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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

With the legacy of Spitzer and current advances in (sub)mm astronomy, a largenumber of 'transitional' disks has been identified which are believed tocontain gaps or have developped large inner holes, some filled with dust. Thismay indicate that complex geometries may be a key feature in disk evolutionthat has to be understood and modeled correctly. The disk around LkCa 15 issuch a disk, with a gap ranging from ~5 - 50 AU, as identified by Espaillat etal. (2007) using 1+1D radiative transfer modelling. To fit the SED, theypropose 2 possible scenarios for the inner (<5 AU) disk - optically thick oroptically thin - and one scenario for the outer disk. We use the gapped disk ofLkCa 15 as a showcase to illustrate the importance of 2D radiative transfer intransitional disks, by showing how the vertical dust distribution indust-filled inner holes determines not only the radial optical depth but alsothe outer disk geometry. We use MCMax, a 2D radiative transfer code with aself-consistent vertical structure, to model the SED. We identify two possiblegeometries for the inner and outer disk, that are both different from those inEspaillat et al. (2007). An inner disk in hydrostatic equilibrium reprocessesenough starlight to fit the near infrared flux, but also casts a shadow on theinner rim of the outer disk. This requires the outer disk scale height to belarge enough to rise out of the shadow. An optically thin inner disk does notcast such a shadow, and the SED can be fitted with a smaller outer disk scaleheight. For the dust in the inner regions to become optically thin however, thescale height would have to be so much larger than its hydrostatic equilibriumvalue that it effectively becomes a dust shell. It is currently unclear if aphysical mechanism exists which could provide for such a configuration.

Full 2D radiative transfer modelling of transitional disk LkCa 15