Solar Chromosphere's guest appearances

Solar Chromosphere

13. Particle Physics and the Sun

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Nancy Grace

Measure H

Ray Corona

Ray Power

Halo Stars

OwlTail

Propagation of transverse waves in the solar chromosphere probed at different heights with ALMA sub-bands by Juan Camilo Guevara Gómez et al.  on Thursday 25 AugustThe Atacama Large Millimeter/sub-millimeter Array (ALMA) has provided us withan excellent diagnostic tool for studies of the dynamics of the Solarchromosphere, albeit through a single receiver band at one time presently. EachALMA band consists of four sub-bands that are comprised of several spectralchannels. To date, however, the spectral domain has been neglected in favour ofensuring optimal imaging, so that time-series observations have been mostlylimited to full-band data products, thereby limiting studies to a singlechromospheric layer. Here, we report the first observations of a dynamicalevent (i.e. wave propagation) for which the ALMA Band 3 data (centred at 3\,mm;100\,GHz) is split into a lower and an upper sideband. In principle, thisapproach is aimed at mapping slightly different layers in the Solar atmosphere.The side-band data were reduced together with the Solar ALMA Pipeline (SoAP),resulting in time series of brightness-temperature maps for each side-band.Through a phase analysis of a magnetically quiet region, where purely acousticwaves are expected to dominate, the average height difference between the twoside-bands is estimated as $73\pm16$~km. Furthermore, we examined thepropagation of transverse waves in small-scale bright structures by means ofwavelet phase analysis between oscillations at the two atmospheric heights. Wefind 6\% of the waves to be standing, while 54\% and 46\% of the remainingwaves are propagating upwards and downwards, respectively, with absolutepropagating speeds on the order of $\approx96$~km/s, resulting in a mean energyflux of $3800$\,W/m$^2$.arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2208.12070v1

Propagation of transverse waves in the solar chromosphere probed at different heights with ALMA sub-bands by Juan Camilo Guevara Gómez et al. on Thursday 25 August The Atacama Large Millimeter/sub-millimeter Array (ALMA) has provided us with an excellent diagnostic tool for studies of the dynamics of the Solar chromosphere, albeit through a single receiver band at one time presently. Each ALMA band consists of four sub-bands that are comprised of several spectral channels. To date, however, the spectral domain has been neglected in favour of ensuring optimal imaging, so that time-series observations have been mostly limited to full-band data products, thereby limiting studies to a single chromospheric layer. Here, we report the first observations of a dynamical event (i.e. wave propagation) for which the ALMA Band 3 data (centred at 3\,mm; 100\,GHz) is split into a lower and an upper sideband. In principle, this approach is aimed at mapping slightly different layers in the Solar atmosphere. The side-band data were reduced together with the Solar ALMA Pipeline (SoAP), resulting in time series of brightness-temperature maps for each side-band. Through a phase analysis of a magnetically quiet region, where purely acoustic waves are expected to dominate, the average height difference between the two side-bands is estimated as $73\pm16$~km. Furthermore, we examined the propagation of transverse waves in small-scale bright structures by means of wavelet phase analysis between oscillations at the two atmospheric heights. We find 6\% of the waves to be standing, while 54\% and 46\% of the remaining waves are propagating upwards and downwards, respectively, with absolute propagating speeds on the order of $\approx96$~km/s, resulting in a mean energy flux of $3800$\,W/m$^2$. arXiv: <a href="http://arxiv.org/abs/http://arxiv.org/abs/2208.12070v1" rel="nofollow" target="_blank">http://arxiv.org/abs/http://arxiv.org/abs/2208.12070v1</a>

Propagation of transverse waves in the solar chromosphere probed at different heights with ALMA sub-bands

Transcript: The visible surface and edge of the Sun and the region where sunspots lie is the Sun’s photosphere.  Just above the photosphere lies the chromosphere or color layer.  This is a slender region of pink gas at a temperature of about ten thousand degrees Kelvin.  The pink color comes from emission from hydrogen alpha, the single spectral transition of an excited hydrogen that comes out in the red part of the visible spectrum.  The solar chromosphere is best seen during a total eclipse when the moon blocks out the Sun’s light, and the delicate radiation of the chromosphere and its color can clearly be seen.  Beyond the chromosphere the Sun fades out into deep space.