Details

Autor(en) / Beteiligte

• Israel, G. L.
• Papitto, A.
• Esposito, P.
• Stella, L.
• Zampieri, L.
• Belfiore, A.
• Rodríguez Castillo, G. A.
• De Luca, A.
• Tiengo, A.
• Haberl, F.
• Greiner, J.
• Salvaterra, R.
• Sandrelli, S.
• Lisini, G.

Titel

Discovery of a 0.42-s pulsar in the ultraluminous X-ray source NGC 7793 P13

Ist Teil von

• Monthly notices of the Royal Astronomical Society. Letters, 2017-03, Vol.466 (1), p.L48-L52

Ort / Verlag

Oxford University Press

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Abstract NGC 7793 P13 is a variable (luminosity range ∼100) ultraluminous X-ray source proposed to host a stellar-mass black hole of less than 15 M⊙ in a binary system with orbital period of 64 d and a 18–23 M⊙ B9Ia companion. Within the EXTraS (Exploring the X-ray Transient and variable Sky) project, we discovered pulsations at a period of ∼0.42 s in two XMM–Newton observations of NGC 7793 P13, during which the source was detected at L X ∼ 2.1 × 1039 and 5 × 1039 erg s−1 (0.3–10 keV band). These findings unambiguously demonstrate that the compact object in NGC 7793 P13 is a neutron star accreting at super-Eddington rates. While standard accretion models face difficulties accounting for the pulsar X-ray luminosity, the presence of a multipolar magnetic field with B ∼ few × 1013 G close to the base of the accretion column appears to be in agreement with the properties of the system.