Z. -M. Zhou | Searcharxiv

arXiv2022

Discovery of Nine Super Li-rich Unevolved Stars from the LAMOST Survey

Based on the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) medium-resolution spectroscopic survey (MRS), we report the discovery of nine super Li-rich unevolved stars with A(Li) $>$ 3.8 dex. These objects show unusually high levels of lithium abundances up to three times higher than the meteoritic value of 3.3 dex, which indicates that they must have experienced a history of lithium enrichment. It is found that seven of our program stars are fast rotators with $vsini>9$ km\,s$^{-1}$, which suggests that the accretion of circumstellar matter may be the main contributor to the lithium enhancement of these unevolved stars, however, other sources cannot be excluded.

astro-ph.SR↗

arXiv2013

Far-Infrared and submillimeter properties of SDSS galaxies in the Herschel ATLAS science demonstration phase field

Using the Herschel ATLAS science demonstration phase data crossidentified with SDSS DR7 spectra, we select 297 galaxies with F250μm > 5σ. The sample galaxies are classified into five morphological types, and more than 40% of the galaxies are peculiar/compact galaxies. The peculiar galaxies show higher far-infrared/submillimeter luminosity-to-mass ratios than the other types. We perform and analyze the correlations of far-infrared/submillimeter and Hα luminosities for different morphological types and different spectral types. The Spearman rank coefficient decreases and the scatter increases with the wavelength increasing from 100 μm to 500 μm. We conclude that a single Herschel SPIRE band is not good for tracing star formation activities in galaxies. AGNs contribute less to the far-infrared/submillimeter luminosities and do not show a difference from star-forming galaxies. However, the earlier type galaxies present significant deviations from the best fit of star-forming galaxies.

astro-ph.CO↗