Leiden University Scholarly Publications

Persistent URL of this record https://hdl.handle.net/1887/60009

In Collections

This item can be found in the following collections:

Najita, J.; Carr, J.; Pontoppidan, K.; Salyk, C.; Dishoeck, E.F. van; Blake, G. (2013)

The HCN-Water Ratio in the Planet Formation Region of Disks

Article / Letter to editor
We find a trend between the mid-infrared HCN/H$_{2}$O flux ratio and submillimeter disk mass among T Tauri stars in Taurus. While it may seem puzzling that the molecular emission properties of the inner disk ({lt}few AU) are related to the properties of the outer disk (beyond ~{}20 AU) probed by the submillimeter continuum, an interesting possible interpretation is that the trend is a result of planetesimal and protoplanet formation. Because objects this large are decoupled from the accretion flow, when they form, they can lock up water (and oxygen) beyond the snow line, thereby enhancing the C/O ratio in the inner disk and altering the molecular abundances there. We discuss the assumptions that underlie this interpretation, a possible alternative explanation, and related open questions that motivate future work. Whatever its origin, understanding the meaning of the relation between the HCN/H$_{2}$O ratio and disk mass is of interest as trends like this among T Tauri disk...Show more We find a trend between the mid-infrared HCN/H$_{2}$O flux ratio and submillimeter disk mass among T Tauri stars in Taurus. While it may seem puzzling that the molecular emission properties of the inner disk ({lt}few AU) are related to the properties of the outer disk (beyond ~{}20 AU) probed by the submillimeter continuum, an interesting possible interpretation is that the trend is a result of planetesimal and protoplanet formation. Because objects this large are decoupled from the accretion flow, when they form, they can lock up water (and oxygen) beyond the snow line, thereby enhancing the C/O ratio in the inner disk and altering the molecular abundances there. We discuss the assumptions that underlie this interpretation, a possible alternative explanation, and related open questions that motivate future work. Whatever its origin, understanding the meaning of the relation between the HCN/H$_{2}$O ratio and disk mass is of interest as trends like this among T Tauri disk properties are relatively rare.Show less
All authors
Najita, J.; Carr, J.; Pontoppidan, K.; Salyk, C.; Dishoeck, E.F. van; Blake, G.
Date
2013
Journal
The Astrophysical Journal
Volume
766
Pages
134
DOI
doi:10.1088/0004-637X/766/2/134
Link
http://iopscience.iop.org/article/10.1088/0004-637X/766/2/134/meta