Metallicity gradients of galaxies in the Herschel Reference Survey

摘要

We introduce a pilot project to measure metallicitiy gradients for a sample of twenty nearby galaxies drawn from the Herschel Reference Survey (HRS), representative of normal, star-forming spiral galaxies. We have obtained optical spectroscopic observations using the Very Large Telescope with the FORS2 instrument in multi-object mode, targeting individual H_Ⅱ and star-forming regions across the galaxy discs (P. I.: L. Cortese). From the ratios of the strong emission lines, we estimate the local gas-phase oxygen abundance and construct metallicity gradients. Combining these new data with Herschel PACS/SPIRE far-infrared photometric observations and H_Ⅰ 21 cm line maps, to trace the cold dust and gas respectively, will allow the study of the relationships between stars, gas, dust and metals on sub-kiloparsec scales.