Structure and Color Gradients of Ultra-diffuse Galaxies in Distant Massive Galaxy Clusters

We have measured structural parameters and radial color profiles of 108 ultra-diffuse galaxies (UDGs), carefully selected from six distant massive galaxy clusters in the Hubble Frontier Fields (HFF) in redshift range from 0.308 to 0.545. Our best-fitting GALFIT models show that the HFF UDGs have a median S\'ersic index of 1.09, which is close to 0.86 for local UDGs in the Coma cluster. The median axis-ratio value is 0.68 for HFF UDGs and 0.74 for Coma UDGs, respectively. The structural similarity between HFF and Coma UDGs suggests that they are the same kind of galaxies seen at different times and the structures of UDGs do not change at least for several billion years. By checking the distribution of HFF UDGs in the rest-frame $UVJ$ and $UVI$ diagrams, we find a large fraction of them are star-forming. Furthermore, a majority of HFF UDGs show small $\rm U-V$ color gradients within \,1\,*\,$R_{e,SMA}$ region, the fluctuation of the median radial color profile of HFF UDGs is smaller than 0.1\,mag, which is compatible to Coma UDGs. Our results indicate that cluster UDGs may fade or quench in a self-similar way, irrespective of the radial distance, in less than $\sim$ 4 Gyrs.Comment: 17 pages, 8 figures, accepted for publication in Ap

Structural and Star-forming Relations since z similar to 3: Connecting Compact Star-forming and Quiescent Galaxies

We study the evolution of the scaling relations that compare the effective density (Sigma(e), r 9.6 -9.3M(circle dot) kpc(-2), allowing the most efficient identification of compact SFGs and quiescent galaxies at every redshift

Application of the direct simulation Monte Carlo method to nanoscale heat transfer between a soot particle and the surrounding gas

Peer reviewed: YesNRC publication: Ye

Numerical Study of Oxygen and Fuel Leakage in Laminar Counterflow CH4-, C2H4-, C3H8-, and CO/H2-Air Diffusion Flames

Peer reviewed: YesNRC publication: Ye

A numerical study of soot aggregate formation in a laminar coflow diffusion flame

Peer reviewed: YesNRC publication: Ye

A numerical study of soot aggregate formation in a laminar coflow diffusion flame

Peer reviewed: YesNRC publication: Ye

Analyses of extinction and flammability limit of stretched premixed flames using the statistical narrow-band model

NRC publication: Ye