Unveiling the Molecular Environment of the Carina Nebula The 2015 - PowerPoint PPT Presentation

Unveiling the Molecular Environment of the Carina Nebula The 2015 Nanten2 Consortium Workshop February 6th David Rebolledo Postdoctoral Fellow University of Sydney University of New South Wales

Motivation a b 0:30 • The Carina Nebula is one 0:00 of the nearest regions of active star formation. -0:30 Galactic Latitude NGC3324 • Located at 2.3 kpc, it is -1:00 the nearest extreme star formation region. -1:30 • Excellent place for -2:00 studying clustered star Parkes [O III ] 3.4 cm H α formation, stellar -2:30 continuum [S II ] feedback and triggered 287 286 287 286 star formation. 288 288 Galactic Longitude Galactic Longitude b- Huchtmeier & Day (1975) a- Smith et al. (2000)

• Previously considered as as an evolved HII region with no current star formation activity. • However, infrared observations revealed several candidates for sites of current star formation. • Those compact infrared sources are located at the heads of dust pillars or dark globules behind ionization fronts • Recent high resolution surveys at X-rays, optical and infrared wavelengths. However, radio has been absent.

A fast visit to Mopra ...

CO Survey of Carina with Mopra Back in 2014 ...

CO Survey of Carina with Mopra Today! 8.5 deg 2

CO Survey of Carina with Mopra 12 CO(1 → 0)

CO Survey of Carina with Mopra 13 CO(1 → 0)

SED fitting Herschel 500 µ m Hi-Gal* (Molinari et al. 2010) 70 µ m 160 µ m 250 µ m 350 µ m 500 µ m * The Herschel Infrared Galactic Plane Survey

F ν = Ω B ν ( T cold )(1 − e − τ ν ) T cold τ ν = τ 0 ( ν/ν 0 ) β ν 0 β = 2 τ 0 = 1 Dust opacity κ ν Dust to gas ratio R DG M gas

K T cold

HI integrated intensity McClure-Griffiths et al. (2005) The Southern Galactic Plane Survey (SGPS) K km s − 1 N HI � atoms / cm 2 = 1 . 82 × 10 18 M HI T B dv

12 CO integrated intensity M H2 � L CO � � X CO � = 4 . 4 K km s − 1 pc 2 2 × 10 20 cm − 2 / (K km s − 1 ) M sun

vs. M H2+HI M gas log( M HI + M H2 ) M sun log( M gas ) M sun

� cm − 2 / (K km s − 1 ) X CO � X CO = M gas − M HI log F CO log( M gas ) M sun

Summary With Mopra Telescope, we have mapped 12 CO and 13 CO over 8.5 deg 2 across the Carina Nebula. I fit Herschel SEDs of each pixel with a modified blackbody to obtain the temperature of the cold gas in the central part of the Nebula. Under the current assumptions, I found that atomic + molecular hydrogen mass overestimates the gas mass provided by the SEDs analysis. X co factor is one order of magnitude smaller than the value commonly assumed. Range is about two orders of magnitude.