Poster Presentation

Molecular hydrogen emission in the interstellar medium of the Large Magellanic Cloud

Naslim Neelamkodan (ASIAA, Taiwan), Ciska Kemper (ASIAA, Taiwan), + SAGE-spec collaboration team

We present the physical conditions of molecular hydrogen emission and their relation to dust and PAH emission towards some selected interstellar regions in the Large Magellanic Cloud. We used the spectroscopic and photometric data obtained with Spitzer and Herschel space telescopes as part of SAGE-LMC and HERITAGE projects. Using the low-J rotational transitional lines of H2 detected in Spitzer spectra, we determined the excitation temperature and mass of the warm gas by rotational diagram measurements. The bulk of excited H2 gas is found at the temperature range 86-137K and contributes nearly 5-17% of the total gas mass. Our analysis show that the H2 in the observed regions is excited by photo-processes in low dense photodissociation regions (PDR) in the LMC, showing tight correlation of H2 with PAH emission, dust physical conditions and average starlight intensity. We find the excitation of H2 by this process is equally important in both molecular dominated and atomic dominated regions. Two of our observed regions are associated with HII regions, N55 and N75 in the LMC. The morphology and spatial distribution of H2 emission correlates well with PAH and dust emission showing filamentary structures in the edge on view of PDR.