English
Related papers

Related papers: Spectral actinometry at SMEAR-Estonia

200 papers

We report on the measurement of the all-particle cosmic ray energy spectrum with the IceTop air shower array in the energy range from 1.58 PeV to 1.26 EeV. The IceTop air shower array is the surface component of the IceCube Neutrino…

High Energy Astrophysical Phenomena · Physics 2016-12-22 IceCube collaboration

The Ramaty High Energy Solar Spectroscopic Imager (RHESSI) X-ray data base (February 2002 -- May 2006) has been searched to find solar flares with weak thermal components and flat photon spectra. Using a regularised inversion technique, we…

Astrophysics · Physics 2009-11-13 E. P. Kontar , E. Dickson , J. Kasparova

We construct mean spectral energy distributions (SEDs) for a substantial sample of 56,969 Sloan Digital Sky Survey DR16 quasars with $z < 0.75$, utilizing multiwavelength data from the mid-infrared (MIR) to ultraviolet (UV). These SEDs are…

Astrophysics of Galaxies · Physics 2026-04-28 Yan-Song Ma , Yu-Meng Guan , Jian-Xia Jiang , Shao-Jun Li , Xiang-Wei Ning , Yi Tang , Wei-Hao Bian

The Solar Radiospectrograph of the University of Athens (ARTEMIS-IV) is in operation at the Thermopylae Satellite Communication Station since 1996. The observations extend from the base of the Solar Corona (650 MHz) to about 2 Solar Radii…

The Siberian Solar Radio Telescope (SSRT) is a solar-dedicated directly-imaging interferometer observing the Sun at 5.7 GHz. The SSRT operates in the two-dimensional mode since 1996. The imaging principle of the SSRT restricts its…

Solar and Stellar Astrophysics · Physics 2014-10-20 Alexey Kochanov , Sergey Anfinogentov , Dmitry Prosovetsky , George Rudenko , Victor Grechnev

The Extreme ultraviolet SpectroPhotometer (ESP) is one of five channels of the Extreme ultraviolet Variability Experiment (EVE) onboard the NASA Solar Dynamics Observatory (SDO). The ESP channel design is based on a highly stable…

Solar and Stellar Astrophysics · Physics 2015-05-14 Leonid Didkovsky , Darrell Judge , Seth Wieman , Tom Woods , Andrew Jones

Regular observations of active processes in the solar atmosphere have been started using the first stage of the multiwave Siberian Radioheliograph (SRH), a T-shaped 48-antenna array with a 4-8 GHz operating frequency range and a 10 MHz…

The EUV Imaging Spectrometer (EIS) on the Hinode satellite is capable of measuring emission line center positions for Gaussian line profiles to a fraction of a spectral pixel, resulting in relative solar Doppler-shift measurements with an…

Solar observations with the Atacama Large Millimeter/submillimeter Array (ALMA) provide us with direct measurements of the brightness temperature in the solar chromosphere. We study the temperature distributions obtained with ALMA Band 6…

Solar and Stellar Astrophysics · Physics 2019-02-13 Shahin Jafarzadeh , Sven Wedemeyer , Mikolaj Szydlarski , Bart De Pontieu , Reza Rezaei , Mats Carlsson

Satellite Synthetic Aperture Radar (SAR) observations can provide a global view of ocean swell fields when using a specific "wave mode" sampling. A methodology is presented to routinely derive integral properties of the longer wavelength…

Atmospheric and Oceanic Physics · Physics 2009-02-23 Fabrice Collard , Fabrice Ardhuin , Bertrand Chapron

Major solar flares are prone to occur in active region atmospheres associated with large, complex, dynamically-evolving sunspots. This points to the importance of monitoring the evolution of starspots, not only in visible but also in ultra…

Solar and Stellar Astrophysics · Physics 2020-10-14 Shin Toriumi , Vladimir S. Airapetian , Hugh S. Hudson , Carolus J. Schrijver , Mark C. M. Cheung , Marc L. DeRosa

We present maps of surface composition of Europa's anti-jovian hemisphere acquired using high spatial resolution IFU multi-spectral data from the SPHERE instrument on the Very Large Telescope (0.95 to 1.65$\mu$m) and the NIMS instrument on…

Earth and Planetary Astrophysics · Physics 2022-09-07 Oliver King , Leigh N Fletcher , Nicolas Ligier

Passive long-wave infrared (LWIR) absorption-based ranging relies on atmospheric absorption to estimate distances to objects from their emitted thermal radiation. First demonstrated decades ago for objects much hotter than the air and…

Computer Vision and Pattern Recognition · Computer Science 2026-03-03 Unay Dorken Gallastegi , Wentao Shangguan , Vaibhav Choudhary , Akshay Agarwal , Hoover Rueda-Chacón , Martin J. Stevens , Vivek K Goyal

This paper presents initial values of global and diffuse luminous efficacy at Saint-Pierre (Reunion Island). Firstly, data used were measured for a period of 6 months, from February to June 2008. During this period, all defined day-types…

Atmospheric and Oceanic Physics · Physics 2012-12-24 Ali Hamada Fakra , Harry Boyer , Frédéric Miranville , Dimitri Bigot

NASA's Spitzer Infrared Spectrometer (IRS) acquired mid-infrared (5-37 microns) disc-averaged spectra of Uranus very near to its equinox in December 2007. A mean spectrum was constructed from observations of multiple central meridian…

For the past six years, the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory has been monitoring changes in the Sun's extreme ultraviolet output over a range of timescales. Its primary function is to provide…

Solar and Stellar Astrophysics · Physics 2017-01-11 Ryan O. Milligan

We present results derived from the analysis of spectropolarimetric measurements of active region AR12546, which represents one of the largest sunspots to have emerged onto the solar surface over the last $20$ years. The region was observed…

Solar and Stellar Astrophysics · Physics 2018-12-26 M. Stangalini , S. Jafarzadeh , I. Ermolli , R. Erdélyi , D. B. Jess , P. H. Keys , F. Giorgi , M. Murabito , F. Berrilli , D. Del Moro

On 2007 December 16-17, spectra were acquired of the disk of Uranus by the Spitzer Infrared Spectrometer (IRS) when its equator was close to the sub-earth point. This spectrum provides the highest-resolution broad-band spectrum ever…

CONTEXT: Spectral-line asymmetries and wavelength shifts are signatures of hydrodynamics in solar and stellar atmospheres. Theory may precisely predict idealized lines, but observed spectra are limited by blends, too few suitable lines,…

Astrophysics · Physics 2009-11-13 Dainis Dravins

Our knowledge of the diffuse emission that encompasses active regions is very limited. In the present paper we investigate two off-limb active regions, namely AR10939 and AR10961, to probe the underlying heating mechanisms. For this purpose…

Solar and Stellar Astrophysics · Physics 2015-06-22 Srividya Subramanian , Durgesh Tripathi , James A. Klimchuk , Helen E. Mason
‹ Prev 1 4 5 6 7 8 10 Next ›