Astrophysical exploitation of the GRAVITY instrument


  • Call:

    IDPASC Portugal - PHD Programme 2017

  • Academic Year:

    2017 / 2018

  • Domain:


  • Supervisor:

    Paulo Garcia

  • Co-Supervisor:

    Alexandre Correia

  • Institution:

    Universidade do Porto

  • Host Institution:


  • Abstract:

    GRAVITY is the most advanced ground based optical instrument ever built. It is based at the Paranal Observatory of the European Southern Observatory, Chile. It combines the four telescopes of the Very Large Telescope Interferometer. GRAVITY allows spectro-imaging at an impressive angular resolution of 4 milli-arcseconds in the K-band at varying spectral resolutions. An astonishing astrometric precision of up to 10 micro-arcseconds is also accessible. The CENTRA/SIM team is a full member of the GRAVITY consortium with the responsibility of the instrument acquisition camera and beam monitoring system. The instrumentation activities lasted from 2009 to 2016. Currently, GRAVITY is already deployed in Paranal Observatory, Chile. The thesis topic is the astrophysical exploitation of the GRAVITY instrument. The thesis can develop along two lines depending on the candidate profile. The first is more connected to observational astrophysics. The consortium has prepared several large programmes in the domains of interest: a) planet forming disks; b) young star forming clusters; c) galactic centre supermassive black hole. The student will be integrated in one of the previous programmes. S/he will have specific responsibilities and tasks within the consortium including a well-defined astrophysical programme leading to a PhD thesis. Overall the tasks will include: a) state-of-the-art review; b) observations at Paranal Observatory – Chile; c) data reduction; d) results interpretation and publications. The second is connected to modelling orbital effects in the vicinity of the supermassive black hole. One is tidal interactions – indeed the closest stars orbiting the supermassive black hole have very eccentric orbits and tidal effects will play an important role. Another is mutual stellar interactions in the dense stellar environment of the supermassive black hole. Overall the tasks will include: a) state-of-the-art review; b) modelling tidal interactions; c) modelling stellar interactions; d) results interpretation and publications. Profile: Student with strong interest in astrophysics, data/signal processing and mathematical/physical numerical modelling. The student will be fully integrated in the GRAVITY consortium, mobility across Europe and Chile is required. References: Eisenhauer et al., “GRAVITY: Observing the Universe in Motion”, The Messenger, vol. 143, p. 16, Correia et al., “Tidal evolution of hierarchical and inclined systems”, CeMDA, 111, 105 (2011), Garcia et al., “Pre-main-sequence binaries with tidally disrupted discs: the Brgamma in HD 104237”, MNRAS; 430, 1839 (2013),