Related papers: 60Fe and Massive Stars
The properties of the Galactic Ridge X-ray Emission (GRXE) observed in the 2-10 keV band place fundamental constraints on various types of X-ray sources in the Milky Way. Although the primarily discrete origin of the emission is now well…
Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of ~ 10^15 eV. We report the detection of gamma rays -- tracers…
Weakly interacting massive particles, as a major candidate of dark matter (DM), may directly annihilate or decay into high-energy photons, producing monochromatic spectral lines in the gamma-ray band. These spectral lines, if detected, are…
We study the spatial distribution of the Fe 6.4 and 6.7 keV lines in the nuclear region of M82 using the Chandra archival data with a total exposure time of 500 ks. The deep exposure provides a significant detection of the Fe 6.4 keV line.…
The $\gamma$-ray background from supernovae is calculated on the basis of the reconstructed efficiency of supernova explosions from star formation at various redshifts. The calculations presented here show how Type Ia SN rates compatible…
26Al is a short-lived radioactive isotope thought to be injected into the interstellar medium (ISM) by massive stellar winds and supernovae. However, all-sky maps of 26Al emission show a distribution with a much larger scale height and…
Several short-lived radionuclides (SLRs) are know to have existed in the early Solar System (ESS). These species, which typically decay with half-lives of the order of a few million years, can be used to probe the timescale of events…
In massive stars (initial mass of > 9 solar masses), the weak s (slow neutron capture) process produces elements between Fe and Zr, enriching the Galaxy with these elements through core-collapse supernova explosions. The weak s-process…
Meteoritic evidence shows that the Solar system at birth contained significant quantities of short-lived radioisotopes (SLRs) such as 60Fe and 26Al (with half-lives of 2.6 and 0.7 Myr respectively) produced in supernova explosions and in…
We have studied the sensitivity to variations in the the triple alpha and 12C(a,g)16O reaction rates of the production of 26Al, 44Ti, and 60Fe in core-collapse supernovae. We used the KEPLER code to model the evolution of 15, 20, and 25…
We report the discovery of thermal X-ray emission from the youngest Galactic supernova remnant G1.9+0.3, from a 237-ks Chandra observation. We detect strong K-shell lines of Si, S, Ar, Ca, and Fe. In addition, we detect a 4.1 keV line with…
In this paper, we investigated the Fe K-shell lines in the supernova remnant W51C and hard X-ray sources in the proximity. We measured the intensities of Fe I K$\alpha$ and Fe XXV He$\alpha$ lines at 6.40 keV and 6.68 keV, respectively, and…
We have studied the radioactive line emission expected from solar active regions after large flares, following the production of long-lived radioisotopes by nuclear interactions of flare-accelerated ions. This delayed X- and gamma-ray line…
The nuclear $\gamma$-ray lines in the MeV range of the electromagnetic spectrum hold a vast variety of astrophysical, particle-physical, and fundamental physical information that is otherwise extreme difficult to access. MeV $\gamma$-ray…
Phosphorus (P) is one of the key ingredients for life, yet its origins in galaxies remain poorly understood. In order to investigate the production of P by supernovae, we performed near-infrared (IR) [P II] and [Fe II] line mapping of 26…
The majority of galactic gamma rays are produced by interaction of cosmic rays with matter or radiation fields. This results in a diffuse radiation concentrated in the galactic plane where the flux of cosmic rays and the density of material…
We report the detection of several absorption lines of neutral phosphorus (P, Z=15) in archival near ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We derive phosphorus…
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 consider decaying dark matter with masses $10^{7} \lesssim M \lesssim 10^{16}$ GeV, as a source of ultra-high energy (UHE) gamma rays. Using recent limits on UHE gamma-ray flux for energies $E_\gamma > 2 \cdot 10^{14}$ eV, provided by…
The observation of a radioactively powered kilonova AT~2017gfo associated with the gravitational wave-event GW170817 from binary neutron star merger proves that these events are ideal sites for the production of heavy $r$-process elements.…