Understanding the origin of the [OI] low-velocity component from T Tauri STARS

E. Rigliaco, Ilaria Pascucci, U. Gorti, S. Edwards, D. Hollenbach

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

The formation time, masses, and location of planets are strongly impacted by the physical mechanisms that disperse protoplanetary disks and the timescale over which protoplanetary material is cleared out. Accretion of matter onto the central star, protostellar winds/jets, magnetic disk winds, and photoevaporative winds operate concurrently. Hence, disentangling their relative contribution to disk dispersal requires identifying diagnostics that trace different star-disk environments. Here, we analyze the low-velocity component (LVC) of the oxygen optical forbidden lines, which is found to be blueshifted by a few km s -1 with respect to the stellar velocity. We find that the [O I] LVC profiles are different from those of [Ne II] at 12.81 μm and CO at 4.7 μm lines pointing to different origins for these gas lines. We report a correlation between the luminosity of the [OI] LVC and the accretion luminosity L acc. We do not find any correlation with the X-ray luminosity, while we find that the higher is the stellar far-UV (FUV) luminosity, the higher is the luminosity of the [OI] LVC. In addition, we show that the [OI] λ6300/λ5577 ratio is low (ranging between 1 and 8). These findings favor an origin of the [O I] LVC in a region where OH is photodissociated by stellar FUV photons and argue against thermal emission from an X-ray-heated layer. Detailed modeling of two spectra with the highest S/N and resolution shows that there are two components within the LVC: a broad, centrally peaked component that can be attributed to gas arising in a warm disk surface in Keplerian rotation (with FWHM between ∼40 and ∼60 km s-1), and a narrow component (with FWHM ∼ 10 km s-1 and small blueshifts of ∼2 km s -1) that may arise in a cool (≲1000 K) molecular wind.

Original languageEnglish (US)
Article number60
JournalAstrophysical Journal
Volume772
Issue number1
DOIs
StatePublished - Jul 20 2013

Fingerprint

low speed
luminosity
accretion
magnetic disks
stars
gas
protoplanetary disks
thermal emission
planet
gases
timescale
planets
x rays
oxygen
modeling
photons
profiles

Keywords

  • accretion, accretion disks
  • protoplanetary disks
  • stars: formation
  • stars: pre-main sequence
  • ultraviolet: stars

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Understanding the origin of the [OI] low-velocity component from T Tauri STARS. / Rigliaco, E.; Pascucci, Ilaria; Gorti, U.; Edwards, S.; Hollenbach, D.

In: Astrophysical Journal, Vol. 772, No. 1, 60, 20.07.2013.

Research output: Contribution to journalArticle

Rigliaco, E. ; Pascucci, Ilaria ; Gorti, U. ; Edwards, S. ; Hollenbach, D. / Understanding the origin of the [OI] low-velocity component from T Tauri STARS. In: Astrophysical Journal. 2013 ; Vol. 772, No. 1.
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