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We present high spatial resolution spectroscopic measurements of dynamic fibrils (DFs) in the Ca {\small{II}} 8662 {\AA} line. These data show clear Doppler shifts in the identified DFs, which demonstrates that at least a subset of DFs are…

Using radiative magneto-hydrodynamic simulations of the magnetised solar photosphere and detailed spectro-polarimetric diagnostics with the FeI $6301.5\mathrm{\AA}$ and $6302.5\mathrm{\AA}$ photospheric lines in the local thermodynamic…

Solar and Stellar Astrophysics · Physics 2015-06-23 S. Shelyag

Scattering polarization signals in the Sr I 4607 \AA\ spectral line are among the strongest originating from the solar photosphere, offering a powerful diagnostic of tangled magnetic fields in the 3--300 G range via the Hanle effect.…

A new generation of Ge-based high-resolution gamma-ray spectrometers has allowed accurate measurements to be made of the profiles, widths and energies of the gamma-ray lines emitted in the impulsive phases of solar flares. Here we present…

Astrophysics · Physics 2009-11-11 M. J. Harris , V. Tatischeff , J. Kiener , M. Gros , G. Weidenspointner

In sunspot umbrae, the core of some chromospheric lines exhibits periodic brightness enhancements known as umbral flashes. The consensus is that they are produced by the upward propagation of shock waves. This view has recently been…

We measured the isotope shift in the $^2$S$_{1/2}$-$^2$P$_{3/2}$ (D2) transition in singly-ionized calcium ions using photon recoil spectroscopy. The high accuracy of the technique enables us to resolve the difference between the isotope…

In this work, we present a new methodology to fit the observed and synthetic spectrum of solar-like stars at millimeter, submillimeter and infrared wavelengths through semiempirical models of the solar chromosphere. We use the…

Solar and Stellar Astrophysics · Physics 2020-01-15 F. Tapia-Vazquez , V. De la Luz

This is the first release of optical spectroscopic data of low-redshift Type Ia supernovae (SNe Ia) by the Carnegie Supernova Project including 604 previously unpublished spectra of 93 SNe Ia. The observations cover a range of phases from…

Recent atomic physics calculations for Si II are employed within the Cloudy modelling code to analyse Hubble Space Telescope (HST) STIS ultraviolet spectra of three cool stars, Beta-Geminorum, Alpha-Centauri A and B, as well as previously…

We present a 30 - 50 GHz survey of Sagittarius B2(N) conducted with the Australia Telescope Compact Array (ATCA) with 5 - 10 arcsec resolution. This work releases the survey data and demonstrates the utility of scripts that perform…

We present a radiative transfer model, which is applicable to the study of submillimetre spectral line observations of protostellar envelopes. The model uses an exact, non-LTE, spherically symmetric radiative transfer `Stenholm' method,…

Astrophysics · Physics 2009-11-06 D. Ward-Thompson , H. D. Buckley

We investigate the statistics of the intensity distributions as function of the wavelength for Ca II H and the CA II IR line at 854.2 nm to estimate the energy content. We derived the intensity variations at different heights of the solar…

Solar and Stellar Astrophysics · Physics 2013-03-14 C. Beck , R. Rezaei , K. G. Puschmann

We use radiation hydrodynamic simulations to examine two models of solar flare chromospheric heating: Alfv\'en wave dissipation and electron beam collisional losses. Both mechanisms are capable of strong chromospheric heating, and we show…

Solar and Stellar Astrophysics · Physics 2016-08-17 Graham S. Kerr , Lyndsay Fletcher , Alexander J. B. Russell , Joel C. Allred

We demonstrate a new method for the direct measurement of atomic dipole transition matrix elements based on techniques developed for quantum information purposes. The scheme consists of measuring dispersive and absorptive off-resonant…

Scattering polarization tends to dominate the linear polarization signals of the Ca II 8542 A line in weakly magnetized areas ($B \lesssim 100$ G), especially when the observing geometry is close to the limb. In this paper we evaluate the…

Solar and Stellar Astrophysics · Physics 2021-09-08 Rebecca Centeno , Jaime de la Cruz Rodriguez , Tanausu del Pino Aleman

We study chromospheric oscillations including umbral flashes and running penumbral waves in a sunspot of active region (AR) using scanning spectroscopy in H-alpha and Ca II 8542A, with the Fast Imaging Solar Spectrograph (FISS) at the 1.6…

Solar and Stellar Astrophysics · Physics 2013-02-07 Ram Ajor Maurya , Jongchul Chae , Hyungmin Park , Heesu Yang , Donguk Song , Kyuhyoun Cho

We introduce an iterative spectral disentangling technique combined with Doppler imaging in order to recover surface temperature maps for both components of double-lined active binary systems. Our method provides an opportunity to separate…

Solar and Stellar Astrophysics · Physics 2015-06-17 Levente Kriskovics , Krisztián Vida , Zsolt Kővári , David Garcia-Alvarez , Katalin Oláh

We present synthetic spectra corresponding to a 2.5D magnetohydrodynamical simulation of a rotating prominence in the Ca II 8542 \r{A}, H$\alpha$, Ca II K, Mg II k, Ly $\alpha$, and Ly $\beta$ lines. The prominence rotation resulted from…

Solar and Stellar Astrophysics · Physics 2024-10-07 A. G. M. Pietrow , V. Liakh , C. M. J. Osborne , J. Jenkins , R. Keppens

The Sentinel-2 satellite, launched by the European Space Agency (ESA), offers extensive spatial coverage and has become indispensable in a wide range of remote sensing applications. However, it just has 12 spectral bands, making…

Image and Video Processing · Electrical Eng. & Systems 2025-07-10 Chia-Hsiang Lin , Jui-Ting Chen , Zi-Chao Leng , Jhao-Ting Lin

The reliability of quiet Sun magnetic field diagnostics based on the \ion{Fe}{1} lines at 6302 \AA has been questioned by recent work. We present here the results of a thorough study of high-resolution multi-line observations taken with the…

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