DUST AND POLYCYCLIC AROMATIC HYDROCARBON IN THE HD 34700 DEBRIS DISK

• Published in: The Astrophysical journal Vol. 809; no. 1; pp. 1 - 10
• Main Authors: Seok, Ji Yeon, Li, Aigen
• Format: Journal Article
• Language: English
• Published: United Kingdom The American Astronomical Society 10-08-2015
• Subjects: Accretion disks; ASTEROIDS; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; circumstellar matter; COSMIC DUST; Debris; Disks; DISSOCIATION; Drag; Dust; ELEMENT ABUNDANCE; EMISSION; ENERGY SPECTRA; INFRARED RADIATION; infrared: stars; MOLECULES; PHOTOLYSIS; Polyallylamine hydrochloride; POLYCYCLIC AROMATIC HYDROCARBONS; POROUS MATERIALS; STARS; stars: individual (HD 34700); STELLAR RADIATION
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.1088/0004-637X/809/1/22

ABSTRACT The debris disk around the Vega-type star HD 34700 is detected in dust thermal emission from the near-infrared (IR) to millimeter (mm) and submm wavelength range. Also detected is a distinct set of emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and , which are commonly attributed to polycyclic aromatic hydrocarbon (PAH) molecules. We model the observed dust IR spectral energy distribution (SED) and PAH emission features of the HD 34700 disk in terms of porous dust and astronomical-PAHs. Porous dust together with a mixture of neutral and ionized PAHs closely explains the dust IR SED and PAH emission features observed in the HD 34700 disk. Due to the stellar radiation pressure and Poynting-Robertson drag together with the photodissociation of PAHs, substantial removal of dust and PAHs has occurred in the disk, and continuous replenishment of these materials is required to maintain their current abundances. This implies that these materials are not primitive but secondary products probably originating from mutual collisions among planetesimals, asteroids, and comets.