1212CO(1-0) emission in CO(1-0) emission in the Magellanic Clouds, the Magellanic Clouds,
according to Mopraaccording to Mopra(Also starring the Magellanic Bridge…)(Also starring the Magellanic Bridge…)
Erik MullerErik Muller
ATNF/CSIROATNF/CSIROCollaborators so far: Collaborators so far:
Juergen Ott (PI, ATNF), Annie Hughes Juergen Ott (PI, ATNF), Annie Hughes (Swinburne), Tony Wong (ATNF/UNSW), (Swinburne), Tony Wong (ATNF/UNSW),
Jorge Pineda (Bonn) and more. Jorge Pineda (Bonn) and more.
Why CO in the Mag. Clouds?Why CO in the Mag. Clouds?
►1212CO(1-0) is a tracer for lower-density CO(1-0) is a tracer for lower-density molecular gas - signpost for SF.molecular gas - signpost for SF.
►MCs are nearby (50-60 kpc) & have MCs are nearby (50-60 kpc) & have very low metallicities very low metallicities (LMC=0.5 Z(LMC=0.5 Zsolsol, SMC = 0.1 Z, SMC = 0.1 Zsolsol) , ) , Emulate conditions as they were in the Emulate conditions as they were in the
early universe?early universe?
Technical…Technical…► Observation strategy:Observation strategy:
Observe ~5x5 amin Observe ~5x5 amin region in OTF mode (RA - region in OTF mode (RA - direction)direction)
► CO(1-0) (115.271 GHz)CO(1-0) (115.271 GHz)► ~1.75 hrs per area ~1.75 hrs per area
BW~64 MHzBW~64 MHz ΔΔV = ~0.16 Km/s V = ~0.16 Km/s RMS~0.4 K (before RMS~0.4 K (before
smoothing)smoothing)
► Tsys @115 GHz ~>400 Tsys @115 GHz ~>400 KK
SMC: SW SF region.SMC: SW SF region.
Spitzer data: Bolatto et al. 2005 (Priv. Comm)
SMC: CO according to SMC: CO according to NANTENNANTEN
Nanten 12CO(1-0) overlaid on SERC-J.
Mizuno et al, 2001
N84
N27
N66
N12
CO
SMC: SMC: 1212CO(1-0)CO(1-0)CO + NANTENRubio et al, 1993a, 1993b,1996
Latest result, smoothed to 90 asec, rebinned in velocity to ~0.5km/s, 3sig clip.
CO
SMC: SMC: 1212CO(1-0)CO(1-0)
N27/LIRS 49N12/LIRS 36
N25/26
N21/23
Latest result, smoothed to 90 asec, rebinned in velocity to ~0.5km/s, 3sig clip.
??
SMC B1#1Data is ‘first pass’ only.Very noisy!
Only three peaks appear where ICO>5sig!
Need deeper observations…
SMC: SMC: 1212CO(1-0)CO(1-0)
Rubio et al, 1993a, 1993b, Rubio et al, 1993a, 1993b,
1996 (1996 (θθ~43”)~43”)MX002 (MX002 (θθ~25”) ~25”)
- fit by eye.- fit by eye.
LIRS 49LIRS 49 V=114.6, V=114.6, ΔΔV=5.2 , V=5.2 ,
Tmb=1.99 ITmb=1.99 ICOCO=11.0, R=11.0, Rcc~16.7 ~16.7 pcpc
MMVIRVIR=8.9 10=8.9 104 4 (M (Msolsol))**
V=115, V=115, ΔΔV=~4V=~4±1.6±1.6 , ,
Tmb=~1.6Tmb=~1.6±0.4,.±0.4,. I ICOCO=6.4=6.4±3, ±3, RRcc~13~13
MMVIRVIR~5.2x10~5.2x104 4 (M(Msolsol) ) (!)(!)
LIRS 36LIRS 36 V=126.1, V=126.1, ΔΔV=3.4 , V=3.4 ,
Tmb=2.32 ITmb=2.32 ICOCO=8.45, R=8.45, Rcc~18.6~18.6
MMVIRVIR=1.2 10=1.2 105 5 (M (Msolsol) ) **
V=126, V=126, ΔΔV=3 V=3 ±1.6±1.6 , ,
Tmb=2.23 Tmb=2.23 ±0.4±0.4 I ICOCO=6.7 =6.7 ± 4, R± 4, Rcc~ ~ 15 pc15 pc
MMVIRVIR~3.3x10~3.3x104 4 (M(Msolsol) ) (!)(!)
New Mopra Results are generally consistent with the literature.
“Clumpfind” does not perform well with noisy data.
Using alternatives…
SMC: SMC: 1212CO(1-0), HCO(1-0), HIICO
N27/LIRS 49N12/LIRS 36
N25/26
N21/23
??
SMC B1#1
HI (1/25)CO
• APEX, high order transitions of CO (4-3) •Comparable resolutions to Mopra
• ASTE observations are underway (U Nagoya)
SMC: ASTE/APEX SMC: ASTE/APEX
Contours: APEX CO(4-3) transition.Background image: 2MASS J band – (UMASS/IPAC)
• ICO, Tmb are much lower for SMC than for LMC (can be x ~10!)
• Cloud radii are much smaller in SMC than for LMC• More exact quantifiction of ‘much smaller’ pending less noisy results •~Rlmc/Rsmc ~2-3 for brightest clouds).•ΔVlmc/ ΔVsmc ~2
•Mvirlmc/Mvirsmc ~ 8-12 (or more..)
LMC, SMC: LMC, SMC: 1212CO(1-0)CO(1-0)
Hα
SMC: CO, HSMC: CO, HααCO
N27/LIRS 49 N12/LIRS 36
N25/26
N21/23
SMC. Where to with Mopra?SMC. Where to with Mopra?
• Continue to fully sample SW area with Mopra? • Multi wavelength obs for N88/N66 ?• ASTE @ CO(3-2) has comparable resolution to Mopra @ CO(1-0)
• Other regions in SMC?• Existing CO(1-0) (and (2-1)) data for N66 are small field and mostly under sampled
•Dense core tracers (or ATCA? E.g. Muller+Ott in prep. HCO+, HCN)