Cosmology

Three galaxies simulated in the IllustrisTNG Project

An article published in “The Astronomical Journal” reports the first results of an analysis of the data of the Data Release 3 (DR3) of the Lega-C astronomical survey, the largest spectroscopic survey of galaxies that we could define in their midlife since we see them as they were between about five and eight billion years ago. It offers information crucial to fully understand certain phases of the evolution of galaxies and star formation within them. Good news offered by a team of researchers led by Po-Feng Wu of the Institute of Astronomy and Astrophysics in Taipei (Taiwan) is the good consistency between the simulations of the IllustrisTNG program and of the observations conducted in that sort of census that was Lega-C.

Hamilton's Object seen by Hubble

An article published in the journal “The Monthly Notices of the Royal Astronomical Society” reports a solution to an astronomical mystery involving two galaxies that appeared to be mirror images of each other and turned out to be two images of the same galaxy doubled by a gravitational lens. A team of researchers led by Richard Griffiths of the University of Hawaii at Hilo used observations made with the Hubble Space Telescope to obtain enough information to understand the nature of what was named Hamilton’s Object because it was discovered by astronomer Timothy Hamilton. Meanwhile, a third image of the galaxy was discovered, visible in another area of ​​the sky again thanks to the gravitational lens.

The dancing ghosts seen by ASKAP

An article accepted for publication in the journal “Publications of the Astronomical Society of Australia” reports the first results of the EMU (Evolutionary Map of the Universe) survey, which allowed to discover several objects and phenomena. One of those phenomena is made by strange clouds of electrons surrounding two galaxies about a billion light-years from Earth. This survey was conducted using the ASKAP radio telescope and led to the cataloging of about 220,000 sources including the electron clouds that were compared to dancing ghosts due to their curious shape.

An article published in “The Astrophysical Journal Letters” reports a model of supermassive black hole formation that explains the rapid growth of the ones observed in the early universe. Wei-Xiang Feng, Hai-Bo Yu, and Yi-Ming Zhong propose a model in which the so-called seeds from which these gigantic black holes are formed are generated by a halo of self-interacting dark matter. According to this model, the collapse that forms the seed is accelerated by baryonic matter, common matter, a unified scenario between the two types of matter.

The galaxy NGC1052-DF2 (Image NASA, ESA, Z. Shen and P. van Dokkum (Yale University), and S. Danieli (Institute for Advanced Study))

An article published in “The Astrophysical Journal Letters” reports a precise measurement of the distance of the galaxy NGC1052-DF2 that was used to confirm that it’s almost devoid of dark matter, a notable anomaly. A team of researchers led by Pieter van Dokkum of Yale University used the Hubble Space Telescope to observe the red giants on the outskirts of NGC1052-DF2 using them as “standard candles” taking advantage of the fact that they all reach the same peak in brightness. Understanding why so few of the gravitational effects attributed to dark matter are detected in this galaxy may offer new clues to its nature.