AstroUnit

Astronomers J. Scholtz and J. Unwin in a new study investigated the anomalous orbits of trans-Neptunian objects (TNOs) and excess in microlensing events using the 5-year Optical Gravitational Lensing Experiment (OGLE) and came to the conclusion that these gravitational anomalies can be explained if a tiny primordial black hole with a mass few times that of the Earth were to be lurking in the outskirts of the Solar System. According to the leading Planet 9 hypothesis, it is believed that a super Earth-sized rogue planet must be present to shepherd the orbits of the TNOs. However, the new study suggested that the probability of the Sun capturing a primordial black hole is comparable to the capturing of a rogue planet and suggested ways by which the scenario could be verified or falsified.    An Artist's illustration of the Solar system. Credit:  pixel4k Until now, two distinct but seemingly interconnected gravitational anomalies have been detected with no consensus reg...

A team of astronomers made a groundbreaking discovery of six closely bound galaxies being powered by a single supermassive black hole with a mass greater than a billion solar masses at a redshift of 6.31. Out of the six galaxies, four are massive star-forming galaxies and the other two are comparatively low mass galaxies. This is the first discovery of a galactic overdensity around a supermassive black hole in the first billion years of the Universe and confirms the idea that the most distant and massive black holes form and grow within massive dark matter halos in large scale structures.   MS 0735.6+7421: Six objects ranging in location from within the Milky Way to billions of light-years away: Source:  Chandra One of the major challenges in astronomy is to explain the existence of supermassive black holes powering luminous quasars at high redshifts. A quasar is an extremely bright active galactic nucleus fueled by a supermassive black hole. Quasars are typical of the size of...

 A new study proposed an interesting and robust test that can be used to infer the origin of solar mass black holes. Solar mass black holes are not expected to form from the conventional stellar evolution but can be produced naturally via neutron star (NS) implosions from the capture of small primordial black holes (PBHs) or from the accumulation of dark matter (DM). The study reports that the mass distribution of such solar-mass BHs would be similar to that of the NSs. This would differ from the mass distribution of black holes in the solar-mass range predicted either by conventional stellar evolution or early universe PBH production.  An artist's impression of IGR J17091-3624: The stellar-mass black hole with the fastest Wind. Source:  Chandra Solar mass black holes should not be confused with stellar-mass black holes. A stellar-mass black hole is a black hole formed by the gravitational collapse of a star. They have masses between 5 to several tens of solar m...

  A team of cosmologists compared the theoretical predictions of the maximal abundance of massive galaxies predicted in different dynamical dark energy (DDE) models at high redshifts z ≈ 4 − 7 with the observed abundance and derived constraints for the evolution of the dark energy equation of state parameter which is complementary to the existing probes. The study employed three different, independent probes, namely the luminous end of the stellar mass function at z ≥ 6, the spatial density of luminous galaxies detected in the submillimeter range at z = 4 − 5, and the rareness of the extreme hyperluminous infrared galaxy SPT031158 at z ≈ 7. The analysis excluded a significant fraction of parameter spaces for the DDE models but interestingly does not completely exclude the possibility that dark energy may be dynamical (i.e, changing with time). Deepest visible-light image of the Universe containing nearly 10000 galaxies. Source:  Hubble According to our current understanding of...