Lientjie de Villiers PhD Supervisor: Dr. M.A. Thompson University of Hertfordshire

1. A SEARCH FOR MOLECULAR OUTFLOWS IN THE JCMT HARP SURVEY OF 6.7 GHZ METHANOL MASERS Lientjie de VilliersPhD Supervisor: Dr. M.A. ThompsonUniversity of Hertfordshire

2. CONTENTS • Methanol masers and the 6.7 GHz methanol maser survey • Molecular outflows • HARP instrument on the JCMT • Data reduction process • Results: • outflow detection script • 3D representation and possible outflows • 3D overlay of different molecular emissons • Future work: • Expand data from other surveys – Galactic plane • Medical imaging analysis

3. METHANOL MASERS & 6.7 GHz MASER survey • Maser = Microwave Amplification by Stimulated Emission of Radiation • Trace an IR bright stage  immediately prior to development of UC HII regions1 • ~ 104 year • # molecules in quantum state 2 = n2state 1 = n1If n2/n1> 1  population inversiondue to radiative pumping  MASER. • 2 Classes2 :Class I – collisionally pumped, often associated with outflowsClass II - radiatively pumped – far IR emission by dust cocoon around the maser, uniquely associated with high mass star formation3,4,5 • Class II methanol masers: brightest radio sources in sky, & compact.Galaxy = transparent at 6.67 GHz ideal tracers for star formation in Galactic structure. 1 Codella et al. 2004; 2. Sobolev et al. 2005; 3. Sobolevet al. 1997; 4.Minier et al. 2003; 5. Ellingsen, 2005

4. STELLAR OUTFLOWS • Outflowing wind > vsound from protostar – accelerate surrounding molecular gas to vmg>> vcloudof quiescent cloud gas  produce molecular outflow, a turbulent expanse of cloud gas from the vicinity of a stellar source • Part of the SF process  mass-loss phase during their protostellar stages 1 • Search for outflows associated with methanol masers – the latter always associated with high mass SF  its dynamic lifetime = upper bound on maser lifetime • De Buizier (2009) observed the SiO (6-5) transition of 10 maser sources. Broad line wings indicate outflows  all the sources with bright SiO lines, displayed broad line wings  indicitave of outflow. Not finally confirmed. 1 Arce et al. 2007

5. HARP RECEIVER ON THE JCMT SUB-MM TELESCOPE • Heterodyne Array Receiver Program  16 pix heterodyne focal-plane array receiver • 4x4 element array with SIS detectors • Beam size 14” @ 345 GHz • High 3D mapping speed •  sensitivity at 325-375 GHz

6. DATA COLLECTED • Selection from a HARP-B outflow survey of 200 Class II methanol masers drawn from MMB catalogue of 6.7 GHz (4.49 cm) masers. • 13CO J=3-2 (trace outflows) C18O J=3-2 (see core) • Masers selected with wide range of luminosities, distances and galactic longitudes  analyse differences in outflow properties.

7. DATA REDUCTION Starlink’s NAMAKA version of the REDUCE SCIENCE PIPELINE ~ Clip noisy ends ~ Sub 1 baseline Raw timeseries image Bl. Subtracted timeseries 3 baseline fit on timeseries ~ Sub 3 baselline ~ Makecube Clumpfind baseline mask Pipeline reduced cube Collapsed image Collapse along velocity axis – quality control

8. DATA REDUCTION Example: 13CO images from Maser source G30.704 -0.06 Time ~ Clip noisy ends ~ Sub 1 baseline Bl. Subtracted timeseries Receptor # 3 baseline fit on timeseries ~ Sub 3 baselline ~ Makecube Clumpfind baseline mask • More edge clipping • Despike • Rebin velocity • Switch of noisy receptors CUBE COLLAPSED CUBE RA Dec Collapsed along v over (peak-20km/s; peak+20 km/s) Dec RA

9. RESULTS • Aim of this phase: • Simple outflow detection & contour mapping • 3D image rendering with current astronomical software (GAIA) of both 13CO and C18O. • Detect outflows in 3D by eye • Create a 3D training set for future medical image analysis programs

10. RESULTS • Simple outflow detection method1: • Using median filter: determine central v and width of source peak • Derive  from above: define BLUE = (-10 ; -2) GREEN = (-2; 2) RED = (2; 10) 1. Private communication: Antonio Chrysostomou – JAC, Hawaii

11. RESULTS • Simple outflow detection method1: • Using median filter: determine central v and width of source peak • Derive  from above: define BLUE = (-10 ; -2) GREEN = (-2; 2) RED = (2; 10) • Create 3 separate images by collapsing over above regions. Example: 13CO image from Maser source G30.760 -0.05 1. Private communication: Antonio Chrysostomou – JAC, Hawaii

12. RESULTS Example: 13CO image from Maser source G30.760 -0.05 C18O :  abundance thus opacity  see core 3D rendering in Gaia 13CO > abundant than C18O, see more structure like outflows. Both molecules low enough density & low opacity – trace dense gas in molecular cores where masers are embedded. Blue: 13CO; Yellow: C18O; Plane: image plane located at central peak velocity 3 separation between contours (receptor temp). Levels: 6.6 K; 4.3 K, 2.1 K

13. RESULTS Another example of high velocity structures (possible outflows?) Contours and 3D rendering of 13CO and C18O images of G24.790 +0.08 3 separation between contours (receptor temp). Levels: 6.1 K; 3.8 K, 1.5 K However, still inconclusive, need to be confirmed.

14. IMMEDIATE FUTURE WORK • Expand data • Expand current data set of 80 sources with 13CO and C18O maser observations from T. Moore • Get 12CO images for all maser sources from 12CO galactic plane survey (JAC)

15. IMMEDIATE FUTURE WORK – Training set • Investigate Medical Imaging options • Outflows = irregular 3D shapes  similarities with typical medical imaging problems • Arce et al. (2010) visualized the molecular clouds from Perseus 3D in Ra-Dec-v space  detected high velocity features (e.g. outflows) • Used3D Slicer from MIT Artificial Intelligence Lab & Surgical Planning Lab at Brighham and Women’s Hospital  designed to help surgeons in image-guided surgery, diagnostics and brain research visualization.1 1. Borkin et al. 2005

16. THANK YOU! “If the whole universe has no meaning, we should never have found out that it has no meaning: just as, if there were no light in the universe and therefore no creatures with eyes, we should never know it was dark. Dark would be without meaning.” C.S. Lewis