CONSTRAINTS ON EMBEDDED DISK STRUCTURES AND MASSES AS SEEN BY CARMA AND ALMA

Transcription

1 CONSTRAINTS ON EMBEDDED DISK STRUCTURES AND MASSES AS SEEN BY CARMA AND ALMA PATRICK SHEEHAN UNIVERSITY OF OKLAHOMA OLYMPIAN SYMPOSIUM 2018 MAY, Image credit: Reynolds et al., in prep.

2 STAGES OF STAR FORMATION Prestellar Core Class 0 Protostellar disks Class I AU AU 300 AU Planetary System Class III Class II 50 AU 100 AU 100 AU Protoplanetary disks

3 PROTOPLANETARY DISK STRUCTURE HAS BEEN WELL STUDIED Ansdell et al Perez et al tion for the ONC compared with previous work ll et al. 2016), Cham 1 (Pascucci et al. 2016), nfeld et al. 2016). The distributions and the 1 ated using the Kaplan-Meier estimator. In the left NC. In the right panel we use both detections and β ISM β C =1.0 3σ 2σ 1σ ted in Table 1 with those in other star-forming me way, are available for Taurus (Andrews et al. cucci et al. 2016), Ori (Ansdell et al. 2017), and ection 4.2, these regions span a range Eisner of ages et al. from 2018

4 PROTOPLANETARY DISKS ARE NOT PRIMORDIAL

5 ANATOMY OF A PROTOSTAR Class 0 and Class I outflow Envelope Envelope Disk (100 AU) outflow Image: Bill Saxton (NRAO)

6 RADIATIVE TRANSFER MODELING 60 Density SED 1.3 mm Visibilities z [AU] Fit radiative transfer models with MCMC: Free parameters - L, M disk, R in, R disk, γ, beta, h 0, M env, R env, f cav, ζ, a max, i, pa Run using the emcee code (Foreman-Mackey et al. 2013) r [AU] With 200 walkers, fits converge in a few weeks when run on a 28 cpu processor Temperature 0.8 µm Image 1.3 mm Image z [AU] Calculate X 2 for each dataset, and combine: X 2 = w vis 2 vis + w SED 2 SED r [AU]

7 log10(rdisk) M C M C F I T S O F R A D I AT I V E T R A N S F E R MODELS Steps

8 EXAMPLE MODEL FIT Adapted from Sheehan & Eisner 2017b

9 CLASS I PROTOSTARS IN TAURUS Sheehan & Eisner 2017b 10 Class I Protostars in Taurus: CARMA 1.3mm visibilities Broadband SEDs from the literature. Near-infrared scattered light imaging (0.8 microns) when available

10 CLASS I PROTOSTARS IN TAURUS Sheehan & Eisner 2017b

11 THE INITIAL MASS BUDGET FOR FORMING PLANETS? Adapted from Tychoniec+2018 with masses from Sheehan & Eisner 2017b

12 DISK MASES IN OPHIUCHUS Sheehan & Eisner, in prep MMSN Median Class I disk mass ~ M_sun Median Class II disk mass ~ M_sun Data from Andrews et al. 2007

13 LARGER PROTOSTELLAR DISK SAMPLES VANDAM (VLA/ALMA Nascent Disk and Multiplicity) Survey Perseus ~80 sources Continuum only 8 mm/1 cm/4.1 cm/6.4cm 15 AU resolution (0.08 ) Segura-Cox+2016, Tobin+2015;2016, Cox+2015, Tychoniec+2018 Orion ~325 sources 8 mm/1 cm/0.87 mm 30 AU

14 THE VANDAM TEAMS VANDAM Perseus Team: John Tobin (PI) Leslie Looney (Illinois) Zhi-Yun Li (Virginia) Claire Chandler (NRAO) Mike Dunham (CfA/SUNY-Fredonia) Kaitlin Kratter (Arizona) Dominique Segura-Cox (Illinois/MPE) Sarah Sadavoy (CfA) Laura Perez (U. Chile) Carl Melis (UCSD) Robert Harris (Illinois) Lukasz Tychoniec (Leiden) Erin Cox (Illinois) VANDAM Orion + ALMA Team: John Tobin (PI) VANDAM Perseus+ Tom Megeath (Toldeo) Will Fischer (STSci) Magnus Persson (Onsala) Mihkel Kama (Cambridge) Nadia Murillo (Leiden) Stella Offner (UMASS) Marina Kounkel (Michigan) Ewine van Dishoeck (Leiden) Ana Karla Diaz Rodriguez (IAA) Mayra Osorio (IAA) Guillem Anglada (IAA) Joesph Booker (Toledo) Frederick Wyrowski (MPIfR) Elise Furlan (IPAC) Ruud Visser (ESO) James Di Francesco (HIA) Amy Stutz (U. Concepcion) Nick Reynolds (OU) Rajeeb Sharma (OU) Brian Stephenson (OU) Lisa Patel (OU) Nicole Karnath (Toledo)

15 ORION FLAT SPECTRUM/CLASS I Visual inspection of each source for presence of resolved disk Sizes greater than about ~1.5 beam ( AU radius) Class 0 - ~55% Class I - ~55% Flat Spectrum - ~55% Median/Max Radii (includes unresolved) Class 0 33 AU / 159 AU Class I 35 AU / 240 AU Flat Spectrum 25 AU / 360 AU

16 PROTOSTELLAR TO PROTOPLANETARY DISKS Lupus - Ansdell+2016 Taurus - Andrews+2013 Cha/σ Ori - Pascucci+2016 U Sco - Barenfeld+2016 VANDAM: Perseus sample larger Adapted from Tychoniec+2018 Class 0 and Class I 8mm emission, free-free removed (Tychoniec+2018) Sheehan & Eisner (2017) approx. consistent w/class I Comparable to distribution of Bate (2018)

17 PROTOSTELLAR TO PROTOPLANETARY DISKS Lupus - Ansdell+2016 Taurus - Andrews+2013 Cha/σ Ori - Pascucci+2016 U Sco - Barenfeld+2016 VANDAM: Perseus sample larger Adapted from Tychoniec+2018 Class 0 and Class I 8mm emission, free-free removed (Tychoniec+2018) Sheehan & Eisner (2017) approx. consistent w/class I Comparable to distribution of Bate (2018)

18 PROTOSTELLAR TO PROTOPLANETARY DISKS Lupus - Ansdell+2016 Taurus - Andrews+2013 Cha/σ Ori - Pascucci+2016 U Sco - Barenfeld+2016 VANDAM: Perseus sample larger Adapted from Tychoniec+2018 Class 0 and Class I 8mm emission, free-free removed (Tychoniec+2018) Sheehan & Eisner (2017) approx. consistent w/class I Comparable to distribution of Bate (2018)

19 OTHER STRUCTURES IN EMBEDDED DISKS Sheehan & Eisner 2018 Sheehan & Eisner 2017a

20 SUMMARY Class 0/I disks are, on average, more massive than older Class II disks. VANDAM Survey of Orion/Perseus Median/Max Radii (includes unresolved) Class 0 33 AU / 159 AU Class I 35 AU / 240 AU Flat Spectrum 25 AU / 360 AU Detailed radiative transfer modeling to determine disk structure in progress Young disks with interesting structures (gravitational instability driven spiral arms, cavities, gaps) are being found.