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Related papers: Possibility of Terahertz Observations at the ALMA …

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We present the 3.5-yr monitoring results of 225 GHz opacity at the summit of the Greenland ice sheet (Greenland Summit Camp) at an altitude of 3200 m using a tipping radiometer. We chose this site as our submillimeter telescope (Greenland…

Instrumentation and Methods for Astrophysics · Physics 2017-01-12 Satoki Matsushita , Keiichi Asada , Pierre L. Martin-Cocher , Ming-Tang Chen , Paul T. P. Ho , Makoto Inoue , Patrick M. Koch , Scott N. Paine , David D. Turner

We present ALMA observations at 233, 678, and 870 GHz of the Galactic Center black hole, Sagittarius A*. These observations reveal a flat spectrum over this frequency range with spectral index $\alpha \approx -0.3$, where the flux density…

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of a quiet-Sun region at a wavelength of 3 mm, obtained during the first solar ALMA cycle on April 27, 2017, and compare them with available chromospheric…

Solar and Stellar Astrophysics · Physics 2019-06-05 Maria A. Loukitcheva , Stephen M. White , Sami K. Solanki

Observations of the Sun at millimeter and submillimeter wavelengths offer a unique probe into the structure, dynamics, and heating of the chromosphere; the structure of sunspots; the formation and eruption of prominences and filaments; and…

The Atacama Large Millimeter-Submillimeter Array (ALMA) has opened a new window for studying the Sun via high-resolution high-sensitivity imaging at millimeter wavelengths. In this contribution I review the capabilities of the instrument…

Solar and Stellar Astrophysics · Physics 2019-02-13 Maria Loukitcheva

We report the latest results of 225 GHz atmospheric opacity measurements from two arctic sites; one on high coastal terrain near the Eureka weather station, on Ellesmere Island, Canada, and the other at the Summit Station near the peak of…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 S. Matsushita , M. -T. Chen , P. Martin-Cocher , K. Asada , C. -P. Chen , M. Inoue , S. Paine , D. Turner , E. Steinbring

The Atacama Large Millimeter-submillimeter Array (ALMA), sited on the high desert plains of Chajnantor in Chile, has opened a new window onto solar physics in 2016 by providing continuum observations at millimeter and sub-millimeter…

Instrumentation and Methods for Astrophysics · Physics 2022-09-07 Timothy Bastian , Masumi Shimojo , Miroslav Barta , Stephen White , Kazumasa Iwai

The Atacama Large Millimeter-submillimeter Array (ALMA) is a general purpose telescope that performs a broad program of astrophysical observations. Beginning in late-2016, solar observations with ALMA became available, thereby opening a new…

Solar and Stellar Astrophysics · Physics 2024-02-14 Masumi Shimojo , Timothy S. Bastian , Seiji Kameno , Antonio S. Hales

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…

If the dark matter halos of galaxies contain large numbers of subhalos as predicted by the $\Lambda$CDM model, these subhalos are expected to appear in strong galaxy--galaxy lens systems as small--scale perturbations in individual images.…

Astrophysics of Galaxies · Physics 2017-09-13 Saghar Asadi , Erik Zackrisson , Emily Freeland

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

The Atacama Millimeter/Submillimeter Array (ALMA) remains unparalleled in sensitivity at radio frequencies above 35 GHz. In this paper, we explore ALMA's potential for narrowband technosignature detection, considering factors such as the…

Instrumentation and Methods for Astrophysics · Physics 2024-12-02 Louisa A Mason , Michael A Garrett , Kelvin Wandia , Andrew P V Siemion

We report detection of oscillations in brightness temperature, size, and horizontal velocity of three small bright features in the chromosphere of a plage/enhanced-network region. The observations, which were taken with high temporal…

We report Karl G. Jansky Very Large Array (VLA) and Atacama Large Millimeter Array (ALMA) spectroscopy in the redshifted molecular oxygen (O$_2$) 56.265~GHz and 424.763~GHz transitions from the $z=0.88582$ gravitational lens towards…

Astrophysics of Galaxies · Physics 2015-09-30 Nissim Kanekar , David S. Meier

The observational study of stars in the sub-millimetre regime has only rather recently begun and was made possible mainly by the Atacama Large Millimeter/submillimeter Array (ALMA). The emission mechanisms of this radiation from normal MS…

Solar and Stellar Astrophysics · Physics 2019-04-08 Rene' Liseau

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) combines large collecting area and location on a high dry site to provide it with unparalleled potential for sensitive millimeter/submillimeter spectral line observations. Its wide…

Astrophysics · Physics 2008-11-26 Alwyn Wootten

The strongest known correspondence between ALMA 3mm emission and other solar observations is between the H-alpha line width and 3 mm brightness temperature, while the typical 3-5min p-mode oscillations found in many chromospheric…

Solar and Stellar Astrophysics · Physics 2023-01-10 Lucas A. Tarr , Adam R. Kobelski , Sarah A. Jaeggli , Momchil Molnar , Gianna Cauzzi , Kevin P. Reardon

The Atacama Large Millimeter/submillimeter Array offers an unprecedented view of our Sun at sub-/millimeter wavelengths. The high spatial, temporal, and spectral resolution facilitates the measurement of gas temperatures and magnetic fields…

Solar and Stellar Astrophysics · Physics 2015-02-18 Sven Wedemeyer , Asbjorn Parmer

Atmospheric transmission from Dome A, Antarctica, presents new possibilities in the field of terahertz astronomy, where space telescopes have been the only observational tools until now. Using atmospheric transmission measurements from Dome…

Instrumentation and Methods for Astrophysics · Physics 2019-02-19 Hiroshi Matsuo , Sheng-Cai Shi , Scott Paine , Qi-Jun Yao , Zhen-Hui Lin
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