Probing the Birth of Super Star Clusters

Probing the Birth of Super Star Clusters Kelsey Johnson With help from: Alan Aversa, Crystal Brogan, Rosie Chen, Jeremy Darling, Miller Goss, Remy Indebetouw, Amanda Kepley, Chip Kobulnicky, Amy Reines, Bill Vacca, David Whelan NOAO Summer Program 1995 Remy Regina Indebetouw Jorgenson Angelle Tanner Seth Redfield Reed Riddle Kelsey Johnson Amy Winebarger Super Star Clusters: Cluster formaon in the Extreme • Plausibly proto‐globular clusters • Formaon common in early universe • Impact on the ISM & IGM 1) What physical conditions are required to form these clusters? 2) Does this extreme environment affect affect the SF process itself? Strategy: Look for sources with similar SEDs to Ultracompact HII regions Compact, “inverted spectrum” sources Very dense HII regions non-thermal Sn free-free optically-thick free-free 100 1 l (cm) Wood & Churchwell 1989 II ZW 40 NGC 4490 NGC 4449 Aversa et al.sub Image credit: Michael Gariepy/ Kepley et al. in prep, Beck et et al. Adam Block/NOAO/AURA/NSF Reines et al. 08 NGC 2537 NGC 5253 NGC 3125 Aversa et al. sub Turner et al. 00 Aversa et al. sub Image Credit: Sloan Digital Sky Survey Image credit: Angel Lopez-Sanchez Haro 3 IC 4662 NGC 4214 Beck et al. 00 Image Credit: NASA and Hubble Heritage Team (STScI) Johnson et al. 03 Johnson et al. 04 Natal Clusters are rare! (i.e. short‐lived) Recent radio survey of nearby “star-forming” galaxies: Only 9/28 have detected thermal sources Aversa, Johnson, et al.submitted Henize 2-10 ACS optical, Vacca et al. in prep NICMOS Pa a, Reines et al. prep Early Universe Analog? SBS 0335‐052 ultra‐low metallicity: 12 + log(O/H) = 7.25 VLA + Pie Town X‐band, HST opcal 10,000 O-type* stars HST ACS Ha, V‐band, UV Johnson, Hunt, & Reines 09 What can we learn from the radio continuum? Radii of HII regions as small as a few pc 7 Electron densies Pressures > 10 kB Ionizing ﬂux Stellar Masses: up to 1000s O7‐type stars Radio recombination lines - a better tool? (e.g. Mohan, Anantharamaiah, & Goss 2001) 4 -3 • Densities: ne > 10 cm • Radii: r ~ 2-10 pc 52 • Ionizing Flux: Nlyc > 10 Nearly perfect agreement with simple models! Example: prediction for H92a line EVLA + GBT Radio Recombination Line survey being led by Amanda Kepley RadioRecombination Linesurveybeingledby +GBT EVLA (1 s , 12 hours) Staytuned! H71a H70a H69a H68a H67a H66a H65a Don’t forget the H64a EVLA! H63a H62a Ubiquitous Water Masers! Darling, Brogan, & Johnson 08 Water masers! All maser sources appear to be extremely young Brogan, Johnson & Darling in prep. Natal SSCs are really darn bright in the IR! He 2-10 The radio sources alone account for at least 60% of the mid-IR flux from the entire galaxy VLA 2 cm, Gemini 10um (Vacca, Johnson, & Conti 2002) • Electron densities • Hardness of radiation field • Ionizing flux Spitzer ch1,ch4, 24um (b,g,r) Radio 3.6cm contours Johnson, Whelan, Indebetouw, & Reines in prep Panchromatic data is essential: stars, dust, and gas all contributing Infrared excess ® Hot dust Reines, Johnson, & Hunt 08 Nebular continuum Paschen break Reines et al. 2010 Breaking the age-extinction degeneracy NGC4449 VLA 3.6cm HST V-band Reines, Johnson, & Goss 08 Modeling the observable properes of natal star clusters Near‐IR Spitzer IRAC Spitzer MIPS J, H, K 3.6, (4.5+5.8), 8.0 m 24, 70, 160 m Indebetouw, Whitney, Johnson, & Wood, ApJ 2006 Whelan, Johnson, et al. in prep ALMA early science simulaon Amanda Kepley, Rosie Chen, et al. in prep Summary • Super star clusters are important • Natal clusters are rare • Extreme pressures and densities • Possibly ubiquitous masers • Clumps are important • Panchromatic observations are essential • At least some super star clusters are special • We will know more soon … .

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