Regulation of black-hole accretion by a disk wind during a violent outburst of V404 Cygni

Average, normalized spectra corresponding to days 9 to 11 of the outburst. During this period the X-ray, optical and radio fluxes dropped by three orders of magnitude from the outburst peak. The spectra are very rich in emission lines that, while typical
Average, normalized spectra corresponding to days 9 to 11 of the outburst. During this period the X-ray, optical and radio fluxes dropped by three orders of magnitude from the outburst peak. The spectra are very rich in emission lines that, while typical
Advertised on
References
2016 Nature 534 75

V404 Cygni is a black hole within a binary system where a black hole of around 10 times the mass of the Sun is swallowing material from a very nearby star. During this process material falls onto the black hole and forms an accretion disc, whose hotter, innermost zones emit in X-rays. On June 2015 V404 Cygni went into outburst after a quiescence of over 25 years. During this period its brightness increased on million fold in a few days, becoming the brightest X-ray source in the sky. Optical observations carried out with the GTC 10.4m discovered the presence of a wind of cold material, which is formed in the outer layers of the accretion disc, regulating the accretion of material by the black hole. This wind, detected for the first time in a system of this type, has a very high velocity (3,000 kilometres per second) so that it can escape from the gravitational field around the black hole. At the end of this outburst the GTC observations revealed the presence of a nebula formed from material expelled by the wind (dubbed nebular phase). This phenomenon, which has been observed for the first time in a black hole, also allows us to estimate the quantity of mass ejected into the interstellar medium (see Figure).

News type
Research news

It may interest you

  • alpha_plot_density_gamma_b
    Research news
    The universal variability of the stellar initial mass function probed by the TIMER survey
    The universality of the stellar initial mass function (IMF) is one of the most widespread assumptions in modern Astronomy and yet, it might be flawed. While observations in the Milky Way generally support an IMF that is invariant with respect to the local conditions under which stars form, measurements of massive early-type galaxies systematically point towards a non-universal IMF. To bridge the gap between both sets of evidence, in this work we measured for the first time the low-mass end of the IMF from the integrated spectra of a Milky Way-like galaxy, NGC3351. We found that the slope of
    Advertised on
  • Asteroid reflectance spectra from Gaia DR3
    Research news
    Asteroid reflectance spectra from Gaia DR3: Near-UV in primitive asteroids
    Asteroids are the remnants of the planetary formation in the Solar System and so, their study helps us to understand the conditions during the early stages of the formation of our planetary system. Among asteroids, those classified as primitives present similar spectra to that of carbonaceous chondrites, i.e., they are rich in carbon and organic compounds and silicates altered by the presence of liquid water (phyllosilicates). Primitive asteroids are well characterized in various wavelength regions, showing their most diagnostic feature at 3μm. However, there is a lack of information in the
    Advertised on
  • log_n_c_n_o_bsgs_ann_groups7
    Research news
    The origin of the brightest stars in any Galaxy lies in stellar mergers
    Massive stars, those over ten times heavier than our Sun, are the conduits of most elements of the periodic table and drive the morphological and chemical makeup of their host galaxies. Yet the origin of the most luminous and hottest stars among them, called 'blue supergiants', has been debated for many decades. Blue supergiants are strange stars. First, they are observed in large numbers, despite conventional stellar physics expecting them to live only briefly. Second, they are typically found alone, despite most massive stars being born with companions. Third, the majority of them harbour
    Advertised on