437 research outputs found
The violent youth of bright and massive cluster galaxies and their maturation over 7 billion years
In this study, we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift (z ∼ 0.9), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift (z ∼ 0.1) counterparts drawn from the MCXC meta-catalogue, supplemented by Sloan Digital Sky Survey imaging and spectroscopy. We observed striking differences in the morphological, colour, spectral, and stellar mass properties of the BCGs/MMCGs in the two samples. High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies, with blue broad-band colours, properties largely absent amongst the low-redshift BCGs/MMCGs. The stellar mass of BCGs was found to increase by an average factor of 2.51 ± 0.71 from z ∼ 0.9 to z ∼ 0.1. Through this and other comparisons, we conclude that a combination of major merging (mainly wet or mixed) and in situ star formation are the main mechanisms which build stellar mass in BCGs/MMCGs. The stellar mass growth of the BCGs/MMCGs also appears to grow in lockstep with both the stellar baryonic and total mass of the cluster. Additionally, BCGs/MMCGs were found to grow in size, on average, a factor of ∼3, while their average Sérsic index increased by ∼0.45 from z ∼ 0.9 to z ∼ 0.1, also supporting a scenario involving major merging, though some adiabatic expansion is required. These observational results are compared to both models and simulations to further explore the implications on processes which shape and evolve BCGs/MMCGs over the past ∼7 Gyr
Influence of the Anchoring Modes on the Electronic and Photovoltaic Properties of D−π–A Dyes
Enhanced Electron Lifetime of CdSe/CdS Quantum Dot (QD) Sensitized Solar Cells Using ZnSe Core–Shell Structure with Efficient Regeneration of Quantum Dots
Quantum dot-sensitized solar cells having 3D-TiO2 flower-like structures on the surface of titania nanorods with CuS counter electrode
Effect of Extended π-Conjugation of the Donor Structure of Organic D–A−π–A Dyes on the Photovoltaic Performance of Dye-Sensitized Solar Cells
A Nonconjugated Bridge in Dimer-Sensitized Solar Cells Retards Charge Recombination without Decreasing Charge Injection Efficiency
Metal oxide semiconducting interfacial layers for photovoltaic and photocatalytic applications
Synthesis of Hierarchically Grown ZnO@NT-WS2 Nanocomposites
A chemically specific and facile method for growth of ZnO nanorods on WS2 nanotubes (NT-WS2) is reported. The modification strategy is based on the chalcophilic affinity of Zn, which serves as an anchor to immobilize ZnO colloids onto the WS2 nanotubes. The surface bound ZnO colloids have been used as a seed to grow ZnO nanorods on WS2 nanotubes. The immobilization of ZnO colloids was monitored by UV-vis spectroscopy and photoluminescence spectroscopy whereas the growth of ZnO nanorods was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM)
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