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Here we report on the first detection of circular polarization in molecular lines formed in cool magnetic regions (starspots) and in chromospheric emission lines formed in hot plages on the surfaces of active stars. Our survey of G-K-M…

Astrophysics · Physics 2007-05-23 S. V. Berdyugina , D. M. Fluri , N. Afram , F. Suwald , P. Petit , J. Arnaud , D. M. Harrington , J. R. Kuhn

Recent asteroseismic analyses have revealed the presence of strong (B $\gtrsim 10^5$ G) magnetic fields in the cores of many red giant stars. Here, we examine the implications of these results for the evolution of stellar magnetic fields,…

Solar and Stellar Astrophysics · Physics 2016-06-15 Matteo Cantiello , Jim Fuller , Lars Bildsten

Magnetic fields are believed to have a vital role in regulating and shaping the flow of material onto and away from protostars during their initial mass accretion phase. It is becoming increasingly accepted that bipolar outflows are…

Astrophysics · Physics 2009-07-09 Antonio Chrysostomou , Philip W. Lucas , James H. Hough

[Abridged] Theoretical and numerical studies of star formation have shown that magnetic field (B) has a strong influence on both disk formation and fragmentation; even a relatively low B can prevent these processes. However, very few…

Solar and Stellar Astrophysics · Physics 2015-06-12 Marc Joos , Patrick Hennebelle , Andrea Ciardi , Sebastien Fromang

Starlight that becomes linearly polarized by magnetically aligned dust grains provides a viable diagnostic of the interstellar magnetic field (ISMF). A survey is underway to map the local ISMF using data collected at eight observatories in…

We present in this paper the first results of a spectropolarimetric analysis of a small sample (~ 20) of active stars ranging from spectral type M0 to M8, which are either fully-convective or possess a very small radiative core. This study…

Magnetic fields are expected to play an important role in accretion processes for circumstellar disks. Measuring the magnetic field morphology is difficult, especially since polarimetric (sub)millimeter continuum observations may not trace…

Solar and Stellar Astrophysics · Physics 2020-09-30 Ian W. Stephens , Manuel Fernandez-Lopez , Zhi-Yun Li , Leslie W. Looney , Richard Teague

Turbulence and magnetic fields are expected to be important for regulating molecular cloud formation and evolution. However, their effects on subparsec to 100 parsec scales, leading to the formation of starless cores, is not well…

The role of magnetic fields in regulating the formation of massive stars remains much debated. Here we present sub-millimeter polarimetric observations with JCMT-POL2 at $850\:\mu$m of 13 regions of massive star formation selected from the…

Astrophysics of Galaxies · Physics 2025-07-04 Tuva Källberg , Chi Yan Law , Jonathan C. Tan , Kate Pattle , Zacariyya Khan

We present a study of the relative orientation between the magnetic field projected onto the plane of sky ($B_{\perp}$) on scales down to 0.4 pc, inferred from the polarized thermal emission of Galactic dust observed by Planck at 353 GHz,…

Astrophysics of Galaxies · Physics 2020-03-04 Juan D. Soler

Magnetic fields have only recently been included in theoretical simulations of high-mass star formation. The simulations show that magnetic fields can play a crucial role not only in the formation and dynamics of molecular outflows, but…

Solar and Stellar Astrophysics · Physics 2015-03-10 G. Surcis , W. H. T. Vlemmings , H. J. van Langevelde , B. Hutawarakorn Kramer , A. Bartkiewicz , H. Engelkamp

In this work we investigate the effects of the primordial magnetic fields on cosmic microwave background anisotropies (CMB). Based on cosmological magnetohydrodynamic (MHD) simulations we calculate the CMB anisotropy spectra and…

Astrophysics · Physics 2009-11-13 Hiroyuki Tashiro , Naoshi Sugiyama , Robi Banerjee

Synchrotron emission, its polarization and its Faraday rotation at radio frequencies of 0.2-10 GHz are powerful tools to study the strength and structure of cosmic magnetic fields. The observational results are reviewed for spiral, barred…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Rainer Beck

Magnetic fields have an impact on galaxy evolution at multiple scales. They are particularly important for starburst galaxies, where they play a crucial role in shaping the interstellar medium (ISM), influencing star formation processes and…

It is shown that small-scale magnetic fields present before recombination induce baryonic density inhomogeneities of appreciable magnitude. The presence of such inhomogeneities changes the ionization history of the Universe, which in turn…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Karsten Jedamzik , Tom Abel

We present results of our $R-$band polarimetry of a cometary globule, LBN 437 (Gal96-15, $\ell$ $=$ 96$\degree$, \textit{b} $=-15\degree$), to study magnetic field geometry of the cloud. We estimated a distance of $360\pm65$ pc to LBN 437…

Astrophysics of Galaxies · Physics 2013-04-08 Archana Soam , G. Maheswar , H. C. Bhatt , Chang Won Lee , A. N. Ramaprakash

Magnetic fields likely play an important role in the formation of young protostars. Multiscale and multiwavelength dust polarization observations can reveal the inferred magnetic field from scales of the cloud to core to protostar. We…

Recent magnetic field surveys in O- and B-type stars revealed that about 10% of the core-hydrogen-burning massive stars host large-scale magnetic fields. The physical origin of these fields is highly debated. To identify and model the…

The question whether magnetic fields play an important role in the processes of molecular cloud and star formation has been debated for decades. Recent observations have revealed a simple picture that may help illuminate these questions:…

Astrophysics of Galaxies · Physics 2015-06-19 Hua-bai Li , Alyssa Goodman , T. K. Sridharan , Martin Houde , Zhi-Yun Li , Giles Novak , Kwok Sun Tang

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…