X-Ray Irradiation of the LkCa 15 Protoplanetary Disk

Author(s)

Stephen L. Skinner, Manuel Güdel

Abstract

LkCa 15 in the Taurus star-forming region has recently gained attention

as the first accreting T Tauri star likely to host a young protoplanet.

High spatial resolution infrared observations have detected the

suspected protoplanet within a dust-depleted inner gap of the LkCa 15

transition disk at a distance of ~15 AU from the star. If this object's

status as a protoplanet is confirmed, then LkCa 15 will serve as a

unique laboratory for constraining physical conditions within a

planet-forming disk. Previous models of the LkCa 15 disk have accounted

for disk heating by the stellar photosphere but have ignored the

potential importance of X-ray ionization and heating. We report here the

detection of LkCa 15 as a bright X-ray source with Chandra. The X-ray

emission is characterized by a cool, heavily absorbed plasma component

at kT cool ≈ 0.3 keV and a harder component at kT

hot ≈ 5 keV. We use the observed X-ray properties to

provide initial estimates of the X-ray ionization and heating rates

within the tenuous inner disk. These estimates and the observed X-ray

properties of LkCa 15 can be used as a starting point for developing

more realistic disk models of this benchmark system.

Organisation(s)

Department of Astrophysics

External organisation(s)

University of Colorado, Boulder

Journal

The Astrophysical Journal: an international review of astronomy and astronomical physics

Volume

765

No. of pages

7

ISSN

0004-637X

DOI

https://doi.org/10.1088/0004-637X/765/1/3

Publication date

03-2013

Peer reviewed

Yes

Austrian Fields of Science 2012

103004 Astrophysics

Keywords

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