Dust and Polycyclic Aromatic Hydrocarbon in the Pre-Transitional Disk around HD 169142

Abstract

The pre-transitional disk around the Herbig Ae star HD 169142 shows a complex structure of possible ongoing planet formation in dust thermal emission from the near infrared (IR) to millimeter wavelength range. Also, a distinct set of broad emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 $\mu$m, commonly attributed to polycyclic aromatic hydrocarbons (PAHs), are detected prominently in the HD 169142 disk. We model the spectral energy distribution (SED) as well as the PAH emission features of the HD 169142 disk simultaneously with porous dust and astronomical-PAHs taking into account the spatially resolved disk structure. Our porous dust model consisting of three distinct components that are primarily concentrated in the inner ring, middle ring, and outer disk, respectively, provides an excellent fit to the entire SED, and the PAH model closely reproduces the observed PAH features. The accretion of ice mantles onto porous dust aggregates occurs between ~16 AU and 60 AU, which overlaps with the spatial extent (~50 AU) of the observed PAH emission features. Finally, we discuss the role of PAHs in the formation of planets possibly taking place in the HD 169142 system.

35 pages, 8 figures, 2 tables, accepted for publication in ApJ

References in corpus (11)

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Cited by in corpus (10)

• The State-of-Play of Anomalous Microwave Emission (AME) Research
• Polarized disk emission from Herbig Ae/Be stars observed using Gemini Planet Imager: HD 144432, HD 150193, HD 163296, and HD 169142
• Polycyclic Aromatic Hydrocarbon in Protoplanetary Disks around Herbig Ae/Be and T Tauri Stars
• Probing midplane CO abundance and gas temperature with DCO${}^{+}$ in the protoplanetary disk around HD 169142
• The shadow knows: using shadows to investigate the structure of the pretransitional disk of HD 100453
• Nano carbon dust emission in proto-planetary disks: the aliphatic-aromatic components
• Quantitative polarimetry of the disk around HD 169142
• Spatially resolving polycyclic aromatic hydrocarbons in Herbig Ae disks with VISIR-NEAR at the VLT
• Tiny Grains Shining Bright in the Gaps of Herbig Ae Transitional Discs
• Radial distribution of the carbonaceous nano-grains in the protoplanetary disk around HD 169142