Discovery of a new nearby globular cluster with extreme kinematics
  located in the extension of a halo stream
  Context. We report the discovery of VVV-CL160, a new nearby globular cluster
(GC) with extreme kinematics, located in the Galactic plane at $l = 10.1477$
deg, $b = 0.2999$ deg. Aims. We aim to characterize the physical properties of
this new GC and place it in the context of the Milky Way, exploring its
possible connection with the known GC NGC 6544 and with the Hrid halo stream.
Methods. VVV-CL160 was originally detected in the VISTA Variables in the V\'ia
L\'actea (VVV) survey. We use the proper motions (PMs) from the updated VVV
Infrared Astrometric Catalog (VIRAC2) to select GC members and make deep
near-infrared color-magnitude diagrams (CMDs) to study the cluster properties.
We also fit King models to the decontaminated sample to determine the GC
structural parameters. Results. VVV-CL160 has an unusually large PM for a
Galactic GC as measured with VIRAC2 and Gaia EDR3: $\mu_{\alpha}\cos(\delta)$ =
$-2.3 \pm 0.1 $ mas yr$^{-1}$ and $\mu_{\delta}$ = $-16.8 \pm 0.1 $ mas
yr$^{-1}$. The kinematics are similar to those of the known GC NGC 6544 and the
Hrid halo stream. We estimate a reddening of $E(J-K) = 1.95$ mag and an
extinction of $A_{k}= 1.40$ mag for VVV-CL160. We also measure a distance
modulus of $(m-M) = 13.01$ mag and a distance of $D_{\odot} = 4.0 \pm 0.5$ kpc.
This places the GC at $z=29$ pc above the Galactic plane and at a
galactocentric distance of $R_G=4.2$ kpc. We also measure a metallicity of
$[Fe/H] = -1.4 \pm 0.2$ dex for an adopted age of $t=12$ Gyr; King model fits
of the PM-decontaminated sample reveal a concentrated GC, with core radius
$r_{c}= 22.8"$ and tidal radius $r_{t}= 50'$. .... We also explore the possible
association of this new GC with other GCs and halo streams. Conclusions. Based
on the locations and kinematics, we suggest that VVV-CL160, along with NGC
6544, may be associated with the extension of the Hrid halo stream.
