Oral Presentation
A massive star forming region N55 in the LMC observed with ALMA
Presenter: Naslim Neelamkodan (NAOJ)
We present the molecular cloud properties of N55 star forming region in the LMC with ALMA observation of 12CO(1-0) and 13CO(1-0) emission. This cloud is strongly irradiated by a young star cluster LH 72 within an expanding SGS LMC4. ALMA observations reveal clumpy
nature of CO clouds in N55. The cloud properties are analysed using dendrogram which gives two sets of clumps, leaves and trunks. We use both leaves and trunks separately to understand their physical properties such as radii, linewidths, luminosities and masses, scaling relations and their relation to star formation. We found that,
molecular cores that associated with YSOs generally show larger linewidths, column densities and masses. The massive clumps are associated with high mass and intermediate mass YSOs. The size-linewidth relation in N55 show a similar trend as in Galactic clouds such as Orion and Gemini-Augira. The trend shows a power-law relation with index 0.5. This results suggest that N55 clouds are
gravitationally bound and effect of any external pressure is
negligible. Power-law relation between 12CO virial mass and luminosity gives an XCO factor 7X10^20 K Km s^-1 pc^2 which is about two-three times higher than Galactic clouds. 12CO and 13CO clump mass functions show a turnover at 200Msun. This turnover separates steep high mass end from shallow low-mass part. The steep high-mass end is fitted with
a power law index -2.5 for 13CO clumps and -2.0 for 12CO. Our studies show that clump mass function in N55 show similar trend as that have been found for Galactic clouds.
asiaa.sinica.edu.tw