English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The majority of High Mass X-ray Binaries (HMXBs) behave as X-ray pulsars,revealing that they contain a magnetised neutron star. Among the four HMXBs notshowing pulsations, and that do not show the characteristics of accreting blackholes, there is the unusual HMXB 4U 2206+54. Here we present contemporaneoushigh-energy and radio observations of this system conducted with INTEGRAL andthe VLA in order to unveil its nature. The high-energy spectra show clearindications of the presence of an absorption feature at ~32 keV. This is thethird high-energy observatory which reveals marginal evidence of this feature,giving strong support to the existence of a cyclotron resonance scatteringfeature, which implies a magnetic field of 3.6 x 10^12 G. On the other hand,the source is not detected at centimetre radio wavelengths with a 3 sigma upperlimit of 0.039 mJy. The expected radio emission for an accreting black hole inthe low/hard state, inferred from X-ray flux measurements, would be at least 60times greater than the measured upper limit. Both results firmly indicate that,in spite of the absence of pulsations, 4U 2206+54 hosts a magnetic accretingneutron star, the first one not to be observed as an X-ray pulsar.Comment: 10 pages, 7 figures. Submitted to A&A on 2004 October 19; Accepted  for Publication on 2005 March 2

Further evidence for the presence of a neutron star in 4U 2206+54. INTEGRAL and VLA observations