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Related papers: Frequency rising sub-THz emission from solar flare…

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Solar flares are sudden energy release events in the solar corona, resulting from magnetic reconnection, that accelerates particles and heats the ambient plasma. During a flare, there are often multiple, temporally and spatially separated…

Solar and Stellar Astrophysics · Physics 2020-12-02 Rohit Sharma , Marina Battaglia , Yingjie Luo , Bin Chen , Sijie Yu

In this paper, we discuss the temperature distribution and evolution of a microflare, simultaneously observed by Hinode XRT, EIS, and SDO AIA. We find using EIS lines that during peak emission the distribution is nearly isothermal and…

Solar and Stellar Astrophysics · Physics 2019-08-21 Urmila Mitra-Kraev , Giulio Del Zanna

Solar flare ribbons are features in the lower atmosphere that show enhanced emission intensity, particularly noticeable in H$\alpha$ and EUV images of the transition region and upper chromosphere. In this study, we provide observational…

Temporary enhancements of the coronal emission measure in a quiet region have been shown to constitute a significant energy input. Here some relatively large events are studied for simultaneous brightenings in transition region lines and in…

Astrophysics · Physics 2015-06-24 Sam Krucker , Arnold O. Benz

Recent observations of coherent radiation from the Crab pulsar (Bij et al 2021) suggest the emission is driven by an ultra - relativistic ($\gamma \sim 10^4$), cold plasma flow. A relativistically expanding plasma shell can compress the…

High Energy Astrophysical Phenomena · Physics 2022-08-03 Almog Yalinewich , Ue-Li Pen

The microwave zebra pattern (ZP) is the most interesting, intriguing, and complex spectral structure frequently observed in solar flares. A comprehensive statistical study will certainly help us to understand the formation mechanism, which…

Solar and Stellar Astrophysics · Physics 2015-06-18 Baolin Tan , Chengming Tan , Yin Zhang , H. Meszarosova , M. Karlicky

In this work, I have presented a multi-frequency variability and correlation study of the blazar Ton 599, which was observed first time in flaring state at the end of 2017. Data from \textit{Fermi}-LAT, Swift-XRT/UVOT, Steward Observatory,…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Raj Prince

We present a flare temperature study of the highly active M~dwarf Wolf~359 using simultaneous multiband ($u$, $g$, $r$, $i$, and $z$) photometric observations from the Lulin 1-m and 41-cm telescopes. Twelve flares were detected over five…

Solar and Stellar Astrophysics · Physics 2025-09-29 Chia-Lung Lin , Li-Ching Huang , Wei-Jie Hou , Hsiang-Yao Hsiao , Wing-Huen Ip

Even in the absence of resolved flares, the corona is heated to several million degrees. However, despite its importance for the structure, dynamics, and evolution of the solar atmosphere, the origin of this heating remains poorly…

Recent solar flare observations in the sub-THz range have provided evidence of a new spectral component with fluxes increasing for larger frequencies, separated from the well-known microwave emission that maximizes in the GHz range.…

Solar and Stellar Astrophysics · Physics 2015-06-22 J. Michael Klopf , Pierre Kaufmann , Jean-Pierre Raulin , Sérgio Szpigel

Epitaxial graphene mesas and ribbons are investigated using terahertz (THz) nearfield microscopy to probe surface plasmon excitation and THz transmission properties on the sub-wavelength scale. The THz near-field images show variation of…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 Oleg Mitrofanov , Wenlong Yu , Robert J. Thompson , Yuxuan Jiang , Igal Brener , Wei Pan , Claire Berger , Walter A. de Heer , Zhigang Jiang

The radiation of a Fast Radio Burst (FRB) reflects from the Moon and Sun. If a reflection is detected, the time interval between the direct and reflected signals constrains the source to a narrow arc on the sky. If both Lunar and Solar…

Instrumentation and Methods for Astrophysics · Physics 2022-11-30 S. Wang , J. I. Katz

We use RHESSI high-resolution imaging and spectroscopy observations from ~6 to 100 keV to determine the statistical relationships between measured parameters (temperature, emission measure, etc.) of hot, thermal plasma in 37 intense (GOES…

Solar and Stellar Astrophysics · Physics 2014-06-25 Amir Caspi , Säm Krucker , R. P. Lin

Energetic flares are observed in the Galactic supermassive black hole Sagittarius A* from radio to X-ray wavelengths. On a few occasions, simultaneous flares have been detected in IR and X-ray observations, but clear counterparts at longer…

The quiet solar corona emits meter-wave thermal bremsstrahlung. Coronal radio emission can only propagate above that radius, $R_\omega$, where the local plasma frequency eqals the observing frequency. The radio interferometer LOw Frequency…

Solar and Stellar Astrophysics · Physics 2018-06-13 C. Vocks , G. Mann , F. Breitling , M. M. Bisi , B. Dabrowski , R. Fallows , P. T. Gallagher , A. Krankowski , J. Magdalenic , C. Marque , D. Morosan , H. Rucker

Sympathetic solar flares are eruptions that occur nearby in space and time, driven by an apparent interaction between the active regions in which they are triggered. Their statistical existence on the Sun has yet to be firmly established.…

Solar and Stellar Astrophysics · Physics 2025-02-05 Louis-Simon Guité , Antoine Strugarek , Paul Charbonneau

In this article, we measure the mean magnetic shear from the morphological evolution of flare ribbons, and examine the evolution of flare thermal and non-thermal X-ray emissions during the progress of flare reconnection. We analyze three…

Solar and Stellar Astrophysics · Physics 2022-07-20 Jiong Qiu , Jianxia Cheng

The transition region between the Sun's corona and chromosphere is important to the mass and energy transfer from the lower atmosphere to the corona; consequently, this region has been studied intensely with ultraviolet (UV) and extreme…

Solar and Stellar Astrophysics · Physics 2023-02-08 C. Gontikakis , S. K. Antiochos , P. R. Young

A southwest region of the Carina nebula was observed with the Suzaku observatory for 47 ks in 2010 December. This region shows distinctively soft X-ray emission in the Chandra campaign observations. Suzaku clearly detects the diffuse…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Yuichiro Ezoe , Kenji Hamaguchi , Aoto Fukushima , Tomohiro Ogawa , Takaya Ohashi

The study aims to examine the spectral dynamics of the low-frequency, optically thick gyrosynchrotron microwave emission in solar flares to determine the characteristics of the emitting source. We present the high-resolution spectra of a…

Solar and Stellar Astrophysics · Physics 2021-09-29 Shaheda Begum Shaik , Dale E. Gary