The Molecular Ism of Low Surface Brightness Spiral Galaxies
نویسنده
چکیده
I summarize some results from the recent CO survey of late-type, low surface brightness (LSB) spiral galaxies by Matthews et al. (2005). We have now detected CO emission from six late-type, LSB spirals, demonstrating that despite their typical low metallicities and low mean gas surface densities, some LSB galaxies contain a molecular medium that is traced by CO. We find that the CO-detected LSB spirals adhere to the same MH2 -FIR correlation as brighter galaxies. We also find a significant drop-off in the detectability of CO among low-to-intermediate surface brightness galaxies with Vrot < ∼ 90km s, pointing toward fundamental changes in the physical conditions of the ISM with decreasing disk mass.
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