分类： 天文学 >> 天文学 提交时间： 2023-02-19
Rongjun Huang
Andrew J. Battisti
Kathryn Grasha
Elisabete da Cunha
Claudia del P Lagos
Sarah K. Leslie
Emily Wisnioski
摘要： Previous studies have shown that the normalization and scatter of the galaxy
'main sequence' (MS), the relation between star formation rate (SFR) and
stellar mass ($M_*$), evolves over cosmic time. However, such studies often
rely on photometric redshifts and/or only rest-frame UV to near-IR data, which
may underestimate the SFR and $M_*$ uncertainties. We use MAGPHYS+photo-z to
fit the UV to radio spectral energy distributions of 12,380 galaxies in the
COSMOS field at $0.5
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Qian-Hui Chen
Kathryn Grasha
Andrew J. Battisti
Lisa J. Kewley
Barry F. Madore
Mark Seibert
Jeff A. Rich
Rachael L. Beaton
摘要： Bars play an important role in mixing material in the inner regions of galaxies and stimulating radial migration. Previous observations have found evidence for the impact of a bar on metallicity gradients but the effect is still inconclusive. We use the TYPHOON/PrISM survey to investigate the metallicity gradients along and beyond the bar region across the entire star-forming disk of five nearby galaxies. Using emission line diagrams to identify star-forming spaxels, we recover the global metallicity gradients ranging from -0.0162 to -0.073 dex/kpc with evidence that the galactic bars act as an agent in affecting in-situ star formation as well as the motions of gas and stars. We observe cases with a `shallow-steep' metallicity radial profile, with evidence of the bar flattening the metallicity gradients inside the bar region (NGC~5068 and NGC~1566) and also note instances where the bar appears to drive a steeper metallicity gradient producing `steep-shallow' metallicity profiles (NGC~1365 and NGC~1744). For NGC~2835, a `steep-shallow' metallicity gradient break occurs at a distance $\sim$ 4 times the bar radius, which is more likely driven by gas accretion to the outskirt of the galaxy instead of the bar. The variation of metallicity gradients around the bar region traces the fluctuations of star formation rate surface density in NGC~1365, NGC~1566 and NGC~1744. A larger sample combined with hydrodynamical simulations is required to further explore the diversity and the relative importance of different ISM mixing mechanisms on the gas-phase metallicity gradients in local galaxies.
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