Spallation Model for the Titanium-Rich Supernova Remnant Cassiopeia A

Abstract

Titanium-rich subluminous supernovae are rare and challenge current SN nucleosynthesis models. We present a model in which ejecta from a standard supernova is impacted by a second explosion of the neutron star (a quark nova), resulting in spallation reactions that lead to (56)Ni destruction and (44)Ti creation under the right conditions. Basic calculations of the spallation products shows that a delay between the two explosions of ∼5 days reproduces the observed abundance of (44)Ti in Cas A and explains its low luminosity as a result of the destruction of (56)Ni. Our results could have important implications for light curves of subluminous as well as superluminous supernovae.

Properties and Composition of Magnetized Nuclei

“…therein. Consideration of specific SN explosion scenarios leads, in some cases, c.f., e.g., [12,13], to mass values approaching those in the observational data.…”

Hints of a second explosion (a quark nova) in Cassiopeia A supernova

“…i Spallation products: 44 Ti is a spallation by-product resulting from the interaction between the relativistic QN neutrons and the preceding SN ejecta. In particular, for time delays of a few days, we find that 44 Ti is one of the main spallation by-products on 56 Ni and amounts to ∼ 10 −4 M ⊙ (see Figure 2 in Ouyed et al 2011): a typical 10 GeV QN neutron (i.e. a Γ QN = 10) induces a multiplicity of ∼ 13 which yields a spallation by-product peaking at around A ∼ (56 − 13) = 43.…”

“…We start with predictions relevant to nucleosynthesis in Cas A: -For a time delay of a few days, among the products of spallation on 56 Ni, other than 44 Ti, are Hydrogen, Helium and Carbon in equal proportion (see Figure 2 in Ouyed et al 2011). We predict about ∼ 10 −4 M ⊙ of light nuclei adjacent to 44 Ti in the inner ejecta of Cas A, particularly in the SE direction.…”

“…This is much less than the 10 GeV which leaves most of the energy in kinetic energy of the spallated neutrons and protons. Once the kinetic energy per particle drops below ∼ 30 MeV the spallation stops (see Ouyed et al 2011) and the energy is dissipated in heat. massive SN ejecta.…”

Electrically charged strange quark stars with a non-linear equation-of-state

“…Therefore a new class of compact objects has been postulated to exist as an alternative to neutron stars. As a matter of fact, they provide us with a plausible explanation of the puzzling observation of some super-luminous supernovae [12,13], which occur in about one out of every 1000 supernovae explosions, and are more than 100 times brighter than normal supernovae. The compact objects called "strange a e-mail: grigorios.panotopoulos@tecnico.ulisboa.pt b e-mail: angel.rincon@pucv.cl quark stars" [14][15][16][17][18][19], since they are a much more stable configuration compared to neutron stars, may explain the origin of the huge amount of energy released in super-luminous supernovae.…”