Detalles de publicación
PP 023091
The omnipresent flux-dependent optical dips of the black hole transient Swift J1357.2-0933
(1) Instituto de Astrofísica de Canarias, (2) Departamento de Astrofísica, Universidad de La laguna, (3) School of Physics and Astronomy, Monash University, (4) Center for Astrophysics and Space Science, New York University Abu Dhabi, (5) New York University Abu Dhabi, (6) INAF, Osservatorio Astronomico di Brera, (7) Anton Pannekoek Institute for Astronomy, University of Amsterdam, (8) European Southern Observatory, (9) Faulkes Telescope Project, School of Physics and Astronomy, Cardiff University, (10) Astrophysics Research Institute, Liverpool John Moores University.
Swift J1357.2-0933 is a black hole transient of particular interest due to the optical, recurrent dips found during its first two outbursts (in 2011 and 2017), with no obvious X-ray equivalent. We present fast optical photometry during its two most recent outbursts, in 2019 and 2021. Our observations reveal that the optical dips were present in every observed outburst of the source, although they were shallower and showed longer recurrence periods in the two most recent and fainter events. We perform a global study of the dips properties in the four outbursts, and find that they do not follow a common temporal evolution. In addition, we discover a correlation with the X-ray and optical fluxes, with dips being more profound and showing shorter recurrence periods for brighter stages. This trend seems to extend even to the faintest, quiescent states of the source. Finally, we discuss these results in the context of the possible connection between optical dips and outflows found in previous works.

