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Related papers: Counterclockwise magnetic fields in the Norma spir…

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The polarization data of the radio galaxy NGC4869, belonging to the Coma cluster and located in its central region, allow us to obtain information on the structure of magnetic field associated with the cluster itself. A magnetic field of…

Astrophysics · Physics 2008-02-03 L. Feretti , D. Dallacasa , G. Giovannini , A. Tagliani

Spiral arms, if they are massive, exert gravitational torques that transport angular momentum radially within galactic disks. These torques depend not on the pattern speed or permanence of the arms but only on the nonaxisymmetric mass…

Astrophysics · Physics 2016-08-30 Oleg Y. Gnedin , Jeremy Goodman , Zsolt Frei

To determine the properties of the Faraday screen and the magnetic field near the central region of the Galaxy, we measured the Faraday rotation measure (RM) towards 60 background extragalactic source components through the -6 deg < l <6…

Astrophysics · Physics 2009-11-13 Subhashis Roy , A. Pramesh Rao , Ravi Subrahmanyan

We carry out analyses of some parameters of the galactic spiral arms, in the currently available samples. We present a catalog of the observed pitch angle for each spiral arm in the Milky Way disk. For each long spiral arm in the Milky Way,…

Astrophysics of Galaxies · Physics 2017-11-15 Jacques P Vallee

Faraday rotation of radio source polarization provides a measure of the integrated magnetic field along the observational lines of sight. We compare a new, large sample of Faraday rotation measures (RMs) of polarized extragalactic sources…

Astrophysics · Physics 2009-11-13 Yongzhong Xu , Philipp P. Kronberg , Salman Habib , Quentin W. Dufton

We show that in the anticenter region, between Galactic longitudes of $110^\circ<l<229^\circ$, there is an oscillating asymmetry in the main sequence star counts on either side of the Galactic plane using data from the Sloan Digital Sky…

Astrophysics of Galaxies · Physics 2015-06-24 Yan Xu , Heidi Jo Newberg , Jeffrey L. Carlin , Chao Liu , Licai Deng , Jing Li , Ralph Schönrich , Brian Yanny

Interstellar magnetic fields are strong: up to 25 muG in spiral arms and 40 muG in nuclear regions. In the spiral galaxy NGC 6946 the average magnetic energy density exceeds that of the thermal gas. Magnetic fields control the evolution of…

Astrophysics · Physics 2017-01-25 Rainer Beck

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

Since the launch of the Fermi Gamma-Ray Space Telescope, several hundred gamma-ray pulsars have been discovered, some being radio-loud and some radio-quiet with time-aligned radio and gamma-ray light curves. In the second Fermi Pulsar…

High Energy Astrophysical Phenomena · Physics 2021-03-17 O. Benli , J. Petri , Dipanjan Mitra

Spiral arms are the defining features of broad morphological classes of disc galaxies, but their nature and influence on galaxy evolution is still under debate. A key diagnostic for their nature is the spiral arm pattern speed: the radial…

Instrumentation and Methods for Astrophysics · Physics 2025-12-22 Robert J. J. Grand , Martin Roth

We investigate the geometry of the magnetic field of rotation-powered pulsars. A new method for calculating an angle ($\beta$) between the spin and magnetic dipole axes of a neutron star (NS) in the ejector stage is considered within the…

High Energy Astrophysical Phenomena · Physics 2023-08-16 Vitaliy Kim , Adel Umirbayeva , Yerlan Aimuratov

Magnetic fields in the Milky Way are present on a wide variety of sizes and strengths, influencing many processes in the Galactic ecosystem such as star formation, gas dynamics, jets, and evolution of supernova remnants or pulsar wind…

Large-scale coherent magnetic fields in the intergalactic medium are presumed to play a key role in the formation and evolution of the cosmic web, and in large scale feedback mechanisms. However, they are theorized to be extremely weak, in…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-23 Ariel Amaral , Tessa Vernstrom , Bryan M. Gaensler

We present a map of the spiral structure of the Galaxy, as traced by molecular CS emission associated with IRAS sources which are believed to be compact HII regions. The CS line velocities are used to determine the kinematic distances of…

Astrophysics of Galaxies · Physics 2015-05-20 J. R. D. Lepine , A. Roman-Lopes , Zulema Abraham , T. C. Junqueira , Yu. N. Mishurov

In a large range of physics and space experiments, the direction of the magnetic field needs to be determined with an accuracy on the level of one milli radian or better. We have proposed a new type of magnetic compass - a rotation-based…

Nuclear Experiment · Physics 2024-06-18 B. Wojtsekhowski

Magnetic fields are fundamental to the dynamics of the interstellar medium (ISM) in spiral galaxies and are often separated into large-scale, regular ($\boldsymbol{B}$) and small-scale, random ($\boldsymbol{b}$) components. The thermal…

Astrophysics of Galaxies · Physics 2025-11-26 Saakshi Dhakal , Amit Seta

We use cosmological magneto-hydrodynamic simulations to study the evolution of magnetic fields in galaxy clusters in two different cosmological models, a standard-CDM and a $\Lambda$-CDM model. We show that the magnetic field strength…

Astrophysics · Physics 2008-11-26 Klaus Dolag , Matthias Bartelmann , Harald Lesch

We seek the conditions for a {\it steady} mean field galactic dynamo. The parameter set is reduced to those appearing in the $\alpha^2$ and $\alpha/\omega$ dynamo, namely velocity amplitudes, and the ratio of sub-scale helicity to…

Astrophysics of Galaxies · Physics 2017-06-28 R. N. Henriksen

Stationary force-free magnetosphere of an axisymmetric pulsar is shown to have a separatrix inclination angle of 77.3$^\circ$. The electromagnetic field has an $R^{-1/2}$ singularity inside the separatrix near the light cylinder. A…

Astrophysics · Physics 2009-11-10 Andrei Gruzinov

We report measurements of parallaxes and proper motions of ten high-mass star-forming regions in the Sagittarius spiral arm of the Milky Way as part of the BeSSeL Survey with the VLBA. Combining these results with eight others from the…

Astrophysics of Galaxies · Physics 2014-06-04 Y. W. Wu , M. Sato , M. J. Reid , L. Moscadelli , B. Zhang , Y. Xu , A. Brunthaler , K. M. Menten , T. M. Dame , X. W. Zheng
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