相关论文: Time resolved 2 million year old supernova activit…
X-ray emission in young stellar objects (YSOs) is orders of magnitude more intense than in main sequence stars1,2, suggestive of cosmic ray irradiation of surrounding accretion disks. Protoplanetary disk irradiation has been detected around…
To foresee a solar flare neutrino signal we infer its upper and lower bound. The upper bound was derived since a few years by general energy equipartition arguments on observed solar particle flare. The lower bound, the most compelling one…
Several short-lived radionuclides (SLRs) were present in the early solar system, some of which should have formed just prior to or soon after the solar system formation. Stellar nucleosynthesis has been proposed as the mechanism for…
When a star exhausts its nuclear fuel, it either explodes as a supernova or more quiescently becomes a white dwarf, an object about half the mass of our Sun with a radius of about that of the Earth. About one fifth of white dwarfs exhibit…
We present VLA observations of 16 Type IIn and Type II-L supernovae (SNe IIn and SNe II-L) at ~1000--7000 days after explosion, probing circumstellar matter (CSM) at distances >10^16 cm from the progenitor corresponding to mass-loss over…
We argue that the radiative zone above the iron core in pre-collapse cores of massive stars can store strong magnetic fields. To reach this conclusion we use the stellar evolutionary code MESA to simulate the evolution of two stellar models…
We perform three-dimensional simulations of magnetorotational supernovae using a $39\,M_{\odot}$ progenitor star with two different initial magnetic field strengths of $10^{10}$ G and $10^{12}$ G in the core. Both models rapidly undergo…
Solar activity in the past millennia can only be reconstructed from cosmogenic radionuclide records in terrestrial archives. However, because of the diversity of the proxy archives, it is difficult to build a homogeneous reconstruction.…
Fast radio bursts (FRBs) are millisecond-duration radio bursts with unidentified extra-galactic origin. Some FRBs exhibit mild magneto-ionic environmental variations, possibly attributed to plasma turbulence or binary configuration. We…
Since its launch, the Alpha Magnetic Spectrometer - 02 (AMS-02) has delivered outstanding quality measurements of the spectra of cosmic-ray (CR) species, $\bar{p}$, $e^{\pm}$, and nuclei, $_1$H-$_8$O, $_{10}$Ne, $_{12}$Mg, $_{14}$Si, which…
Theory holds that a star born with an initial mass between about 8 and 140 times the mass of the Sun will end its life through the catastrophic gravitational collapse of its iron core to a neutron star or black hole. This core collapse…
The point X-ray source 1E 161348-5055 is observed to display pulsations with the period 6.67 hr and |\dot{P}| \leq 1.6 x 10^{-9} s/s. It is associated with the supernova remnant RCW\,103 and is widely believed to be a ~2000 yr old neutron…
We report a possible $\gamma$-ray enhancement event detected from Tycho's supernova remnant (SNR), the outcome of a type Ia supernova explosion that occurred in year 1572. The event lasted for 1.5 years and showed a factor of 3.6 flux…
We discuss the possibility of obtaining Fast Radio Bursts (FRBs) from the interior of supernovae, in particular SN 1986J. Young neutron stars are involved in many of the possible scenarios for the origin of FRBs, and it has been suggested…
With the SPI high-resolution spectrometer on INTEGRAL, new results have been obtained for long-lived radioactive 26Al and 60Fe in our Galaxy: 26Al sources apparently share the pattern of Galactic rotation in the inner Galaxy, and thus allow…
Our Sun, like all stars, formed within a cold molecular cloud. Astronomical observations and theory provide considerable detail into this process. Yet cosmochemical observations of short lived radionuclides in primitive meteorites, in…
In an effort to better calibrate the supernova rate of starburst galaxies as determined from near-IR [Fe II] features, we report on a [Fe II] 1.644 microns line-imaging survey of a sample of 42 optically-selected SNRs in M33. A wide range…
In most astrophysical situations, the radioactive decay of 56Ni to 56Co occurs via electron capture with a fixed half-life of 6.1 days. However, this decay rate is significantly slowed when the nuclei are fully ionized because K-shell…
The present study examines the response of the terrestrial magnetosphere to the long-term steady declining trends observed in solar magnetic fields and solar wind micro-turbulence levels since mid-1990's that has been continuing beyond the…
The role of magnetic field decay in normal radio pulsars is still debated. In this paper we present results which demonstrate that an episode of magnetic field decay in hot young neutron stars can explain anomalous values of braking indices…