Category Astronomy/Space

The galaxy Markarian 231, the nearest quasar to Earth, as seen by the Hubble Space Telescope. The galaxy is the product of a merger between two galaxies. Astronomers have discovered the signatures of the ionized molecules OH+ and H2O+ in its massive outflow and argue that shock-induced cosmic rays are responsible for their ionization. Credit: NASA, ESA, the Hubble Heritage Team STScI/AURA-ESA/Hubble Collaboration, and A. Evans University of Virginia, Charlottesville/NRAO/Stony Brook University

There is a process at work in most galaxies that affects both the central black hole mass as well as the galaxy’s global velocity structure and luminosity. Astronomers suspect that feedback of some kind is involved, and one popular mechanism is outflowing gas...

Space Observatory Captures the Details of an Unusual Stellar Detonation

The universe is full of mysterious exploding phenomena that go boom in the dark. One particular type of ephemeral event, called a Fast-Evolving Luminous Transient (FELT), has bewildered astronomers for a decade because of its very brief duration. Now, NASA’s Kepler Space Telescope—designed to go hunting for planets across our galaxy—has also been used to catch FELTs in the act and determine their nature. They appear to be a new kind of supernova that gets a brief turbo boost in brightness from its surroundings.

Kepler’s ability to precisely sample sudden changes in starlight has allowed astronomers to quickly arrive at this model for explaining FELTs, and rule out alternative explanations...

This is a photo mosaic of an edge-on view of the Milky Way galaxy, looking toward the central bulge. Superimposed on it are radio-telescope images, colored pink, of the stretched, arc-shaped Magellanic Stream below the plane of the galaxy and the shredded, fragmented Leading Arm crossing the galaxy’s plane and extending above it. These gas clouds are being gravitationally pulled apart like taffy from the Small and Large Magellanic Clouds—satellite galaxies to our Milky Way—which appear as bright clumps within the gas. Credit: Illustration: D. Nidever et al., NRAO/AUI/NSF and A. Mellinger, Leiden-Argentine-Bonn (LAB) Survey, Parkes Observatory, Westerbork Observatory, Arecibo Observatory, and A. Feild (STScI) Science: NASA, ESA, and A. Fox (STScI)

On the outskirts of our galaxy, a cos...

Artist’s impression of an inner accretion flow and a jet from a supermassive black hole when it is actively feeding, for example, from a star that it recent tore apart. Image: ESO/L. Calçada

Signals suggest black hole emits a jet of energy proportional to the stellar material it gobbles up. On Nov. 11, 2014, a global network of telescopes picked up signals from 300 million light years away that were created by a tidal disruption flare – an explosion of electromagnetic energy that occurs when a black hole rips apart a passing star. Since this discovery, astronomers have trained other telescopes on this very rare event to learn more about how black holes devour matter and regulate the growth of galaxies.

Scientists from MIT and Johns Hopkins University have now detected radio signals from t...