First high-resolution look at the quiet Sun with ALMA at 3 mm
by A. Nindos et al.*

2018-11-27 451 views

Observations of the radio continuum at millimeter (mm) wavelengths provide a unique chromospheric diagnostic. The quiet Sun mm-wavelength emission mechanism is free-free and electrons are almost always in local thermodynamic equilibrium (e.g. Shibasaki et al. 2011 and Wedemeyer et al. 2016). The availability of mm-wavelength solar observations with ALMA can advance our knowledge on the chromosphere because of the instrument’s unique spatial resolution and sensitivity. In a previous study (Alissandrakis […]

Dressing the Coronal Magnetic Extrapolations of Active Regions with a Parameterized Thermal Structure
by Gelu M. Nita et al.

2018-03-06 392 views

The study of time-dependent solar active region morphology and its relation to eruptive events requires analysis of imaging data obtained in multiple wavelength domains with differing spatial and time resolutions, ideally in combination with 3D physical models. To facilitate this goal, we have undertaken a major enhancement of our IDL-based simulation tool, GX Simulator, originally developed for modeling microwave and X-ray emission from flaring loops (Nita et al. 2015), to […]

The Brightness Temperature of the Quiet Solar Chromosphere at 2.6 mm
by Kazumasa Iwai et al

2017-04-25 983 views

The brightness temperature of the Sun constitutes a basic property of the solar atmosphere. The main emission mechanism of the Sun at millimeter and submillimeter wavelengths is thermal free–free emission from the chromosphere, which is an atmospheric layer with a temperature ranging between 6000 to 20,000 K. The opacity of thermal free–free emission depends on the temperature and density in the emission region. In addition, the Rayleigh– Jeans law is applicable […]