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Related papers: Dynamic spectral mapping of interstellar plasma le…

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We present a simple, yet powerful column density diagnostic for plasmas enabled by X-ray microcalorimeter observations. With the recent developments of the spectral simulation code Cloudy, inspired by the high spectral resolution of the…

High Energy Astrophysical Phenomena · Physics 2025-02-19 Chamani M. Gunasekera , Peter A. M. van Hoof , Masahiro Tsujimoto , Gary J. Ferland

Sub-millimetre dust emission is an important tracer of density N of dense interstellar clouds. One has to combine surface brightness information at different spatial resolutions, and specific methods are needed to derive N at a resolution…

Astrophysics of Galaxies · Physics 2015-06-16 M. Juvela , J. Montillaud

This paper reports on the use of coherent microwave scattering (CMS) for spatially resolved electron number density measurements of elongated plasma structures induced at mid-IR femtosecond filamentation in air. The presented studies…

Short-pulse intense lasers have the potential to model extreme astrophysical environments in laboratories. Although there are diagnostics for energetic electrons and ions resulting from laser-plasma interactions, the diagnostics to measure…

The Extreme Ultraviolet Variability Experiment (EVE) on the Solar Dynamics Observatory obtains extreme-ultraviolet (EUV) spectra of the full-disk Sun at a spectral resolution of ~1 A and cadence of 10 s. Such a spectral resolution would…

Solar and Stellar Astrophysics · Physics 2017-04-12 F. P. Keenan , R. O. Milligan , M. Mathioudakis , D. J. Christian

The 21 cm hyperfine transition of the atomic hydrogen (HI) in ground state is a powerful probe of the neutral gas content of the universe. This radio frequency transition has been used routinely for decades to observe, both in emission and…

Astrophysics of Galaxies · Physics 2019-11-26 Preetha Saha , Nirupam Roy , Mukul Bhattacharya

Observations of the Sun in the visible spectral range belong to standard measurements obtained by instruments both on the ground and in the space. Nowadays, both nearly continuous full-disc observations with medium resolution and dedicated…

Solar and Stellar Astrophysics · Physics 2020-06-30 Michal Švanda , Jan Jurčák , David Korda , Jana Kašparová

The physical interpretation of spectropolarimetric observations of lines of neutral helium, such as those of the 10830 A multiplet, represents an excellent opportunity for investigating the magnetism of plasma structures in the solar…

Astrophysics · Physics 2007-05-23 A. Asensio Ramos , J. Trujillo Bueno

The intensity of the \oiv~2s$^{2}$ 2p $^{2}$P-2s2p$^{2}$ $^{4}$P and \siv~3 s$^{2}$ 3p $^{2}$P- 3s 3p$^{2}$ $^{4}$ P intercombination lines around 1400~\AA~observed with the \textit{Interface Region Imaging Spectrograph} (IRIS) provide a…

Solar and Stellar Astrophysics · Physics 2016-10-19 V. Polito , G. Del Zanna , J. Dudík , H. E. Mason , A. Giunta , K. K. Reeves

Recently the Li-Beam Emission Spectroscopy (Li-BES) system on COMPASS has reached its full diagnostic power in terms of routine automatic operation in any kind of plasma scenarios and it is normally used as a standard tool for…

Plasma Physics · Physics 2019-07-24 A. Bencze , M. Berta , A. Buzas , P. Hacek , J. Krbec , M. Szutyanyi

The calculation of the optical properties of hot dense plasmas with a model that has self-consistent plasma physics is a grand challenge for high energy density science. Here we exploit a recently developed electronic structure model that…

Plasma Physics · Physics 2022-01-07 Nathaniel R. Shaffer , Charles E. Starrett

An ultrarelativistic electron beam passing through an intense laser pulse emits radiation around its direction of propagation into a characteristic angular profile. Here we show that measurement of the variances of this profile in the…

Plasma Physics · Physics 2020-07-01 T. G. Blackburn , E. Gerstmayr , S. P. D. Mangles , M. Marklund

The submillimeter opacity of dust in the diffuse Galactic interstellar medium (ISM) has been quantified using a pixel-by-pixel correlation of images of continuum emission with a proxy for column density. We used three BLAST bands at 250,…

In extreme scattering events, the brightness of a compact radio source drops significantly, as light is refracted out of the line of sight by foreground plasma lenses. Despite recent efforts, the nature of these lenses has remained a…

High Energy Astrophysical Phenomena · Physics 2023-06-28 Hengrui Zhu , Daniel Baker , Ue-Li Pen , Dan R. Stinebring , Marten H. van Kerkwijk

A simple analytical model of the barrier discharge in a long gap between opposing plane electrodes is developed. It is shown that the plasma density becomes uniform over large part of the gap in the course of the discharge development, so…

Plasma Physics · Physics 2009-11-11 A. Shvydky , V. N. Khudik , V. P. Nagorny , C. E. Theodosiou

The dynamic spectrum of a radio pulsar is an in-line digital hologram of the ionised interstellar medium. It has previously been demonstrated that such holograms permit image reconstruction, in the sense that one can determine an…

Astrophysics · Physics 2009-11-13 Mark Walker , Leon Koopmans , Dan Stinebring , Willem van Straten

We report on a recently developed laser-probing diagnostic which allows direct measurements of ray-deflection angles in one axis, whilst retaining imaging capabilities in the other axis. This allows us to measure the spectrum of angular…

We present a new, approximate method of calculating the column density of ammonia in mapping observations of the 23 GHz inversion lines. The temperature regime typically found in star forming regions allows for the assumption of a slowly…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 L. K. Morgan , T. J. T. Moore , J. Allsopp , D. J. Eden

We present light curves for 149 sources monitored with the Green Bank Interferometer. The light curves are at two radio frequencies (approximately 2.5 and 8.2 GHz) and range from 3 to 15 yrs in length, covering the interval 1979--1996, and…