Imaging the photoevaporating disk and radio jet of GM Aur

Abstract

Photoevaporation is probably the main agent for gas dispersal during the last stages of protoplanetary disk evolution. However, the overall mass loss rate in the photoevaporative wind and its driving mechanism are still not well understood. Here we report multi-configuration Very Large Array observations at 0.7, 3, and 5 cm towards the transitional disk of GM Aur. Our radio continuum observations allow us to image and spatially resolve, for the first time, the three main components at work in this stage of the disk evolution: the disk of dust, the ionized radio jet perpendicular to it, and the photoevaporative wind arising from the disk. The mass loss rate inferred from the flux density of the radio jet is consistent with the ratio between ejection and accretion rates found in younger objects, suggesting that transitional disks can power collimated ejections of material apparently following the same physical mechanisms as much younger protostars. Our results indicate that extreme-UV (EUV) radiation is the main ionizing mechanism of the photoevaporative wind traced by the free-free emission. The required low EUV photon luminosity of $\sim 6\times 10^{40}$ s${}^{-1}$ would produce a photoevaporation rate of only ${\dot{M}}_{\mathrm{w},\mathrm{EUV}}\simeq 1.3\times 10^{-10}{M}_{\odot }$ yr${}^{-1}$. Therefore, other mechanisms are required to disperse the disk in the timescale imposed by observations.

20 pages, 3 figures, accepted for publication in ApJ

References in corpus (6)

• [NeII] emission line profiles from photoevaporative disc winds
• Low EUV Luminosities Impinging on Protoplanetary Disks
• An Ionized Outflow from AB Aur, a Herbig Ae Star with a Transitional Disk
• Using FUV to IR Variability to Probe the Star-Disk Connection in the Transitional Disk of GM Aur
• Constraints on photoevaporation models from (lack of) radio emission in the Corona Australis protoplanetary disks
• High Angular Resolution Observations at 7-mm of the Core of the Quadrupolar HH 111/121 Outflow

Cited by in corpus (5)

• An Inner Disk in the Large Gap of the Transition Disk SR 24S
• Dust concentration and emission in protoplanetary disks vortices
• Revealing the Star-Disk-Jet Connection in GM Aur using Multiwavelength Variability
• 3.3 cm JVLA observations of transitional disks: searching for centimeter pebbles
• Full inversion of solar relativistic electron events measured by the Helios spacecraft