Magnetic fields and the outer rotation curve of M31

Abstract

Recent observations of the rotation curve of M31 show a rise of the outer part that can not be understood in terms of standard dark matter models or perturbations of the galactic disc by M31's satellites. Here, we propose an explanation of this dynamical feature based on the influence of the magnetic field within the thin disc. We have considered standard mass models for the luminous mass distribution, a NFW model to describe the dark halo, and we have added up the contribution to the rotation curve of a magnetic field in the disc, which is described by an axisymmetric pattern. Our conclusion is that a significant improvement of the fit in the outer part is obtained when magnetic effects are considered. The best-fit solution requires an amplitude of ~4 microG with a weak radial dependence between 10 and 38 kpc.

Accepted for publication in ApJL

References in corpus (23)

• A Universal Density Profile from Hierarchical Clustering
• The Structure of Cold Dark Matter Halos
• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• A giant stream of metal-rich stars in the halo of the galaxy M31
• Magnetic Field in Clusters of Galaxies
• Galactic and extragalactic magnetic fields
• Magnetism in the spiral galaxy NGC 6946: magnetic arms, depolarization rings, dynamo modes and helical fields
• HI kinematics and dynamics of Messier 31
• GHASP : an H alpha kinematic survey of spiral and irregular galaxies. V. Dark matter distribution in 36 nearby spiral galaxies
• A wide-field HI mosaic of Messier 31. II.The disk warp, rotation and the dark matter halo
• The mass distribution in early-type disk galaxies: declining rotation curves and correlations with optical properties
• A Wide-field High Resolution HI Mosaic of Messier 31: I. Opaque Atomic Gas and Star Formation Rate Density
• Investigating the Andromeda Stream: I. Simple Analytic Bulge-Disk-Halo Model for M31
• The magnetic field of M31 from multi-wavelength radio polarization observations
• Investigating the Andromeda Stream: II. Orbital Fits and Properties of the Progenitor
• Dark and Baryonic Matter in Bright Spiral Galaxies: II. Radial Distributions for 34 Galaxies
• Dust Penetrated Arm Classes: Insights from rising and falling rotation curves
• Magnetic field structures of galaxies derived from analysis of Faraday rotation measures, and perspectives for the SKA
• Magnetic fields in the Milky Way and other spiral galaxies
• The Role of Magnetic Fields in Spiral Galaxies
• Darwin Tames an Andromeda Dwarf: Unraveling the Orbit of NGC 205 Using a Genetic Algorithm
• Are rotation curves in NGC 6946 and the Milky Way magnetically supported?
• The Magnetic Field in Galaxies, Galaxy Clusters, and the InterGalactic Space

Cited by in corpus (16)

• Magnetic fields in the nearby spiral galaxy IC 342: A multi-frequency radio polarization study
• How primordial magnetic fields shrink galaxies
• Extragalactic Magnetism with SOFIA (Legacy Program) -- I: The magnetic field in the multi-phase interstellar medium of M51
• Ruling out $\sim 100-300$ GeV thermal relic annihilating dark matter by radio observation of the Andromeda galaxy
• Extragalactic magnetism with SOFIA (SALSA Legacy Program) -- V: First results on the magnetic field orientation of galaxies
• Do magnetic fields influence gas rotation in galaxies?
• Revisiting the constraints on annihilating dark matter by radio observational data of M31
• Updated constraints on WIMP dark matter annihilation by radio observations of M31
• Magnetic fields: Impact on the rotation curve of the Galaxy
• An excess of excesses examined via dark matter radio emissions from galaxies
• Exact semianalytical calculation of rotation curves with Bekenstein-Milgrom nonrelativistic MOND
• Indirect detection prospects for d${}^{\ast }$(2380) dark matter
• Influence of Magnetic Fields on the Gas Rotation in the Galaxy $NGC6946$
• Axion-like particle searches with MeerKAT and SKA
• The effect of magnetic field on the inner Galactic rotation curve
• Magnetic flux density from the relative circular motion of stars and partially ionized gas in the Galaxy mid-plane vicinity