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

  • log_n_c_n_o_bsgs_ann_groups7
    Research news
    The origin of the brightest stars in any Galaxy lies in stellar mergers
    Massive stars, those over ten times heavier than our Sun, are the conduits of most elements of the periodic table and drive the morphological and chemical makeup of their host galaxies. Yet the origin of the most luminous and hottest stars among them, called 'blue supergiants', has been debated for many decades. Blue supergiants are strange stars. First, they are observed in large numbers, despite conventional stellar physics expecting them to live only briefly. Second, they are typically found alone, despite most massive stars being born with companions. Third, the majority of them harbour
    Advertised on
  • Black Hole Swift J1727.8-162
    Research news
    Evidence for inflows and outflows in the nearby black hole transient Swift J1727.8-162
    The transient Swift J1727.8-162 is the latest member of the X-ray binary black hole family to be discovered. They are formed by a black hole and a low-mass star whose gas is stripped off and accreted to the black hole via an accretion disc. The high temperature of the accretion disc makes it shine in all energy bands up to X-rays, and is particularly bright during epochs known as outbursts. In this novel study, published just a few months after the discovery of the system, we present 20 epochs of optical spectroscopy obtained with the GTC-10.4m telescope. The spectra cover the main accretion
    Advertised on
  • light bridges
    Research news
    Dissecting light bridges: the stratification of their physical properties in geometric height
    Light bridges are elongated and bright structures protruding into the umbra of sunspots. The presence of light bridges has a significant role in the evolution of sunspots and the heating of their overlying atmosphere. Therefore, investigating these structures is crucial to understanding fundamental aspects of sunspots. By applying a novel code based on deep-learning algorithms called SICON to spectropolarimetric observations acquired with the Hinode satellite, we computed atmospheric parameters that allowed us to infer the variation of the physical properties of light bridges on a geometric
    Advertised on