Searcharxiv⌕ Search

arXiv subjects

Milton Jair Santibañez-Armenta

Publications and source records attributed to Milton Jair Santibañez-Armenta.

2 recordsLinked to original sources

Modeling the shadow of Sgr A* through an eclipsing black hole

The Event Horizon Telescope (EHT) observations of Sgr\,A* resolved the shadow image and emission ring-like structure, which is associated to the photon ring of the supermassive black hole, at the galactic centre, revealing a diameter of $51.8~μ\text{as}$. The ring-like structure is consistent with that of a Kerr black hole. However, the source of the high bright regions in the image and the time variability remain an open question. Besides the plasma properties and emission models, the spacetime geometry also holds an important role. We present an image depicting the bright hot spots consistent with Sgr\,A* observations at a wavelength $ λ= 1.3\, {\rm mm}$. The image is the result of an eclipsing Schwarzschild black hole situated along the line of sight between the galactic centre and Earth. The separation from both, primary (Sgr\,A*) and secondary (eclipsing) black holes is $10233\, {\rm AU}$. The central supermassive black hole located at the centre of the galaxy has an observational mass of $4.14\times10^6\,M_{\odot}$ and the secondary eclipsing black hole has an inferred mass of $1035\,M_{\odot}$.

astro-ph.HE↗

A comparison between the deflection angles of massive and massless particles in the Shchwarzschild space-time and their consequences on black hole shadows

We present comparisons of the deflection angles of massless and massive particles in the Schwarzschild space-time. For the case of photons in a general static space-time, we construct a spatial 3D equation of motion for their path that leads to an implicit formula for the deflection angle. We then compare our results with well known results of the literature in the Schwarzschild space-time. For the case of massive particles we calculate the deflection angle only in the Schwarzschild space-time. The end result is that as the velocity of any massive particle diminishes, the deflection angle increases. To show the relevance of these comparisons, we constructed different black hole shadows for massive particles in order to be compared with a shadow made by of photons.

gr-qc↗