Abstract
We calculate the temperature structures of protoplanetary disks (PPDs) around T Tauri stars heated by both incident starlight and viscous dissipation. We present a new algorithm for calculating the temperatures in disks in hydrostatic and radiative equilibrium, based on Rybicki's method for iteratively calculating the vertical temperature structure within an annulus. At each iteration, the method solves for the temperature at all locations simultaneously, and converges rapidly even at high (≫104) optical depth. The method retains the full frequency dependence of the radiation field. We use this algorithm to study for the first time disks evolving via the magnetorotational instability. Because PPD midplanes are weakly ionized, this instability operates preferentially in their surface layers, and disks will undergo layered accretion. We find that the midplane temperatures T mid are strongly affected by the column density Σa of the active layers, even for fixed mass accretion rate . Models assuming uniform accretion predict midplane temperatures in the terrestrial planet forming region several × 102 K higher than our layered accretion models do. For and the column densities Σa < 10 g cm-2 associated with layered accretion, disk temperatures are indistinguishable from those of a passively heated disk. We find emergent spectra are insensitive to Σa, making it difficult to observationally identify disks undergoing layered versus uniform accretion.
| Original language | English (US) |
|---|---|
| Article number | 118 |
| Journal | Astrophysical Journal |
| Volume | 740 |
| Issue number | 2 |
| DOIs | |
| State | Published - Oct 20 2011 |
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Keywords
- accretion, accretion disks
- protoplanetary disks
- radiative transfer
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
Temperature structure of protoplanetary disks undergoing layered accretion. / Lesniak, M. V.; Desch, Steven.
In: Astrophysical Journal, Vol. 740, No. 2, 118, 20.10.2011.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Temperature structure of protoplanetary disks undergoing layered accretion
AU - Lesniak, M. V.
AU - Desch, Steven
PY - 2011/10/20
Y1 - 2011/10/20
N2 - We calculate the temperature structures of protoplanetary disks (PPDs) around T Tauri stars heated by both incident starlight and viscous dissipation. We present a new algorithm for calculating the temperatures in disks in hydrostatic and radiative equilibrium, based on Rybicki's method for iteratively calculating the vertical temperature structure within an annulus. At each iteration, the method solves for the temperature at all locations simultaneously, and converges rapidly even at high (≫104) optical depth. The method retains the full frequency dependence of the radiation field. We use this algorithm to study for the first time disks evolving via the magnetorotational instability. Because PPD midplanes are weakly ionized, this instability operates preferentially in their surface layers, and disks will undergo layered accretion. We find that the midplane temperatures T mid are strongly affected by the column density Σa of the active layers, even for fixed mass accretion rate . Models assuming uniform accretion predict midplane temperatures in the terrestrial planet forming region several × 102 K higher than our layered accretion models do. For and the column densities Σa < 10 g cm-2 associated with layered accretion, disk temperatures are indistinguishable from those of a passively heated disk. We find emergent spectra are insensitive to Σa, making it difficult to observationally identify disks undergoing layered versus uniform accretion.
AB - We calculate the temperature structures of protoplanetary disks (PPDs) around T Tauri stars heated by both incident starlight and viscous dissipation. We present a new algorithm for calculating the temperatures in disks in hydrostatic and radiative equilibrium, based on Rybicki's method for iteratively calculating the vertical temperature structure within an annulus. At each iteration, the method solves for the temperature at all locations simultaneously, and converges rapidly even at high (≫104) optical depth. The method retains the full frequency dependence of the radiation field. We use this algorithm to study for the first time disks evolving via the magnetorotational instability. Because PPD midplanes are weakly ionized, this instability operates preferentially in their surface layers, and disks will undergo layered accretion. We find that the midplane temperatures T mid are strongly affected by the column density Σa of the active layers, even for fixed mass accretion rate . Models assuming uniform accretion predict midplane temperatures in the terrestrial planet forming region several × 102 K higher than our layered accretion models do. For and the column densities Σa < 10 g cm-2 associated with layered accretion, disk temperatures are indistinguishable from those of a passively heated disk. We find emergent spectra are insensitive to Σa, making it difficult to observationally identify disks undergoing layered versus uniform accretion.
KW - accretion, accretion disks
KW - protoplanetary disks
KW - radiative transfer
UR - http://www.scopus.com/inward/record.url?scp=80053977069&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80053977069&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/740/2/118
DO - 10.1088/0004-637X/740/2/118
M3 - Article
AN - SCOPUS:80053977069
VL - 740
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 118
ER -