Warm HCN in the planet formation zone of GV Tau N

Abstract

The Plateau de Bure Interferometer has been used to map the continuum emission at 3.4 mm and 1.1 mm together with the J=1->0 and J=3->2 lines of HCN and HCO+ towards the binary star GV Tau. The 3.4 mm observations did not resolve the binary components and the HCN J=1->0 and HCO+ J=1->0 line emissions trace the circumbinary disk and the flattened envelope. However, the 1.1 mm observations resolved the individual disks of GV Tau N and GV Tau S and allowed us to study their chemistry. We detected the HCN 3->2 line only towards the individual disk of GV Tau N, and the emission of the HCO+ 3->2 line towards GV Tau S. Simple calculations indicate that the 3->2 line of HCN is formed in the inner R<12 AU of the disk around GV Tau N where the HCN/HCO+ abundance ratio is >300. On the contrary, this ratio is <1.6 in the disk around GV Tau S. The high HCN abundance measured in GV Tau N is well explained by photo-chemical processes in the warm (>400K) and dense disk surface.

5 pages, 4 figures, accepted for publication in Astrophysical Journal Letters

References in corpus (6)

• Monte Carlo radiative transfer in protoplanetary disks
• Formation of simple organic molecules in inner T Tauri disks
• Warm HCN, C2H2, and CO in the disk of GV Tau
• Stellar and Circumstellar Properties of the Pre-Main Sequence Binary GV Tau from Infrared Spectroscopy
• Multi-wavelength observations of the young binary system Haro 6-10: The case of misaligned discs
• A Proper Motion Study of the Haro 6-10 Outflow: Evidence for a Subarcsecond Binary

Cited by in corpus (7)

• Further ALMA observations and detailed modeling of the Red Rectangle
• The chemistry of disks around T Tauri and Herbig Ae/Be stars
• Exploring organic chemistry in planet-forming zones
• Constraining the Disk Masses of the Class I Binary Protostar GV Tau
• H${}_2$S observations in young stellar disks in Taurus
• Probing the kinematics and chemistry of the hot core Mon R 2 IRS 3 using ALMA observations
• Gas kinematics of key prebiotic molecules in GV Tau N revealed with an ALMA, PdBI, and Herschel synergy