The Formation of Habitable Planetary Systems. Dániel Apai Space Telescope Science Institute

Size: px

Start display at page:

Download "The Formation of Habitable Planetary Systems. Dániel Apai Space Telescope Science Institute"

Ernest Manning
6 years ago
Views:

1 The Formation of Habitable Planetary Systems Dániel Apai Space Telescope Science Institute

2 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Habitability Liquid water stable on the surface Which parameters determine whether or not a forming planetary system will have planets in the habitable zone? How frequent rocky planets with Earth-like bulk compositions? How does this vary with stellar mass? Which habitable planets have the potential to sustain life?

3 Astrobio2010 / Santiago D. Apai Mg, Al Si, O Mg, Al Si, O Mg, Al Si, O Mg, Al Si, O Fe/Ni Fe/Ni Fe/Ni Fe/Ni

4 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Pre-solar SiC grain, Nittler Earth-like planet 1 μm 10,000,000,000,000 1 REarth

5 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Embedded Protostars Accretion Disks Protoplanetary Disks Debris Disks See talk by Eric Mamajek

6 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Embedded Protostars Accretion Disks Protoplanetary Disks Debris Disks See talk by Eric Mamajek

7 Chronology of Planet Formation Astrobio2010 / Santiago D. Apai [Myr] [Myr] Cha I U Sco Taurus Orion Nebula Cluster TW Hya Beta Pic Tuc-Hor Embedded Protostars Accretion Disks Protoplanetary Disks Debris Disks Apai & Lauretta 2009

Cha I U Sco Taurus Orion Nebula Cluster TW Hya

8 Chronology of Planet Formation Astrobio2010 / Santiago D. Apai Pre-solar Grains SN explosion CAIs Chondrules Chondrites Vesta Mars Moon-forming Cataclysm ( Myr) [Ma] [Myr] [Ma] [Myr] Cha I U Sco Taurus Orion Nebula Cluster TW Hya Beta Pic Tuc-Hor Embedded Protostars Accretion Disks Protoplanetary Disks Debris Disks Apai & Lauretta 2009

Collisions Eimpact < Erolling-friction Fractal growth works for sizes

Compaction, growth (see Blum & Wurm 2008, Pontoppidan & Brearley 2010

9 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Interstellar medium: sub-micron sized amorphous grains Monomer Collisions Eimpact < Erolling-friction Fractal growth works for sizes <0.1-1m Cluster-Cluster Collisions Eimpact > Erolling-friction Compaction, growth (see Blum & Wurm 2008, Pontoppidan & Brearley 2010 for reviews) SiC Graphite Nanodiamonds Al2O3 Clayton & Nittler Blum & Wurm 2008

10 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Growth of grains to micron-mm sizes observed in many disks Scattered light images of disks: e.g. Wolf et al. 2003, Apai et al. 2004; Padgett et al Apai et al. Science 2005 Millimeter Dust Emissivity: cf. Testi et al. 2003, Rodmann et al. 2008; scattering: Wolf et al. 2003, Apai et al Mid-IR Spectroscopy e.g. Przygodda et al. 2003, Apai et al. 2005, van Boekel et al. 2005, Furlan et al. 2006, Pascucci et al. 2008, 2009; Merin et al. 2008, Buoy et al. 2008, Watson et al. 2009

11 The Formation of Planetary Embryos Astrobio2010 / Santiago D. Apai Planetesimals to Planetary Embryos dm dt dm dt = 1 2 Σ Ωπ R 2 p s Σ p ΩR s 2 Σ p ΩM 2/3 R s t Slow initial growth

12 The Formation of Planetary Embryos Astrobio2010 / Santiago D. Apai Planetary Embryos to Planets dm dt = 1 2 Σ Ωπ R 2 p s 1 + v 2 esc σ 2 F g = 1 + v 2 esc σ 2 1 dm dt MR s 2 Rapid, mass-dependent growth

13 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Formation of Rocky Planets Highly stochastic N-body interactions

14 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Planet Formation as a Function of Stellar Parameters Disk mass scales proportionally with stellar mass down to Brown Dwarf regime (Klein et al. 2003, Scholz et al. 2006, Andrews & Williams 2006) Core accretion and Gas Giant formation slow around cool stars e.g. Laughlin et al. (2004), Ida & Lin (2005), Kornet et al. (2006) Planet formation around BDs 5 ME max. Payne & Lodato (2007) Earth-mass planets may form around stars of all masses E-ELT and JWST: detailed mineralogy/composition of pre-planetary materials See talk by Alan Boss on super-earths around cool stars

15 Delivery of Volatiles and Organics Astrobio2010 / Santiago D. Apai Delivery of Volatiles & Organics Gas-phase Volatile Ice/Icy Bodies H C N P O 54.7 ppm 120 ppm 2 ppm 90 ppm wt% Vapor Ice See Talk by Dumas Tcond Temperature

16 Delivery of Volatiles and Organics Astrobio2010 / Santiago D. Apai Raymond, Quinn & Lunine 2006

17 The Formation of Habitable Planetary Systems Astrobio2010 / Santiago D. Apai Abundance of most common elements in living organisms in Earth mantle/crust H C N P O 54.7 ppm 120 ppm 2 ppm 90 ppm wt% N 3-4 wt% (dry) of terrestrial organisms N2 strongest triple bond in nature N2 (ice) T ~ 50 K Water (ice) T ~ 273 K

18 Delivery of Volatiles and Organics Astrobio2010 / Santiago D. Apai Highly Statistically Significant Difference in the observed abundances of HCN and C2H2 Pascucci, Apai et al ApJ

19 Delivery of Volatiles and Organics Astrobio2010 / Santiago D. Apai Bottleneck in HCN production is the dissociation of N2 (Bergin et al. 1995, 2003; van Dishoeck et al. 2008) ISM N2 2 N 2 HCN Energy barrier C2H2 Major difference in the chemical network, N-deficiency No N-containing ices Planets around M-dwarfs N-deficient? Pascucci, Apai et al ApJ

20 Dániel Apai Space Telescope Science Institute

21 Apai & Lauretta Gail & Hoppe Ciesla & Dullemond Semenov, Chakraborty & Thiemens Brucato & Nuth III Min & Flynn Pontoppidan & Brearley Apai, Connolly, Jr. & Lauretta Pascucci & Tachibana Chambers, O Brien & Davis Dániel Apai Space Telescope Science Institute

22 Dániel Apai Space Telescope Science Institute

23 Formation of Habitable Planetary Systems Astrobio Santiago de Chile Daniel Apai Summary Rocky Planet Formation Habitable planets may form around any and most stars Volatile Budget: Important Limiting Factor Disk chemistry is stellar mass-dependent Nitrogen-depleted Chemistry around Cool Stars? Dániel Apai Space Telescope Science Institute

24 Delivery of Volatiles and Organics Astrobio2010 / Santiago D. Apai Raymond, Quinn & Lunine 2006

25 Delivery of Volatiles and Organics Astrobio2010 / Santiago D. Apai Raymond, Quinn & Lunine 2006 e.g. Drake & Righter (2002)

Forming habitable planets on the computer

Forming habitable planets on the computer Anders Johansen Lund University, Department of Astronomy and Theoretical Physics 1/9 Two protoplanetary discs (Andrews et al., 2016) (ALMA Partnership, 2015) Two