The globular cluster VVV CL002 falling down to the hazardous Galactic centre

Minniti, Dante; Matsunaga, Noriyuki; Fernández-Trincado, José G.; Otsubo, Shogo; Sarugaku, Yuki; Takeuchi, Tomomi; Katoh, Haruki; Hamano, Satoshi; Ikeda, Yuji; Kawakita, Hideyo; Lucas, Philip W.; Smith, Leigh C.; Petralia, Ilaria; Rita Garro, Elisa; Saito, Roberto K.; Alonso-García, Javier; Gómez, Matías; Gabriela Navarro, María

doi:10.1051/0004-6361/202348100

Cited by 7 publications

(1 citation statement)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to the classification of IRS 13 displayed in Figure 8, a comprehensive global point of view on the dynamical behavior of the cluster is required to confirm the scenario proposed here of an inspiraling cluster. Speculatively, the recent observation of the globular cluster VVV CL002 could serve as a link between the inner parsec region and distances of about 300 pc (Minniti et al 2024).…”

Section: Alternative Interpretationsmentioning

confidence: 99%

The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. II. Kinematic Structure

Peißker,

Zajaček,

Labaj

et al. 2024

ApJ

View full text Add to dashboard Cite

The existence of two distinct and apparently unrelated populations of dusty stellar objects in the Nuclear Stellar Cluster of the Milky Way, namely IRS 13 and the S-cluster, are potentially prone to a general process describing the star formation history in the Galactic center (GC). The former cluster is thought to be entangled in the clockwise and counterclockwise disks, a large-scale stellar distribution revealed by the analysis of stars at different distances from Sgr A*, the supermassive black hole in the GC. Recently, this large-scale distribution was reported to exhibit a multidisk structure with at least four components. Motivated by this finding, we revisit the anisotropic IRS 13 cluster and find strong evidence for a disk-like structure. An examination of about 50 individual stellar orbits reveals a new structure that does not follow any trend known in the literature. Furthermore, we investigate the possibility of an inspiral cluster undergoing star formation processes, as proposed by several authors. Using a simplified N-body simulation to reproduce our observational results, we conclude that, under certain conditions, a massive cluster can migrate from the Circum Nuclear Disk toward the inner parsec. Based on this classification, we revisit the large-scale NACO Very Large Telescope (VLT) observations of IRS 13 and find evidence for a separation of the cluster into a gravitationally stable core remnant and a dissipating part. With the velocity-resolved H30α line and the broadband spectral energy distribution of IRS 13 E3, we provide tentative support for the existence of an intermediate-mass black hole of ∼3 × 104 M ⊙ surrounded by a hot gaseous stream.

show abstract

Section: Alternative Interpretationsmentioning

confidence: 99%

The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. II. Kinematic Structure

Peißker,

Zajaček,

Labaj

et al. 2024

ApJ

View full text Add to dashboard Cite

show abstract

A census of new globular clusters in the Galactic bulge

Bica,

Ortolani,

Barbuy

et al. 2024

A&A

View full text Add to dashboard Cite

Context. The number of known globular clusters in the Galactic bulge has been increasing steadily thanks to different new surveys. Aims. The aim of this study is to provide a census of the newly revealed globular clusters in the Galactic bulge, and analyze their characteristics. Methods. In recent years, many globular clusters have been discovered or identified. The stellar populations to which they belong are indicated in their original studies: they are mostly bulge clusters, with some identified as disk or halo members. We collected 41 new globular clusters revealed in the last decade and compared them to the known bulge clusters. Results. The new clusters are intrinsically faint with MV of around −6.0 mag. The distance to the Sun of the ensemble of well-known and new bulge clusters is compatible with the Galactocentric distance measurements from the Galactic black hole location. The ensemble sample shows metallicity peaks at [Fe/H] ∼ −1.08 ± 0.35 and −0.51 ± 0.25 dex, confirming previous findings. The age–metallicity relation of the new clusters younger than 10 Gyr is compatible with that of the ex situ samples of the dwarf galaxies Sagittarius, Canis Majoris, and Gaia-Enceladus-Sausage. The clusters with ages between 11.5 and 13.5 Gyr show no age–metallicity relation, because they are all old. This is compatible with their formation in situ in the early Galaxy.

show abstract

Over 200 globular clusters in the Milky Way and still none with super-Solar metallicity

Garro,

Minniti,

Fernández-Trincado

2024

A&A

View full text Add to dashboard Cite

A large number of globular clusters in the Milky Way have been studied in recent years, especially in hidden regions such as those of the Galactic bulge. The main goal of this work is to understand what we can learn if we include these new objects into the Milky Way globular cluster (GC) system that we know today. We compiled a catalog of 37 recently discovered globular clusters. Most of them are located in the Galactic bulge, but we also included some of the GCs for comparison. We used a range of distributions for investigating the Galactic GC system based on the metallicity, luminosity function, and age. We considered three samples. We first treated the new GC sample separately from the known and well characterized GCs. Consequently, we merged these two samples, thereby upgrading the Milky Way GC system. Furthermore, we performed a comparison between our clusters sample and the field star population. We found a double-peaked distribution for the luminosity function, which shows an elongated faint end tail. Considering the "merged" sample, the luminosity function peaks at $M_ V up 1.3$ mag and at V up 0.48$ mag. The metallicity distributions also display a bimodality trend. In this case, we compare our new sample compilation with previously published ones, finding that the distributions are in good general agreement. We also constructed the metallicity distribution for the field star sample and, by comparing it with that of the GCs, we learned that a high percentage of field stars show Fe/H $>0$; whereas we did not detect any GCs in the same metallicity range. To understand this inconsistency, we constructed the age-metallicity diagram for both samples, noting that the old and metal-poor population (age $ Gyr and Fe/H -1.0$) is represented by Gcs, while the young and metal-rich population (age $<8$ Gyr and Fe/H $>-1.0$) corresponds to field stars. From the analysis of the GC luminosity function and metallicity distribution, we can conclude that many GCs, probably those that are very faint, have survived strong dynamical processes that are typical of the bulge regions. Moreover, we cannot exclude the possibility that some of them have been accreted during past merging events, especially the metal-poor component, whereas the metal-rich population may be related to the formation of the bulge and/or disk. Finally, the difference that we notice between the cluster and field star samples should be explored in the context of the evolutionary differences among these two stellar populations.

show abstract

The globular cluster VVV CL002 falling down to the hazardous Galactic centre

Cited by 7 publications

References 42 publications

The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. II. Kinematic Structure

The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. II. Kinematic Structure

A census of new globular clusters in the Galactic bulge

Over 200 globular clusters in the Milky Way and still none with super-Solar metallicity

Contact Info

Product

Resources

About