Sunday, January 26, 2020

The Core of Massive Dying Galaxies Already Formed 1.5 Billion Years After the Big Bang

A blow-up of a small portion of the Subaru/XMM-Newton Deep Field.  The red galaxy at the center is a dying galaxy at 12 billion years ago.  Astronomers measured the motion of stars in the galaxy and found that the core of the galaxy is nearly fully formed. Credit: NAOJ/M. Tanaka

The most distant dying galaxy discovered so far, more massive than our Milky Way -- with more than a trillion stars -- has revealed that the 'cores' of these systems had formed already 1.5 billion years after the Big Bang, about 1 billion years earlier than previous measurements revealed.

Taking the Temperature of Dark Matter

This image from the Hubble Space Telescope shows lensing of distant galaxies by gravity. UC Davis astronomers are using this phenomenon to learn more about the properties of dark matter.

Warm, cold, just right? Physicists at the University of California, Davis are taking the temperature of dark matter, the mysterious substance that makes up about a quarter of our universe.

Dating a Galaxy Crash

A snapshot from TESS of part of the southern sky showing the location of ν Indi (blue circle), the plane of the Milky Way (bottom left) and the southern ecliptic pole (top). These snapshots come from data collected in TESS observing sectors 1, 12 and 13. © J. T. Mackereth

The dwarf galaxy Gaia-Enceladus collided with the Milky Way probably approximately 11.5 billion years ago. A team of researchers including scientists from the Max Planck Institute for Solar System Research in Germany for the first time used a single star affected by the collision as a clue for dating. Using observational data from ground-based observatories and space telescopes, the scientists led by the University of Birmingham were able to determine the age of the star and the role it played in the collision. The research group describes its results in Nature Astronomy.

Astronomers Discover Class of Strange Objects Near Our Galaxy’s Enormous Black Hole

Orbits of the G objects at the center of our galaxy, with the supermassive black hole indicated with a white cross. Stars, gas and dust are in the background.  Credit: Anna Ciurlo, Tuan Do/UCLA Galactic Center Group

Astronomers from UCLA’s Galactic Center Orbits Initiative have discovered a new class of bizarre objects at the center of our galaxy, not far from the supermassive black hole called Sagittarius A*. They published their research in the Jan. 16 issue of the journal Nature.

Saturday, January 25, 2020

Astronomers Reveal Interstellar Thread of One of Life’s Building Blocks

This infographic shows the key results from a study that has revealed the interstellar thread of phosphorus, one of life’s building blocks. Credit: ALMA (ESO/NAOJ/NRAO), Rivilla et al.; ESO/L. Calçada; ESA/Rosetta/NAVCAM; Mario Weigand, www.SkyTrip.de

Phosphorus, present in our DNA and cell membranes, is an essential element for life as we know it. But how it arrived on the early Earth is something of a mystery. Astronomers have now traced the journey of phosphorus from star-forming regions to comets using the combined powers of ALMA and the European Space Agency’s probe Rosetta. Their research shows, for the first time, where molecules containing phosphorus form, how this element is carried in comets, and how a particular molecule may have played a crucial role in starting life on our planet.

Galactic Gamma-ray Sources Reveal Birthplaces of High-energy Particles

A map of the galactic plane indicates the highest energy gamma ray sources yet discovered. The sources comprise a new catalog compiled by the members of the High Altitude Water Cherenkov Observatory collaboration.

Nine sources of extremely high-energy gamma rays comprise a new catalog compiled by researchers with the High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. All produce gamma rays with energies over 56 trillion electron volts (TeV) and three emit gamma rays extending to 100 TeV and beyond, making these the highest-energy sources ever observed in our galaxy. The catalog helps to explain where the particles originate and how they are accelerated to such extremes.

Final Images from Cassini Spacecraft

Composite of a true color image of Saturn, observed by Cassini in 2016, overlaid with a false colour representation of the ultraviolet aurora in the northern hemisphere as observed on 20 August 2017. Credit: NASA/JPL-Caltech/Space Science Institute/A. Bader (Lancaster University).

Lancaster researchers are busy analyzing some of the final data sent back from the Cassini spacecraft which has been in orbit around Saturn for more than 13 years until the end of its mission in September 2017.

Friday, January 24, 2020

'Cold Neptune' and Two Temperate Super-Earths Found Orbiting Nearby Stars

Artist’s concept of GJ229Ac, the nearest temperate super-Earth to us that is in a system in which the host star has a brown dwarf companion. Top Right Image: An artist’s concept of GJ180d, which is the nearest temperate super-Earth to us that is not tidally locked to its star, making it more likely to be able to host and sustain life. Illustrations are by Robin Dienel, courtesy of the Carnegie Institution for Science.

A “cold Neptune” and two potentially habitable worlds are part of a cache of five newly discovered exoplanets and eight exoplanet candidates found orbiting nearby red dwarf stars, which are reported in The Astrophysical Journal Supplement Series by a team led by Carnegie’s Fabo Feng and Paul Butler.