173 citations · 576 across the 30 of their papers we have counts for
31 papers
Polarization geometry of magnetohydrodynamic turbulence
Raphael Skalidis
We introduce a geometric framework that organizes the second-order statistics of the Elasser fields into polarization states on generalized Poincaré spheres. In this representation…
WALOP-South: a four camera one shot imaging polarimeter for the PASIPHAE survey. Paper III -- PSF modelling
Indrajit Paul, Kishan Deka, Tuhin Ghosh +22
The two WALOP instruments, built for the PASIPHAE survey, will measure the linear polarization of large numbers of stars in the Galactic polar regions in the SDSS- band. They ar…
The multiphase interstellar medium as a common origin for magnetic misalignment and TB parity violation
Andrea Bracco, Ari J. Cukierman, Raphael Skalidis +1
We present an original data analysis and a physical model that provide new insights into the origin of, and relationship between, two observables of the dusty, polarized Galaxy at…
Evidence for cloud-to-cloud variations in the ratio of polarized thermal dust emission to starlight polarization
Nidhi Mehandiratta, Georgia V. Panopoulou, Eirik Gjerløw +12
The correlation between optical starlight polarization and polarized thermal dust emission can be used to infer intrinsic dust properties. This correlation is quantified by the rat…
Investigating the role of magnetic fields in the formation and evolution of striations in interstellar clouds with PRIMA
Raphael Skalidis, Konstantinos Tassis, Aris Tritsis +1
Striations are diffuse, linear, quasi-periodic, and magnetized structures located in the outskirts of molecular clouds. These structures seem to play an important role during the e…
Wide Area Linear Optical Polarimeter Control Software
John A. Kypriotakis, Bhushan Joshi, Dmitry Blinov +19
The WALOPControl software is designed to facilitate comprehensive control and operation of the WALOP (Wide Area Linear Optical Polarimeter) polarimeters, ensuring safe and concurre…
A three-step approach to reliably estimate magnetic field strengths in star-forming regions
Aristeidis Polychronakis, Aris Tritsis, Raphael Skalidis +1
The magnetic field is known to play a crucial role in star formation. Dust polarization is an effective tool for probing the morphology of the field, yet it does not directly trace…
The H2 Glow of a Quiescent Molecular Cloud Observed with JWST
Paul F. Goldsmith, Shengzhe Wang, Xin Wang +6
We report JWST MIRI/MRS observations of the H2 S(1) 17.04 micron transition in two regions in the boundary of the Taurus Molecular Cloud. The two regions, denoted Edge (near the re…
The WALOP-North Instrument I: Optical Design, Filter Design, Calibration
John A. Kypriotakis, Siddharth Maharana, Ramya M. Anche +18
The Wide Area Linear Optical Polarimeter North (WALOP-North) is an optical polarimeter designed for the needs of the PASIPHAE survey. It will be installed on the 1.3m telescope at…
Challenges in constraining dust properties from starlight polarization
Raphael Skalidis
Dust polarization, which comes from the alignment of aspherical grains to magnetic fields, has been widely employed to study the interstellar medium (ISM) dust properties. The wave…
3D ISM structure challenges the Serkowski relation
Nikolaos Mandarakas, Konstantinos Tassis, Raphael Skalidis
The Serkowski relation is the cornerstone of studies of starlight polarization as a function of wavelength. Although empirical, its extensive use since its inception to describe po…
Systems design, assembly, integration and lab testing of WALOP-South Polarimeter
Siddharth Maharana, A. N. Ramaprakash, Chaitanya Rajarshi +28
Wide-Area Linear Optical Polarimeter (WALOP)-South is the first wide-field and survey-capacity polarimeter in the optical wavelengths. On schedule for commissioning in 2024, it wil…
Microphysical Regulation of Non-Ideal MHD in Weakly-Ionized Systems: Does the Hall Effect Matter?
Philip F. Hopkins, Jonathan Squire, Raphael Skalidis +1
The magnetohydrodynamics (MHD) equations plus 'non-ideal' (Ohmic, Hall, ambipolar) resistivities are widely used to model weakly-ionized astrophysical systems. We show that if grad…
Polarized Light from Massive Protoclusters (POLIMAP). I. Dissecting the role of magnetic fields in the massive infrared dark cloud G28.37+0.07
C-Y Law, Jonathan C. Tan, Raphael Skalidis +11
Magnetic fields may play a crucial role in setting the initial conditions of massive star and star cluster formation. To investigate this, we report SOFIA-HAWC+ m observati…
Detection of X-ray Polarization from the Blazar 1ES 1959+650 with the Imaging X-ray Polarimetry Explorer
Manel Errando, Ioannis Liodakis, Alan P. Marscher +142
Observations of linear polarization in the 2-8 keV energy range with the Imaging X-ray Polarimetry Explorer (IXPE) explore the magnetic field geometry and dynamics of the regions g…
Constraining the H2 column densities in the diffuse interstellar medium using dust extinction and HI data
Raphael Skalidis, Paul F. Goldsmith, Philip F. Hopkins +1
Carbon monoxide (CO) is a poor tracer of H in the diffuse interstellar medium (ISM), where most of the carbon is not incorporated into CO molecules unlike the situation at hi…
Observations of Low and Intermediate Spectral Peak Blazars with the Imaging X-ray Polarimetry Explorer
Herman L. Marshall, Ioannis Liodakis, Alan P. Marscher +145
We present X-ray polarimetry observations from the Imaging X-ray Polarimetry Explorer (IXPE) of three low spectral peak and one intermediate spectral peak blazars, namely 3C 273, 3…
Magnetic Field Properties inside the Jet of Mrk 421: Multiwavelength Polarimetry Including the Imaging X-ray Polarimetry Explorer
Dawoon E. Kim, Laura Di Gesu, Ioannis Liodakis +133
We conducted a polarimetry campaign from radio to X-ray wavelengths of the high-synchrotron-peak (HSP) blazar Mrk 421, including Imaging X-ray Polarimetry Explorer (IXPE) measureme…
Synchrotron Signatures of Cosmic Ray Transport Physics in Galaxies
Sam B. Ponnada, Iryna S. Butsky, Raphael Skalidis +7
Cosmic rays (CRs) may drive outflows and alter the phase structure of the circumgalactic medium, with potentially important implications on galaxy formation. However, these effects…
Synchrotron Emission on FIRE: Equipartition Estimators of Magnetic Fields in Simulated Galaxies with Spectrally-Resolved Cosmic Rays
Sam B. Ponnada, Georgia V. Panopoulou, Iryna S. Butsky +7
Synchrotron emission is one of few observable tracers of galactic magnetic fields (\textbf{B}) and cosmic rays (CRs). Much of our understanding of \textbf{B} in galaxies comes from…
Discovery of X-ray polarization angle rotation in active galaxy Mrk 421
Laura Di Gesu, Herman L. Marshall, Steven R. Ehlert +140
The magnetic field conditions in astrophysical relativistic jets can be probed by multiwavelength polarimetry, which has been recently extended to X-rays. For example, one can trac…
X-ray Polarization Observations of BL Lacertae
Riccardo Middei, Ioannis Liodakis, Matteo Perri +143
Blazars are a class of jet-dominated active galactic nuclei with a typical double-humped spectral energy distribution. It is of common consensus the Synchrotron emission to be resp…
WALOP-South: A Four-Camera One-Shot Imaging Polarimeter for PASIPHAE Survey. Paper II -- Polarimetric Modelling and Calibration
Siddharth Maharana, Ramya M. Anche, A. N. Ramaprakash +22
The Wide-Area Linear Optical Polarimeter (WALOP)-South instrument is an upcoming wide-field and high-accuracy optical polarimeter to be used as a survey instrument for carrying out…
Starlight-polarization-based tomography of the magnetized interstellar medium: PASIPHAE's line-of-sight inversion method
V. Pelgrims, G. V. Panopoulou, K. Tassis +20
We present the first Bayesian method for tomographic decomposition of the plane-of-sky orientation of the magnetic field with the use of stellar polarimetry and distance. This stan…