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Related papers: Center-to-limb observations of the Sun with ALMA

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Science Verification (SV) data of solar observations with Atacama Large Millimeter-submillimeter Array (ALMA) telescope were released to the scientific community. Understanding the centre to limb brightness function is necessary to compare…

Solar and Stellar Astrophysics · Physics 2019-09-20 Davor Sudar , Roman Brajša , Ivica Skokić , Arnold O. Benz

ALMA observations of the Sun at mm-$\lambda$ offer a unique opportunity to investigate the temperature structure of the solar chromosphere. In this article we expand our previous work on modeling the chromospheric temperature of the quiet…

Solar and Stellar Astrophysics · Physics 2020-08-19 C. E. Alissandrakis , A. Nindos , T. S. Bastian , S. Patsourakos

We present the first full-disk solar images obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 7 (0.86 mm; 347 GHz). In spite of the low spatial resolution (21"), several interesting results were obtained. During…

Solar and Stellar Astrophysics · Physics 2022-05-25 C. E. Alissandrakis , T. S. Bastian , A. Nindos

Polar brightening of the Sun at radio frequencies has been studied for almost fifty years and yet a disagreement persists between solar atmospheric models and observations. Some observations reported brightening values much smaller than the…

Solar observations with the Atacama Large Millimeter/submillimeter Array (ALMA) provide us with direct measurements of the brightness temperature in the solar chromosphere. We study the temperature distributions obtained with ALMA Band 6…

Solar and Stellar Astrophysics · Physics 2019-02-13 Shahin Jafarzadeh , Sven Wedemeyer , Mikolaj Szydlarski , Bart De Pontieu , Reza Rezaei , Mats Carlsson

Measurements of the radius and limb brightening of the Sun provide important information about the solar atmosphere structure and temperature. The solar radius increases as the observation at radio frequency decreases, indicating that each…

Solar and Stellar Astrophysics · Physics 2021-12-15 Fabian Menezes , Caius L. Selhorst , Carlos Guillermo Giménez de Castro , Adriana Valio

We present an overview of high resolution quiet Sun observations, from disk center to the limb, obtained with the Atacama Large mm and sub-mm Array (ALMA) at 3 mm. Seven quiet Sun regions were observed with resolution of up to 2.5" by 4.5".…

The intensity of radiation at millimeter wavelengths from the solar atmosphere is closely related to the plasma temperature and the height of formation of the radiation is wavelength dependent. From that follows that the slope of the…

Solar and Stellar Astrophysics · Physics 2023-01-18 Henrik Eklund , Mikolaj Szydlarski , Sven Wedemeyer

It is generally accepted that densities of quiet sun and active region plasma are sufficiently low to justify the optically thin approximation, and it is commonly used in the analysis of line emissions from plasma in the solar corona.…

Solar and Stellar Astrophysics · Physics 2018-02-14 Edward Thiemann , Phillip Chamberlin , Francis Eparvier , Luke Epp

Using ALMA observations, we performed the first systematic survey for transient brightenings (i.e. weak, small-scale episodes of energy release) in the quiet solar chromosphere at 3 mm. Our dataset included images of six 87'' x 87'' regions…

Solar and Stellar Astrophysics · Physics 2020-07-01 A. Nindos , C. E. Alissandrakis , S. Patsourakos , T. S. Bastian

Using Atacama Large Millimeter/submillimeter Array (ALMA) observations of the quiet Sun at 1.26 and 3 mm, we study spatially resolved oscillations and transient brightenings, i.e. small, weak events of energy release. Both phenomena may…

Solar and Stellar Astrophysics · Physics 2021-08-18 A. Nindos , S. Patsourakos , C. E. Alissandrakis , T. S. Bastian

We present an initial study of one of the first ALMA Band 3 observations of the Sun with the aim to characterise the diagnostic potential of brightness temperatures measured with ALMA on the Sun. The observation covers 48min at a cadence of…

We studied chromospheric oscillations using Atacama Large millimeter and sub-millimeter Array (ALMA) time-series of interferometric observations of the quiet Sun obtained at 3 mm with a 2-s cadence and a spatial resolution of a few arcsec.…

Solar and Stellar Astrophysics · Physics 2020-02-12 S. Patsourakos , C. E. Alissandrakis , A. Nindos , T. S. Bastian

By direct measurements of the gas temperature, the Atacama Large Millimeter/sub-millimeter Array (ALMA) has yielded a new diagnostic tool to study the solar chromosphere. Here we present an overview of the brightness-temperature…

We present the first high-resolution, simultaneous observations of the solar chromosphere in the optical and millimeter wavelength ranges, obtained with ALMA and the IBIS instrument at the Dunn Solar Telescope. In this paper we concentrate…

Solar and Stellar Astrophysics · Physics 2019-08-27 Momchil E. Molnar , Kevin P. Reardon , Yi Chai , Dale Gary , Han Uitenbroek , Gianna Cauzzi , Steven R. Cranmer

The aim of this study is to demonstrate how the logarithmic millimeter continuum gradient observed using the Atacama Large Millimeter/submillimeter Array (ALMA) may be used to estimate optical thickness in the solar atmosphere. We discuss…

Solar and Stellar Astrophysics · Physics 2019-05-01 Andrew S. Rodger , Nicolas Labrosse , Sven Wedemeyer , Mikolaj Szydlarski , Paulo J. A. Simões , Lyndsay Fletcher

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

Our aim is to test potential solar prominence plasma diagnostics as obtained with the new solar capability of the Atacama Large Millimeter / submillimeter Array (ALMA). We investigate the thermal and plasma diagnostic potential of ALMA for…

Solar and Stellar Astrophysics · Physics 2017-09-13 Andrew S Rodger , Nicolas Labrosse

We report the results of the Atacama Large Millimeter/sub-millimeter Array (ALMA) observations of the solar chromosphere on the southern polar limb. Coordinated observations with the Interface Region Imaging Spectrograph (IRIS) are also…

Solar and Stellar Astrophysics · Physics 2018-08-22 Takaaki Yokoyama , Masumi Shimojo , Takenori J. Okamoto , Haruhisa Iijima

We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph (IRIS). The observations were made of a solar active region on 2015 December 18 as part of the…

Solar and Stellar Astrophysics · Physics 2017-08-30 T. S. Bastian , G. Chintzoglou , B. De Pontieu , M. Shimojo , D. Schmit , J. Leenaarts , M. Loukitcheva
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