Potentially unstable planet forming disks • Planet forming disks • Disk masses and surface densities • The high angular resolution revolution • The demographics revolution • Young disks
Leonardo Testi - INAF-Osservatorio Astrofisico di Arcetri/ESO Tobin et al. 2016 From Cores to Planetary Systems
Core L (Beckwith and Sargent1996) (Beckwithand
Disk
Debris Disk From Cores to Planetary Systems
Core (Hernandez et al. 2007)(Hernandez etal.
Disk
Inner disk clearing: Debris Disk e-folding time t~2-3 Myr (but see Bell et al. 2013 for a possible revision) Planet Formation Processes • Core accretion • Slow, need to overcome growth barriers, terrestrial planets
• Gravitational instabilities • Fast, effective at large radii, giant planets Disk masses Mass distribution
Isella+2009
Andrews et al. 2015 The ALMA Revolution
Kwon+2011
ALMA+2015
Radius (AU) HL Tau - ALMA-VLA
Carrasco-Gonzalez et al. 2016 2015 etal. Dipierro • Optically this dust and “mild” gaps? Are there planets formed(/ing)?
ALMA+2015 LBTI/L’
Testi+2015 • No large planets in the system Elias 2-27
Perez+2016 Elias 2-27 ALMA
Meru+2017 Demographics of grain growth
• ALMA is delivering ~0.2” surveys of disks in the Solar neighbourhood • From studying the odd beasts to understanding populations
Ansdell et al. 2016 Demographics of grain growth
• ALMA is delivering ~0.2” surveys of disks in the Solar neighbourhood • From studying the odd beasts to understanding populations
Ansdell et al. 2016 Miotello et al. 2016 Demographics of grain growth
• ALMA is delivering ~0.2” surveys of disks in the Solar neighbourhood • From studying the odd beasts to understanding populations
Ansdell et al. 2016 Manara et al. 2016 Demographics of grain growth
• ALMA is delivering ~0.2” surveys of disks in the Solar neighbourhood • From studying the odd beasts to understanding populations
Ansdell et al. 2016 Tazzari et al. 2017a Demographics of grain growth
• ALMA is delivering ~0.2” surveys of disks in the Solar neighbourhood • From studying the odd beasts to understanding populations
Ansdell et al. 2016 Ansdell et al. 2017 Demographics of grain growth
• ALMA is delivering ~0.2” surveys of disks in the Solar neighbourhood • From studying the odd beasts to understanding populations
Ansdell et al. 2016 Tazzari et al. 2017b Disks around Brown dwarfs
• Small central object more chance for gravitational unstable disk?
Testi et al. 2016 Disks around Brown dwarfs
• Small central object more chance for gravitational unstable disk?
Testi et al. 2016 All nice, but…
• BDs have massive planetary systems! (assuming TRAPPIST-1 typical) • Where us the mass required to form all these rocky planets?
Testi et al. 2016 • … not in their current disks: => early planet formation in massive disks! From dust to planets (and disk dissipation) ALMA LBT • Early planet formation • Planet cores, GIs? HL Tau (~0.5 Myr) - Planets or Earth-mass cores?
• Disk-planets coevolution?
ALMA
HD163296 (~5 Myr) - sub-Jupiter mass young-planets 2015 etal. Partnership+2015, Testi ALMA LT+2016 Guidi, Isella, Perez+2017,Testi+2017 • Disk dissipation ALMA VLT/SPHERE and emergence of complete
planetary system Transition Disk with formed planets 4 Interferometry Young disks? and Aperture Syntesis
• Young disks may be gravitationally unstable
CHAPTER 6. ANALYSIS CHAPTER 6. ANALYSIS
Figure 4.1: Three of the six 22-m antennas of the Australia Telescope Compact Ar- ray (ATCA), located about 25 km west of the town of Narrabri in rural NSW (about 500 km north-west of Sydney). The Array is used for Radio Astronomy. Mercury, Venus and the Moon appeared very closed one to each other in the Australian sky, on March 11th 2008. )
50 (Miotello et al. 2014 etal. (Miotello
Figure 6.5: WL 12: average values of in the disk and in the envelope. Figure 6.3: Elias 29:average values of in the disk and in the envelope.
84 81 Young disks?
• Young disks may be gravitationally unstable
CHAPTER 6. ANALYSIS CHAPTER 6. ANALYSIS
Cold and vey optically thick disks => potentially unstable disks ) (Miotello et al. 2014 etal. (Miotello
Figure 6.5: WL 12: average values of in the disk and in the envelope. Figure 6.3: Elias 29:average values of in the disk and in the envelope.
84 81 Summary • Some young disks show evidence for early planet formation and potentially signs of instabilities • Caveats planets or GIs (or GIs=>planets), unclear • Planet forming disks surveys suggest that the bulk of the disk population is relatively low-mass • Expected: if GIs play a role, this must happen very early on and last for a short period of time • BD planetary system and young disks suggest that planet formation must happen on shorter timescales • Early disk consumption (GIs or otherwise) • Properties of young disks still unclear