JWST and ALMA Multiple-Line Study in and around a Galaxy at $z=8.496$: Optical to FIR Line Ratios and the Onset of an Outflow Promoting Ionizing Photon Escape

Understand

We present ALMA deep spectroscopy for a lensed galaxy at $z_{\rm spec}=8.496$ with $\log(M_{\rm star}/M_{\odot})\sim7.8$ whose optical nebular lines and stellar continuum are detected by JWST/NIRSpec and NIRCam Early Release Observations in SMACS0723.

• Our ALMA spectrum shows [OIII]88$\mu$m and [CII]158$\mu$m line detections at $4.0\sigma$ and $4.5\sigma$, respectively.
• The redshift and position of the [OIII] line coincide with those of the JWST source, while the [CII] line is blue-shifted by 90 km s$^{-1}$ with a spatial offset of $0.''5$ ($\approx0.5$ kpc in source plane) from the JWST source.
• The NIRCam F444W image, including [OIII]$\lambda$5007 and H$\beta$ line emission, spatially extends beyond the stellar components by a factor of $>8$.