Dark Matter, Magnetic Fields, and the Rotation Curve of the Milky Way.

Out best-fit model for the rotation curve of the Milky Way. Asterisks represent the natural weighted radial bins derived from observational data by Sofue et al. (2009) with their associated error bars. The different lines represent the contribution of the
Out best-fit model for the rotation curve of the Milky Way. Asterisks represent the natural weighted radial bins derived from observational data by Sofue et al. (2009) with their associated error bars. The different lines represent the contribution of the
Advertised on
References
(2012), The Astrophysical Journal Letters, Volume 755, Issue 2, article id. L23

The study of the disk rotation curve of our Galaxy at large distances provides an interesting scenario for us to test whether magnetic fields should be considered as a non-negligible dynamical ingredient. By assuming a bulge, an exponential disk for the stellar and gaseous distributions, and a dark halo and disk magnetic fields, we fit the rotation velocity of the Milky Way. In general, when the magnetic contribution is added to the dynamics, a better description of the rotation curve is obtained. Our main conclusion is that magnetic fields should be taken into account for the Milky Way dynamics. Azimuthal magnetic field strengths of B phi ~ 2 μG at distances of ~2 R0(i.e. 16 kpc) are able to explain the rise-up for the rotation curve in the outer disk.

News type
Research news

It may interest you

  • CLASP2 observation from the sounding rocket.
    Research news
    Mapping the Magnetic Field in the Chromosphere of Solar Active Regions
    The magnetic field in the solar chromosphere plays a key role in the heating of the outer solar atmosphere and in the build-up and sudden release of energy in solar flares. However, uncovering the magnetic field vector in the solar chromosphere is a difficult task because the magnetic field leaves its fingerprints in the very faint polarization of the light, which is far from easy to measure and interpret. We analyse the spectropolarimetric observations obtained with the Chromospheric Layer Spectropolarimeter on board a sounding rocket. This suborbital space experiment observed the near
    Advertised on
  • Planetary Nebula M57
    Research news
    Hydrogenated amorphous carbon grains as a carrier of unidentified IR bands in planetary nebulae
    It is well known that fullerenes – big, complex, and highly resistant carbon molecules with potential applications in nanotechnology – are mostly seen in planetary nebulae (PNe); old dying stars with progenitor masses similar to our Sun. Fullerenes, like C60 and C70, have been detected in PNe whose infrared (IR) spectra are dominated by broad unidentified IR (UIR) plateau emissions. The identification of the chemical species (structure and composition) responsible for such UIR emission widely present in the Universe is a mystery in astrochemistry; although they are believed to be carbon-rich
    Advertised on
  • RSOph_MWL_TransientsUniverse
    Research news
    A Very-High-Energy Gamma-Ray View of the Transient Sky
    The development of the latest generation of Imaging Atmospheric Cherenkov Telescopes (IACTs) over recent decades has led to the discovery of new extreme astrophysical phenomena in the very-high-energy (VHE, E > 100 GeV) gamma-ray regime. Time-domain and multi-messenger astronomy are inevitably connected to the physics of transient VHE emitters, which show unexpected (and mostly unpredictable) flaring or exploding episodes at different timescales. These transients often share the physical processes responsible for the production of the gamma-ray emission, through cosmic-ray acceleration
    Advertised on