A relic from a past merger event in the Large Magellanic Cloud

Mucciarelli, A.; Massari, D.; Minelli, A.; Romano, D.; Bellazzini, M.; Ferraro, F. R.; Matteuccí, F.; Origlia, L.

doi:10.1038/s41550-021-01493-y

Cited by 29 publications

(40 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3. In particular, we adopted the samples recently analysed through spectroscopic observations by Song et al (2021) and Mucciarelli et al (2021). While the old LMC GCs are on average all metal-poor (the majority have [Fe/H] ≤ −1.3 dex), the younger SCs have on average [Fe/H] −0.7 dex, thus they are separated by a considerable gap in the metal content.…”

Section: Discussionmentioning

confidence: 99%

KMHK 1762: Another star cluster in the Large Magellanic Cloud age gap

Gatto

Ripepi

Bellazzini³

et al. 2022

A&A

Self Cite

View full text Add to dashboard Cite

Context. The star cluster (SC) age distribution of the Large Magellanic Cloud (LMC) exhibits a gap from ∼4 to 10 Gyr ago, with an almost total absence of SCs. Within this age gap, only two confirmed SCs have been identified hitherto. Nonetheless, the star field counterpart does not show the same characteristics, making the LMC a peculiar galaxy where the star formation history and cluster formation history appear to differ significantly. Aims. We re-analysed the colour-magnitude diagram (CMD) of the KMHK 1762 SC by using the deep optical photometry provided by the ‘Yes, Magellanic Clouds Again’ survey, so as to robustly assess its age. Methods. First, we partially removed foreground and/or field stars by means of parallaxes and proper motions obtained from the Gaia Early Data Release 3. Then, we applied the Automated Stellar Cluster Analysis package to the cleaned photometric catalogue to identify the isochrone that best matches the CMD of KMHK 1762. Results. The estimated age of KMHK 1762 is log(t)=9.74 ± 0.15 dex (∼5.5 Gyr), which is more than 2 Gyr older than the previous estimation which was obtained with shallower photometry. This value makes KMHK 1762 the third confirmed age-gap SC of the LMC. Conclusions. The physical existence of a quiescent period of the LMC SC formation is questioned. We suggest it can be the result of an observational bias, originating from the combination of shallow photometry and limited investigation of the LMC periphery.

show abstract

Section: Discussionmentioning

confidence: 99%

KMHK 1762: Another star cluster in the Large Magellanic Cloud age gap

Gatto

Ripepi

Bellazzini³

et al. 2022

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…7 We also see support for several features found in the LMC's stellar population, such as counter-rotation in the LMC's core near the bar (Gaia Collaboration et al 2021), with four of the innermost six GCs exhibiting counter-rotation. This includes NGC 2005, which was recently speculated to be part of a small dwarf accreted by the LMC (Mucciarelli et al 2021), indicating there may be other clusters that were part of this accreted dwarf. However, this observed counter-rotation in the GCs may be due to distance uncertainties.…”

Section: Kinematics Of the Lmc Gc Systemmentioning

confidence: 99%

Kinematic Structure of the Large Magellanic Cloud Globular Cluster System from Gaia eDR3 and Hubble Space Telescope Proper Motions

Bennet

Alfaro-Cuello

Molina

et al. 2022

ApJ

View full text Add to dashboard Cite

We have determined bulk proper motions (PMs) for 31 LMC GCs from Gaia eDR3 and Hubble Space Telescope data using multiple independent analysis techniques. Combined with literature values for distances, line-of-sight velocities, and existing bulk PMs, we extract full 6D phase-space information for 32 clusters, allowing us to examine the kinematics of the LMC GC system in detail. Except for two GCs (NGC 2159 and NGC 2210) whose high velocities suggest they are not long-term members of the LMC system, the data are consistent with a flattened configuration that rotates like the stellar disk. The one-dimensional velocity dispersions are on the order of 30 km s−1, similar to that of old stellar populations in the LMC disk. Similarly to the case for Milky Way disk clusters, the velocity anisotropy is such that the dispersion is smallest in the azimuthal direction; however, alternative anisotropies cannot be ruled out, due to distance uncertainties. The data are consistent with a single multidimensional Gaussian velocity distribution. Given the non-collisional nature of the LMC disk, this suggests that most, if not all, of the LMC GCs are formed by a single formation mechanism in the stellar disk, despite a significant spread in age and metallicity. Any accreted halo GC population is absent or far smaller in the LMC compared to the Milky Way.

show abstract

“…In addition, we found that the average escape time of GCs from Fornax is about 6 Gyr, implying that the GCs escape process is probably over today. Mucciarelli et al (2021) investigated chemical abundances of one of LMC GCs (NGC 2005). They concluded that it may have escaped from the Fornax dSph and then has been captured by the LMC.…”

Section: Dsphs Of the Mwmentioning

confidence: 99%

The Escape of Globular Clusters from the Satellite Dwarf Galaxies of the Milky Way

Shirazi,

Haghi,

Khalaj

et al. 2022

Preprint

View full text Add to dashboard Cite

Using numerical simulations, we have studied the escape of globular clusters (GCs) from the satellite dwarf spheroidal galaxies (dSphs) of the Milky Way (MW). We start by following the orbits of a large sample of GCs around dSphs in the presence of the MW potential field. We then obtain the fraction of GCs leaving their host dSphs within a Hubble Time. We model dSphs by a Hernquist density profile with masses between 10 7 M and 7 × 10 9 M . All dSphs lie on the Galactic disc plane, but they have different orbital eccentricities and apogalactic distances. We compute the escape fraction of GCs from 13 of the most massive dSphs of the MW, using their realistic orbits around the MW (as determined by Gaia). The escape fraction of GCs from 13 dSphs is in the range 12% to 93%. The average escape time of GCs from these dSphs was less than 8 Gyrs, indicating that the escape process of GCs from dSphs was over. We then adopt a set of observationally-constrained density profiles for specific case of the Fornax dSph. According to our results, the escape fraction of GCs shows a negative correlation with both the mass and the apogalactic distance of the dSphs, as well as a positive correlation with the orbital eccentricity of dSphs. In particular, we find that the escape fraction of GCs from the Fornax dSph is between 13% and 38%. Finally, we observe that when GCs leave their host dSphs, their final orbit around the MW does not differ much from their host dSphs.

show abstract

A relic from a past merger event in the Large Magellanic Cloud

Cited by 29 publications

References 76 publications

KMHK 1762: Another star cluster in the Large Magellanic Cloud age gap

KMHK 1762: Another star cluster in the Large Magellanic Cloud age gap

Kinematic Structure of the Large Magellanic Cloud Globular Cluster System from Gaia eDR3 and Hubble Space Telescope Proper Motions

The Escape of Globular Clusters from the Satellite Dwarf Galaxies of the Milky Way

Contact Info

Product

Resources

About