Supervisors: Maria Cunningham (UNSW), James Urquhart (CSIRO) Michael Burton (UNSW) Collaborators: Nadia Lo (UNSW/CSIRO), Bhaswati Mookerjea (Tata Institute) Great Barriers in High Mass Star Formation, 14 th September 2010 Vicki Lowe University of New South Wales CSIRO Astronomy and Space Science

 “Low mass stars are like weeds in the Galaxy” – Tom Megeath  Characterising turbulence in molecular clouds (power spectrum analysis,  -variance analysis)  Following molecular abundances through an entire cloud complex (e.g. principal component analysis, Lo et al., 2009; 13 CO & masers, Breen et al., 2007) Vicki Lowe UNSW/CSIRO Great Barriers in High Mass Star Formation, 14 th September 2010 Motivation  G333 GMC  CLUMPFIND  Abundances  EGOs

Spitzer GLIMPSE: 3.6 µm (blue, starlight), 4.5 µm (green, shocked gas), 8.0 µm (red, ionised HII regions) Within the Galactic Molecular Ring, 3.6 kpc away 13 CO Bains et al. (2006) C 18 O Wong et al. (2008) b l Vicki Lowe UNSW/CSIRO Great Barriers in High Mass Star Formation, 14 th September 2010 Motivation  G333 GMC  CLUMPFIND  Abundances  EGOs 1.2 mm dust continuum Mookerjea et al. (2004) HII region (RCW 106) Green Fuzzy Motivation  G333 GMC  CLUMPFIND  Abundances  EGOs

 SIMBA on SEST 1.2 mm dust continuum  Cool, dense gas tracer  Molecules are complex  depletion, excitation  Use millimetre continuum to create a mask for molecules Mookerjea et al. (2004) Vicki Lowe UNSW/CSIRO Great Barriers in High Mass Star Formation, 14 th September 2010 Motivation  G333 GMC  CLUMPFIND  Abundances  EGOs

 1.2 mm continuum dust clumps was used as a mask to compare all molecular data  STARLINK (  Clump identification algorithms  CLUMPFIND, GAUSSCLUMP, FELLWALKER, REINHOLD  63 dust clumps were identified (3σ cut-off) CLUMPFIND Vicki Lowe UNSW/CSIRO Great Barriers in High Mass Star Formation, 14 th September 2010 Motivation  G333 GMC  CLUMPFIND  Abundances  EGOs

/C 18 O 13 COHCNCSHNCHCO + N2H+N2H+ Mean Median Stdev Min Max % detect100% Optically thinUbiquitous gas tracer High density tracer n ~ 10 4 cm -3 Dense cold (< 20 K) gas tracer n ~ 10 5 cm -3 Outflow & inflow tracer Cold dense quiescent gas tracer Vicki Lowe UNSW/CSIRO Great Barriers in High Mass Star Formation, 14 th September 2010 Motivation  G333 GMC  CLUMPFIND  Abundances  EGOs

/C 18 OHC 3 N(10-9)HC 3 N(11-10)C2HC2HSiOSO Mean Median Stdev Min Max % detect70%40% 30% High density (n ~ 10 6 cm -3 ) tracer & Hot core molecule Photodissociation regions Shocked gas High density (n ~ 10 6 cm -3 ) tracer & Chemical clock Vicki Lowe UNSW/CSIRO Great Barriers in High Mass Star Formation, 14 th September 2010 Motivation  G333 GMC  CLUMPFIND  Abundances  EGOs

C 2 H – PDRs N 2 H + – Cold, dense quiescent gas tracer

 The Mopra G333 Survey mapped approx. 20 different molecular transitions  Used 1.2 mm continuum dust clumps as a mask to compare all molecular data  CLUMPFIND with 3σ cut-off produced 63 millimetre continuum clumps  Variety of chemical conditions  e.g. green fuzzies Thank you  Poster #37 Vicki Lowe UNSW/CSIRO Great Barriers in High Mass Star Formation, 14 th September 2010 Motivation  G333 GMC  CLUMPFIND  Abundances  EGOs Website: