English
Related papers

Related papers: Active Region Moss: Basic physical parameters and …

200 papers

Using {\em RHESSI} hard X-ray imaging spectroscopy observations, we analyze electron flux maps for a number of extended coronal loop flares. For each event, we fit a collisional model with an extended acceleration region to the observed…

Solar and Stellar Astrophysics · Physics 2015-06-05 Jingnan Guo , A. Gordon Emslie , Anna Maria Massone , Michele Piana

The Galactic HII region G353.2+0.9 is excited by the massive open cluster Pismis-24. By analyzing (sub-)mm molecular-line and -continuum we study the detailed morphology of the gas and dust, as well as their physical parameters and their…

Astrophysics of Galaxies · Physics 2015-06-03 A. Giannetti , J. Brand , F. Massi , A. Tieftrunk , M. T. Beltran

The temperature distribution of the emitting plasma is a crucial constraint when studying the heating of solar flare footpoints. However, determining this for impulsive phase footpoints has been difficult in the past due to insufficient…

Solar and Stellar Astrophysics · Physics 2015-06-15 D. R. Graham , I. G. Hannah , L. Fletcher , R. O. Milligan

Nanoflares, short and intense heat pulses within spatially unresolved magnetic strands, are now considered a leading candidate to solve the coronal heating problem. However, the frequent occurrence of nanoflares requires that flare-hot…

Solar and Stellar Astrophysics · Physics 2011-02-11 Fabio Reale , Paola Testa , James A. Klimchuk , Susanna Parenti

Previous solar observations have shown that coronal loops near 1 MK are difficult to reconcile with simple heating models. These loops have lifetimes that are long relative to a radiative cooling time, suggesting quasi-steady heating. The…

Effects of radio-frequency power and driven frequency on the two-dimensional (axial and radial) distributions of electron density and temperature were experimentally investigated in low pressure capacitively coupled argon plasmas. The…

Plasma Physics · Physics 2020-10-22 Jidun Wu , Hao Zheng , Yanfei Wang , Fengzhu Zhou , Xiaojiang Huang

This work reports a peculiar and interesting train of microwave type III pair bursts in the impulsive rising phase of a solar flare on 2011 September 26. The observations include radio spectrometers at frequency of 0.80 - 2.00 GHz, hard…

Solar and Stellar Astrophysics · Physics 2016-09-28 Baolin Tan , Marian Karlicky , Hana Meszarosova , Larisa Kashapova , Jing Huang , Yan Yan , Eduard P. Kontar

Measurements of the temperature and density structure of the solar corona provide critical constraints on theories of coronal heating. Unfortunately, the complexity of the solar atmosphere, observational uncertainties, and the limitations…

Solar and Stellar Astrophysics · Physics 2009-07-22 Harry P. Warren , David H. Brooks

Temporally-resolved electron density measurements of solar flare plasmas are presented using data from the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO). The EVE spectral range contains emission lines formed…

Solar and Stellar Astrophysics · Physics 2015-06-05 Ryan O. Milligan , Michael B. Kennedy , Mihalis Mathioudakis , Francis P. Keenan

We analyze coordinated Hinode XRT and EIS observations of a non-flaring active region to investigate the thermal properties of coronal plasma taking advantage of the complementary diagnostics provided by the two instruments. In particular…

Solar and Stellar Astrophysics · Physics 2015-05-20 Paola Testa , Fabio Reale , Enrico Landi , Ed DeLuca , Vinay Kashyap

In this work we investigate the thermal structure of an off-limb active region in various non-flaring areas, as it provides key information on the way these structures are heated. In particular, we concentrate in the very hot component (>3…

Solar and Stellar Astrophysics · Physics 2017-09-06 Susanna Parenti , Giulio del Zanna , Antonino Petralia , Fabio Reale , Luca Teriaca , Paola Testa , Helen E. Mason

Constraining the frequency of energy deposition in magnetically-closed active region cores requires sophisticated hydrodynamic simulations of the coronal plasma and detailed forward modeling of the optically-thin line-of-sight integrated…

Solar and Stellar Astrophysics · Physics 2021-10-13 W. T. Barnes , S. J. Bradshaw , N. M. Viall

A detailed study of emission lines from Fe VII, Fe VIII and Fe IX observed by the EUV Imaging Spectrometer on board the Hinode satellite is presented. Spectra in the ranges 170-212 A and 246-292 A show strongly enhanced lines from the upper…

Solar and Stellar Astrophysics · Physics 2015-05-13 P. R. Young , E. Landi

Time integrated spectroscopic measurements are carried out to characterize transient plasma stream produced in a coaxial pulsed plasma accelerator. This method allows the estimation of different plasma parameters and its evolution with…

Plasma Physics · Physics 2020-08-04 A. Ahmed , S. Singha , S. Borthakur , N. K. Neog , T. K. Borthakur , J. Ghosh

We present ALMA sub-arcsecond-resolution observations of both continuum and molecular lines at 345 GHz towards the massive star-forming region IRAS 16351-4722 (hereafter I16351). A total of 12 dust cores were detected based on high spatial…

A central problem of space plasma physics is how protons and electrons are heated in a turbulent, magnetized plasma. The differential heating of charged species due to dissipation of turbulent fluctuations plays a key role in solar wind…

The moss is the area at the footpoint of the hot (3 to 5 MK) loops forming the core of the active region where emission is believed to result from the heat flux conducted down to the transition region from the hot loops. Studying the…

Solar and Stellar Astrophysics · Physics 2012-11-26 Neda Dadashi , Luca Teriaca , Durgesh Tripathi , Sami K. Solanki , Thomas Wiegelmann

The relative amount of high temperature plasma has been found to be a useful diagnostic to determine the frequency of coronal heating on sub-resolution structures. When the loops are infrequently heated, a broad emission measure (EM) over a…

We present a mid-infrared spectroscopic data cube of the central part of 30 Doradus, observed with Spitzer's IRS and MIPS/SED mode. Aromatic dust emission features and emission lines from molecular and atomic hydrogen are detected but not…

Accurate measurements of electron density are critical for determination of the plasma properties in the solar corona. We compare the electron densities diagnosed from Fe XIII lines observed by the Extreme-Ultraviolet Imaging Spectrometer…