is expected when focusing optics will be available also in this energy range.…

Intensity, wavevector, phase, and polarization are the most important parameters of any light beam. Understanding the wavevector distribution has emerged as a very important problem in recent days, especially at nanoscale. It provides…

Optics · Physics 2020-01-22 Adarsh B. Vasista , Deepak K. Sharma , G V Pavan Kumar

We study theoretically the accuracy of the method based on the Fourier property of lenses that is commonly used for the far field measurement. We consider a simple optical setup in which the far-field intensity pattern of a light beam…

Optics · Physics 2013-07-19 Pierre Suret , Stephane Randoux

We investigate the prospects for discovering blazars at very high-redshifts (z>3-6) with the Fermi Gamma-Ray Space Telescope (Fermi), employing a model for the evolving gamma-ray luminosity function (GLF) of the blazar population. Our…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Yoshiyuki Inoue , Susumu Inoue , Tomonori Totani , Masakazu A. R. Kobayashi , Jun Kataoka , Rie Sato

Aims. Radio observing efficiency can be improved by calibrating and reducing the observations in total power mode rather than in frequency, beam, or position-switching modes. Methods. We selected a sample of spectra obtained from the…

Instrumentation and Methods for Astrophysics · Physics 2020-11-11 Laurent Pagani , David Frayer , Bruno Pagani , Charlène Lefèvre

The paper describes the MAGIC multi-mode focal reducer (Monitoring of Active Galaxies by Investigation of their Cores), commissioned on the 1-m Zeiss-1000 telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences…

We report Spitzer 3.6 and 4.5 $\mu$m photometry of 11 bright stars relative to Sirius, exploiting the unique optical stability of the Spitzer Space Telescope point spread function (PSF). Spitzer's extremely stable beryllium optics in its…

Solar and Stellar Astrophysics · Physics 2022-01-12 Kate Y. L. Su , G. H. Rieke , M. Marengo , Everett Schlawin

A forward model is presented to an inverse scattering problem that arises in the application of reflective Fourier ptychographic microscopy. The model allows us to determine the 3D distributions of refractive index for weakly scattering…

Optics · Physics 2020-08-25 Shuhe Zhang , Tos Berendschot , Shuo Zhang

We investigate interferometric techniques to estimate the deflection angle of an optical beam and compare them to the direct detection of the beam deflection. We show that quantum metrology methods lead to a unifying treatment for both…

Quantum Physics · Physics 2020-08-12 S. P. Walborn , G. H. Aguilar , P. L. Saldanha , L. Davidovich , R. L. de Matos Filho

We propose a method to build an astronomical interferometer using continuous variable quantum teleportation to overcome the transmission loss between distant telescopes. The scheme relies on two-mode squeezed states shared by distant…

Quantum Physics · Physics 2025-09-03 Yunkai Wang , Yujie Zhang , Virginia O. Lorenz

Fourier imaging is an indirect imaging method which records the diffraction pattern of the object scene coherently in the focal plane of the imaging system and reconstructs the image using computational resources. The spatial resolution,…

Optics · Physics 2023-06-05 Hui Yuan , Alvydas Lisauskas , Mark D. Thomson , Hartmut G. Roskos

In this paper we continue to develop the m-mode formalism, a technique for efficient and optimal analysis of wide-field transit radio telescopes, targeted at 21 cm cosmology. We extend this formalism to give an accurate treatment of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-16 J. Richard Shaw , Kris Sigurdson , Michael Sitwell , Albert Stebbins , Ue-Li Pen

Procedures based on current methods to detect sources in X-ray images are applied to simulated XMM images. All significant instrumental effects are taken into account, and two kinds of sources are considered -- unresolved sources…

Astrophysics · Physics 2009-11-06 I. Valtchanov , M. Pierre , R. Gastaud

We systematically characterize the focusing behavior of laser-driven proton beams from hemispherical targets of various diameters using mesh radiography. The proton focal location is inferred to be near the geometrical center for the…

In near-field beam focusing for finite-sized arrays, focal shift is a non-negligible issue. The actual focal point often appears closer to the array than the predefined focal distance, significantly degrading the focusing performance of…

Signal Processing · Electrical Eng. & Systems 2025-05-13 Jiawang Li , Yingjie Xu , Hanieh Aliakbari

Measurements of the Fermi surface are a fundamental technique for determining the electrical and magnetic properties of solids. In 2D systems, the area and diameter of the Fermi surface is typically measured using Shubnikov-de Haas…

Mesoscale and Nanoscale Physics · Physics 2025-01-07 M. J. Rendell , S. D. Liles , S. Bladwell , A. Srinivasan , O. Klochan , I. Farrer , D. A. Ritchie , O. P. Sushkov , A. R. Hamilton

We present a novel method to measure precisely the relative spectral response of the fluorescence telescopes of the Pierre Auger Observatory. We used a portable light source based on a xenon flasher and a monochromator to measure the…

Instrumentation and Methods for Astrophysics · Physics 2017-10-03 The Pierre Auger Collaboration , A. Aab , P. Abreu , M. Aglietta , I. Al Samarai , I. F. M. Albuquerque , I. Allekotte , A. Almela , J. Alvarez Castillo , J. Alvarez-Muñiz , G. A. Anastasi , L. Anchordoqui , B. Andrada , S. Andringa , C. Aramo , F. Arqueros , N. Arsene , H. Asorey , P. Assis , J. Aublin , G. Avila , A. M. Badescu , A. Balaceanu , F. Barbato , R. J. Barreira Luz , J. J. Beatty , K. H. Becker , J. A. Bellido , C. Berat , M. E. Bertaina , P. L. Biermann , J. Biteau , S. G. Blaess , A. Blanco , J. Blazek , C. Bleve , M. Boháčová , D. Boncioli , C. Bonifazi , N. Borodai , A. M. Botti , J. Brack , I. Brancus , T. Bretz , A. Bridgeman , F. L. Briechle , P. Buchholz , A. Bueno , S. Buitink , M. Buscemi , K. S. Caballero-Mora , L. Caccianiga , A. Cancio , F. Canfora , L. Caramete , R. Caruso , A. Castellina , F. Catalani , G. Cataldi , L. Cazon , A. G. Chavez , J. A. Chinellato , J. Chudoba , R. W. Clay , A. Cobos , R. Colalillo , A. Coleman , L. Collica , M. R. Coluccia , R. Conceição , G. Consolati , F. Contreras , M. J. Cooper , S. Coutu , C. E. Covault , J. Cronin , S. D'Amico , B. Daniel , S. Dasso , K. Daumiller , B. R. Dawson , R. M. de Almeida , S. J. de Jong , G. De Mauro , J. R. T. de Mello Neto , I. De Mitri , J. de Oliveira , V. de Souza , J. Debatin , O. Deligny , M. L. Díaz Castro , F. Diogo , C. Dobrigkeit , J. C. D'Olivo , Q. Dorosti , R. C. dos Anjos , M. T. Dova , A. Dundovic , J. Ebr , R. Engel , M. Erdmann , M. Erfani , C. O. Escobar , J. Espadanal , A. Etchegoyen , H. Falcke , J. Farmer , G. Farrar , A. C. Fauth , N. Fazzini , F. Fenu , B. Fick , J. M. Figueira , A. Filipčič , O. Fratu , M. M. Freire , T. Fujii , A. Fuster , R. Gaior , B. García , D. Garcia-Pinto , F. Gaté , H. Gemmeke , A. Gherghel-Lascu , P. L. Ghia , U. Giaccari , M. Giammarchi , M. Giller , D. Głas , C. Glaser , G. Golup , M. Gómez Berisso , P. F. Gómez Vitale , N. González , B. Gookin , A. Gorgi , P. Gorham , A. F. Grillo , T. D. Grubb , F. Guarino , G. P. Guedes , R. Halliday , M. R. Hampel , P. Hansen , D. Harari , T. A. Harrison , J. L. Harton , A. Haungs , T. Hebbeker , D. Heck , P. Heimann , A. E. Herve , G. C. Hill , C. Hojvat , E. Holt , P. Homola , J. R. Hörandel , P. Horvath , M. Hrabovský , T. Huege , J. Hulsman , A. Insolia , P. G. Isar , I. Jandt , J. A. Johnsen , M. Josebachuili , J. Jurysek , A. Kääpä , O. Kambeitz , K. H. Kampert , B. Keilhauer , N. Kemmerich , E. Kemp , J. Kemp , R. M. Kieckhafer , H. O. Klages , M. Kleifges , J. Kleinfeller , R. Krause , N. Krohm , D. Kuempel , G. Kukec Mezek , N. Kunka , A. Kuotb Awad , B. L. Lago , D. LaHurd , R. G. Lang , M. Lauscher , R. Legumina , M. A. Leigui de Oliveira , A. Letessier-Selvon , I. Lhenry-Yvon , K. Link , D. Lo Presti , L. Lopes , R. López , A. López Casado , R. Lorek , Q. Luce , A. Lucero , M. Malacari , M. Mallamaci , D. Mandat , P. Mantsch , A. G. Mariazzi , I. C. Mariş , G. Marsella , D. Martello , H. Martinez , O. Martínez Bravo , J. J. Masías Meza , H. J. Mathes , S. Mathys , J. Matthews , J. A. J. Matthews , G. Matthiae , E. Mayotte , P. O. Mazur , C. Medina , G. Medina-Tanco , D. Melo , A. Menshikov , K. -D. Merenda , S. Michal , M. I. Micheletti , L. Middendorf , L. Miramonti , B. Mitrica , D. Mockler , S. Mollerach , F. Montanet , C. Morello , M. Mostafá , A. L. Müller , G. Müller , M. A. Muller , S. Müller , R. Mussa , I. Naranjo , L. Nellen , P. H. Nguyen , M. Niculescu-Oglinzanu , M. Niechciol , L. Niemietz , T. Niggemann , D. Nitz , D. Nosek , V. Novotny , L. Nožka , L. A. Núñez , L. Ochilo , F. Oikonomou , A. Olinto , M. Palatka , J. Pallotta , P. Papenbreer , G. Parente , A. Parra , T. Paul , M. Pech , F. Pedreira , J. Pękala , R. Pelayo , J. Peña-Rodriguez , L. A. S. Pereira , M. Perlin , L. Perrone , C. Peters , S. Petrera , J. Phuntsok , R. Piegaia , T. Pierog , M. Pimenta , V. Pirronello , M. Platino , M. Plum , C. Porowski , R. R. Prado , P. Privitera , M. Prouza , E. J. Quel , S. Querchfeld , S. Quinn , R. Ramos-Pollan , J. Rautenberg , D. Ravignani , J. Ridky , F. Riehn , M. Risse , P. Ristori , V. Rizi , W. Rodrigues de Carvalho , G. Rodriguez Fernandez , J. Rodriguez Rojo , D. Rogozin , M. J. Roncoroni , M. Roth , E. Roulet , A. C. Rovero , P. Ruehl , S. J. Saffi , A. Saftoiu , F. Salamida , H. Salazar , A. Saleh , F. Salesa Greus , G. Salina , F. Sánchez , P. Sanchez-Lucas , E. M. Santos , E. Santos , F. Sarazin , R. Sarmento , C. Sarmiento-Cano , R. Sato , M. Schauer , V. Scherini , H. Schieler , M. Schimp , D. Schmidt , O. Scholten , P. Schovánek , F. G. Schröder , S. Schröder , A. Schulz , J. Schumacher , S. J. Sciutto , A. Segreto , A. Shadkam , R. C. Shellard , G. Sigl , G. Silli , O. Sima , A. Śmiałkowski , R. Šmída , G. R. Snow , P. Sommers , S. Sonntag , R. Squartini , D. Stanca , S. Stanič , J. Stasielak , P. Stassi , M. Stolpovskiy , F. Strafella , A. Streich , F. Suarez , M. Suarez Durán , T. Sudholz , T. Suomijärvi , A. D. Supanitsky , J. Šupík , J. Swain , Z. Szadkowski , A. Taboada , O. A. Taborda , V. M. Theodoro , C. Timmermans , C. J. Todero Peixoto , L. Tomankova , B. Tomé , G. Torralba Elipe , P. Travnicek , M. Trini , R. Ulrich , M. Unger , M. Urban , J. F. Valdés Galicia , I. Valiño , L. Valore , G. van Aar , P. van Bodegom , A. M. van den Berg , A. van Vliet , E. Varela , B. Vargas Cárdenas , G. Varner , R. A. Vázquez , D. Veberič , C. Ventura , I. D. Vergara Quispe , V. Verzi , J. Vicha , L. Villaseñor , S. Vorobiov , H. Wahlberg , O. Wainberg , D. Walz , A. A. Watson , M. Weber , A. Weindl , L. Wiencke , H. Wilczyński , M. Wirtz , D. Wittkowski , B. Wundheiler , L. Yang , A. Yushkov , E. Zas , D. Zavrtanik , M. Zavrtanik , A. Zepeda , B. Zimmermann , M. Ziolkowski , Z. Zong , F. Zuccarello

The Schwarzschild-Couder Telescope (SCT) is a candidate technology for a medium-sized telescope within the Cherenkov Telescope Array, the next generation ground based observatory for very high energy gamma ray astronomy. The SCT uses a…

‹ Prev 1 3 4 5 6 7 10 Next ›