We report the results of the first X-ray observation of the luminous and helium-rich O-type subdwarf BD +37° 442 carried out with the XMM-Newton satellite in 2011 August. X-ray emission is detected with a flux of about 3× 10-14 erg cm-2 s-1 (0.2-1 keV) and a very soft spectrum, well fit by the sum of a blackbody with temperature kT BB = 45+11 - 9 eV, and a power law with a poorly constrained photon index. Significant pulsations with a period of 19.2 s are detected, indicating that the X-ray emission originates in a white dwarf or neutron star companion, most likely powered by accretion from the wind of BD +37° 442.

Discovery of a Compact Companion to the Hot Subdwarf Star BD +37° 442

Tiengo A;Esposito P
2012-01-01

Abstract

We report the results of the first X-ray observation of the luminous and helium-rich O-type subdwarf BD +37° 442 carried out with the XMM-Newton satellite in 2011 August. X-ray emission is detected with a flux of about 3× 10-14 erg cm-2 s-1 (0.2-1 keV) and a very soft spectrum, well fit by the sum of a blackbody with temperature kT BB = 45+11 - 9 eV, and a power law with a poorly constrained photon index. Significant pulsations with a period of 19.2 s are detected, indicating that the X-ray emission originates in a white dwarf or neutron star companion, most likely powered by accretion from the wind of BD +37° 442.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12076/95
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 17
  • ???jsp.display-item.citation.isi??? 16
social impact