FERMI-LAT GAMMA-RAY DETECTIONS OF CLASSICAL NOVAE V1369 CENTAURI 2013 AND V5668 SAGITTARII 2015

• Published in: The Astrophysical journal Vol. 826; no. 2; p. 142
• Main Authors: Cheung, C. C., Jean, P., Shore, S. N., Stawarz, ., Corbet, R. H. D., Knödlseder, J., Starrfield, S., Wood, D. L., Desiante, R., Longo, F., Pivato, G., Wood, K. S.
• Format: Journal Article
• Language: English
• Published: United States The American Astronomical Society 01.08.2016; American Astronomical Society; Institute of Physics (IOP)
• Subjects: ASTRONOMY AND ASTROPHYSICS; cataclysmic variables; Emission; Exposure; Gamma rays; gamma-rays: stars; Novae; novae, cataclysmic variables; radiation mechanisms: general; Sciences of the Universe; Spectra; Telescopes; cataclysmic variables; novae; Astrophysics - High Energy Astrophysical Phenomena; radiation mechanisms: general; gamma-rays: stars
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/0004-637X/826/2/142

ABSTRACT We report the Fermi Large Area Telescope (LAT) detections of high-energy (>100 MeV) γ-ray emission from two recent optically bright classical novae, V1369 Centauri 2013 and V5668 Sagittarii 2015. At early times, Fermi target-of-opportunity observations prompted by their optical discoveries provided enhanced LAT exposure that enabled the detections of γ-ray onsets beginning ∼2 days after their first optical peaks. Significant γ-ray emission was found extending to 39-55 days after their initial LAT detections, with systematically fainter and longer-duration emission compared to previous γ-ray-detected classical novae. These novae were distinguished by multiple bright optical peaks that encompassed the time spans of the observed γ-rays. The γ-ray light curves and spectra of the two novae are presented along with representative hadronic and leptonic models, and comparisons with other novae detected by the LAT are discussed.