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

A UNIVERSE WITHOUT A CENTER?

Image Credit: Eugenio Bianchi, Carlo Rovelli & Rocky Kolb. According to the standard theories of cosmology, there is no center of the universe. In a conventional explosion, material expand out from a central point and the instinct suggests that with the Big Bang happened something similar. But the Big Bang was not an explosion like that at all: it was an explosion of space, not an explosion in space . The Big Bang happened everywhere in the Universe.

UNIVERSE IS FINITE OR INFINITE?

Art by Moonrunner Design   At present there is no answer to this question. However I will try to list the hypothesys currently on the table with related issues.

New research looks at how ‘cosmic web’ of filaments alters star formation in galaxies

Cosmic Web. Credit: NASA Astronomer Gregory Rudnick sees the universe crisscrossed by something like an interstellar superhighway system. Filaments — the strands of aggregated matter that stretch millions of light years across the universe to connect galaxy clusters — are the freeways. “Galaxies will flow along filaments from less dense parts of the universe to more dense parts of the universe, kind of like cars flowing down a highway to the big city. In this case, they are going toward big clusters, being pulled by the gravity of those large concentrations of matter,” he said. “I’m interested in how galaxies are affected by the regions in which they live,” Rudnick said. “Filaments are the first place where galaxies come into contact with higher density regions of the universe. If a galaxy in a ‘rural’ part of the universe enters a dense part, I want to know how its properties change — for example, does it change the number of stars it forms, or does its shape get altered? Us...