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Related papers: Tracing Magnetic Fields by Atomic Alignment in Ext…

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Magnetic fields have important or dominant effects in many areas of astrophysics, but have been very difficult to quantify. Spectropolarimetry from Ground State Alignment (GSA) has been suggested as a direct tracer of magnetic field in…

Astrophysics of Galaxies · Physics 2019-03-28 Huirong Yan , Cecile Gry , Francois Boulanger , Francesco Leone

We demonstrate a new way of studying interplanetary magnetic field -- Ground State Alignment (GSA). Instead of sending thousands of space probes, GSA allows magnetic mapping with any ground telescope facilities equipped with…

Instrumentation and Methods for Astrophysics · Physics 2012-10-03 Jinyi Shangguan , Huirong Yan

Observational studies of magnetic fields are vital as magnetic fields play a crucial role in various astrophysical processes, including star formation, accretion of matter, transport processes (e.g., transport of heat), and cosmic rays. We…

Astrophysics of Galaxies · Physics 2015-06-04 Huirong Yan , A. Lazarian

We discuss a new technique of studying magnetic fields in diffuse astrophysical media, e.g. interstellar and intergalactic gas/plasma. This technique is based on the angular momentum alignment of atoms and ions in their ground or metastable…

Astrophysics · Physics 2008-06-24 Huirong Yan , A. Lazarian

Spectroscopic observations play a fundamental role in astrophysics. They are crutial to determine important physical parameters, provide information about the composition of various objects in the universe, as well as depict motions in the…

Instrumentation and Methods for Astrophysics · Physics 2018-06-21 Heshou Zhang , Huirong Yan , Philipp Richter

Observational studies of magnetic fields are crucial. We introduce a process "ground state alignment" as a new way to determine the magnetic field direction in diffuse medium. The alignment is due to anisotropic radiation impinging on the…

Astrophysics of Galaxies · Physics 2013-02-15 Huirong Yan , A. Lazarian

We present our attempts to detect magnetic fields in filamentary large-scale structure (LSS) by observing polarized synchrotron emission emitted by structure formation shocks. Little is known about the strength and order of magnetic fields…

Astrophysics · Physics 2009-11-13 Shea Brown , Lawrence Rudnick , Damon Farnsworth

Measurements of interplanetary magnetic fields have long relied on spacecraft measurements, which provide only in-situ sampling and therefore cannot capture the global magnetic structure. Faraday rotation of radio signals extends in-situ…

Space Physics · Physics 2026-05-28 Chuanpeng Hou , Huirong Yan , Siqi Zhao

Magnetic field sensing provides crucial insights into various geophysical phenomena such as atmospheric currents, crustal magnetism, and oceanic circulation. In this paper, a method for remote detection of magnetic fields using mesospheric…

Probing magnetic fields in astrophysical environments is both important and challenging. The Gradient Technique (GT) is a new tool for tracing magnetic fields, rooted in the properties of magnetohydrodynamic (MHD) turbulence and turbulent…

Astrophysics of Galaxies · Physics 2024-06-18 Yue Hu , Alex Lazarian

We continue our studies of atomic alignment in diffuse media, in particularly, in interstellar and circumstellar media, with the goal of developing new diagnostics of magnetic fields in these environments. We understand atomic alignment as…

Astrophysics · Physics 2009-11-13 Huirong Yan , A. Lazarian

Submillimeter dust polarization measurements of a sample of 50 star-forming regions, observed with the SMA and the CSO covering pc-scale clouds to mpc-scale cores, are analyzed in order to quantify the magnetic field importance. The…

We explore potential of current and next-generation gamma-ray telescopes for the detection of weak magnetic fields in the intergalactic medium. We demonstrate that using two complementary techniques, observation of extended emission around…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-31 A. Neronov , D. Semikoz

Regular magnetic field structures can be derived from the Faraday rotation measures (RM) of polarized background sources observable at 1.4 GHz with the SKA. At lower frequencies ($<250$ MHz) polarimetry of radio sources with the Low…

Cosmology and Nongalactic Astrophysics · Physics 2009-04-20 Tigran G. Arshakian , Rainer Beck

We show that atomic alignment presents a reliable way to study topology of astrophysical magnetic fields. The effect of atomic alignment arises from modulation of the relative population of the sublevels of atomic ground state pumped by…

Astrophysics · Physics 2008-11-26 Huirong Yan , A. Lazarian

Magnetic fields are an important component of the interstellar medium, especially in low-mass galaxies like irregulars where the magnetic pressure may be significant. However, few irregular galaxies have observed magnetic field structures.…

The extragalactic magnetic field could be detected by searching for signatures of the electromagnetic cascade initiated by high-energy photons on the intergalactic radiation and deflected by the field. This process produces a time delay and…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-04 Boris Stern , Igor Tkachev

The joint analysis of the Dispersion and Faraday Rotation Measure from distant, polarised Fast Radio Bursts may be used to put constraints on the origin and distribution of extragalactic magnetic fields on cosmological scales. While the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-24 F. Vazza , M. Brüggen , P. M. Hinz , D. Wittor , N. Locatelli , C. Gheller

Interstellar magnetic fields play critical roles in many astrophysical processes. Yet despite their importance, our knowledge about magnetic fields in our Galaxy remains limited. For the field within the Milky Way, much of what we do know…

Astrophysics of Galaxies · Physics 2010-12-15 Cameron Van Eck , Jo-Anne Brown

In this review, I will first introduce possible methods to probe the large-scale magnetic fields in our Galaxy and discuss their limitations. The magnetic fields in the Galactic halo, mainly revealed by the sky distribution of rotation…

Astrophysics · Physics 2007-05-23 J. L. Han
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