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

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1 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: ) With: Amelia Stutz, Thomas Stanke, Jorge Abreu-Vicente, Henrik Beuther, Thomas Henning, Katharine G. Johnston, Tom Megeath Jouni Kainulainen 13th February 2017 Cologne

2 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: ) With: Amelia Stutz, Thomas Stanke, Jorge Abreu-Vicente, Henrik Beuther, Thomas Henning, Katharine G. Johnston, Tom Megeath Jouni Kainulainen 13th February 2017 Cologne

3 ~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

4 Catalog of 100-pc long, massive filaments Abreu-Vicente+2015 See poster by Zhang How much stars do they form?

5 ~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

6 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)

7 OMC 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)

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

9 ALMA+ACA Starless core 3 mm continuum emission FIR 3 FIR pc

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

11 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

12 ~200 pc -2 Number of cores per unit area 1.6 pc ~ AU = 0.3 pc ~4000 pc -2 ~ AU = 0.15 pc

13 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: )

14 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: )

15 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 ~ kau (core grouping ~ 55 kau) + λjeans ~ 10 kau (increasing grouping < 20 kau) In partial agreement with grav. fragmentation models. λ

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

17 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: )

18 1.6 pc Surface density of sources Surface density of sources ALMA dense cores (40) HOPS Protostars (43) OMC2 and OMC3 Disks (54)

19 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)

20 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.