Skip to main content

FIVE CONCENTRIC RINGS AROUND THE BLACK HOLE V404CYG


Image Credit: G. Vasilopoulos & M. Petropoulou.
RGB image of the X-ray dust scattered rings observed by Swift/XRT. The Swift/XRT field-of-view is enclosed by the green circle, while a white circle of radius 9′ is overplotted for guiding the eye. The black hole is located at the center of the rings.

First detection of X-ray dust scattered rings from the Galactic low mass X-ray binary V404 Cyg. The observation of the system with Swift/XRT on June 30 2015 revealed the presence of five concentric ring-like structures centred at the position of V404 Cyg.


A low-mass X-ray binary (LMXB) is a binary star where one of the components is either a black hole or neutron star. The X-rays are produced by matter falling from the donor star that usually is a relatively normal star less massive than the compact object.
V404 Cyg is an  X-ray transient  source with three confirmed historical outbursts in 1936, 1958 and 1989. The black hole has an estimated mass of ~12 solar mass. The donor star has a mass of ∼1 solar mass and it is a late type G or early type K star (it is similar to our sun).

The study of the rings can provide information for the properties of the interstellar medium and the dust distribution in the direction of the black hole.

► Read more>>
http://arxiv.org/pdf/1511.00932v1.pdf
http://mnras.oxfordjournals.org/content/455/4/4426.abstract

► Image Credit:
G. Vasilopoulos & M. Petropoulou

Comments

Popular posts from this blog

ORBITAL PERIODS OF THE PLANETS

For orbital period generally we refer to the sidereal period, that is the temporal cycle that it takes an object to make a full orbit, relative to the stars. This is the orbital period in an inertial (non-rotating) frame of reference (365,25 days for the earth).

A Sapphire Super-Earth

Twenty-one light years away, in the constellation Cassiopeia, a planet by the name of HD219134 b orbits its star with a year that is just three days long. With a mass almost five times that of Earth, it is what is known as a super-Earth. Unlike our planet, however, these super-Earths were formed at high temperatures close to their host star and contain high quantities of calcium, aluminum and their oxides – including sapphire and ruby. HD219134 b is one of three candidates likely to belong to a new, exotic class of exoplanets. These objects are completely different from the majority of Earth-like planets. They have 10 to 20 percent lower densities than Earth. Researchers looked at different scenarios to explain the observed densities. For example, a thick atmosphere could lead to a lower overall density. But two of the exoplanets studied, 55 Cancri e and WASP-47 e, orbit their star so closely that their surface temperature is almost 3,000 degrees and they would have lost this ...

CONTAMINATION BY SUPERNOVAE IN GLOBULAR CLUSTERS

Credit: ALMA (ESO/NAOJ/NRAO)/Alexandra Angelich (NRAO/AUI/NSF) Only a small amount of the supernovae products remains trapped within globular clusters and this "catch" only occurs in the most massive cases (mass cluster ≥ 10^6 solar masses).