相关论文: Low-metallicity (sub-SMC) massive stars

The question how much star formation is occurring at low metallicity throughout the cosmic history appears crucial for the discussion of the origin of various energetic transients, and possibly - double black hole mergers. We revisit the…

Host star metallicities have been used to infer observational constraints on planet formation throughout the history of the exoplanet field. The giant planet metallicity correlation has now been widely accepted, but questions remain as to…

The spatial metallicity distribution of star clusters in the Small Magellanic Cloud (SMC) has recently been found to correlate as a V-shaped function with the semi-major axis of an elliptical framework proposed to assume a projected galaxy…

We highlight the importance of eclipsing double-line binaries in our understanding on star formation and evolution. We review the recent discoveries of low-mass and sub-stellar eclipsing binaries belonging to star-forming regions, open…

The compilation of the metallicity values of $\omega$~Centauri stars led to detection of spatial asymmetry in the metallicity distribution of the bright giants. It was found that the most and least metal-poor objects are separated along…

Metallicity is one of the crucial factors that determine stellar evolution. To characterize the properties of stellar populations one needs to know the fraction of stars forming at different metallicities. Knowing how this fraction evolves…

We present the discovery of twelve metal-poor and distant pre-main sequence (PMS) candidates in the dwarf irregular galaxy Wolf-Lundmark-Melotte (WLM)~968 kpc away, at a present-day metallicity of [Fe/H] around $-$0.9. These candidates have…

The Hubble Space Telescope has provided the first clear evidence for weaker winds of metal-poor massive stars in the Small Magellanic Cloud, confirming theoretical predictions of the metallicity dependence of mass-loss rates and wind…

We investigate the evolution of the mass-metallicity (MZ) relation with a large sample of 53,444 star-forming galaxies (SFGs) at $0.04<z<0.12$, selected from the catalog of MPA-JHU emission-line measurements for the Sloan Digital Sky Survey…

The metal content of a galaxy's interstellar medium reflects the interplay between different evolutionary processes such as feedback from massive stars and the accretion of gas from the intergalactic medium. Despite the expected abundance…

We report on the discovery of seven low-metallicity stars selected from the Hamburg/ESO Survey, six of which are extremely metal-poor ([Fe/H]<-3.0), with four having [Fe/H]<-3.5. Chemical abundances or upper limits are derived for these…

Elliptical galaxies probably host the most metal rich stellar populations in the Universe. The processes leading to both the formation and the evolution of such stars are discussed by means of a new multi-zone photo-chemical evolution…

The emission line survey within the Calar Alto Deep Imaging Survey (CADIS) detects galaxies with very low continuum brightness by using an imaging Fabry-Perot interferometer. With spectroscopic follow-up observations of MB>~-19 CADIS…

A brief review concludes that there is now good overall agreement between theoretical estimates of the energy associated with the production of the observed metal content of the Universe and the observed extragalactic background light. In…

Surveys in the Milky Way and Large Magellanic Cloud revealed that the majority of massive stars will interact with companions during their lives. However, knowledge of the binary properties of massive stars at low metallicity, which…

We explored the regions within a radius of 25 arcsec around 473 nearby, low-metallicity G- to M-type stars using (VR)I optical filters and small-aperture telescopes. About 10% of the sample was searched up to angular separations of 90…

Utilizing low-luminosity star-forming systems discovered in the H$\alpha$ Dots survey, we present spectroscopic observations undertaken using the KPNO 4m telescope for twenty-six sources. With determinations of robust, "direct"-method metal…

We investigate the Luminosity-Metallicity (L-Z) relation in the local universe (z < 0.15) using spectra of 6387 star-forming galaxies extracted from the 2dF Galaxy Redshift Survey. This sample is by far the largest to date used to perform…

We present a catalog of 8,440 candidate very metal-poor (VMP; [Fe/H] < -2.0) main-sequence turn-off (MSTO) and red giant stars in the Milky Way, identified from low-resolution spectra in LAMOST DR10. More than 7,000 of these candidates are…

In the past few years, astronomers have uncovered several very low-temperature, metal-poor stars with halo or thick disk kinematics and peculiar spectral and photometric properties, so-called ultracool subdwarfs. These include the first…