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Atmospheric water vapor causes significant undesired phase fluctuations for the Submillimeter Array (SMA) interferometer, particularly in its highest frequency observing band of 690 GHz. One proposed solution to this atmospheric effect is…

Astrophysics · Physics 2007-05-23 D. Y. Kubo , T. R. Hunter , R. D. Christensen , P. I. Yamaguchi

Based on a joint analysis of the data from 10 midlatitude decameter radars the effects are investigated during 80 x-ray flares in the period 2013-2017. For the investigation nine mid-latitude SuperDARN radars of the northern hemisphere and…

One of the major challenges of mid-infrared astronomical heterodyne interferometry is its sensitivity limitations. Detectors capable of handling several 10 GHz bandwidths have been identified as key building blocks of future instruments.…

Instrumentation and Methods for Astrophysics · Physics 2022-09-19 Tituan Allain , Mohammadreza Saemian , Carlo Sirtori , Jean-Philippe Berger

We discuss the design, construction, and operation of a new intensity interferometer, based on the campus of Southern Connecticut State University in New Haven, Connecticut. While this paper will focus on observations taken with an original…

Instrumentation and Methods for Astrophysics · Physics 2022-02-02 Elliott P. Horch , Samuel A. Weiss , Paul M. Klaucke , Richard A. Pellegrino , Justin D. Rupert

On August 21, 2017, the Airborne Infrared Spectrometer (AIR-Spec) observed the total solar eclipse at an altitude of 14 km from aboard the NSF/NCAR Gulfstream V research aircraft. The instrument successfully observed the five coronal…

We present results of a study of intermittency and multifractality of magnetic structures in solar active regions (ARs). Line-of-sight magnetograms for 214 ARs of different flare productivity observed at the center of the solar disk from…

Solar and Stellar Astrophysics · Physics 2010-12-08 Valentyna Abramenko , Vasyl Yurchyshyn

High precision interferometers such as gravitational-wave detectors require complex seismic isolation systems in order to decouple the experiment from unwanted ground motion. Improved inertial sensors for active isolation potentially…

Optical intensity interferometry, developed in the 1950s, is a simple and inexpensive method for achieving angular resolutions on microarcsecond scales. Its low sensitivity has limited intensity interferometric observations to bright stars…

Instrumentation and Methods for Astrophysics · Physics 2020-11-25 Junghwan Oh , Jan Wagner , Sascha Trippe , Taeseok Lee , Bangwon Lee , Chang Hee Kim

In this work, a microwave photonic prototype for concurrent radar detection and spectrum sensing is proposed, designed, built, and investigated. A direct digital synthesizer and an analog electronic circuit are integrated to generate an…

Dual sideband (2SB) receivers are well suited for the spectral observation of complex astronomical signals over a wide frequency range. They are extensively used in radio astronomy, their main advantages being to avoid spectral confusion…

Instrumentation and Methods for Astrophysics · Physics 2018-05-17 Ricardo Finger , Patricio Mena , Nicolas Reyes , Rafael Rodriguez , Leonardo Bronfman

Stellar seismology reveals some interior properties of thousands of solar-type stars but the solar seismic sound speed stays puzzling since a decade as it disagrees with the Standard Solar Model (SSM) prediction. One of the explanations of…

Solar and Stellar Astrophysics · Physics 2015-09-14 M. Le Pennec , X. Ribeyre , J. -E. Ducret , S. Turck-Chièze

We present a database of solar flares registered by the Konus-Wind instrument during more than 27 years of operation, from 1994 November to now (2022 June). The constantly updated database (hereafter KW-Sun) contains over 1000 events…

Wavefront cleaning by single-mode fibers has proved to be efficient in optical-infrared interferometry to improve calibration quality. For instance, the FLUOR instrument has demonstrated the capability of fluoride glass single-mode fibers…

A Michelson-type interferometer with two-mode squeezed coherent state input is considered. Such an interferometer has a better phase sensitivity over the shot-noise limit by a factor of $e^{2r}$, where $r$ is the squeezing parameter [Phys.…

Quantum Physics · Physics 2023-03-03 Stav Haldar , Pratik J. Barge , Xiao-Qi Xiao , Hwang Lee

The recently released spacecraft potential measured by the RPW instrument on-board Solar Orbiter has been used to estimate the solar wind electron density in the inner heliosphere. Solar-wind electron density measured during June 2020 has…

Radioactive sources presented annual periodical half-life changes in several accurate measurements, although customary practice claims that radioactive decay should be a physical constant for each radionuclide. Besides that, the Purdue…

Nuclear Experiment · Physics 2020-02-26 Jonathan Walg , Anatoly Rodnianski , Itzhak Orion

We report characterization results for an engineering prototype of a next-generation low-frequency radio astronomy array. This prototype, which we refer to as the Aperture Array Verification System 0.5 (AAVS0.5), is a sparse pseudo-random…

We present the spectra of 14 quasars with a wide coverage of rest wavelengths from 1000 to 7300 A. The redshift ranges from z = 0.061 to 0.555 and the luminosity from M_{B} = -22.69 to -26.32. We describe the procedure of generating the…

Radio interferometers can potentially detect the sky-averaged signal from the Cosmic Dawn (CD) and the Epoch of Reionisation (EoR) by studying the Moon as a thermal block to the foreground sky. The first step is to mitigate the Earth-based…

Instrumentation and Methods for Astrophysics · Physics 2023-12-19 Himanshu Tiwari , Benjamin McKinley , Cathryn M. Trott , Nithyanandan Thyagarajan

Every 11 years, the Sun goes through periods of activity, with the occurrence of many solar flares and mass ejections, both energetic phenomena of magnetic origin. Due to its effects on Earth, the study of solar activity is of paramount…

Solar and Stellar Astrophysics · Physics 2023-09-14 Vanessa Lessa , Adriana Valio
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