NuSTAR Detection of X-Rays Concurrent with Gamma-Rays in the Nova V5855 Sgr
| Autor: | Thomas Nelson, Terry Bohlsen, Koji Mukai, Brian D. Metzger, Indrek Vurm, J. L. Sokoloski, K. L. Li, Paul Luckas, Justin D. Linford, Laura Chomiuk |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics 010504 meteorology & atmospheric sciences Astrophysics::High Energy Astrophysical Phenomena Gamma ray FOS: Physical sciences Astronomy and Astrophysics Astrophysics Nova (laser) 01 natural sciences Shock (mechanics) Luminosity Particle acceleration 13. Climate action Space and Planetary Science 0103 physical sciences Thermal Astrophysics::Solar and Stellar Astrophysics Astrophysics - High Energy Astrophysical Phenomena Spectroscopy Ejecta 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences |
| Zdroj: | The Astrophysical Journal. 872:86 |
| ISSN: | 1538-4357 |
| Popis: | We report the first detection of hard (>10 keV) X-ray emission simultaneous with gamma rays in a nova eruption. Observations of the nova V5855 Sgr carried out with the NuSTAR satellite on Day 12 of the eruption revealed faint, highly absorbed thermal X-rays. The extreme equivalent hydrogen column density towards the X-ray emitting region (~3 x 10$^{24}$ cm$^{-2}$) indicates that the shock producing the X-rays was deeply embedded within the nova ejecta. The slope of the X-ray spectrum favors a thermal origin for the bulk of the emission, and the constraints of the temperature in the shocked region suggest a shock velocity compatible with the ejecta velocities inferred from optical spectroscopy. While we do not claim the detection of non-thermal X-rays, the data do not allow us to rule out an additional, fainter component dominating at energy above 20 keV, for which we obtained upper limits. The inferred luminosity of the thermal X-rays is too low to be consistent with the gamma-ray luminosities if both are powered by the same shock under standard assumptions regarding the efficiency of non-thermal particle acceleration and the temperature distribution of the shocked gas. Accepted for publication in the Astrophysical Journal - 10 pages, 5 figures |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|