Swift X-ray detection of Nova Scorpii 2024 (V1723 Sco)
ATel #16484; Kirill Sokolovsky (UIUC), Gerardo Juan Manuel Luna (CONICET/UNAHUR), Paul Kuin (UCL/MSSL), Elias Aydi, Laura Chomiuk, Peter Craig, Isabella Molina, Jay Strader (MSU), Jennifer Sokoloski (Columbia), Justin Linford (NRAO), Koji Mukai (NASA/GSFC)
on 26 Feb 2024; 02:38 UT
Credential Certification: Kirill Sokolovsky (kirx@scan.sai.msu.ru)
The eruption of Nova Scorpii 2024 (V1723 Sco,
PNV J17261813-3809354) was first detected on 2024-02-08.827 UT and
reported the next night by A. Pearce and Y. Sakurai (CBET #5346,
ATel #16440, #16442, #16454). V1723 Sco was detected as a gamma-ray
source by Fermi-LAT starting on 2024-02-09.50 (ATel #16439,
#16441). The 63ks NuSTAR 3-78 keV X-ray observation that started on
2024-02-10.299 resulted in a non-detection (ATel #16444).
From 2024-02-10, Swift was regularly pointed at V1723 Sco.
The Swift/XRT observations resulted in non-detections with
a typical upper limit of 0.005 cts/s until 2024-02-22.268 when
the new X-ray source appeared at the nova position with a count
rate of 0.027 +/-0.006 cts/s (0.9ks exposure). Preliminary analysis
assuming the absorbing column density of n_H = 8.48x10^21 cm^-2
(Kalberla et al. 2005, A&A, 440, 775) indicates that the observed
counts may be produced by a kT=0.7 keV thermal plasma with
the unabsorbed 0.3-10 keV flux 8x10^-13 ergs/cm^2/s. The assumed
column density corresponds to the optical reddening of E(B-V) = 1.2
according to the relation of Guver & Ozel (2009, MNRAS, 400, 2050)
for R = A_V / E(B-V) = 3.1.
We thank the Neil Gehrels Swift Observatory team and
the PI, Brad Cenko, for supporting the V1723 Sco monitoring.
