How do high line-mass filaments fragment? Towards an evolutionary sequence with ALMA

How do high line-mass filaments fragment? Towards an evolutionary sequence with ALMA Jouni Kainulainen Max-Planck-Institute for Astronomy Kainulainen+2017 (A&A accepted; arxiv:1603.05688) With: Amelia Stutz, Thomas Stanke, Jorge Abreu-Vicente, Henrik Beuther, Thomas Henning, Katharine G. Johnston, Tom Megeath Jouni Kainulainen 13th February 2017 Cologne

~30 pc ml ~ 500 MSUN pc -1 ml >> ml crit ~ 20 MSUN pc -1 (Stodolkiewitz 1963; Ostriker 1964) High-mass stars star clusters Common in the Galaxy G11.1 Dust extinction Kainulainen+2013

Catalog of 100-pc long, massive filaments Abreu-Vicente+2015 See poster by Zhang+ 50 40 How much stars do they form? 30 20 10 0 0 20 40 60 80 100

~30 pc ml >> ml crit ~ 20 MSUN pc -1 (Stodolkiewitz 1963; Ostriker 1964) High-mass stars star clusters Common in the Galaxy Different from near-critical filaments (grav. pot.; velocity structure) G11.1 Dust extinction Kainulainen+2013

Motivation ALMA view of the ISF Conclusions This Work: The Integral Shaped Filament (ISF) in Orion A 50 pc Kainulainen+(2017) Outstanding target: The nearest highly super-critical filament (d=420 pc, ml ~ 400 MSUN pc -1 ) 1) A census of the young stellar population (Spitzer+Herschel; the HOPS survey; Megeath+2012, Furlan+2016). 2) Sensitive mapping down to disk scales possible with ALMA. Herschel column density Stutz & Kainulainen (2015)

OMC-3 1.6 pc OMC-2 OMC-1 ALMA Cycle 2 study of OMC-2 (PI: Kainulainen, Co-Is: Stutz, Stanke, Abreu Vicente, Beuther, Henning, Johnston, Megeath) 3 mm continuum emission FWHM = ~1 200 AU (3.8 x2.3 ) Herschel-derived column density Stutz & Kainulainen (2015)

ALMA ACA ALMA+ACA 3 mm continuum emission natural weighting rms = 0.15 mjy beam -1 (combined data) 1.6 pc

ALMA+ACA Starless core 3 mm continuum emission FIR 3 FIR 4 1.6 pc

Motivation ALMA view of the ISF Conclusions Fragmentation pattern of the ISF down to 1 000 AU? Jouni Kainulainen 13th February 2017 Cologne

Motivation ALMA view of the ISF Conclusions Fragmentation pattern of the ISF? Identification of compact objects + GaussClumps (starlink/cupid) + 40 objects + Resolved, D ~ a few 1000 AU. + M=0.2-3 MSUN Kainulainen+2017

~200 pc -2 Number of cores per unit area 1.6 pc ~55 000 AU = 0.3 pc ~4000 pc -2 ~30 000 AU = 0.15 pc

ξ(r) Motivation ALMA view of the ISF Conclusions Two-point correlation function of the core separations PDD(r) - 2 PDR(r) + PR(r) PRR P(r) = distribution of separations, r - 1 D = observed data point R = random data point Excess Deficit Kainulainen et al. (submitted; arxiv:1603.05688)

Motivation ALMA view of the ISF Conclusions Two-point correlation function of the core separations PDD(r) - 2 PDR(r) + PR(r) ξ(r) - 1 PRR P(r) = distribution of separations, r Dense cores (40) D = observed data point R = random data point ~30 kau Kainulainen et al. (submitted; arxiv:1603.05688)

Motivation ALMA view of the ISF Conclusions Gravitational fragmentation? + Near-critical filaments, linear growth of perturbations: periodic fragmentation with λ ~ a few x FWHM, also, λ = λ(ρ0) (e.g., Nagasaki 1987; Inutsuka & Miyama 1992; Fischer & Martin 2012, ). + Note: Applicability is questionable. + For ISF: λ ~ 30-40 kau (core grouping ~ 55 kau) + λjeans ~ 10 kau (increasing grouping < 20 kau) In partial agreement with grav. fragmentation models. λ

Motivation ALMA view of the ISF Conclusions Connection to the young stellar population? Jouni Kainulainen 13th February 2017 Cologne

Plusses: Protostars (Class 0 and 1 YSO) Crosses: Stars with disks (Class II YSO) Protostars and disks (Class II) + Spitzer Orion Survey (Megeath et al. 2012). + Herschel Orion Protostar Survey (HOPS; Furlan et al. 2016). Kainulainen et al. (submitted; arxiv:1603.05688)

1.6 pc Surface density of sources Surface density of sources ALMA dense cores (40) HOPS Protostars (43) OMC2 and OMC3 Disks (54)

1.6 pc Surface density of sources Surface density of sources + Maternal grouping is not (entirely) erased during the protostar life-time (~0.5 Myr). It is erased during the life-time of stars with disks (~1-2 Myr). ALMA dense cores (40) HOPS Protostars (43) OMC2 and OMC3 Disks (54)

Motivation ALMA view of the ISF Conclusions Summary: Two-mode fragmentation of high line-mass filaments. Gravitational fragmentation probably plays a role, but simple models do not capture the full picture Crucial need for multi-scale models. Distribution of protostars carries signatures of the fragmentation process. Signatures erased in ~ 2 Myr.