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XPOL, the first correlation polarimeter at a large millimeter telescope, uses a flexible digital correlator to measure all four Stokes parameters simultaneously, i.e. the total power I, the linear polarization components Q and U, and the…

Astrophysics · Physics 2009-11-13 Clemens Thum , Helmut Wiesemeyer , Gabriel Paubert , Santiago Navarro , David Morris

We consider cross-spectral purity in random nonstationary electromagnetic beams in terms of the Stokes parameters representing the spectral density and the spectral polarization state. We show that a Stokes parameter being cross-spectrally…

Optics · Physics 2023-07-24 Jyrki Laatikainen , Ari T. Friberg , Tero Setälä

Inferring stellar parameters and chemical abundances by forward modeling stellar spectra usually requires a spectral synthesis code, or an emulator constructed from a curated training set. In these situations continuum normalization is…

Solar and Stellar Astrophysics · Physics 2026-01-29 Andrew R. Casey , Adam Wheeler , Megan Bedell , David W. Hogg , Andrew Sayjdari , Lily Zhao

Linearly polarized emission is described, in general, in terms of the Stokes parameters $Q$ and $U$, from which the polarization intensity and polarization angle can be determined. Although the polarization intensity and polarization angle…

Astrophysics of Galaxies · Physics 2018-01-31 C. A. Herron , B. M. Gaensler , G. F. Lewis , N. M. McClure-Griffiths

The polarization of light across spectral lines contains information about the circumstellar material on small spatial scales. Many models relate the circumstellar environment to observable polarization changes across spectral lines.…

Astrophysics · Physics 2008-10-28 D. M. Harrington

A method is developed for fitting theoretically predicted astronomical spectra to an observed spectrum. Using a hierarchical Bayesian principle, the method takes both systematic and statistical measurement errors into account, which has not…

Astrophysics · Physics 2008-11-26 Z. Shkedy , L. Decin , G. Molenberghs , C. Aerts

Fast electrons spectromicroscopies enable to measure quantitatively the optical response of excitations with unrivaled spatial resolution. However, due to their inherently scalar nature, electron waves cannot access to polarization-related…

Optics · Physics 2021-05-26 Hugo Lourenço-Martins , Davy Gérard , Mathieu Kociak

Given its unchallenged capabilities in terms of sensitivity and spatial resolution, the combination of imaging spectropolarimetry and numeric Stokes inversion represents the dominant technique currently used to remotely sense the physical…

Instrumentation and Methods for Astrophysics · Physics 2019-11-05 Francisco A. Iglesias , Alex Feller

An approach for measuring linear X-ray polarization over a broad-band using conventional spectroscopic optics is described. A set of multilayer-coated flats reflect the dispersed X-rays to the instrument detectors. The intensity variation…

Astrophysics · Physics 2009-11-13 Herman L. Marshall

The observable spectrum of an unresolved binary star system is a superposition of two single-star spectra. Even without a detectable velocity offset between the two stellar components, the combined spectrum of a binary system is in general…

Here, I overview one of the available techniques for the analysis of broad-band spectropolarimetric data, the Stokes QU-fitting. Since broad-band receivers have been installed at most radio facilities, the collection of radio data, both the…

Astrophysics of Galaxies · Physics 2021-08-24 Alice Pasetto

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

The design and later use of modern spectropolarimeters and magnetographs require a number of tolerance specifications that allow the developers to build the instrument and then the scientists to interpret the data accuracy. Such…

Solar and Stellar Astrophysics · Physics 2015-06-05 J. C. del Toro Iniesta , V. Martínez Pillet

We investigate the potential of photonic lantern (PL) fiber fed spectrometers for two-dimensional spectroastrometry. Spectroastrometry, a technique for studying small angular scales by measuring centroid shifts as a function of wavelength,…

Instrumentation and Methods for Astrophysics · Physics 2024-09-17 Yoo Jung Kim , Michael P. Fitzgerald , Jonathan Lin , Yinzi Xin , Daniel Levinstein , Steph Sallum , Nemanja Jovanovic , Sergio Leon-Saval

We have developed a vacuum-ultraviolet spectropolarimeter to measure the linear polarization of spectral lines around the Lyman-$\alpha$ wavelength. The main components for polarimetry are a rotatable MgF$_2$ waveplate and a SiO$_2$/MgF$_2$…

Atomic Physics · Physics 2026-04-10 Nobuyuki Nakamura , Ryohko Ishikawa , Motoshi Goto

Spectropolarimetry is a powerful technique that has provided critical support for the geometric unification model of local active galactic nuclei. In this paper, we present optical (rest-frame UV) Keck spectropolarimetry of five luminous…

X-ray polarimetry promises to deliver unique information about the geometry of the inner accretion flow of astrophysical black holes and the nature of matter and electromagnetism in and around neutron stars. In this paper, we discuss the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 F. Kislat , B. Clark , M. Beilicke , H. Krawczynski

We developed an instrument design capable of measuring linear X-ray polarization over a broad-band using conventional spectroscopic optics. A set of multilayer-coated flats reflects the dispersed X-rays to the instrument detectors. The…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 Herman L. Marshall , Ralf Heilmann , Norbert Schulz , Kendrah Murphy

Emission spectroscopy is an invaluable tool for probing the atmospheres of brown dwarfs and exoplanets, but interpretations based on flux spectra alone often suffer from degeneracies among temperature structure, chemical composition, and…

Earth and Planetary Astrophysics · Physics 2025-12-16 Fei Wang , Yuka Fujii , Ben Burningham , Jinping He

Using photoemission intensities and a detection system employed by many groups in the electron spectroscopy community as an example, we have quantitatively characterized and corrected detector non-linearity effects over the full dynamic…

Instrumentation and Detectors · Physics 2007-05-23 N. Mannella , S. Marchesini , A. W. Kay , A. Nambu , T. Gresch , S. -H. Yang , B. S. Mun , J. M. Bussat , A. Rosenhahn , C. S. Fadley