Galaxies

An ancient galaxy with a frantic star formation

An article published in the journal “Nature” describes the mapping of a galaxy known as COSMOS-AzTEC-1 that showed peculiar characteristics. A team of astronomers used the ALMA radio telescope to study this starburst galaxy, a class in which there’s considerable star formation. COSMOS-AzTEC-1 is very far away so we see it as it was 12.4 million years ago and very massive and could be the progenitor of today’s large elliptical galaxies so this type of research could provide new information on their evolution.

Milky Way panorama (Image ESO/S. Brunier)

An article published in the journal “Nature” describes a research on star formation in the Milky Way. According to Masafumi Noguchi of Tohoku University there were two star formation periods separated by 2 billion years. In essence, our galaxy had a first period in which it was vital then it died and after about 2 billion years star formation restarted in a sort of second life. According to this theory, during that period of death the gas present in the Milky Way got enriched with iron, the reason why stars like the Sun have a greater amount of it than others.

HDUV GOODS-North Field Compass (Image NASA, ESA, P. Oesch (University of Geneva), and M. Montes (University of New South Wales))

An article published in the journal “Astrophysical Journal Supplement Series” presents the Hubble Deep UV (HDUV) Legacy Survey program, a great panorama of the universe’s evolutionary history based on observations carried out with the Hubble Space Telescope. A team of researchers exploited Hubble’s ultraviolet detection capabilities, combining it with infrared and visible light observations, also from other telescopes, to extend previous surveys with a field of view that includes about 15,000 galaxies, including 12,000 in which there’s star formation.

A Hot DOG galaxy seen at X-rays

An article to be published in the journal “Astronomy & Astrophysics” describes the first detailed X-ray observation of a galaxy cataloged as W1835+4355 of a rare type because at its center there’s a quasar of the Hot DOG (Hot Dust-Obscured Galaxies) type. A team led by Luca Zappacosta of INAF in Rome, Italy, used data collected by ESA’s XMM-Newton and NASA’s NuSTAR space telescopes to obtain the most accurate X-ray emission detections from a Hot DOG galaxy. This will be useful to better understand the nature of this type of galaxies and the activity of the supermassive black hole at their center.

The sky around NGC 5018

An article accepted for publication in “The Astrophysical Journal” describes the VST Early-type GAlaxy Survey (VEGAS). A team of researchers led by Marilena Spavone from INAF-Astronomical Observatory of Capodimonte in Naples, Italy, used ESO’s VLT Survey Telescope (VST) in Chile to obtain highly detailed images of many elliptical galaxies. Among them there’s NGC 5018, interesting among other things for structures such as what’s called a tidal tail, a stream of gas containing various stars stretching outwards from that galaxy. These are evidence of interactions between galaxies that provide information on the characteristics of primordial galaxies.