Search results for "pair-instability"
showing 3 items of 3 documents
GW190521: A Binary Black Hole Merger with a Total Mass of 150 M⊙
2020
LIGO Scientific Collaboration and Virgo Collaboration: et al.
ALMA observations of Molecules in Supernova 1987A
2017
AbstractSupernova (SN) 1987A has provided a unique opportunity to study how SN ejecta evolve in 30 years time scale. We report our ALMA spectral observations of SN 1987A, taken in 2014, 2015 and 2016, with detections of CO, 28SiO, HCO+ and SO, with weaker lines of 29SiO.We find a dip in the SiO line profiles, suggesting that the ejecta morphology is likely elongated. The difference of the CO and SiO line profiles is consistent with hydrodynamic simulations, which show that Rayleigh-Taylor instabilities causes mixing of gas, with heavier elements much more disturbed, making more elongated structure.Using 28SiO and its isotopologues, Si isotope ratios were estimated for the first time in SN 1…
Probing the effects of hadronic acceleration at the SN 1006 shock front
2014
AbstractSupernova remnant shocks are strong candidates for being the source of energetic cosmic rays and hadron acceleration is expected to increase the shock compression ratio, providing higher post-shock densities. We exploited the deep observations of the XMM-Newton Large Program on SN 1006 to verify this prediction. Spatially resolved spectral analysis led us to detect X-ray emission from the shocked ambient medium in SN 1006 and to find that its density significantly increases in regions where particle acceleration is efficient. Our results provide evidence for the effects of acceleration of cosmic ray hadrons on the post-shock plasma in supernova remnants.