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We present here the first infrared spectra of meteoritic SiC grains. The mid-infrared transmission spectra of meteoritic SiC grains isolated from the Murchison meteorite were measured in the wavelength range 2.5--16.5 micron, in order to…

Astrophysics · Physics 2007-05-23 A. C. Andersen , C. Jager , H. Mutschke , A. Braatz , C. Clement , Th. Henning , U. G. Jorgensen , U. Ott

We have analyzed IRIS spectral and slit-jaw observations of a quiet region near the South Pole. In this article we present an overview of the observations, the corrections, and the absolute calibration of the intensity. We focus on the…

Solar and Stellar Astrophysics · Physics 2018-01-09 C. E. Alissandrakis , J. -C. Vial , A. Koukras , E. Buchlin , M. Chane-Yook

NASA's Interface Region Imaging Spectrograph (IRIS) provides high resolution observations of the solar atmosphere through UV spectroscopy and imaging. Since the launch of IRIS in June 2013, we have conducted systematic observation campaigns…

The solar transition region satisfies the conditions for presence of non-Maxwellian electron energy distributions with high-energy tails at energies corresponding to the ionization potentials of many ions emitting in the EUV and UV portions…

Solar and Stellar Astrophysics · Physics 2017-07-19 E. Dzifcakova , C. Vocks , J. Dudik

Recently discovered scattered light from molecular cloud cores in the wavelength range 3-5 {\mu}m (called "coreshine") seems to indicate the presence of grains with sizes above 0.5 {\mu}m. We aim to analyze 3.6 and 4.5 {\mu}m coreshine from…

Solar and Stellar Astrophysics · Physics 2015-10-21 J. Steinacker , M. Andersen , W. -F. Thi , R. Paladini , M. Juvela , A. Bacmann , V. -M. Pelkonen , L. Pagani , C. Lefèvre , Th. Henning , A. Noriega-Crespo

The formation of the transition-region O IV and Si IV lines observable by the Interface Region Imaging Spectrograph (IRIS) is investigated for both Maxwellian and non-Maxellian conditions characterized by a kappa-distribution exhibiting a…

Solar and Stellar Astrophysics · Physics 2015-06-18 Jaroslav Dudík , Giulio Del Zanna , Elena Dzifčáková , Helen E. Mason , Leon Golub

The Mg II h&k doublet are two of the primary spectral lines observed by the Sun-pointing Interface Region Imaging Spectrograph (IRIS). These lines are tracers of the magnetic and thermal environment that spans from the photosphere to the…

Solar and Stellar Astrophysics · Physics 2015-10-07 Donald Schmit , Paul Bryans , Bart De Pontieu , Scott McIntosh , Jorrit Leenaarts , Mats Carlsson

We present mid-IR imaging observations of a high Galactic latitude cirrus obtained with the ISO camera ISOCAM at 6" angular resolution. The observations were done with two filters LW2 (5-8.5 microns) and LW3 (12-18 microns) that measure…

Astrophysics · Physics 2009-11-07 M. -A. Miville-Deschenes , F. Boulanger , G. Joncas , E. Falgarone

The bulk of solar flare energy is deposited in the chromosphere. Flare ribbons and footpoints in the chromosphere therefore offer great diagnostic potential of flare energy release and transport processes. High quality observations from the…

Solar and Stellar Astrophysics · Physics 2023-10-12 Graham S. Kerr , Adam F. Kowalski , Joel C. Allred , Adrian N. Daw , Melissa R. Kane

The Interface Region Imaging Spectrograph (IRIS) of the NASA small explorer mission provides significantly more complete and higher resolution spectral coverage of the dynamical conditions inside the chromosphere and transition region (TR)…

Solar and Stellar Astrophysics · Physics 2015-10-28 E. Tavabi , S. Koutchmy , L. Golub

Interface Region Imaging Spectrograph (IRIS) bursts are localised features thought to be driven by magnetic reconnection. Although these events are well-studied, it remains unknown whether their properties vary as their host active regions…

Solar and Stellar Astrophysics · Physics 2022-10-12 C. J. Nelson , L. Kleint

Downflows at supersonic speeds have been observed in the transition region (TR) above sunspots for more than three decades. These downflows are often seen in different TR spectral lines above sunspots. We have performed a statistical…

Solar and Stellar Astrophysics · Physics 2018-06-27 Tanmoy Samanta , Hui Tian , Debi Prasad Choudhary

IRIS is a near-infrared (0.84 to 2.4 microns) integral field spectrograph and wide-field imager being developed for first light with the Thirty Meter (TMT). It mounts to the advanced optics (AO) system NFIRAOS and has integrated…

On 12 March 1996 we obtained observations of the quiet Sun with the SUMER instrument. The observa- tions were sequences of 15-20 second exposures of ultraviolet emission line profiles and of the neighboring continua. These data contain…

Astrophysics · Physics 2009-10-30 Mats Carlsson , Philip G. Judge , Klaus Wilhelm

Context. The largest grains (0.5-1 micron) in the interstellar size distribution are efficient in scattering near- and mid-infrared radiation. These wavelengths are therefore particularly well suited to probe the still uncertain high-end of…

Astrophysics of Galaxies · Physics 2015-06-17 M. Andersen , J. Steinacker , W-F. Thi , L. Pagani , A. Bacmann , R. Paladini

The composition of the solar corona differs from that of the photosphere, with the plasma thought to fractionate in the solar chromosphere according to the First Ionisation Potential (FIP) of the different elements. This produces a FIP…

The R CrA region was observed in the 3.5 and 6.2 cm continuum with high angular resolutions (0.6--1.7 arcseconds) using the Very Large Array. Archival data sets were also analyzed for comparison, which provided angular resolutions up to 0.3…

Astrophysics · Physics 2009-11-13 Minho Choi , Kenji Hamaguchi , Jeong-Eun Lee , Ken'ichi Tatematsu

While previous work explored the fractality and self-organized criticality (SOC) of flares and nanoflares in wavelengths emitted in the solar corona (such as in hard X-rays, soft X-rays, and EUV wavelenghts), we focus here on impulsive…

Solar and Stellar Astrophysics · Physics 2022-07-27 Markus J. Aschwanden , Nived Vilangot Nhalil

The Interface Region Imaging Spectrograph(IRIS) with its high spatial and temporal resolution brings exceptional plasma diagnostics of solar chromospheric and coronal activity during magnetic reconnection. The aim of this work is to study…

Solar and Stellar Astrophysics · Physics 2021-01-20 Reetika Joshi , Brigitte Schmieder , Akiko Tei , Guillaume Aulanier , Juraj Lörinčík , Ramesh Chandra , Petr Heinzel

The 133.5 nm lines are important observables for the NASA/SMEX mission Interface Region Imaging Spectrograph (IRIS). To make 3D non-LTE radiative transfer computationally feasible it is crucial to have a model atom with as few levels as…

Solar and Stellar Astrophysics · Physics 2015-09-30 Bhavna Rathore , Mats Carlsson
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