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Related papers: Magnetic fields along the pre-main-sequence phase

200 papers

We discuss the evolution of cosmological magnetic fields from the early universe to the present. We review different scenarios for magnetogenesis in the early universe and follow the subsequent evolution of these fields as the universe…

Astrophysics · Physics 2007-05-23 Angela V. Olinto

Observations of stable mainly dipolar magnetic fields at the surface of ~7% of single hot stars indicate that these fields are of fossil origin, i.e. they descend from the seed field in the molecular clouds from which the stars were formed.…

Solar and Stellar Astrophysics · Physics 2015-02-03 C. Neiner , S. Mathis , E. Alecian , C. Emeriau , J. Grunhut , the BinaMIcS , MiMeS collaborations

Some main-sequence stars of spectral type A are observed to have a strong (300-30000 G), static, large-scale magnetic field, of a chiefly dipolar shape -- the `Ap stars' (for example Alioth, the fifth star in the Big Dipper). Following…

Astrophysics · Physics 2009-11-10 J. Braithwaite , H. C. Spruit

Magnetic fields are observed not only in stars, but in galaxies, clusters, and even high redshift Lyman-alpha systems. In principle, these fields could play an important role in structure formation and also affect the anisotropies in the…

Astrophysics · Physics 2009-10-31 Roy Maartens

The magnetic field plays an important role in every stage of the star-formation process from the collapse of the initial protostellar core to the star's arrival on the main sequence. Consequently, the goal of this science case is to explore…

Magnetic fields are known to reside in many astrophysical objects and are now believed to be crucially important for the creation of phenomena on a wide variety of scales. However, the role of the magnetic field in the bodies that we…

Astrophysics · Physics 2009-11-13 L. J. Silvers

Different mechanisms which may possibly explain existence of magnetic fields on astronomically large scales are described. A recently suggested model of magnetic fields generation slightly before hydrogen recombination is discussed in more…

Astrophysics · Physics 2007-05-23 A. D. Dolgov

A variety of observations suggest that magnetic fields are present in all galaxies and galaxy clusters. These fields are characterized by a modest strength (10^{-7}-10^{-5} G) and huge spatial scale (~Mpc). It is generally assumed that…

Astrophysics · Physics 2008-11-26 Lawrence M. Widrow

Most of the baryonic matter in the Universe is permeated by magnetic fields which affect many, if not most, of astrophysical phenomena both, in compact sources and in diffuse gas. Recent years have been marked by a worldwide surge of…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-23 Elisabete M. de Gouveia Dal Pino

The observed galactic magnetic fields may have a primordial origin. I briefly review the observations, their interpretation in terms of the dynamo theory, and the current limits on cosmological magnetic fields. Several possible mechanisms…

Astrophysics · Physics 2007-05-23 Kari Enqvist

In this talk, I review a number of particle-physics models that lead to the creation of magnetic fields in the early universe and address the complex problem of evolving such primordial magnetic fields into the fields observed today.…

Astrophysics · Physics 2016-11-03 Ola Tornkvist

Stars with radiative envelopes, specifically the upper main sequence chemically peculiar (Ap) stars, were among the first objects outside our solar system for which surface magnetic fields have been detected. Currently magnetic Ap stars…

Solar and Stellar Astrophysics · Physics 2015-06-17 O. Kochukhov

We have obtained high-quality magnetic field measurements of 19 sharp-lined B-type stars with precisely-measured N/C abundance ratios. Our primary goal is to test the idea that a magnetic field may explain extra drag (through the wind) on…

Solar and Stellar Astrophysics · Physics 2015-06-22 G. A. Wade , C. P. Folsom , J. Grunhut , J. D. Landstreet , V. Petit

Whereas the understanding of most phases of stellar evolution made considerable progress throughout the whole of the twentieth century, stellar formation remained rather enigmatic and poorly constrained by observations until about three…

Astrophysics · Physics 2015-05-13 J. F. Donati , M. M. Jardine , S. G. Gregory , J. Bouvier , C. Dougados , F. Menard

Observations of nearby star forming clouds with imaging X-ray telescopes have revealed that X-ray emission is elevated $10^1-10^4$ above main sequence levels in low-mass pre-main sequence (PMS) stars. The variability and spectral X-ray…

Astrophysics · Physics 2007-05-23 Eric D. Feigelson

About 10% of hot stars host a fossil magnetic field on the pre-main sequence and main sequence. However, the first magnetic evolved hot stars have been discovered only recently. An observing program has been set up to find more such…

Solar and Stellar Astrophysics · Physics 2018-11-14 C. Neiner , A. Martin , G. Wade , M. Oksala

This review concerns the origin and the possible effects of magnetic fields in the early Universe. We start by providing to the reader with a short overview of the current state of art of observations of cosmic magnetic fields. We then…

Astrophysics · Physics 2009-07-09 Dario Grasso , H. R. Rubinstein

Magnetic fields are found in many astrophysical objects, ranging from galaxy clusters to the interstellar medium of galaxies and neutron stars. Strong magnetic fields are also observed in massive stars, but it is still unclear how they are…

I review the development of ideas regarding the angular momentum evolution of solar-type stars, from the early 60's to the most recent years. Magnetic fields are the central agent that dictates the rotational evolution of solar-type stars,…

Astrophysics · Physics 2015-05-13 Jerome Bouvier

Blazar observations point toward the possible presence of magnetic fields over intergalactic scales of the order of up to $\sim1\,$Mpc, with strengths of at least $\sim10^{-16}\,$G. Understanding the origin of these large-scale magnetic…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-17 Tina Kahniashvili , Axel Brandenburg , Arthur Kosowsky , Sayan Mandal , Alberto Roper Pol