e-MERLIN Key Project on Massive Star Formation School of Physics & Astronomy FACULTY OF MATHEMATICS & PHYSICAL SCIENCES e-MERLIN Key Project on Massive Star Formation Melvin Hoare Jim Jackson (Boston University) Gary Fuller (University of Manchester) Janet Drew (Imperial College London)

Why Massive Star Formation? Underpins much of astrophysics Pop III & Primeval galaxies Starbursts Galaxy evolution Feedback, Superwinds, Chemical evolution Extreme environments SNe, GRBs NS, BH Gemini Observatory - GMOS Team

Key Unsolved Questions What determines the upper IMF? Accretion physics? Outflow physics? Evolutionary scheme?

Accretion Physics Magnetically/turbulently controlled collapse or triggering? IRAM 30m 13CO 1-0 map Spitzer 8mm image Krumholz et al. (2005)

Outflow Physics Radiation or magnetically driven winds and outflows? X-wind (Shu et al. 1997) or disk wind (Ouyed et al. 2003) Drew et al. (1998); Proga (2000)

Outflow Physics Bipolar or cometary at the onset of the H II region phase NGC 7538 IRS 1

Evolutionary Scheme Massive pre-stellar core Inactive IR Dark Cloud Methanol masers Hot molecular core Massive young stellar object Water masers Hyper-compact H II region Ultra-compact H II region OB cluster

Context Exploitation of Galactic Plane surveys at a range of wavelengths – many UK led Build on discoveries made with MERLIN and the VLA Currently only a few bright/nearby examples of the later stages have been studied

Equatorial Winds and Jets Blue/red contours 8/22 GHz VLA map Image: SMA 850mm dust continuum MERLIN 5 GHz 0.1" (image) 2mm speckle 0.2" (contours) Patel et al. (2005) Hoare (2002)

Galactic Plane Surveys

Key Project Sample Well selected sub-samples from the surveys that cover a range of masses and evolutionary stages UCHIIs Transition objects? MYSOs HMCs/IRDCs

Key Project Outline Active IR Dark Clouds from GLIMPSE/MIPSGAL/GRS Methanol maser sources from Arecibo/MMB Massive YSOs from Red MSX Source survey Herbig Be stars from IPHAS UCHII regions from CORNISH survey Distance limited samples (e.g. < 7 kpc) to preserve physical spatial resolution

Key Project Outline 20/40 from each category for full/half tracks at 4-8 GHz 1/16th BW on the methanol maser 6.7 GHz line Including Lovell gives 2-3 mJy/beam noise level 1000 hours in total

Why Key Project? Avoid piecemeal approach through PI programmes Good sample selection only way to unlock evolutionary trends Builds co-operation between Galactic Plane survey teams Pools expertise within these teams Will answer key questions Onset of wind and H II region phases Driving mechanisms

Low-Mass YSO Key Project WFPC2 NICMOS VLA 8 GHz

Stellar Jets Key tests of MHD driving mechanisms Shang et al. (2002; 2004) 6/1.5 AU resolution at 140 pc