Extreme resonance line profile variations in the ultraviolet spectra of NGC 1624-2: Probing the giant magnetosphere of the most strongly magnetized known O-type star
In this paper, we present high-resolution HST/COS observations of the extreme magnetic O star NGC 1624-2. These represent the first ultraviolet spectra of this archetypal object. We examine the variability of its wind-sensitive resonance lines, comparing it to that of other known magnetic O stars. In particular, the observed variations in the profiles of the C IV and Si IV doublets between low state and high state are the largest observed in any magnetic O-type star, consistent with the expected properties of NGC 1624-2's magnetosphere. We also observe a redshifted absorption component in the low state, a feature not seen in most stars. We present preliminary modelling efforts based on the Analytic Dynamical Magnetosphere (ADM) formalism, demonstrating the necessity of using non-spherically symmetric models to determine wind/magnetospheric properties of magnetic O stars.
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society: © 2018 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Files
Metadata
Work Title | Extreme resonance line profile variations in the ultraviolet spectra of NGC 1624-2: Probing the giant magnetosphere of the most strongly magnetized known O-type star |
---|---|
Access | |
Creators |
|
Keyword |
|
License | In Copyright (Rights Reserved) |
Work Type | Article |
Publisher |
|
Publication Date | November 28, 2018 |
Publisher Identifier (DOI) |
|
Deposited | January 25, 2024 |
Versions
Analytics
Collections
This resource is currently not in any collection.