arXiv subjects

K. Rossi

Publications and source records attributed to K. Rossi.

2 recordsLinked to original sources

arXiv2021

CCAT-prime Collaboration: Science Goals and Forecasts with Prime-Cam on the Fred Young Submillimeter Telescope

We present a detailed overview of the science goals and predictions for the Prime-Cam direct detection camera/spectrometer being constructed by the CCAT-prime collaboration for dedicated use on the Fred Young Submillimeter Telescope (FYST). The FYST is a wide-field, 6-m aperture submillimeter telescope being built (first light in mid-2024) by an international consortium of institutions led by Cornell University and sited at more than 5600 meters on Cerro Chajnantor in northern Chile. Prime-Cam is one of two instruments planned for FYST and will provide unprecedented spectroscopic and broadband measurement capabilities to address important astrophysical questions ranging from Big Bang cosmology through reionization and the formation of the first galaxies to star formation within our own Milky Way galaxy. Prime-Cam on the FYST will have a mapping speed that is over ten times greater than existing and near-term facilities for high-redshift science and broadband polarimetric imaging at frequencies above 300 GHz. We describe details of the science program enabled by this system and our preliminary survey strategies.

astro-ph.CO↗

arXiv2020

A universal signature in the melting of metallic nanoparticles

Characterizing the melting behaviour of monometallic nanoparticles is a great challenge from both the experimental and the theoretical point of view. To this end, we disclose a universal signature based on the cluster's pair distribution function, a measurable quantity from X-ray experimental analysis tools. From a systematic investigation of metallic nanoparticles of different chemical species (Ni, Cu, Pd, Ag, Au and Pt), in a wide size range (146 to 976 atoms), and using both crystalline and five-fold twinned shapes as initial configurations, it emerges that the melting transition is signalled by the disappearance of a peak at the second nearest neighbours in the pair distribution function. To this end, we show that the relative cross-entropy of the pair distribution function between a "cold" and a "hot" reference structure correlates with their caloric curves, thus also presenting a quasi-first order transition at the melting temperature. Finally, we demonstrate the fruitful application of the proposed structural characterization method to identify the melting temperature of nanoparticles in a strongly interacting environment, where low-symmetry solid and melted phases are quasi-degenerate in energy.

cond-mat.mes-hall↗