相关论文: Radioactive 26Al from the Scorpius-Centaurus Assoc…
The radioactive decay of short-lived 26Al to 26Mg has been used to estimate the timescales over which 26Al was produced in a nearby star and the protosolar disk evolved. The chronology commonly assumes that 26Al was uniformly distributed in…
We present ALMA Band 7 continuum (340 GHz) and CO J=3-2 observations for an extended sample of disks in the Upper Scorpius OB Association (Upper Sco, age ~ 10 Myr). The targets were selected from previous studies that identified new members…
Deep-sea archives that include intermediate-lived radioactive $^{60}\mathrm{Fe}$ particles suggest the occurrence of several recent supernovae inside the present-day volume of the Local Bubble during the last $\sim 10$ Myr. The isotope…
The composition of the most primitive Solar System condensates, such as calcium-aluminum-rich inclusions (CAI) and micron-sized corundum grains, show that short-lived radionuclides (SLR), e.g., 26Al, were present in the early Solar System.…
The detection of $\sim 1.5-3.2$ Myr old $^{60}$Fe on Earth indicates recent nearby core-collapse supernovae. For supernovae in multiple stars, the primary stars may become neutron stars, while former companions may become unbound and become…
Galaxy clusters could produce gamma-rays from inverse Compton scattering of cosmic ray electrons or hadronic interactions of cosmic ray protons with the intracluster medium. It is still an open question on whether gamma-ray emission ($>$…
The Scutum complex in the inner disk of the Galaxy hosts a number of young clusters and associations of red supergiant stars that are heavily obscured by dust extinction. These stars are important tracers of the recent star formation and…
We investigate the effects of thermonuclear reaction rate variations on 26Al production in massive stars. The dominant production sites in such events were recently investigated by using stellar model calculations: explosive neon-carbon…
We report on X-ray emission from members of the recently discovered Tucanae association, a group of stars with youth signatures and similar space motion. The Tucanae association is the nearest known region of recent star formation (at 45…
The kinematic properties of the Scorpius-Centaurus association were studied using spatial velocities of approximately 700 young T Tauri stars. Their proper motions and trigonometric parallaxes were selected by Zari et al. from the Gaia DR2…
We present observations of a massive star cluster near the nuclear region of the nearby starburst galaxy NGC 253. The peak of near-infrared emission, which is spatially separated by 4" from the kinematic center of the galaxy, is coincident…
When determining absolute ages of identifiably young stellar populations, results strongly depend on which stars are studied. Cooler (K, M) stars typically yield ages that are systematically younger than warmer (A, F, G) stars by a factor…
The nucleosynthesis and ejection of radioactive $^{26}$Al (t$_{1/2} \sim$ 0.72\,Myr) and $^{60}$Fe, (t$_{1/2} \sim$ 2.5\,Myr) into the interstellar medium is dominated by the stellar winds of massive stars and supernova type II explosions.…
I have used high-precision photometry and astrometry from the second data release of the Gaia mission to perform a survey for young stars associated with the Lupus clouds, which have distances of ~160 pc and reside within the Sco-Cen OB…
Short-lived radionuclides (SLRs) with lifetimes \tau < 100 Ma are known to have been extant when the Solar System formed over 4.5 billion years ago. Identifying the sources of SLRs is important for understanding the timescales of Solar…
The measurement of gamma rays at MeV energies from cosmic radioactivities is one of the key tools for nuclear astrophysics, in its study of nuclear reactions and how they shape objects such as massive stars and supernova explosions.…
We discuss how detection of gamma-ray emission from the decay of r-process nuclei can improve our understanding of r-process nucleosynthesis. We find that a gamma-ray detector with a sensitivity of 10**(-7)/cm**2/s at 100-700 keV may detect…
The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large Area…
Context. The diffuse gamma-ray emission of $^{26}{\rm Al}$ at 1.8 MeV reflects ongoing nucleosynthesis in the Milky Way, and traces massive-star feedback in the interstellar medium due to its 1 Myr radioactive lifetime. Interstellar-medium…
We discuss the properties of companions to B stars in the Scorpius-Centaurus association (age ~15 Myr, 181 B-stars). We gathered available data combining high contrast imaging samples with evidence of companions from Gaia, from eclipsing…