Supergiant, fast, but not so transient 4U 1907+09
Institut für Astronomie und Astrophysik, Sand 1, 72076 Tübingen, Germany
Received: 23 July 2012
Accepted: 10 October 2012
We have investigated the dipping activity observed in the high-mass X-ray binary 4U 1907+09 and shown that the source continues to pulsate in the “off” state, noting that the transition between the “on” and “off” states may be either dip-like or flare-like. This behavior may be explained in the framework of the “gated accretion” scenario proposed to explain the flares in supergiant fast X-ray transients (SFXTs). We conclude that 4U 1907 + 09 might prove to be a missing link between the SFXTs and ordinary accreting pulsars.
Key words: stars: neutron / pulsars: individual: 4U 1907+09 / X-rays: binaries
© ESO, 2012