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Predicting the severity of the solar eruptive phenomena like flares and Coronal Mass Ejections (CMEs) remains a great challenge despite concerted efforts for several decades. The advent of high quality vector magnetograms obtained from…

Solar and Stellar Astrophysics · Physics 2015-05-19 Sanjiv Kumar Tiwari , P. Venkatakrishnan , Sanjay Gosain

We present a statistical method based on a maximum likelihood approach to constrain the number counts of extragalactic sources below the nominal flux-density limit of continuum imaging surveys. We extract flux densities from a radio map…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Ketron Mitchell-Wynne , Mario G. Santos , Jose Afonso , Matt J. Jarvis

Accurate prediction of solar activity calls for precise calibration of solar cycle models. Consequently we aim to find optimal parameters for models which describe the physical processes on the solar surface, which in turn act as proxies…

Solar and Stellar Astrophysics · Physics 2017-11-22 T. Whitbread , A. R. Yeates , A. Muñoz-Jaramillo , G. J. D. Petrie

The expansion with height of the solar photospheric magnetic field and the plasma flows is investigated for three isolated bright points (BPs). The BPs were observed simultaneously with 3 instruments at the GREGOR telescope: (1) filtergrams…

Solar and Stellar Astrophysics · Physics 2019-10-09 Christoph Kuckein

We compare photospheric line-of-sight magnetograms from the Synoptic Long-term Investigations of the Sun (SOLIS) vector spectromagnetograph (VSM) instrument with observations from the 150-foot Solar Tower at Mt. Wilson (MWO), Helioseismic…

Solar and Stellar Astrophysics · Physics 2012-10-01 A. Pietarila , L. Bertello , J. W. Harvey , A. A. Pevtsov

A statistical study is carried out on the photospheric magnetic nonpotentiality in solar active regions and its relationship with associated flares. We select 2173 photospheric vector magnetograms from 1106 active regions observed by the…

Solar and Stellar Astrophysics · Physics 2012-08-10 Xiao Yang , HongQi Zhang , Yu Gao , Juan Guo , GangHua Lin

The dynamics of the solar wind depends intrinsically on the structure of the global solar magnetic field, which undergoes fundamental changes over the 11-yr solar cycle. For instance, the wind terminal velocity is thought to be…

Solar and Stellar Astrophysics · Physics 2017-11-29 Victor Réville , Allan Sacha Brun

Solar magnetic fields play a key role in understanding the nature of the coronal phenomena. Global coronal magnetic fields are usually extrapolated from photospheric fields, for which farside data is taken when it was at the frontside,…

Solar and Stellar Astrophysics · Physics 2022-04-28 Hyun-Jin Jeong , Yong-Jae Moon , Eunsu Park , Harim Lee

The Space-Weather ANalytics for Solar Flares (SWAN-SF) is a multivariate time series benchmark dataset recently created to serve the heliophysics community as a testbed for solar flare forecasting models. SWAN-SF contains 54 unique…

Photometric surveys require precise point spread function (PSF) characterization, as it varies across filters and is crucial for accurate photometry and low surface brightness (LSB) studies. However, the small PSF size provided by default…

Assuming the solar neutrino deficit is resolved by the resonant interaction of the neutrino magnetic moment with the solar magnetic field --in the framework of Resonant Spin Flavour Precession (RSFP) scenario-- the solar magnetic field…

High Energy Physics - Phenomenology · Physics 2016-09-06 Bhag C. Chauhan

Observations with the Hinode space observatory led to the discovery of predominantly horizontal magnetic fields in the photosphere of the quiet internetwork region. Here we investigate realistic numerical simulations of the surface layers…

Astrophysics · Physics 2009-11-13 O. Steiner , R. Rezaei , W. Schaffenberger , S. Wedemeyer-Böhm

We use Vector Spectromagnetograph (VSM) chromospheric full-disk magnetograms, from the Synoptic Optical Long-term Investigations of the Sun (SOLIS) project, to study the distribution of magnetic field flux concentrations within the polar…

Astrophysics · Physics 2008-01-08 N. -E. Raouafi , J. W. Harvey , C. J. Henney

In the last decade, the photospheric abundances of the Sun had been revised several times by many observers. The standard solar models (SSM) constructed with the new low-metal abundances disagree with helioseismic results and detected…

Solar and Stellar Astrophysics · Physics 2016-04-27 Wuming Yang

We simulate the dynamics and the evolution of quiet Sun magnetic elements to produce a probability density function of the field strengths associated with such elements. The dynamics of the magnetic field are simulated through a numerical…

Astrophysics · Physics 2009-11-13 F. Berrilli , D. Del Moro , B. Viticchie

Using a classification scheme for solar wind type based on the heliocentric distance of the observation, we look at near perihelion observations from Parker Solar Probe Encounters Four to Fourteen to study the sources of the slow…

Solar and Stellar Astrophysics · Physics 2024-09-18 Tamar Ervin , Kai Jaffarove , Samuel T. Badman , Jia Huang , Yeimy J. Rivera , Stuart D. Bale

We present the reduction of the 24 micron data obtained during the first cosmological survey performed by the Spitzer Space Telescope (First Look Survey, FLS). The survey consists of a shallow observation of 2.5x2 sq deg centered at 17h18m…

We describe the PDFI_SS software library, which is designed to find the electric field at the Sun's photosphere from a sequence of vector magnetogram and Doppler velocity measurements, and estimates of horizontal velocities obtained from…

A new model has been proposed for magnetic field determination at different distances from the Sun during different solar cycle phases. The model depends on the observed large-scale non-polar photospheric magnetic fields and that measured…

Solar and Stellar Astrophysics · Physics 2018-08-08 Irina A. Bilenko

The quiet Sun photospheric plasma has a variety of magnetic field strengths going from zero to 1800 G. The empirical characterization of these field strengths requires a probability density function (PDF), i.e., a function P(B) describing…

Astrophysics · Physics 2009-11-13 I. Dominguez Cerdena , J. Sanchez Almeida , F. Kneer