Next Article in Journal
Modeling Polarized Emission from Black Hole Jets: Application to M87 Core Jet
Next Article in Special Issue
Constraints on the Formation of M31’s Stellar Halo from the SPLASH Survey
Previous Article in Journal / Special Issue
Dust Deficiency in the Interacting Galaxy NGC 3077
Article Menu
Issue 3 (September) cover image

Export Article

Open AccessArticle

Upper Limits to Magnetic Fields in the Outskirts of Galaxies

Observatorio Astronómico de Quito, Escuela Politécnica Nacional, Av. Gran Colombia S/N, Quito 170403, Ecuador
*
Author to whom correspondence should be addressed.
Academic Editor: Tomotsugu Goto
Galaxies 2017, 5(3), 55; https://doi.org/10.3390/galaxies5030055
Received: 31 July 2017 / Revised: 12 September 2017 / Accepted: 18 September 2017 / Published: 19 September 2017
(This article belongs to the Special Issue On the Origin (and Evolution) of Baryonic Galaxy Halos)
  |  
PDF [328 KB, uploaded 21 September 2017]
  |  

Abstract

Based on CO(2-1) public data, we study the monoxide oxygen gas excitation conditions and the magnetic field strength of four spiral galaxies. For the galaxy outskirts, we found kinetic temperatures in the range of ≲35–38 K, CO column densities ≲ 10 15 10 16 cm - 2 , and H 2 masses ≲ 4 × 10 6 6 × 10 8 M . An H 2 density ≲ 10 3 cm - 3 is suitable to explain the 2 σ upper limits of the CO(2-1) line intensity. We constrain the magnetic field strength for our sample of spiral galaxies and their outskirts by using their masses and H 2 densities to evaluate a simplified magneto-hydrodynamic equation. Our estimations provide values for the magnetic field strength on the order of ≲6–31 μ G. View Full-Text
Keywords: nearby galaxies; magnetic fields; molecules nearby galaxies; magnetic fields; molecules
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed
Printed Edition Available!
A printed edition of this Special Issue is available here.

Share & Cite This Article

MDPI and ACS Style

López, E.; Armijos-Abendaño, J.; Llerena, M.; Aldás, F. Upper Limits to Magnetic Fields in the Outskirts of Galaxies. Galaxies 2017, 5, 55.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Galaxies EISSN 2075-4434 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top