Oral Presentation
On the outskirts of H-alpha emitters at z=0.4
Presenter: Rhythm Shimakawa (NAOJ)
We report the first detections of H-alpha emission and stellar continuum out to approximately 30 physical kpc, and H-alpha directionality in the outskirts of star-forming galaxies at z=0.4 (Shimakawa et al. 2022).
We adopt narrow-band selected H-alpha emitters at z=0.4 based on data in the Deep and Ultradeep layers of the Hyper Suprime-Cam Subaru Strategic Program. Deep narrow- and broad-band images of 8625 H-alpha emitters across 16.8 deg2 enable us to construct deep composite emission-line and continuum images. The stacked images clearly show diffuse H-alpha emission and stellar continuum, extending beyond 10 kpc at stellar masses >10E9 Msun, parts of which may originate from stellar halos. Those radial profiles are broadly consistent with each other. Moreover, we obtain a dependence of the H-alpha emission on the position angle because relatively higher H-alpha equivalent width has been detected along the minor-axis towards galaxy disks.
Our talk will close with a discussion about possible causal factors producing the H-alpha directionality.
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