Modeling the chemical enrichment history of the Bulge Fossil Fragment Terzan 5

Abstract

Terzan 5 is a heavily obscured stellar system located in the inner Galaxy. It has been postulated to be a stellar relic, a Bulge Fossil Fragment witnessing the complex history of the assembly of the Milky Way bulge. In this paper, we follow the chemical enrichment of a set of putative progenitors of Terzan 5 to assess whether the chemical properties of this cluster fit within a formation scenario in which it is the remnant of a primordial building block of the bulge. We can explain the metallicity distribution function and the runs of different element-to-iron abundance ratios as functions of [Fe/H] derived from optical-infrared spectroscopy of giant stars in Terzan 5, by assuming that the cluster experienced two major star formation bursts separated by a long quiescent phase. We further predict that the most metal-rich stars in Terzan 5 are moderately He-enhanced and a large spread of He abundances in the cluster, Y = 0.26-0.335. We conclude that current observations fit within a formation scenario in which Terzan 5 originated from a pristine, or slightly metal-enriched, gas clump about one order of magnitude more massive than its present-day mass. Losses of gas and stars played a major role in shaping Terzan 5 the way we see it now. The iron content of the youngest stellar population is better explained if the white dwarfs that give rise to type Ia supernovae (the main Fe factories) sink towards the cluster center, rather than being stripped by the strong tidal forces exerted by the Milky Way in the outer regions.

14 pages, 2 tables, 8 figures, accepted for publication in ApJ

References in corpus (35)

• Bulge Formation by the Coalescence of Giant Clumps in Primordial Disk Galaxies
• What is a globular cluster? An observational perspective
• Evidence from APOGEE for the presence of a major building block of the halo buried in the inner Galaxy
• Observational constraints on the origin of the elements. IV: The standard composition of the Sun
• Star formation sustained by gas accretion
• Stellar Proper Motions in the Galactic Bulge from deep HST ACS/WFC Photometry
• The evolution of CNO isotopes: a new window on cosmic star-formation history and the stellar IMF in the age of ALMA
• The GIRAFFE Inner Bulge Survey (GIBS) III. Metallicity distributions and kinematics of 26 Galactic bulge fields
• The Gaia-ESO Survey: metallicity and kinematic trends in the Milky Way bulge
• The influence of residual gas expulsion on the evolution of the Galactic globular cluster system and the origin of the Population II halo
• Observations and modelling of a clumpy galaxy at z=1.6: Spectroscopic clues to the origin and evolution of chain galaxies
• Super and massive AGB stars - III. Nucleosynthesis in metal-poor and very metal-poor stars - Z=0.001 and 0.0001
• The Milky Way bar and bulge revealed by APOGEE DR16 and Gaia EDR3
• Ceci n'est pas a globular cluster: the metallicity distribution of the stellar system Terzan 5
• The age of the young bulge-like population in the stellar system Terzan5: linking the Galactic bulge to the high-z Universe
• How Many Components? Quantifying the Complexity of the Metallicity Distribution in the Milky Way Bulge with APOGEE
• Metallicity-dependendent kinematics and morphology of the Milky Way bulge
• A new class of fossil fragments from the hierarchical assembly of the Galactic bulge
• The bimodal [Mg/Fe] versus [Fe/H] bulge sequence as revealed by APOGEE DR14
• Exploring the stellar age distribution of the Milky Way Bulge using APOGEE
• The chemical evolution of Omega Centauri's progenitor system
• Chemical enrichment in very low-metallicity environments: Bootes I
• Mapping the stellar age of the Milky Way bulge with the VVV. I. The method
• Nucleosynthesis of binary-stripped stars
• A panchromatic view of the bulge globular cluster NGC 6569
• GALACTICNUCLEUS: A high-angular-resolution $JH{K}_s$ imaging survey of the Galactic centre. IV. Extinction maps and de-reddened photometry
• The cosmic carbon footprint of massive stars stripped in binary systems
• Mapping the Interstellar Reddening and Extinction towards Baade's Window Using Minimum Light Colors of ab-type RR Lyrae Stars. Revelations from the De-reddened Color-Magnitude Diagrams
• The evolution of white dwarfs resulting from helium-enhanced, low-metallicity progenitor stars
• On the role of Type Ia supernovae in the second generation star formation in globular clusters
• Clues to the formation of Liller 1 from modeling its complex star formation history
• The Blanco DECam Bulge Survey. I. The Survey Description and Early Results
• Pulse Profiles and Polarization of Terzan 5 Pulsars
• Detailed $\alpha$ abundance trends in the inner Galactic bulge
• SDSS-IV MaNGA: the "G-dwarf problem" revisited

Cited by in corpus (9)

• The Bulge Cluster Origin (BulCO) survey at the ESO-VLT: probing the early history of the Milky Way assembling. Design and first results in Liller1
• A Photometric in-depth look at the core-collapsed globular cluster NGC 6284
• On the manifest link between Terzan 5 and the Galactic bulge
• Studying stellar populations in Omega Centauri with phylogenetics
• Bulge Fossil Fragments as a new population of factories of gravitational wave sources in the Galaxy
• Probing populations of dark stellar remnants in the globular clusters 47 Tuc and Terzan 5 using pulsar timing
• The dynamical evolution of the stellar clumps in the Sparkler galaxy
• The multi-age stellar populations of Terzan 5 as revealed by JWST
• A candidate to the long sought optical counterpart to the Rapid Burster in the bulge fossil fragment Liller 1