RT Journal Article
T1 Detection of RS Oph with LST-1 and modelling of its HE/VHE gamma-ray emission
A1 Alvarez Crespo, N.
A1 Baquero Larriva, A.
A1 Barrio Uña, Juan Abel
A1 Contreras González, José Luis
A1 Lainez, M.
A1 López Moya, Marcos
A1 Mas-Aguilar, A.
A1 Miener, Tjark
A1 Moya Zamanillo, V.
A1 Nieto Castaño, Daniel
AB Context. The recurrent nova RS Ophiuchi (RS Oph) underwent a thermonuclear eruption in August 2021. In this event, RS Oph was detected by the High Energy Stereoscopic System (H.E.S.S.), the Major Atmospheric Gamma Imaging Cherenkov (MAGIC), and the first Large-Sized Telescope (LST-1) of the future Cherenkov Telescope Array Observatory (CTAO) at very-high gamma-ray energies above 100 GeV. This means that novae are a new class of very-high-energy (VHE) gamma-ray emitters.Aims. We report the analysis of the RS Oph observations with LST-1. We constrain the particle population that causes the observed emission in hadronic and leptonic scenarios. Additionally, we study the prospects of detecting further novae using LST-1 and the upcoming LST array of CTAO-North.Methods. We conducted target-of-opportunity observations with LST-1 from the first day of this nova event. The data were analysed in the framework of cta-lstchain and Gammapy, the official CTAO-LST reconstruction and analysis packages. One-zone hadronic and leptonic models were considered to model the gamma-ray emission of RS Oph using the spectral information from Fermi-LAT and LST-1, together with public data from the MAGIC and H.E.S.S. telescopes.Results. RS Oph was detected at 6.6σ with LST-1 in the first 6.35 hours of observations following the eruption. The hadronic scenario is preferred over the leptonic scenario considering a proton energy spectrum with a power-law model with an exponential cutoff whose position increases from (0.26 ± 0.08) TeV on day 1 up to (1.6 ± 0.6) TeV on day 4 after the eruption. The deep sensitivity and low energy threshold of the LST-1/LST array will allow us to detect faint novae and increase their discovery rate.
PB EDP Sciences
SN 0004-6361
YR 2025
FD 2025-03
LK https://hdl.handle.net/20.500.14352/136425
UL https://hdl.handle.net/20.500.14352/136425
LA eng
NO Abe, K., et al. «Detection of RS Oph with LST-1 and modelling of its HE/VHE gamma-ray emission». Astronomy & Astrophysics, vol. 695, marzo de 2025, p. A152. DOI.org (Crossref), https://doi.org/10.1051/0004-6361/202452447.
NO Firman 317 autores.Centro de Excelencia Severo Ochoa (CEX2019-000920-S, CEX2020-001007-S, CEX2021-001131-S)Unidad de Excelencia María de Maeztu (CEX2019-000918-M, CEX2020-001058-M)Ramón y Cajal (RYC2021-032991-I, RYC2021-032552-I, RYC2020-028639-I)Juan de la Cierva-Incorporación (IJC2019-040315-I)Juan de la Cierva-formación (JDC2022-049705-I)Atracción de Talento (2019-T2/TIC-12900)Tecnologías avanzadas para la exploración del universo y sus componentes (PR47/21 TAU)Postdoctoral Junior Leader - Incoming (LCF/BQ/PI21/11830030)Plan Complementario de I+D+I  (AST22_0001)Plan Andaluz de Investigación, Desarrollo e Innovación (FQM-322)Programa Operativo de Crecimiento Inteligente (ESFRI-2017-IAC-12)
NO Ministerio de Ciencia e Innovación (España)
NO Comunidad de Madrid
NO Gobierno de Canarias
NO Junta de Andalucía
NO Generalitat de Catalunya
NO European Commission
NO Fundación La Caixa
DS Docta Complutense
RD 30 abr 2026