1122 Hz rotation of XTE J1739-285 as a probe of quark matter in the interior of the neutron star

The recent discovery of burst oscillation at 1122Hz in the X-ray transient XTE J1739-285 supports the suggestion that it contains a submillisecond pulsar. In our estimations of the enormous dissipation effect in the transition boundary layer between quark matter core and hadron matter envelope, combing the viscosities of bulk mater in previous works, we show that XTE J1739-285 can be uniquely restricted to a quark star masquerading as a neutron star (hybrid star) that contains a pure quark matter or mixed quark-hadron matter core from minimizing gravitational wave radiation (r-mode) instability and Keplerian motion constraints at 1122Hz level through a three-parameters image. Such constraints allow the stellar radii in the range $9{\rm km}\leq R\leq 12{\rm km}$andthestellarmassesintherange$1.2M_\odot\leq M\leq 2.0M_\odot$. It perhaps implies that submillisecond pulsars are just probes of quark matter.