Gamma-Ray Lines from Novae

The e-ASTROGAM mission

“…II). With the predicted line sensitivity, e-ASTROGAM will also (i) provide a much better map of the 511 keV radiation from positron annihilation in the inner Galaxy, (ii) uncover ∼10 young, 44 Ti-rich SN remnants in the Galaxy and thus provide new insight on the explosion mechanism of core-collapse SNe (iii) detect for the first time the expected [46] line from 22 Na decay in novae hosted by ONe white dwarfs, (iv) provide a new constraint on the nuclear equation of state of neutron stars by detecting the predicted [31] redshifted 2.2 MeV line from Scorpius X-1, and (iv) measure the energy density of low-energy cosmic rays in the inner With etracking (a) Source spectrum is an E -2 power-law in the range ΔE. (b) ARM radius.…”

The Advanced Compton Telescope mission

“…Therefore, prompt emission consisting of a 511 keV line plus a continuum below this energy (with a cut-off at 20-30 keV) is expected [62,40]. In addition, !-ray lines at 478 keV ( 7 Be decay in CO novae) and 1275 keV ( 22 Na decay in ONe novae), are expected to last a couple of months and years, respectively [20,21,41]. It is known that around a third to half of novae occur on ONe white dwarfs (the global galactic nova rate is 35 per year).…”

Absolute determination of theNa22(p,γ)Sallaska1, Wrede2, Garcı́a3 et al. 2011Phys. Rev. C255340View full textAdd to dashboardCite

“…Indeed, this isotope has been observed in the Galaxy [6], but its long half life precludes the identification of its progenitor, and novae are only expected to make a secondary contri-bution to its Galactic abundance [7,8]. Other gammaray emitters can provide more direct constraints on nova models [9]. An example is 22 Na (t 1/2 = 2.603 years, E γ = 1.275 MeV), which has not yet been observed in the Galaxy.…”