WATER DEPLETION IN THE DISK ATMOSPHERE OF HERBIG AeBe STARS

Journal Article · Tue May 10 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/732/2/106· OSTI ID:21576850

Fedele, D; Pascucci, I ^[1]; Brittain, S ^[2]; Kamp, I ^[3]; Woitke, P ^[4]; Williams, J P ^[5]; Dent, W R. F. ^[6]

---

1. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)
2. Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States)
3. Kapteyn Astronomical Institute, Postbus 800, NL-9700 AV Groningen (Netherlands)
4. Department of Astronomy, University of Vienna, Tuerkenschanzstr. 17, A-1180 Vienna (Austria)
5. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
6. ALMA JAO, Santiago (Chile)

We present high-resolution (R {approx} 100,000) L-band spectroscopy of 11 Herbig AeBe stars with circumstellar disks. The observations were obtained with the VLT/CRIRES to detect hot water and hydroxyl radical emission lines previously detected in disks around T Tauri stars. OH emission lines are detected toward four disks. The OH {sup 2}{Pi}{sub 3/2} P4.5 (1+,1-) doublet is spectrally resolved as well as the velocity profile of each component of the doublet. Its characteristic double-peak profile demonstrates that the gas is in Keplerian rotation and points to an emitting region extending out to {approx}15-30 AU. The OH emission correlates with disk geometry as it is mostly detected toward flaring disks. None of the Herbig stars analyzed here show evidence of hot water vapor at a sensitivity similar to that of the OH lines. The non-detection of hot water vapor emission indicates that the atmospheres of disks around Herbig AeBe stars are depleted of water molecules. Assuming LTE and optically thin emission we derive a lower limit to the OH/H{sub 2}O column density ratio >1-25 in contrast to T Tauri disks for which the column density ratio is 0.3-0.4.

• OSTI ID: 21576850
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 732; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BINARY STARS
DENSITY
EMISSION
ERUPTIVE VARIABLE STARS
FLUIDS
GASES
HOT WATER
HYDROGEN COMPOUNDS
HYDROXYL RADICALS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADICALS
STARS
T TAURI STARS
VAPORS
VARIABLE STARS
WATER
WATER VAPOR