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Related papers: Robust absolute solar flux density calibration for…

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The development of new phased array systems in radio astronomy, as the low frequency array (LOFAR) and the square kilometre array (SKA), formed of a large number of small and flexible elementary antennas, has led to significant challenges.…

This paper provides an overview of the PACS photometer flux calibration concept, in particular for the principal observation mode, the scan map. The absolute flux calibration is tied to the photospheric models of five fiducial stellar…

We present the first observations of the Sun with the Allen Telescope Array (ATA). We used up to six frequencies, from 1.43 to 6 GHz, and baselines from 6 to 300 m. To our knowledge, these are the first simultaneous multifrequency full-Sun…

Solar and Stellar Astrophysics · Physics 2016-11-25 Pascal Saint-Hilaire , Gordon J. Hurford , Garrett Keating , Geoffrey C. Bower , Colby Gutierrez-Kraybill

Observational cosmology employing optical surveys often require precise flux calibration. In this context we present SNIFS Calibration Apparatus (SCALA), a flux calibration system developed for the SuperNova Integral Field Spectrograph…

Instrumentation and Methods for Astrophysics · Physics 2014-12-04 Simona Lombardo , Greg Aldering , Akos Hoffmann , Marek Kowalski , Daniel Kuesters , Klaus Reif , Mickael Rigault

Polarimetric radio observations of the Sun can provide rich information about emission mechanisms and the propagation medium. For the past five decades, solar polarimetric studies at low radio frequencies have almost always assumed the…

Solar and Stellar Astrophysics · Physics 2025-08-05 Soham Dey , Devojyoti Kansabanik , Divya Oberoi , Surajit Mondal

Coronal magnetic fields are well known to be one of the crucial parameters defining coronal physics and space weather. However, measuring the global coronal magnetic fields remains challenging. The polarization properties of coronal radio…

Solar and Stellar Astrophysics · Physics 2022-07-01 Devojyoti Kansabanik , Divya Oberoi , Surajit Mondal

We present the first dedicated observations of Interplanetary Scintillation (IPS) with the Murchison Widefield Array (MWA). We have developed a synthesis imaging technique, tailored to the properties of modern "large-N" low-frequency radio…

Instrumentation and Methods for Astrophysics · Physics 2017-09-12 J . S. Morgan , J-P. Macquart , R. Ekers , R. Chhetri , M. Tokumaru , P. K. Manoharan , S. Tremblay , M. M. Bisi , B. V. Jackson

Continuum intensity observations obtained with the Michelson Doppler Imager (MDI) on-board the SoHO mission provide long time series of filtergrams that are ideal for studying the evolution of large-scale phenomena in the solar atmosphere…

Solar and Stellar Astrophysics · Physics 2015-05-20 S. Criscuoli , I. Ermolli , D. Del Moro , F. Giorgi , A. Tritschler , H. Uitenbroek , N. Vitas

We present the absolute flux and wavelength calibration of the James Webb Space Telescope (JWST) Near-Infrared Camera (NIRCam) Wide Field Slitless Spectroscopy (WFSS) mode. Each of NIRCam's two modules (A and B) provides independent long…

Instrumentation and Methods for Astrophysics · Physics 2026-02-19 Nor Pirzkal , Martha Boyer , Russel E. Ryan

We present results from the first intensive monitoring campaign of a sample of Compact Symmetric Objects (CSOs). We observed seven CSOs at 8.5 GHz over a period of eight months, with an average spacing between observations of 2.7 days. Our…

Astrophysics · Physics 2009-11-06 C. D. Fassnacht , G. B. Taylor

Newly acquired data and improved data reduction algorithms mandate a fresh look at the absolute flux calibration of the CCD cameras on the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The goals are to achieve a 1\%…

Instrumentation and Methods for Astrophysics · Physics 2016-08-31 Ralph C. Bohlin

We have extended our previous work to use the Murchison Widefield Array (MWA) as a non-coherent passive radar system in the FM frequency band, using terrestrial FM transmitters to illuminate objects in Low Earth Orbit LEO) and the MWA as…

Instrumentation and Methods for Astrophysics · Physics 2020-12-16 Steve Prabu , Paul J Hancock , Zhang Xiang , Steven J Tingay

The Fourier transform spectrometer (FTS) is a core instrument for solar observation with high spectral resolution, especially in the infrared. The Infrared System for the Accurate Measurement of Solar Magnetic Field (AIMS), working at 10-13…

Solar and Stellar Astrophysics · Physics 2021-12-08 Xianyong Bai , Zhiyong Zhang , Zhiwei Feng , Yuanyong Deng , Xingming Bao , Xiao Yang , Yongliang Song , Liyue Tong , Shuai Jing

Context. Solar flux atlases observe the spatially integrated light from the Sun, treating it as a star. They are fundamental tools for gaining insight into the composition of the Sun and other stars, and are utilized as reference material…

Solar and Stellar Astrophysics · Physics 2025-10-14 F. Hanassi-Savari , A. G. M. Pietrow , M. K. Druett , M. Cretignier , M. Ellwarth

We present deep polarimetric observations at 154 MHz with the Murchison Widefield Array (MWA), covering 625 deg^2 centered on RA=0 h, Dec=-27 deg. The sensitivity available in our deep observations allows an in-band, frequency-dependent…

Matter-wave interferometry with solids is highly susceptible to minute fluctuations of environmental fields, including gravitational effects from distant sources. Hence, experiments require a degree of shielding that is extraordinarily…

Quantum Physics · Physics 2022-08-23 Julen S. Pedernales , Martin B. Plenio

Solar radio emissions provide several unique diagnostics to estimate different physical parameters of the solar corona, which are otherwise simply inaccessible. However, imaging the highly dynamic solar coronal emissions spanning a large…

The inference of flows of material in the interior of the Sun is a subject of major interest in helioseismology. Here we apply techniques of Full Waveform Inversion (FWI) to synthetic data to test flow inversions. In this idealized setup,…

Solar and Stellar Astrophysics · Physics 2015-06-23 Shravan M Hanasoge

The Very Small Array (VSA) is a synthesis telescope designed to image faint structures in the cosmic microwave background on degree and sub-degree angular scales. The VSA has key differences from other CMB interferometers with the result…

The Atacama Large Millimeter/submillimeter Array (ALMA) allows for solar observations in the wavelength range of 0.3$-$10 mm, giving us a new view of the chromosphere. The measured brightness temperature at various frequencies can be fitted…

Solar and Stellar Astrophysics · Physics 2024-03-01 F. Matković , R. Brajša , M. Kuhar , A. O. Benz , H. -G. Ludwig , C. L. Selhorst , I. Skokić , D. Sudar , A. Hanslmeier