Dynamics of GN-z11 Explored by JWST Integral Field Spectroscopy: Gaseous Rotating Disk at z=10.60 Suggestive of Weak Feedback?
Yi Xu, Masami Ouchi, Hidenobu Yajima, Hajime Fukushima, Yuichi Harikane, Yuki Isobe, Kimihiko Nakajima, Minami Nakane, Yoshiaki Ono, Hiroya Umeda, Hiroto Yanagisawa, Yechi Zhang
arXiv:2404.16963v1 Announce Type: new
Abstract: We investigate the dynamics of GN-z11, a luminous galaxy at $z=10.60$, carefully analyzing the public deep integral field spectroscopy (IFS) data taken with JWST NIRSpec IFU. While the observations of the IFS data originally targeted a He II clump near GN-z11, we find that C III]$lambdalambda1907,1909$ emission from ionized gas at GN-z11 is bright and spatially extended significantly beyond the point-spread function (PSF) in contrast with the GN-z11’s compact UV-continuum morphology. The spatially extended C III] emission of GN-z11 shows a velocity gradient, red- and blue-shifted components in the NE and SW directions, respectively, which cannot be explained by the variation of [C III]$lambda$1907/C III]$lambda$1909 line ratios. We perform forward modeling with GalPak$^mathrm{3D}$, including the effects of PSF smearing and line blending, and find that the best-fit model is a nearly edge-on disk with a rotation velocity of $v_mathrm{rot}$=$376_{-151}^{+110}$ km s$^{-1}$, a velocity dispersion of $sigma_v=113_{-48}^{+24}$ km s$^{-1}$, and a ratio of $v_mathrm{rot}/sigma_v=3.3_{-1.5}^{+1.7}$, indicative of a rotation-dominated disk at $z=10.6$. Interestingly, the disk rotation velocity is faster than the circular velocity at the virial radius, $v_mathrm{c}(r_{200})=205_{-34}^{+28}$ km s$^{-1}$, estimated from the stellar mass, suggesting a compact disk produced under weak feedback such predicted in numerical simulations. In fact, the half-light radius of the C III] emitting gas disk is only $294pm45$ pc, while the one of the stellar UV component is even smaller, $196pm12$ pc. While higher S/N data are necessary for a conclusion, these observational results would suggest that GN-z11 has a fast-rotating gaseous disk whose center possesses luminous stellar components or AGN providing weak feedback.arXiv:2404.16963v1 Announce Type: new
Abstract: We investigate the dynamics of GN-z11, a luminous galaxy at $z=10.60$, carefully analyzing the public deep integral field spectroscopy (IFS) data taken with JWST NIRSpec IFU. While the observations of the IFS data originally targeted a He II clump near GN-z11, we find that C III]$lambdalambda1907,1909$ emission from ionized gas at GN-z11 is bright and spatially extended significantly beyond the point-spread function (PSF) in contrast with the GN-z11’s compact UV-continuum morphology. The spatially extended C III] emission of GN-z11 shows a velocity gradient, red- and blue-shifted components in the NE and SW directions, respectively, which cannot be explained by the variation of [C III]$lambda$1907/C III]$lambda$1909 line ratios. We perform forward modeling with GalPak$^mathrm{3D}$, including the effects of PSF smearing and line blending, and find that the best-fit model is a nearly edge-on disk with a rotation velocity of $v_mathrm{rot}$=$376_{-151}^{+110}$ km s$^{-1}$, a velocity dispersion of $sigma_v=113_{-48}^{+24}$ km s$^{-1}$, and a ratio of $v_mathrm{rot}/sigma_v=3.3_{-1.5}^{+1.7}$, indicative of a rotation-dominated disk at $z=10.6$. Interestingly, the disk rotation velocity is faster than the circular velocity at the virial radius, $v_mathrm{c}(r_{200})=205_{-34}^{+28}$ km s$^{-1}$, estimated from the stellar mass, suggesting a compact disk produced under weak feedback such predicted in numerical simulations. In fact, the half-light radius of the C III] emitting gas disk is only $294pm45$ pc, while the one of the stellar UV component is even smaller, $196pm12$ pc. While higher S/N data are necessary for a conclusion, these observational results would suggest that GN-z11 has a fast-rotating gaseous disk whose center possesses luminous stellar components or AGN providing weak feedback.