Photoevaporation of protoplanetary disks

Zoltan Balog, George H. Rieke, James Muzerolle, John Bally, Kate Y.L. Su, Karl Misselt, András Gáspár

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


We present HST NICMOS Paschen α (Paα) images and low- and high-resolution IRS spectra of photoevaporating disk-tail systems originally detected at 24 μm near O stars. We find no Paα emission in any of the systems. The resulting upper limits correspond to about (2-3) × 10 -6 M of mass in hydrogen in the tails, suggesting that the gas is severely depleted. The IRAC data and the low-resolution 5-12 μm IRS spectra provide evidence for an inner disk, while high-resolution long-wavelength (14-30 μm) IRS spectra confirm the presence of a gas-free tail that consists of ∼0.01 to ∼ 1 μm dust grains originating in the outer parts of the circumstellar disks. Overall, our observations support theoretical predictions in which photoevaporation removes the gas relatively quickly (≤ 105 yr) from the outer region of a protoplanetary disk, but leaves an inner, more robust, and possibly gas-rich disk component of radius 5-10 AU. With the gas gone, larger solid bodies in the outer disk can experience a high rate of collisions and produce elevated amounts of dust. This dust is being stripped from the system by the photon pressure of the O star to form a gas-free dusty tail.

Original languageEnglish (US)
Pages (from-to)408-417
Number of pages10
JournalAstrophysical Journal
Issue number1
StatePublished - Nov 20 2008


  • Circumstellar matter
  • Planetary systems: protoplanetary disks
  • Stars: formation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Photoevaporation of protoplanetary disks'. Together they form a unique fingerprint.

Cite this