6533b854fe1ef96bd12af5f4
RESEARCH PRODUCT
The near-IR counterpart of IGR J17480-2446 in Terzan 5
M. T. MennaVincenzo TestaAntonino D'aiAlessandro PapittoR. IariaT. Di SalvoA. RiggioN. R. RobbaFrancesca D'antonaPaolo VenturaLuciano Burderisubject
Astrophysics::High Energy Astrophysical PhenomenaPopulationFOS: Physical sciencesContext (language use)AstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsLuminositySettore FIS/05 - Astronomia E AstrofisicaPulsarpulsars: general pulsars: individual: IGR J17480-2446 binaries: close globular clusters: individual: Terzan 5Cluster (physics)Astrophysics::Solar and Stellar AstrophysicseducationStellar evolutionSolar and Stellar Astrophysics (astro-ph.SR)Astrophysics::Galaxy AstrophysicsPhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)education.field_of_studygeneral pulsars: individual: IGR J17480-2446 binaries: close globular clusters: individual: Terzan 5 [pulsars]Astronomy and AstrophysicsGalaxyAstrophysics - Solar and Stellar AstrophysicsSpace and Planetary ScienceGlobular clusterAstrophysics - High Energy Astrophysical Phenomenadescription
Some globular clusters in our Galaxy are noticeably rich in low-mass X-ray binaries. Terzan 5 has the richest population among globular clusters of X- and radio-pulsars and low-mass X-ray binaries. The detection and study of optical/IR counterparts of low-mass X-ray binaries is fundamental to characterizing both the low-mass donor in the binary system and investigating the mechanisms of the formation and evolution of this class of objects. We aim at identifying the near-IR counterpart of the 11 Hz pulsar IGRJ17480-2446 discovered in Terzan 5. Adaptive optics (AO) systems represent the only possibility for studying the very dense environment of GC cores from the ground. We carried out observations of the core of Terzan 5 in the near-IR bands with the ESO-VLT NAOS-CONICA instrument. We present the discovery of the likely counterpart in the Ks band and discuss its properties both in outburst and in quiescence. Archival HST observations are used to extend our discussion to the optical bands. The source is located at the blue edge of the turn-off area in the color-magnitude diagram of the cluster. Its luminosity increase from quiescence to outburst, by a factor 2.5, allows us to discuss the nature of the donor star in the context of the double stellar generation population of Terzan 5 by using recent stellar evolution models.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-10-31 |