Astrofísicas: Agujeros negros

  • Publicación
    Simultaneous INTEGRAL, RXTE, Swift and FT South observations of the transition of GX 339-4
    As GX 339-4 has started to leave the Low/Hard State (ATel #2545), we triggered the 2nd part of our INTEGRAL campaign on GX 339-4 in the declining phase of the...
  • Publicación
    Simultaneous NICER and NuSTAR observations of the ultraluminous source NGC 4190 ULX-1
    Aims: We present an X-ray analysis of three different XMM-Newton observations together with simultaneous NICER and NuSTAR observations of the ultraluminous X...
  • Publicación
    Simultaneous X-ray and optical spectroscopy of V404 Cygni supports the multi-phase nature of X-ray binary accretion disc winds
    Observational signatures of accretion disc winds have been found in a significant number of low-mass X-ray binaries at either X-ray or optical wavelengths. The...
  • Publicación
    SOAR/Goodman Spectroscopic Assessment of Candidate Counterparts of the LIGO/Virgo Event GW190814
    On 2019 August 14 at 21:10:39 UTC, the LIGO/Virgo Collaboration (LVC) detected a possible neutron star-black hole merger (NSBH), the first ever identified. An...
  • Publicación
    Soft-state optical spectroscopy of the black hole MAXI J1305-704
    The X-ray dipper MAXI J1305-704 is a dynamically confirmed black hole (BH) X-ray binary discovered a decade ago. While its only outburst has been studied in...
  • Publicación
    Spectroscopic confirmation of the AGN nature of Swift J1933.9+3258 (=1RXS J193347.6+325422)
    We report on optical spectroscopy of Swift J1933.9+3258 (=1RXS J193347.6+325422). This X-ray source has recently been classified as a likely radio-quiet AGN on...
  • Charla
    Stellar black holes at the dawn of the Universe: cosmological implications
    The so called "dark ages" of the universe began about 400.000 years after the Big Bang as matter cooled down and space became filled with neutral hydrogen for...
  • Charla
    Structure of the Kerr-Schild geometry, beam-like solutions and fluctuations of the black-hole horizon
    Exact solutions of the Einstein-Maxwell equations in the Kerr-Schild formalism are discussed. We show that black hole horizon is unstable with respect to...
  • Publicación
    Swift J1357.2-0933: a massive black hole in the Galactic thick disc
    Swift J1357.2-0933 is one of the shortest orbital period black hole X-ray transients. It exhibited deep optical dips together with an extremely broad H α line...