Radial velocities of fifteen double-mode bulge RR Lyrae ( RR01 ) stars are presented , six of which belong to a compact group of RR01 stars in pulsation space , with the ratio of first-overtone period to fundamental-mode period , P _ { fo } / P _ { f } \sim 0.74 , and P _ { f } \sim 0.44 .
It has been suggested that these pulsationally clumped RR01 stars are a relic of a disrupted dwarf galaxy or stellar cluster , as they also appear to be spatially coherent in a vertical strip across the bulge .
However , the radial velocities of the stars presented here , along with proper motions from Gaia DR2 , show a large range of radial velocities , proper motions and distances for the bulge RR01 stars in the pulsation clump , much larger than the RR01 stars in the Sagittarius dwarf galaxy ( Sgr ) .
Therefore , in contrast to the kinematics of the RRL stars belonging to Sgr , and those in and surrounding the bulge globular cluster NGC 6441 , there is no obvious kinematic signature within the pulsationally clumped RR01 stars .
If the pulsationally clumped RR01 stars belonged to the same system in the past and were accreted , their accretion in the inner Galaxy was not recent , as the kinematic signature of this group has been lost ( i . e . , these stars are now well-mixed within the inner Galaxy ) .
We show that the apparent spatial coherence reported for these stars could have been caused by small number statistics .
The orbits of the RR01 stars in the inner Galaxy suggest they are confined to the innermost \sim 4 kpc of the Milky Way .