Environmental Regulation of Dust and Star Formation Unveiled by Subaru Dual Narrow-band Imaging: Degree-scale Balmer Decrement Mapping across a z = 0.9 Supercluster
Year: 2025
Type: preprint
Abstract: We present results from a dual narrow-band imaging survey targeting the CL1604 supercluster at z = 0.9 using the Subaru Telescope. By combining the NB921 filter on HSC and the NB1244 filter on SWIMS, we can detect redshifted H$α$ and H$β$ emission lines from the supercluster. This unique technique allows us to measure both star formation rates and dust extinction for a sample of 94 emission-line galaxies across the supercluster. We find that dust extinction, estimated from the Balmer decrement (H$α$/H$β$ ratio), increases with stellar mass in star-forming galaxies, whereas relatively quiescent systems exhibit comparatively low extinction. Among galaxies with intermediate masses ($10^{8.5} < M_* < 10^{10.5}\,M_\odot$), the dust-corrected H$α$-based star formation rates align with the main sequence at this epoch. More massive galaxies, however, deviate from this relation, exhibit redder colors, and reside predominantly in higher-density environments. Although stellar mass, SFR, and galaxy color are clearly influenced by environment, we detect no strong, systematic environmental dependence of dust extinction for the whole sample.
Source: arXiv (Cornell University)
Authors: Liu, Zhaoran, Kodama, Tadayuki, Lemaux, Brian C., Kubo, Mariko, Pérez-Martínez, Jose Manuel, Koyama, Yusei, Tanaka, Ichi, Daikuhara, Kazuki, Gal, Roy R., Hung, Denise, Konishi, Masahiro, Kushibiki, Kosuke, Laishram, Ronaldo, Lubin, Lori M., Motohara, Kentaro, Takahashi, Hidenori
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7091186665
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