The exceptionally large debris disk around γ ophiuchi

Spitzer images resolve the debris disk around γ Ophiuchi at both 24 and 70 μm. The resolved images suggest a disk radius of ∼520 AU at 70 μm and ≥S260 AU at 24 μm. The images, along with a consistent fit to the spectral energy distribution of the disk from 20 to 350 μm, show that the primary disk structure is inclined by ∼50° from the plane of the sky at a position angle of 55° ± 2°. Among a group of 12 debris disks that have similar host star spectral types, ages, and infrared fractional luminosities, the observed sizes in the infrared and color temperatures indicate that evolution of the debris disks is influenced by multiple parameters in addition to the protoplanetary disk initial mass