Philip Judge

Atomic structure calculations of Land ́e g factors of astrophysical interest with direct applications for solar coronal magnetometry

Non-relativistic Land ́e g factor
Thursday, May 6, 2021

We perform a detailed theoretical study of the atomic structure of ions with ns2npm ground configurations and focus on departures from LS coupling which directly affect the Land ́e g factors of magnetic dipole lines between levels of the ground terms.

Measuring the magnetic origins of solar flares, CMEs and Space Weather

A UV spectrum of α Cen A
Wednesday, April 21, 2021

We take a broad look at the problem of identifying the magnetic solar causes of space weather.

Magnetic structure of the solar chromosphere-corona transition regions

Graphic image of CLASP2 observations
Thursday, March 11, 2021

The bulk of the emission from the plasma called "transition region" plasma originates from structures energetically connected both to the chromosphere and corona.

On single-point inversions of magnetic dipole lines in the corona

Graphic image showing scattering geometry
Wednesday, March 3, 2021

Prompted by a recent paper by Dima and Schad, we re-consider the problem of inferring magnetic properties of the corona using polarimetric observations of magnetic dipole (M1) lines.

On the Cores of Resonance Lines Formed in the Sun's Chromosphere

Graphic image depicting a comparison of 1D and 3D calculations
Wednesday, July 1, 2020

We re-examine a 50+ year-old problem of deep central reversals predicted for strong solar spectral lines, in contrast to the smaller reversals seen in observations.

Neutral hydrogen, helium and solar and stellar coronae

Graphic image of Line Profiles of He I and He II Resonance Line
Wednesday, June 17, 2020

In the context of the solar atmosphere, we re-examine the role of of neutral and ionized species in dissipating the ordered energy of intermediate-mode MHD waves into heat.

Some thoughts on emission-line spectroscopy

Graphic image of intensity and polarization data surrounding the current sheet formed on Sept 10 2017
Tuesday, June 2, 2020

Philip Judge states that the interpretation of emission lines formed in large astrophysical plasmas such as the solar atmosphere faces many challenges. Relatively simple line-ratio estimates of physical parameters, while appealing, are heavily laden with assumptions.

Introducing a Book— The Sun: A Very Short Introduction

Photographic image of the book cover to "The Sun: A Very Short Introduction" by Phil Judge

Philip Judge is a senior researcher in physics at the High Altitude Observatory. Education and outreach has been a major focus and passion during his scientific career. He has influenced and encouraged many young scientists to pursue careers in solar physics.

Spectropolarimetric Insight into Plasma-Sheet Dynamics of a Solar Flare

Graphic of intensity and polarization data
Wednesday, February 12, 2020

We examine spectropolarimetric data from the CoMP instrument, acquired during the evolution of the September 10th 2017 X8.2 solar flare on the western solar limb. CoMP captured linearly polarized light from two emission lines of Fe XIII at 1074.7 and 1079.8 nm, from 1.03 to 1.5 solar radii.

Multiwavelength High-resolution Observations of Chromospheric Swirls in the Quiet Sun

Graphic image of chromospheric swirls
Wednesday, February 5, 2020

We report observations of small-scale swirls seen in the solar chromosphere. They are typically 2 Mm in diameter and last around 10 minutes.

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