Kinematical and dynamical properties of recently discovered bulge and disc star clusters with WINERED

Abstract

Context. Galactic globular clusters are a very important tool in explaining the characteristics of the Milky Way. Therefore it is essential to determine the kinematical and dynamical properties of the new star cluster candidates, especially at the low-latitude regions that suffer from heavy extinction and crowding. Aims. In this work, we report the first spectroscopic analysis for seven recently identified star cluster candidates: CWNU 4193, FSR 1700, Garro 02, Patchick 98, FSR 1767, Mercer 08, and BH 140. Our aim is to determine the kinematical properties, such as the mean cluster radial velocity, and the dynamical properties, such as the orbital parameters and the global dynamical mass, of these clusters in order to spectroscopically confirm the nature of these seven stellar systems. Methods. We collected the high-resolution infrared spectra of 33 candidate members of these clusters using the WINERED spectrograph mounted on the Magellan Clay 6.5 m telescope. Using the WINERED spectra, we measured the radial velocity of each individual star to confirm its membership in the clusters. From the confirmed members, we derived the mean cluster radial velocity of each cluster. In addition, for these clusters, we computed the orbital elements using the GravPot16 model and estimated their global dynamical masses based on the virial theorem. Results. As a result, we confirmed enough member stars (from three to seven stars per cluster) to reliably derive the mean cluster radial velocity and compute the orbital parameters of the clusters CWNU 4193, FSR 1700, Garro 02, and BH 140. For clusters CWNU 4193, FSR 1700, and BH 140, the number of confirmed members also allowed us to estimate their global dynamical masses. Therefore, we successfully derived key kinematical and dynamical properties for four of the most obscured star clusters in the Milky Way.

References in corpus (19)

• Gaia Data Release 3: Summary of the content and survey properties
• Determining stellar atmospheric parameters and chemical abundances of FGK stars with iSpec
• Gaia EDR3 view on Galactic globular clusters
• Modern stellar spectroscopy caveats
• A systematic survey for infrared star clusters with |b|<20deg using 2MASS
• Improved GRAVITY astrometric accuracy from modeling of optical aberrations
• Cross-Correlation and Maximum Likelihood Analysis: A New Approach to Combine Cross-Correlation Functions
• Extinction ratios in the inner Galaxy as revealed by the VVV survey
• Chemodynamics of newly identified giants with globular cluster like abundance patterns in the bulge, disk, and halo of the Milky Way
• The VISTA Variables in the Vía Láctea eXtended (VVVX) ESO public survey: Completion of the observations and legacy
• FSR1767 - a new globular cluster in the Galaxy
• FeI lines in 0.91-1.33 $\mu$m spectra of red giants for measuring the microturbulence and metallicities
• Unveiling the nature of 12 new low-luminosity Galactic Globular Cluster Candidates
• Orbits of globular clusters computed with dynamical friction in the Galactic anisotropic velocity dispersion field
• Survey for Distant Stellar Aggregates in Galactic Disk: Detecting Two Thousand Star Clusters and Candidates, along with the Dwarf Galaxy IC10
• A new low-luminosity globular cluster discovered in the Milky Way with the VVVX survey
• Gaia-IGRINS synergy: Orbits of Newly Identified Milky Way Star Clusters
• Signature of systemic rotation in 21 Galactic Globular Clusters from APOGEE-2
• Three New Galactic Globular Cluster Candidates: FSR1700, Teutsch67, and CWNU4193