Detection of a white dwarf orbiting a Carbon-Oxygen depleted blue straggler in 47 Tucanae

Abstract

We have employed deep far-UV observations secured with the Solar Blind Channel of the Advanced Camera for Surveys onboard the Hubble Space Telescope to search for hot companions to five blue stragglers stars (BSSs) showing significant surface depletion of carbon (C) and oxygen (O), in the Galactic globular cluster 47 Tucanae. Such a chemical pattern has been interpreted as the chemical signature of the mass transfer formation process for the observed blue stragglers. The mass transfer origin is also expected to leave a "photometric signature" in the form of a UV-excess, as the stripped core of the donor star should be observable as a white dwarf (WD) companion orbiting the newborn BSS. We found strong evidence for the presence of a hot (T > 20000 K) WD companion to one of the investigated BSS, indicating that it likely formed through mass transfer less than 12 Myr ago. This is the first simultaneous evidence of the chemical and the photometric signatures of the mass-transfer formation channel. The lack of evidence for a hot companion to the other investigated blue stragglers is consistent with the expectation that the photometric signature (as well as the chemical one) is a transient phenomenon.

arXiv comment13 pages, 11 figures, accepted for publication in Astronomy & Astrophysics

References in corpus (70)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Gaia Data Release 3: Summary of the content and survey properties
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Na-O Anticorrelation and HB. VII. The chemical composition of first and second-generation stars in 15 globular clusters from GIRAFFE spectra
• The giant, horizontal and asymptotic branches of galactic globular clusters. I. The catalog, photometric observables and features
• On the Spectral Evolution of Hot White Dwarf Stars. I. A Detailed Model-Atmosphere Analysis of Hot White Dwarfs from SDSS DR12
• On the triple origin of blue stragglers
• The cluster Terzan 5 as a remnant of a primordial building block of the Galactic bulge
• The updated BaSTI stellar evolution models and isochrones: II. alpha-enhanced calculations
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - XVII. Public Catalogue Release
• Relative Frequencies of Blue Stragglers in Galactic Globular Clusters: Constraints for the Formation Mechanisms
• The Frequency of Binary Stars in the Core of 47 Tucanae
• A Binary Origin for Blue Stragglers in Globular Clusters
• Blue straggler production in globular clusters
• Homogeneous photometry VII. Globular clusters in the Gaia era
• Discovery of Carbon/Oxygen depleted Blue Straggler Stars in 47 Tucanae: the chemical signature of a mass-transfer formation process
• Barium & related stars and their white-dwarf companions I. Giant stars
• Thermohaline mixing and gravitational settling in carbon-enhanced metal-poor stars
• CS22964-161: A Double-Lined Carbon- and s-Process-Enhanced Metal-Poor Binary Star
• Double Blue Straggler sequences in GCs: the case of NGC 362
• Where the Blue Stragglers Roam: Searching for a Link Between Formation and Environment
• The blue plume population in dwarf spheroidal galaxies: genuine blue stragglers or young stellar population?
• Blue Stragglers as Stellar Collision Products: the Angular Momentum Question
• ON BLUE STRAGGLER FORMATION BY DIRECT COLLISIONS OF MAIN-SEQUENCE STARS
• Globular Cluster Abundances from High-Resolution Integrated Light Spectra, I: 47 Tuc
• The puzzling dynamical status of the core of the globular cluster NGC 6752
• 3D Model Atmospheres for Extremely Low-Mass White Dwarfs
• Implications for the Formation of Blue Straggler Stars from HST Ultraviolet Observations of NGC 188
• The age of the young bulge-like population in the stellar system Terzan5: linking the Galactic bulge to the high-z Universe
• Investigating mass segregation process in globular clusters with Blue Straggler Stars: the impact of dark remnants
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - XV. The dynamical clock: reading cluster dynamical evolution from the segregation level of blue straggler stars
• A new, Gaia based, catalogue of blue straggler stars in open clusters
• Detection of white dwarf companions to blue stragglers in the open cluster NGC 188: direct evidence for recent mass transfer
• Barium & related stars and their white-dwarf companions II. Main-sequence and subgiant stars
• Mergers of close primordial binaries
• Blue Straggler masses from pulsation properties. I. The case of NGC6541
• A Correlation between Blue Straggler and Binary Fractions in the core of Galactic Globular Clusters
• A Comprehensive Catalogue of Variable Stars in the field of 47 Tucanae
• The Origins of Blue Stragglers and Binarity in Globular Clusters
• The updated BaSTI stellar evolution models and isochrones. III. White Dwarfs
• Chemical and kinematical properties of BSSs and HB stars in NGC 6397
• Blue straggler stars in dwarf spheroidal galaxies II: Sculptor and Fornax
• Gravity and limb-darkening coefficients for compact stars: DA, DB, and DBA eclipsing white dwarfs
• UV Properties of Galactic Globular Clusters with GALEX II. Integrated colors
• Photometric segregation of dwarf and giant FGK stars using the SVO Filter Profile Service and photometric tools
• Optical Identification of He White Dwarfs Orbiting Four Millisecond Pulsars in the Globular Cluster 47 Tucanae
• A kinematic view of NGC 1261: structural parameters, internal dispersion, absolute proper motion and Blue Straggler Stars
• The "dynamical clock": dating the internal dynamical evolution of star clusters with Blue Straggler Stars
• The Blue Straggler Star Population in NGC 1261: Evidence for a Post-Core-Collapse Bounce State
• An extremely low-mass He white dwarf orbiting the millisecond pulsar J1342+2822B in the globular cluster M3
• Digging for relics of the past: the ancient and obscured bulge globular cluster NGC6256
• PSR J1641+3627F: a low-mass He white dwarf orbiting a possible high-mass neutron star in the globular cluster M13
• Fast rotating Blue Stragglers prefer loose clusters
• FLAMES and XSHOOTER spectroscopy along the two BSS sequences of M30
• Detection of a White Dwarf companion to a Blue Straggler Star in the outskirts of globular cluster NGC 5466 with the Ultraviolet Imaging Telescope (UVIT)
• The WFC3 Galactic Bulge Treasury Program: A First Look at Resolved Stellar Population Tools
• Radial variation of the stellar mass functions in the globular clusters M15 and M30: clues of a non-standard IMF?
• Discovery of a double sequence of blue straggler stars in the core-collapsed globular cluster NGC 6256
• Discovery of a double Blue Straggler sequence in M15: new insight into the core-collapse process
• Spectral Energy Distribution of Blue Stragglers in the core of 47 Tucanae
• Slowly cooling white dwarfs in M13 from stable hydrogen burning
• WIYN Open Cluster Study. LXXXVII. HST Ultraviolet Detection of Hot White Dwarf Companions to Blue Lurkers in M67
• The origin of the two populations of blue stragglers in M30
• Empirical measurement of the dynamical ages of three globular clusters and some considerations on the use of the dynamical clock
• GlobULeS-IV. UVIT/AstroSat detection of extremely low mass white dwarf companions to blue straggler stars in NGC 362
• A young white dwarf orbiting PSR J1835-3259B in the bulge globular cluster NGC 6652
• SAFARI I: A SPHERE discovery of a super metal-rich M dwarf companion to the star HD 86006

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