English
Related papers

Related papers: The Davis-Chandrasekhar-Fermi Method Revisited

200 papers

Context: The importance of magnetic fields at the onset of star formation related to the early fragmentation and collapse processes is largely unexplored today. Aims: We want to understand the magnetic field properties at the earliest…

Astrophysics of Galaxies · Physics 2018-06-13 H. Beuther , J. Soler , W. Vlemmings , H. Linz , Th. Henning , R. Kuiper , R. Rao , R. Smith , T. Sakai , K. Johnston , A. Walsh , S. Feng

Magnetic fields are an important component of the interstellar medium (ISM) of galaxies. The thermal gas in the ISM has a multiphase structure, broadly divided into ionised, atomic, and molecular phases. The connection between the…

Astrophysics of Galaxies · Physics 2025-04-01 Amit Seta , N. M. McClure-Griffiths

Theoretical and numerical works indicate that a strong magnetic field should suppress fragmentation in dense cores. However, this has never been tested observationally in a relatively large sample of fragmenting massive dense cores. Here we…

Understanding the physics of how stars form is a highly-prioritized goal of modern Astrophysics, in part because star formation is linked to both galactic dynamics on large scales and to the formation of planets on small scales. It is…

We describe a method for determining the dispersion of magnetic field vectors about large-scale fields in turbulent molecular clouds. The method is designed to avoid inaccurate estimates of magnetohydrodynamic or turbulent dispersion - and…

A framework is introduced for coupling the evolution of galactic magnetic fields sustained by the mean-field dynamo with the formation and evolution of galaxies in cold dark matter cosmology. Estimates of the steady-state strength of the…

Astrophysics of Galaxies · Physics 2015-05-20 Luiz Felippe S. Rodrigues , Anvar Shukurov , Andrew Fletcher , Carlton Baugh

Magnetohydrodynamic(MHD) turbulence displays velocity anisotropies which reflect the direction of the magnetic field. This anisotropy has led to the development of a number of statistical techniques for studying magnetic fields in the…

Mean-field galactic dynamo theory is the leading theory to explain the prevalence of regular magnetic fields in spiral galaxies, but its systematic comparison with observations is still incomplete and fragmentary. Here we compare…

Astrophysics of Galaxies · Physics 2016-12-14 Luke Chamandy , Anvar Shukurov , A. Russ Taylor

We present the first direct magnetic field measurements on M dwarfs cooler than spectral class M4.5. Utilizing a new method based on the effects of a field on the FeH band near 1 micron, we obtain information on whether the integrated…

Astrophysics · Physics 2008-11-26 A. Reiners , G. Basri

The degree to which the formation and evolution of clouds and filaments in the interstellar medium is regulated by magnetic fields remains an open question. Yet the fundamental properties of the fields (strength and 3D morphology) are not…

Astrophysics of Galaxies · Physics 2020-10-21 Stefan Reissl , Amelia M. Stutz , Ralf S. Klessen , Daniel Seifried , Stefanie Walch

Magnetic fields play a fundamental role in protostellar collapse and disk formation, yet direct measurements of magnetic field strength in deeply embedded protostellar envelopes remain difficult. We present a new method to estimate both the…

Earth and Planetary Astrophysics · Physics 2026-03-24 Yisheng Tu , Xiaoyuan Yang , Zhi-Yun Li

Starlight polarimetry, when combined with accurate distance measurements, allows for exploration of the three-dimensional structure of local magnetic fields in great detail. We present optical polarimetric observations of stars in and close…

The complete three-dimensional structure of the magnetic field within molecular clouds has eluded determination despite its high value in determining controlling factors in the star formation process, as it cannot be directly probed…

Astrophysics of Galaxies · Physics 2019-03-13 Che-Yu Chen , Patrick K. King , Zhi-Yun Li , Laura M. Fissel , Renato R. Mazzei

Both observations and modelling of magnetic fields in the diffuse interstellar gas of spiral galaxies are well developed but the theory has been confronted with observations for only a handful of individual galaxies. There is now sufficient…

Astrophysics of Galaxies · Physics 2015-06-23 Cameron Van Eck , Jo-Anne Brown , Anvar Shukurov , Andrew Fletcher

Circular polarisation measurements of white dwarfs of various ages and spectral types are useful to understand the origin and evolution of the magnetic field in degenerate stars. In the latest stages of white dwarf evolution, when stars are…

Solar and Stellar Astrophysics · Physics 2022-01-19 Andrei V. Berdyugin , Vilppu Piirola , Stefano Bagnulo , John D. Landstreet , Svetlana V. Berdyugina

The gradient technique is a promising tool with theoretical foundations based on the fundamental properties of MHD turbulence and turbulent reconnection. Its various incarnations use spectroscopic, synchrotron, and intensity data to trace…

Astrophysics of Galaxies · Physics 2024-06-04 Alex Lazarian , Ka Ho Yuen , Dmitri Pogosyan

The true nature of primordial magnetic fields (PMFs) and their role in the formation of galaxies still remains elusive. To shed light on these unknowns, we investigate their impact by varying two sets of properties: (i) accounting for the…

Astrophysics of Galaxies · Physics 2024-10-02 Mahsa Sanati , Sergio Martin-Alvarez , Jennifer Schober , Yves Revaz , Adrianne Slyz , Julien Devriendt

The mapping of the Galactic Magnetic Field (GMF) in three dimensions is essential to comprehend various astrophysical processes that occur within the Milky Way. This study endeavors to map the GMF by utilizing the latest MM2 technique, the…

Astrophysics of Galaxies · Physics 2023-07-12 Yue Hu , Alex Lazarian

OB stars exhibit various types of spectral variability associated with wind structures, including the apparently ubiquitous discrete absorption components (DACs). These are proposed to be caused by either magnetic fields or non-radial…