Kavli Affiliate: Luis C. Ho
| First 5 Authors: Xinyue Liang, Si-Yue Yu, Taotao Fang, Luis C. Ho,
| Summary:
Understanding the methodological robustness in identifying and quantifying
high-redshift bars is essential for studying their evolution with the {it
James} {it Webb} Space Telescope (JWST). We used nearby spiral galaxies to
generate simulated images at various resolutions and signal-to-noise ratios,
and obtained the simulated galaxy images observed in the Cosmic Evolution Early
Release Science (CEERS) survey from Yu et al. Through a comparison of
measurements before and after image degradation, we show that the bar
measurements for massive galaxies remain robust against noise. While the
measurement of the bar position angle remains unaffected by resolution, the
measured bar ellipticity is significantly underestimated in low-resolution
images. The size measurement is on average barely affected as long as the
intrinsic bar size $a_{rm bar,,true}>2times{rm FWHM}$. To address these
effects, correction functions are derived. We also find that the effectiveness
of detecting bars remains at $sim$,100% when the $a_{rm bar,,true}/{rm
FWHM}$ is above 2, below which the rate drops sharply, quantitatively
validating the effectiveness of using $a_{rm bar,,true}>2times {rm FWHM}$
as a bar detection threshold. We analyze a set of simulated CEERS images, which
take into account observational effects and plausible galaxy (and bar-size)
evolution models, and show that a significant (and misleading) reduction in
detected bar fraction with increasing redshift would apparently result even if
the true bar fraction remained constant. Our results underscore the importance
of disentangling the true bar fraction evolution from resolution effects and
bar size growth.
| Search Query: ArXiv Query: search_query=au:”Luis C. Ho”&id_list=&start=0&max_results=3