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Related papers: VFISV Inversion Code Documentation for SOLIS/VSM P…

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We attempt to measure possible miscalibration of the wavelength scale of the VLT-UVES spectrograph. We take spectra of QSO HE0515-4414 through the UVES iodine cell which contains thousands of well-calibrated iodine lines and compare these…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 Jonathan B. Whitmore , Michael T. Murphy , Kim Griest

The Ca II H line is one of the strongest lines in the solar spectrum and provides continuous information on the solar atmosphere from the photosphere to the lower chromosphere. We describe an inversion approach that reproduces observed Ca…

Solar and Stellar Astrophysics · Physics 2013-03-14 C. Beck , R. Rezaei , K. G. Puschmann

Inversion codes allow reconstructing a model atmosphere from observations. With the inclusion of optically thick lines that form in the solar chromosphere, such modelling is computationally very expensive because a non-LTE evaluation of the…

Solar and Stellar Astrophysics · Physics 2019-04-19 Alberto Sainz Dalda , Jaime de la Cruz Rodríguez , Bart De Pontieu , Milan Gošić

The iron lines at 630.15 and 630.25 nm are often used to determine the physical conditions of the solar photosphere. A common approach is to invert them simultaneously under the Milne-Eddington approximation. The same thermodynamic…

Solar and Stellar Astrophysics · Physics 2015-05-19 D. Orozco Suárez , L. R. Bellot Rubio , J. C. Del Toro Iniesta

Inversion codes for the polarized radiative transfer equation can be used to infer the temperature $T$, line-of-sight velocity $v_{\rm los}$, and magnetic field $\rm{\bf B}$ as a function of the continuum optical-depth $\tau_{\rm c}$.…

Solar and Stellar Astrophysics · Physics 2019-12-11 J. M. Borrero , A. Pastor Yabar , M. Rempel , B. Ruiz Cobo

Since the early 1970s, inversion techniques have become the most useful tool for inferring the magnetic, dynamic, and thermodynamic properties of the solar atmosphere. The intrinsic model dependence makes it necessary to formulate specific…

Solar and Stellar Astrophysics · Physics 2016-12-07 Jose Carlos del Toro Iniesta , Basilio Ruiz Cobo

We derive closed-form expressions for the poles and zeros of approximate fractional integrator/differentiator filters, which correspond to spectral roll-off filters having any desired log-log slope to a controllable degree of accuracy over…

Computational Engineering, Finance, and Science · Computer Science 2016-06-21 Julius Orion Smith , Harrison Freeman Smith

The formation of unusually shaped Stokes V profiles of the Fe I 630.2 nm line in the solar photosphere are investigated. The results of numerical 2-D MHD simulation of solar magnetogranulation are used for this. In their properties, the…

Solar and Stellar Astrophysics · Physics 2009-02-19 V. A. Sheminova

Observations by the Interface Region Imaging Spectrograph (IRIS) in the Mg II h & k spectral lines have provided a new diagnostic window towards the knowledge of the complex physical conditions in the solar chromosphere. Theoretical efforts…

Solar and Stellar Astrophysics · Physics 2023-03-15 Alberto Sainz Dalda , Bart De Pontieu

The detailed investigation of the polar magnetic field and its time evolution is one of the major achievements of Hinode. Precise measurements of the polar magnetic field are essential for understanding the solar cycle, as they provide…

Analyses of IFU data are typically performed on a per-spaxel basis, with each spectrum modelled independently. For low signal-to-noise (S/N) features such as weak emission lines, estimating properties is difficult and imprecise. Arbitrary…

We propose and explore the potential of a method to extract high signal-to-noise (S/N) integrated spectra related to physical and/or morphological regions on a 2-dimensional field using Integral Field Spectroscopy (IFS) observations by…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 F. F. Rosales-Ortega , S. Arribas , L. Colina

The use of 3D hydrodynamical simulations of stellar surface convection for model atmospheres is computationally expensive. Although these models have been available for quite some time, their use is limited because of the lack of extensive…

Solar and Stellar Astrophysics · Physics 2022-05-25 S. Bertran de Lis , C. Allende Prieto , H. -G. Ludwig , L. Koesterke

The Mg I b$_2$ line at 5173 \r{A} is primarily magnetically sensitive to heights between the mid photosphere and the low chromosphere, a region that has not been sufficiently explored in the solar atmosphere but is crucial for understanding…

Solar and Stellar Astrophysics · Physics 2025-03-18 A. L. Siu-Tapia , L. R. Bellot Rubio , D. Orozco Suárez , R. Gafeira

The Simple Line Access Protocol (SLAP) is an IVOA Data Access protocol which defines a protocol for retrieving spectral lines coming from various Spectral Line Data Collections through a uniform interface within the VO framework. These…

Instrumentation and Methods for Astrophysics · Physics 2019-05-22 Jesus Salgado , Pedro Osuna , Matteo Guainazzi , Isa Barbarisi , Marie-Lise Dubernet , Doug Tody

The Vector Spectromagnetograph (VSM) instrument on the Synoptic Optical Long-term Investigations of the Sun (SOLIS) telescope is designed to obtain high-quality magnetic field observations in both the photosphere and chromosphere by…

Solar and Stellar Astrophysics · Physics 2015-07-30 Luca Bertello , Andrew R. Marble

We present a convenient, all-in-one framework for the scientific analysis of fully reduced, (integral-field) spectroscopic data. The GIST pipeline (Galaxy IFU Spectroscopy Tool) is entirely written in Python3 and conducts all steps from the…

The VIMOS VLT Deep Survey (VVDS), designed to measure 150,000 galaxy redshifts, requires a dedicated data reduction and analysis pipeline to process in a timely fashion the large amount of spectroscopic data being produced. This requirement…

The method of transformation optics has been a powerful tool to manipulate physical fields if governing equations are formally invariant under coordinate transformations. However, regulation of hydrodynamics is still far from satisfactory…

Fluid Dynamics · Physics 2022-10-25 Gaole Dai , Jun Wang

To study the structure of spatially unresolved features of the solar photosphere, we calculated the Stokes profiles of seven photospheric iron lines using two-dimensional nonstationary MHD models of solar granulation for various amounts of…

Solar and Stellar Astrophysics · Physics 2012-11-13 I. N. Atroshchenko , V. A. Sheminova