Discovery of an extended Horizontal Branch in the Large Magellanic Cloud globular cluster NGC1835

Abstract

We present a high angular resolution multi-wavelength study of the massive globular cluster NGC 1835 in the Large Magellanic Cloud. Thanks to a combination of optical and near ultraviolet images acquired with the WFC3 on board the HST, we performed a detailed inspection of the stellar population in this stellar system adopting a ``UV-guided search'' to optimize the detection of relatively hot stars. This allowed us to discover a remarkably extended horizontal branch (HB), spanning more than 4.5 magnitudes in both magnitude and colour from the region redder than the instability strip, up to effective temperatures of 30,000 K, and including a large population of RR Lyrae (67 confirmed variables, and 52 new candidates). This is the first time that such a feature has been detected in an extra-Galactic cluster, demonstrating that the physical conditions responsible for the formation of extended HBs are ubiquitous. The acquired dataset has been also used to redetermine the cluster distance modulus, reddening, and absolute age, yielding $(m-M{)}_0=18.58$, $E(B-V)=0.08$, and $t=12.5$ Gyr, respectively.

arXiv commentAccepted for publication in A&A

References in corpus (66)

• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Gaia Data Release 3: Summary of the content and survey properties
• Evolutionary population synthesis: models, analysis of the ingredients and application to high-z galaxies
• Resolved Massive Star Clusters in the Milky Way and its Satellites: Brightness Profiles and a Catalogue of Fundamental Parameters
• Intrinsic iron spread and a new metallicity scale for Globular Clusters
• A distance to the Large Magellanic Cloud that is precise to one per cent
• PARSEC evolutionary tracks of massive stars up to $350M_{\odot }$ at metallicities 0.0001$\le Z\le$0.04
• The ACS Survey of Galactic Globular Clusters. IX. Horizontal Branch Morphology and the Second Parameter Phenomenon
• The Star Formation History of the Large Magellanic Cloud
• Variable Stars in Galactic Globular Clusters
• Ultraviolet Radiation from Evolved Stellar Populations -- I. Models
• An ACS Survey of Globular Clusters V: Star Catalog for Each Cluster
• The total mass of the Large Magellanic Cloud from its perturbation on the Orphan stream
• Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
• The giant, horizontal and asymptotic branches of galactic globular clusters. I. The catalog, photometric observables and features
• The second and third parameters of the Horizontal Branch in Globular Clusters
• Dynamical age differences among coeval star clusters as revealed by blue stragglers
• The updated BaSTI stellar evolution models and isochrones: II. alpha-enhanced calculations
• Astrometry and photometry with HST WFC3. II. Improved geometric-distortion corrections for 10 filters of the UVIS channel
• The Chemical Composition Contrast between M3 and M13 Revisited: New Abundances for 28 Giant Stars in M3
• Ultraviolet Radiation from Evolved Stellar Populations: II. The Ultraviolet Upturn Phenomenon in Elliptical Galaxies
• Ages and Luminosities of Young SMC/LMC Star Clusters and the recent Star Formation History of the Clouds
• Surface Brightness Profiles and Structural Parameters for Globular Clusters in the Fornax and Sagittarius Dwarf Spheroidal Galaxies
• Blue Straggler Stars: a direct comparison of Star counts and population ratios in six Galactic Globular Clusters
• Blue Straggler Stars: The Spectacular Population in M80
• Multimodal Distributions along the Horizontal Branch
• The star cluster formation history of the LMC
• Global and non-global parameters of horizontal branch morphology of globular clusters
• The Identification of Blue Horizontal Branch Stars in the Integrated Spectra of Globular Clusters
• The peculiar Horizontal Branch of NGC 2808
• Blue Stragglers, Young White Dwarfs and UV-excess stars in the core of 47 Tuc
• The First Empirical Mass Loss Law for Population II Giants
• The Horizontal Branch in the UV Colour Magnitude Diagrams. II. The case of M3, M13 and M79
• 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
• ISOCAM observations of Galactic Globular Clusters: mass loss along the Red Giant Branch
• The Blue Straggler Population of the Globular Cluster M5
• Globular Clusters in the Magellanic Clouds.II: IR-Array Photometry for 12 Globulars and Contributions to the Integrated Cluster Light
• Mass loss along the red giant branch in 46 Globular Clusters and their multiple populations
• Chemical composition of the old globular clusters NGC 1786, NGC 2210 and NGC 2257 in the Large Magellanic Cloud
• UV Properties of Galactic Globular Clusters with GALEX II. Integrated colors
• Horizontal-Branch Morphology and the Photometric Evolution of Old Stellar Populations
• The "UV-route" to search for Blue Straggler Stars in Globular Clusters: first results from the HST UV Legacy Survey
• On the Iron content of NGC 1978 in the LMC: a metal rich, chemically homogeneous cluster
• Red Giant stars in the Large Magellanic Cloud clusters
• An empirical mass-loss law for Population II giants from the Spitzer-IRAC survey of Galactic globular clusters
• Probing the RGB-phase transition: Near-IR photometry of six intermediate age LMC clusters
• The "dynamical clock": dating the internal dynamical evolution of star clusters with Blue Straggler Stars
• An extremely low-mass He white dwarf orbiting the millisecond pulsar J1342+2822B in the globular cluster M3
• PSR J1641+3627F: a low-mass He white dwarf orbiting a possible high-mass neutron star in the globular cluster M13
• Digging for relics of the past: the ancient and obscured bulge globular cluster NGC6256
• Star density profiles of six old star clusters in the Large Magellanic Cloud
• 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
• Modelling realistic horizontal branch morphologies and their impact on spectroscopic ages of unresolved stellar systems
• The UV Upturn: From M32 to Distant Clusters
• Digging into the Galactic Bulge: stellar population and structure of the poorly studied cluster NGC 6316
• Expanding the time domain of multiple populations: evidences of nitrogen variations in the ~1.5 Gyr old star cluster NGC 1783
• Slowly cooling white dwarfs in M13 from stable hydrogen burning
• The double Blue Straggler sequence in NGC2173: a field contamination artefact
• Empirical measurement of the dynamical ages of three globular clusters and some considerations on the use of the dynamical clock
• A young white dwarf orbiting PSR J1835-3259B in the bulge globular cluster NGC 6652
• Slowly cooling white dwarfs in NGC 6752
• The structural properties of multiple populations in the dynamically young globular cluster NGC 2419
• A Photometric in-depth look at the core-collapsed globular cluster NGC 6284
• An ongoing tidal capture in the Large Magellanic Cloud: the low-mass star cluster KMK88-10 captured by the massive globular cluster NGC 1835?
• The "canonical" White Dwarf Cooling Sequence of M5

Cited by in corpus (4)

• Exploring the interaction between the MW and LMC with a large sample of blue horizontal branch stars from the DESI survey
• RR Lyrae Stars in Intermediate-age Magellanic Clusters: Membership Probabilities and Delay Time Distribution
• The dynamical age of the LMC globular cluster NGC 1835 using the "dynamical clock"
• Structural parameters, chronological age and dynamical age of the LMC globular cluster NGC 1754