Publications

  • Unitarization of infinite-range forces: graviton-graviton scattering

    A method to unitarize the scattering amplitude produced by infinite-range forces is developed and applied to Born terms. In order to apply S-matrix techniques, based on unitarity and analyticity, we first derive an S-matrix free of infrared divergences. This is achieved by removing a divergent phase factor due to the interactions mediated by the

    Blas, D. et al.

    Advertised on:

    8
    2022
  • Rapid quasi-periodic oscillations in the relativistic jet of BL Lacertae

    Blazars are active galactic nuclei (AGN) with relativistic jets whose non-thermal radiation is extremely variable on various timescales1-3. This variability seems mostly random, although some quasi-periodic oscillations (QPOs), implying systematic processes, have been reported in blazars and other AGN. QPOs with timescales of days or hours are

    Jorstad, S. G. et al.

    Advertised on:

    9
    2022
  • The Internal Proper Motion Kinematics of NGC 346: Past Formation and Future Evolution

    We investigate the internal kinematics of the young star-forming region NGC 346 in the Small Magellanic Cloud (SMC). We used two epochs of deep F555W and F814W Hubble Space Telescope Advanced Camera for Surveys observations with an 11 yr baseline to determine proper motions and study the kinematics of different populations, as identified by their

    Sabbi, E. et al.

    Advertised on:

    9
    2022
  • A correlation between H α trough depth and inclination in quiescent X-ray transients: evidence for a low-mass black hole in GRO J0422+32

    We present a new method to derive binary inclinations in quiescent black hole (BH) X-ray transients (XRTs), based on the depth of the trough (T) from double-peaked H α emission profiles arising in accretion discs. We find that the inclination angle (i) is linearly correlated with T in phase-averaged spectra with sufficient orbital coverage (≳50 per

    Casares, J. et al.

    Advertised on:

    10
    2022
  • J-PLUS: a catalogue of globular cluster candidates around the M 81/M 82/NGC 3077 triplet of galaxies

    Globular clusters (GCs) are proxies of the formation assemblies of their host galaxies. However, few studies exist targeting GC systems of spiral galaxies up to several effective radii. Through 12-band Javalambre Photometric Local Universe Survey (J-PLUS) imaging, we study the point sources around the M 81/M 82/NGC 3077 triplet in search of new GC

    Chies-Santos, Ana L. et al.

    Advertised on:

    10
    2022