Steggles, HG, Hoare, MG and Pittard, JM orcid.org/0000-0003-2244-5070 (2017) Hydrodynamical models of cometary H ii regions. Monthly Notices of the Royal Astronomical Society, 466 (4). pp. 4573-4591. ISSN 0035-8711
Abstract
We have modelled the evolution of cometary H ii regions produced by zero-age main-sequence stars of O and B spectral types, which are driving strong winds and are born off-centre from spherically symmetric cores with power-law (α = 2) density slopes. A model parameter grid was produced that spans stellar mass, age and core density. Exploring this parameter space, we investigated limb-brightening, a feature commonly seen in cometary H ii regions. We found that stars with mass M⋆ ≥ 12 M⊙ produce this feature. Our models have a cavity bounded by a contact discontinuity separating hot shocked wind and ionized ambient gas that is similar in size to the surrounding H ii region. Because of early pressure confinement, we did not see shocks outside of the contact discontinuity for stars with M⋆ ≤ 40 M⊙, but the cavities were found to continue to grow. The cavity size in each model plateaus as the H ii region stagnates. The spectral energy distributions of our models are similar to those from identical stars evolving in uniform density fields. The turn-over frequency is slightly lower in our power-law models as a result of a higher proportion of low-density gas covered by the H ii regions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This article has been accepted for publication in the Monthly Notices of the Royal Astronomical Society (c) 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. |
Keywords: | hydrodynamics, radiative transfer, stars: evolution, stars: massive, stars: winds, outflows, H ii regions |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Funding Information: | Funder Grant number Science & Technology Facilities Council (STFC) ST/L000628/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 30 Mar 2017 14:26 |
Last Modified: | 23 Jun 2023 22:26 |
Published Version: | https://doi.org/10.1093/mnras/stw3373 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/mnras/stw3373 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:114262 |