Fermi-LAT Gamma-ray Detection of the probable nova PNV J17224490-4137160
ATel #16002; C. C. Cheung (NRL), on behalf of the Fermi Large Area Telescope Collaboration
on 22 Apr 2023; 12:39 UT
Credential Certification: Teddy Cheung (Teddy.Cheung@nrl.navy.mil)
Subjects: Gamma Ray, >GeV, Nova, Transient
The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has detected gamma-ray emission from a source positionally consistent with PNV J17224490-4137160, a likely optical nova discovered by A. Pearce on 2023 Apr 20.6780 UT at 8 mag (http://www.cbat.eps.harvard.edu/unconf/followups/J17224490-4137160.html). Subsequent optical observations indicate brightening of the transient through the end of Apr 21 (AAVSO Alert Notice 821).
Preliminary analysis of LAT data using 1-day time bins indicates its first detection with >5-sigma significance between 2023 April 21.0 - 22.0 UT with a (E >100 MeV) flux of (6.5 +/- 2.1) x 10^-7 photons cm^-2 s^-1 and a photon index = 1.9 +/- 0.2 (statistical uncertainties only). The highest-energy photon, with an energy of 23.5 GeV, was detected on 2023 Apr 21 21:13:24.785.
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the ongoing activity of this source, we encourage multi-wavelength observations. For this source the Fermi LAT contact person is C.C. Cheung (Teddy.Cheung@nrl.navy.mil).
The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
