A New Soft X-Ray Mode in the AM Herculis Object E2003+225
Mukai, Koji; Treves, Aldo; Maraschi, Laura; Osborne, Julian P.; Beuermann, Klaus; Charles, Philip
Netherlands
Abstract
Exosat observations of the AM Her object E2003 + 225 made in June and September 1985, are presented together with optical and ultraviolet observations. The averages of soft X-ray count rate doubled between October 1983 and June 1985; the simultaneously measured V band intensity fell by a factor of 3 and the UV flux by 20 percent. The medium-energy X-ray flux did not increase significantly. In September 1985, E2003 + 225 was observed to have a radically different soft X-ray light curve from that seen previously, but an average intensity similar to that of June 1985. The new soft X-ray light curve showed two similar peaks and two unequal minima separated by half a period. The optical light curve observed 2 days earlier showed no major change in shape. These observations provide a serious challenge to the standard model of AM Her objects.