1. Massive Star Formation Observational Cassandra Fallscheer PhD Advisor: Henrik Beuther Monday 28. March 2007

2. Grew up in California…close to Paradise

3. Cal Poly, San Luis Obispo Studied Physics & Mathematics Studied Physics & Mathematics Spent 2 months on the Golden Bear Spent 2 months on the Golden Bear

4. Disks in Massive Star Formation Two current formation theories 1. scaled-up version of low mass SF 2. coalescence and merging Two current formation theories 1. scaled-up version of low mass SF 2. coalescence and merging Should observe accretion disks in 1 st scenario Should observe accretion disks in 1 st scenario Offset [”] Velocity [km/s] IRAS20126+4102, Cesaroni et al. 2005

5. Accretion Disks Should see velocity gradient perpendicular to the outflow Should see velocity gradient perpendicular to the outflow Use (sub)mm interferometry Use (sub)mm interferometry Tracers of high density regions: C 34 S, CH 3 CN, N 2 H +, etc. Tracers of high density regions: C 34 S, CH 3 CN, N 2 H +, etc.

6. Observational difficulties to overcome D Deeply embedded, far away, clustered environment leads to confusion Distinguish disk emission from the surrounding envelope emission Appropriate spectral line tracer to detect disk unknown

7. Interferometers PdBI PdBI SMA SMA ALMA ALMA 6 x 15m, 408m 8 x 6m, 500m 54 x 12m 12 x 7m, 14km

8. My Contribution thus far: IRDC 18223-3 ~3.7 kpc ~3.7 kpc V LSR ~45.3 kms -1 V LSR ~45.3 kms -1 M~576M  with T~15 K M~0.01M  with T~51 K M~576M  with T~15 K M~0.01M  with T~51 K Hydro-simulations predict accretion rates of 10-4M  yr-1 Hydro-simulations predict accretion rates of 10-4M  yr-1 IRDC 18223-1243 Beuther, Sridharan, & Saito 2005

9. My contribution Need to know whereabouts of outflows Beam size: 1.8” x 1.7”

10. Channel Maps Velocity channel map of C 18 O 44-47 kms -1 (V LSR =45.3)

11. Moment Maps kms -1 ΔR.A. (”) Δ Dec. (”) C 18 O Velocity Moment Map Outline velocity structure of gas *