Low extreme-ultraviolet luminosities impinging on protoplanetary disks

Ilaria Pascucci, L. Ricci, U. Gorti, D. Hollenbach, N. P. Hendler, K. J. Brooks, Y. Contreras

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The amount of high-energy stellar radiation reaching the surface of protoplanetary disks is essential to determine their chemistry and physical evolution. Here, we use millimetric and centimetric radio data to constrain the extreme-ultraviolet (EUV) luminosity impinging on 14 disks around young (∼2-10 Myr) sun-like stars. For each object we identify the long-wavelength emission in excess to the dust thermal emission, attribute that to free-free disk emission, and thereby compute an upper limit to the EUV reaching the disk. We find upper limits lower than 1042 photons s-1 for all sources without jets and lower than 5 × 1040 photons s-1 for the three older sources in our sample. These latter values are low for EUV-driven photoevaporation alone to clear out protoplanetary material in the timescale inferred by observations. In addition, our EUV upper limits are too low to reproduce the [Ne II] 12.81 μm luminosities from three disks with slow [Ne II]-detected winds. This indicates that the [Ne II] line in these sources primarily traces a mostly neutral wind where Ne is ionized by 1 keV X-ray photons, implying higher photoevaporative mass loss rates than those predicted by EUV-driven models alone. In summary, our results suggest that high-energy stellar photons other than EUV may dominate the dispersal of protoplanetary disks around sun-like stars.

Original languageEnglish (US)
Article number1
JournalAstrophysical Journal
Volume795
Issue number1
DOIs
StatePublished - Nov 1 2014

Fingerprint

protoplanetary disks
luminosity
photons
sun
stellar radiation
stars
energy
thermal emission
radio
dust
wavelength
timescale
chemistry
wavelengths
x rays

Keywords

  • Protoplanetary disks
  • Radio continuum: stars
  • Stars: pre-main sequence

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Pascucci, I., Ricci, L., Gorti, U., Hollenbach, D., Hendler, N. P., Brooks, K. J., & Contreras, Y. (2014). Low extreme-ultraviolet luminosities impinging on protoplanetary disks. Astrophysical Journal, 795(1), [1]. https://doi.org/10.1088/0004-637X/795/1/1

Low extreme-ultraviolet luminosities impinging on protoplanetary disks. / Pascucci, Ilaria; Ricci, L.; Gorti, U.; Hollenbach, D.; Hendler, N. P.; Brooks, K. J.; Contreras, Y.

In: Astrophysical Journal, Vol. 795, No. 1, 1, 01.11.2014.

Research output: Contribution to journalArticle

Pascucci, I, Ricci, L, Gorti, U, Hollenbach, D, Hendler, NP, Brooks, KJ & Contreras, Y 2014, 'Low extreme-ultraviolet luminosities impinging on protoplanetary disks', Astrophysical Journal, vol. 795, no. 1, 1. https://doi.org/10.1088/0004-637X/795/1/1
Pascucci, Ilaria ; Ricci, L. ; Gorti, U. ; Hollenbach, D. ; Hendler, N. P. ; Brooks, K. J. ; Contreras, Y. / Low extreme-ultraviolet luminosities impinging on protoplanetary disks. In: Astrophysical Journal. 2014 ; Vol. 795, No. 1.
@article{a93aec4fa38f45478da2cd0293ed0274,
title = "Low extreme-ultraviolet luminosities impinging on protoplanetary disks",
abstract = "The amount of high-energy stellar radiation reaching the surface of protoplanetary disks is essential to determine their chemistry and physical evolution. Here, we use millimetric and centimetric radio data to constrain the extreme-ultraviolet (EUV) luminosity impinging on 14 disks around young (∼2-10 Myr) sun-like stars. For each object we identify the long-wavelength emission in excess to the dust thermal emission, attribute that to free-free disk emission, and thereby compute an upper limit to the EUV reaching the disk. We find upper limits lower than 1042 photons s-1 for all sources without jets and lower than 5 × 1040 photons s-1 for the three older sources in our sample. These latter values are low for EUV-driven photoevaporation alone to clear out protoplanetary material in the timescale inferred by observations. In addition, our EUV upper limits are too low to reproduce the [Ne II] 12.81 μm luminosities from three disks with slow [Ne II]-detected winds. This indicates that the [Ne II] line in these sources primarily traces a mostly neutral wind where Ne is ionized by 1 keV X-ray photons, implying higher photoevaporative mass loss rates than those predicted by EUV-driven models alone. In summary, our results suggest that high-energy stellar photons other than EUV may dominate the dispersal of protoplanetary disks around sun-like stars.",
keywords = "Protoplanetary disks, Radio continuum: stars, Stars: pre-main sequence",
author = "Ilaria Pascucci and L. Ricci and U. Gorti and D. Hollenbach and Hendler, {N. P.} and Brooks, {K. J.} and Y. Contreras",
year = "2014",
month = "11",
day = "1",
doi = "10.1088/0004-637X/795/1/1",
language = "English (US)",
volume = "795",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Low extreme-ultraviolet luminosities impinging on protoplanetary disks

AU - Pascucci, Ilaria

AU - Ricci, L.

AU - Gorti, U.

AU - Hollenbach, D.

AU - Hendler, N. P.

AU - Brooks, K. J.

AU - Contreras, Y.

PY - 2014/11/1

Y1 - 2014/11/1

N2 - The amount of high-energy stellar radiation reaching the surface of protoplanetary disks is essential to determine their chemistry and physical evolution. Here, we use millimetric and centimetric radio data to constrain the extreme-ultraviolet (EUV) luminosity impinging on 14 disks around young (∼2-10 Myr) sun-like stars. For each object we identify the long-wavelength emission in excess to the dust thermal emission, attribute that to free-free disk emission, and thereby compute an upper limit to the EUV reaching the disk. We find upper limits lower than 1042 photons s-1 for all sources without jets and lower than 5 × 1040 photons s-1 for the three older sources in our sample. These latter values are low for EUV-driven photoevaporation alone to clear out protoplanetary material in the timescale inferred by observations. In addition, our EUV upper limits are too low to reproduce the [Ne II] 12.81 μm luminosities from three disks with slow [Ne II]-detected winds. This indicates that the [Ne II] line in these sources primarily traces a mostly neutral wind where Ne is ionized by 1 keV X-ray photons, implying higher photoevaporative mass loss rates than those predicted by EUV-driven models alone. In summary, our results suggest that high-energy stellar photons other than EUV may dominate the dispersal of protoplanetary disks around sun-like stars.

AB - The amount of high-energy stellar radiation reaching the surface of protoplanetary disks is essential to determine their chemistry and physical evolution. Here, we use millimetric and centimetric radio data to constrain the extreme-ultraviolet (EUV) luminosity impinging on 14 disks around young (∼2-10 Myr) sun-like stars. For each object we identify the long-wavelength emission in excess to the dust thermal emission, attribute that to free-free disk emission, and thereby compute an upper limit to the EUV reaching the disk. We find upper limits lower than 1042 photons s-1 for all sources without jets and lower than 5 × 1040 photons s-1 for the three older sources in our sample. These latter values are low for EUV-driven photoevaporation alone to clear out protoplanetary material in the timescale inferred by observations. In addition, our EUV upper limits are too low to reproduce the [Ne II] 12.81 μm luminosities from three disks with slow [Ne II]-detected winds. This indicates that the [Ne II] line in these sources primarily traces a mostly neutral wind where Ne is ionized by 1 keV X-ray photons, implying higher photoevaporative mass loss rates than those predicted by EUV-driven models alone. In summary, our results suggest that high-energy stellar photons other than EUV may dominate the dispersal of protoplanetary disks around sun-like stars.

KW - Protoplanetary disks

KW - Radio continuum: stars

KW - Stars: pre-main sequence

UR - http://www.scopus.com/inward/record.url?scp=84908025708&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84908025708&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/795/1/1

DO - 10.1088/0004-637X/795/1/1

M3 - Article

AN - SCOPUS:84908025708

VL - 795

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 1

ER -