English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Spectral modeling of the large infrared excess in the Spitzer IRS spectra ofHD 172555 suggests that there is more than 10^19 kg of sub-micron dust in thesystem. Using physical arguments and constraints from observations, we rule outthe possibility of the infrared excess being created by a magma ocean planet ora circumplanetary disk or torus. We show that the infrared excess is consistentwith a circumstellar debris disk or torus, located at approximately 6 AU, thatwas created by a planetary scale hypervelocity impact. We find that radiationpressure should remove submicron dust from the debris disk in less than oneyear. However, the system's mid-infrared photometric flux, dominated bysubmicron grains, has been stable within 4 percent over the last 27 years, fromIRAS (1983) to WISE (2010). Our new spectral modeling work and calculations ofthe radiation pressure on fine dust in HD 172555 provide a self-consistentexplanation for this apparent contradiction. We also explore the unconfirmedclaim that 10^47 molecules of SiO vapor are needed to explain an emissionfeature at 8 um in the Spitzer IRS spectrum of HD 172555. We find that unlessthere are 10^48 atoms or 0.05 Earth masses of atomic Si and O vapor in thesystem, SiO vapor should be destroyed by photo-dissociation in less than 0.2years. We argue that a second plausible explanation for the 8 um feature can beemission from solid SiO, which naturally occurs in submicron silicate "smokes"created by quickly condensing vaporized silicate.

A Self-Consistent Model of the Circumstellar Debris Created by a Giant Hypervelocity Impact in the HD172555 System