1 research outputs found
Confirmation Of Two New Galactic Bulge Globular Clusters: FSR 19 and FSR 25
Globular clusters (GCs) in the Milky Way (MW) bulge are very difficult to
study because: i) they suffer from the severe crowding and galactic extinction;
which are characteristic of these inner Galactic regions ii) they are more
prone to be affected by dynamical processes. Therefore, they are relatively
faint and difficult to map. However, deep near-infrared photometry like that
provided by the VISTA Variables in the Via L\'actea Extended Survey (VVVX) is
allowing us to map GCs in this crucial yet relatively uncharted region.
Our results confirm with high confidence that both FSR 19 and FSR 25 are
genuine MW bulge GCs. Each of the performed tests and resulting parameters
provides clear evidence for the GC nature of these targets. We derive distances
of 7.20.7 kpc and D=7.00.6 (corresponding to distance moduli of
14.290.08 and
14.230.07) for FSR 19 and FSR 25, respectively. Their ages and
metallicities are 11 Gyr and [Fe/H]= -0.5 dex for both clusters, which were
determined from Dartmouth and PARSEC isochrone fitting. The integrated
luminosities are M(FSR 19) = -7.72 mag and M(FSR 25) = -7.31 mag
which places them in the faint tail of the GC Luminosity Function. By adopting
a King profile for their number distribution, we determine their core and tidal
radii (, ). For FSR 19, r= 2.760.36 pc and
r=5.310.49 pc, while FSR 25 appears more extended with r=
1.920.59 pc and r=6.851.78 pc. Finally their mean GC PMs (from
Gaia EDR3) are = -2.50 0.76 mas ,
= -5.02 0.47 mas and = -2.61
1.27 mas , = -5.23 0.74 mas for
FSR 19 and FSR 25, respectively.