Hard X-ray emission and ${}^{44}$Ti line features of Tycho Supernova Remnant

Abstract

A deep hard X-ray survey of the INTEGRAL satellite first detected the non-thermal emission up to 90 keV in the Tycho supernova (SN) remnant. Its 3 -- 100 keV spectrum is fitted with a thermal bremsstrahlung of $kT\sim 0.81\pm 0.45$ keV plus a power-law model of $\Gamma \sim 3.01\pm 0.16$. Based on the diffusive shock acceleration theory, this non-thermal emission, together with radio measurements, implies that Tycho remnant may not accelerate protons up to $>$PeV but hundreds TeV. Only heavier nuclei may be accelerated to the cosmic ray spectral "knee". In addition, we search for soft gamma-ray lines at 67.9 and 78.4 keV coming from the decay of radioactive ${}^{44}$Ti in Tycho remnant by INTEGRAL. A bump feature in the 60-90 keV energy band, potentially associated with the ${}^{44}$Ti line emission, is found with a marginal significance level of $\sim$ 2.6 $\sigma$. The corresponding 3 $\sigma$ upper limit on the ${}^{44}$Ti line flux amounts to 1.5 $\times$ 10${}^{-5}$ ph cm${}^{-2}$ s${}^{-1}$. Implications on the progenitor of Tycho SN, considered to be the prototype of type Ia SN, are discussed.

15 pages, 4 figures, accepted for publication in ApJ

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Cited by in corpus (8)

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• Swift/BAT detection of hard X-rays from Tycho's Supernova Remnant: Evidence for Titanium-44
• Spatial distribution of X-ray emitting ejecta in Tycho's SNR: indications of shocked Titanium
• A Nucleosynthetic Origin for the Southwestern Fe-rich Structure in Kepler's Supernova Remnant
• Merging of a CO WD and a He-rich white dwarf to produce a type Ia supernovae
• Exploration of Aspherical Ejecta Properties in Type Ia Supernova: Progenitor Dependence and Applications to Progenitor Classification
• NuSTAR observations of G11.2-0.3
• X-ray Measurements of ${}^{44}$Ti in Four Supernova Remnants