title: A long-period, violently variable X-ray source in a young supernova remnant.
abstract: Observations with the Newton X-ray Multimirror Mission satellite show a strong periodic modulation at 6.67 +/- 0.03 hours of the x-ray source at the center of the 2000-year-old supernova remnant RCW 103. No fast pulsations are visible. If genetically tied to the supernova remnant, the source could either be an x-ray binary, composed of a compact object and a low-mass star in an eccentric orbit, or an isolated neutron star. In the latter case, the combination of its age and period would indicate that it is a peculiar magnetar, dramatically slowed down, possibly by a supernova debris disc. Both scenarios require nonstandard assumptions about the formation and evolution of compact objects in supernova explosions.
authors.affiliation: Istituto Nazionale d'Astrofisica-Istituto di Astrofisica Spaziale e Fisica Cosmica, Via Bassini 15, I-20133 Milano, Italy. deluca@iasf-milano.inaf.it
authors.forename: A
authors.initials: A
authors.lastname: De Luca
authors.forename: P A
authors.initials: PA
authors.lastname: Caraveo
authors.forename: S
authors.initials: S
authors.lastname: Mereghetti
authors.forename: A
authors.initials: A
authors.lastname: Tiengo
authors.forename: G F
authors.initials: GF
authors.lastname: Bignami