Studying Star Formation at High Resolution in the Magellanic Clouds

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1 Studying Star Formation at High Resolution in the Magellanic Clouds Initial Results from the HST SMIDGE Survey & Science Opportunities with JWST Cliff Johnson Postdoctoral Researcher UC San Diego SMIDGE Team: K. Sandstrom (PI), B. Williams, K. Gordon, J. Dalcanton, et al.

2 Studying Evolutionary Timescales of Star Forming Regions in the Small Magellanic Cloud Using Populations of Individual Stars

3 Young Stars in the Magellanic Clouds Hubble Massive Clusters & Star-forming Regions LMC: 30 Dor, LMC-N11, and more SMC: NGC346, NGC602 ALMA Massive Star-forming GMCs LMC: 30 Dor, Molecular Ridge NGC346: Nota+06, Sabbi+07, Schmeja+09, De Marchi+11a,b, Gouliermis+14, Hony+15 N159W in 13 CO(2-1): Fukui+15

4 JWST: Matched High Spatial Resolution Infrared Imaging Statistical samples of young embedded stars that fill in the missing gap in star formation timeline.

5 Evolution of Young Stellar Objects (YSO) Molecular Gas Stage I YSO Stage II YSO Pre-MS Stars log Flux log Flux log Flux λ λ λ ALMA JWST JWST+HST HST Single Dish Surveys Extinction Mapping Spitzer (X-ray+Optical) Combine Embedded & Exposed Tracers of Star Formation

6 Evolution of Molecular Clouds Type I Type II Type III Gas Free Kawamura+09 ~25 Myr Lifetimes for R=30-50 pc, M=10 5 M Clouds Solve for Formation Histories Test Models of Star Formation Progression (e.g., Palla & Stahler 00) Stellar Feedback Timescales and Truncation of Star Formation

7 Goals with JWST: Analyze Low Metallicity Star Formation Regions Across All Evolutionary Phases Expand Samples Beyond Massive Clusters To Low Mass, Galactic Analog Regions Combine ISM & All Stellar Tracers to Map Cloud Evolution Motivation: SMIDGE Observations of SMC

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9 N66/NGC346 N83 SW Bar Herschel 250um

10 Spitzer 8um Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE) Hubble Cycle 22 Program PI: Karin Sandstrom F550M+F658N Primary Science Goals: HST F475W Extinction Curve Fitting Spatial Maps of AV, RV

11 Spitzer 8um Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE) Hubble Cycle 22 Program PI: Karin Sandstrom F550M+F658N HST F475W J. Dalcanton Primary Science Goals: Extinction Curve Fitting Spatial Maps of AV, RV

12 Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE) Hubble Cycle 22 Program PI: Karin Sandstrom F550M+F658N F336W/F814W/F160W Primary Science Goals: Extinction Curve Fitting Spatial Maps of AV, RV

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15 1 Myr 5 Myr 10 Myr Models: Choi (2016), Feiden (2016)

16 1 Myr 5 Myr Differs from Hα-based Identification 10 (De Myr Marchi et al. 2010,11,13): Larger number statistics 3x improvement. Makes use of deep broadband imaging. No issues related to narrowband imaging depth. Models: Choi (2016), Feiden (2016)

17 Eliminate contaminants via NIR-based Color Cut: Reddened MS+TO Stars, Foreground MW Stars Remaining Contaminants: Lower RGB Stars with 1.5<AV<4.0 Given RGB stellar density & AV distribution: <10% contamination Favorable GDR Ratio! MW=100, LMC=380, SMC=1200 (Roman-Duval et al. 2014)

18 20 pc HST Pre-MS Stars Image: Spitzer 8um

19 HST Pre-MS Stars Image: Herschel-based Dust Map (Lee+15)

20 HST Pre-MS Stars Image: APEX 12 CO(2-1) (M. Rubio)

21 15 pc Cloud Apertures HST Pre-MS Stars Image: Pre-MS Star Density Dust CO For SFE: need stable tracers of total gas AND full stellar pop.

22 20 pc HST Pre-MS Stars Image: Spitzer 8um

23 B1-#1 Molecular Cloud 5 pc Image: APEX 28 resolution HST Pre-MS Stars

24 B1-#1 Molecular Cloud 5 pc Image: ALMA 12 1 resolution PI: K. Sandstrom HST Pre-MS Stars

25 N13 / B1-#2 / SWBarS 5 pc ALMA 12 CO(2-1), PI: K. Jameson

26 SW Bar Filamentary Cloud 5 pc Y175 Y169 Image: Spitzer 8um Spitzer YSOs (Sewilo et al. 2013) HST Pre-MS Stars

27 Spatially-resolved Sub-clusters Around 7-10 M YSOs F225W F475W F160W F475W F814W F160W Y Y F814W F814W F475W F814W F475W F814W

28 NIRCam MIRI Making Use of JWST NIRCam + MIRI Imaging Fill in age/evolution gap with embedded, disky sources. Investigate evolutionary differences via Stage I/II Ratios (e.g., Gutermuth et al. 2011). Detailed SED fitting via BEAST (Gordon et al. 2016).

29 B1-#1: K. Sandstrom SWBarS: K. Jameson Orion A: Nishimura CO(2-1) + PMS Stars Matched Physical Scales

30 Cliff Johnson (UCSD) Goals with JWST: Analyze Low Metallicity Star Formation Regions Across All Evolutionary Phases Expand Samples Beyond Massive Clusters To Low Mass, Galactic Analog Regions Combine ISM & All Stellar Tracers to Map Cloud Evolution Thanks!