Year: 2026
Type: article
Abstract: High-energy (GeV) γ -ray emission from nova eruptions was a surprise detection by the Fermi-LAT in 2010. Since then, it has been suggested that the γ -rays from these systems are generated in collisionless nonrelativistic shocks. In this theory, the observed correlation between optical and γ -ray nova lightcurves naturally arises if a portion of the optical luminosity is reprocessed shock power. In this work, we investigate this scenario by analyzing Fermi-LAT-detected novae in varied time bins and then correlating the bin size that maximizes the nova’s significance ( t γ * ) with the nova’s optical eruption data. Furthermore, we investigate whether there is a common optical decay across the sources’ measured t γ * values in the population. We find that across our population, a nova’s t 3 (the time it takes the nova V -band brightness to decay 3 magnitudes) appears to be the favored analysis bin that optimizes the Fermi-LAT detection significance, although there is significant spread. Additionally, we report V679 Car, a source previously noted as a marginally detected γ -ray nova, as a >5 σ detection in this work. We perform cross-correlation analysis of γ -ray and optical lightcurves.
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
OpenAlex ID: W7202416266