Tuesday, November 12, 2019

New Study Suggests ‘Pac-Man-like’ Mergers Could Explain Massive, Spinning Black Holes

Simulation of an accretion disk surrounding a supermassive black hole.

Scientists have reported detecting gravitational waves from 10 black hole mergers to date, but they are still trying to explain the origins of those mergers. The largest merger detected so far seems to have defied previous models because it has a higher spin and mass than the range thought possible. A group of researchers, including Rochester Institute of Technology Assistant Professor Richard O’Shaughnessy, has created simulations that could explain how the merger happened.

Monday, November 11, 2019

Clemson Scientists Further Refine How Quickly the Universe Is Expanding

From left, Clemson’s Marco Ajello, Lea Marcotulli, Abhishek Desai and Dieter Hartmann were co-authors on a newly released paper in The Astrophysical Journal. Image Credit: College of Science

Wielding state-of-the-art technologies and techniques, a team of Clemson University astrophysicists has added a novel approach to quantifying one of the most fundamental laws of the universe. In a paper published Friday, Nov. 8, in The Astrophysical Journal, Clemson scientists Marco Ajello, Abhishek Desai, Lea Marcotulli and Dieter Hartmann have collaborated with six other scientists around the world to devise a new measurement of the Hubble Constant, the unit of measure used to describe the rate of expansion of the universe.

Hubble Captures a Dozen Sunburst Arc Doppelgangers

This image, taken with the NASA/ESA Hubble Space Telescope, shows a massive galaxy cluster, about 4.6 billion light years away. Along its borders four bright arcs are visible; these are copies of the same distant galaxy, nicknamed the Sunburst Arc.  The Sunburst Arc galaxy is almost 11 billion light-years away and the light from it is being lensed into multiple images by gravitational lensing. The Sunburst Arc is among the brightest lensed galaxies known and its image is visible at least 12 times within the four arcs.  Three arcs are visible in the top right of the image, the fourth arc in the lower left. The last one is partially obscured by a bright foreground star, which is located in the Milky Way.  Credit: ESA/Hubble, NASA, Rivera-Thorsen et al.

Astronomers using the NASA/ESA Hubble Space Telescope have observed a galaxy in the distant regions of the Universe which appears duplicated at least 12 times on the night sky. This unique sight, created by strong gravitational lensing, helps astronomers get a better understanding of the cosmic era known as the epoch of reionization.

NICER Catches Record-setting X-ray Burst

Illustration depicting a Type I X-ray burst. The explosion first blows off the hydrogen layer, which expands and ultimately dissipates. Then rising radiation builds to the point where it blows off the helium layer, which overtakes the expanding hydrogen. Some of the X-rays emitted in the blast scatter off of the accretion disk. The fireball then quickly cools, and the helium settles back onto the surface. Credit: NASA's Goddard Space Flight Center/Chris Smith (USRA)

NASA’s Neutron star Interior Composition Explorer (NICER) telescope on the International Space Station detected a sudden spike of X-rays at about 10:04 p.m. EDT on Aug. 20. The burst was caused by a massive thermonuclear flash on the surface of a pulsar, the crushed remains of a star that long ago exploded as a supernova.

Galactic Fountains and Carousels: Order Emerging from Chaos

Images of the optical light emitted by the stars of 16 galaxies from the TNG50 simulation. Each galaxy is seen face-on or from the top (top sub panels), and edge-on or from the side (lower sub panels). Credit D. Nelson (MPA) and the IllustrisTNG team

Scientists from Germany and the United States have unveiled the results of a newly-completed, state of the art simulation of the evolution of galaxies. TNG50 is the most detailed large-scale cosmological simulation yet. It allows researchers to study in detail how galaxies form, and how they have evolved since shortly after the Big Bang. For the first time, it reveals that the geometry of the cosmic gas flows around galaxies determines galaxies' structures, and vice versa. The researchers publish their results in two papers in the journal Monthly Notices of the Royal Astronomical Society.

Sunday, November 10, 2019

Human Heart Cells Are Altered by Spaceflight, But Return to (Mostly) Normal on Earth

Aboard the International Space Station, Astronaut Kate Rubins examines hiPSC-derived cardiomyocytes grown within a fully enclosed cell culture plate. Credit: NASA

Heart muscle cells derived from stem cells show remarkable adaptability to their environment during and after spaceflight, according to a study publishing November 7 in the journal Stem Cell Reports. The researchers examined cell-level cardiac function and gene expression in human heart cells cultured aboard the International Space Station for 5.5 weeks. Exposure to microgravity altered the expression of thousands of genes, but largely normal patterns of gene expression reappeared within 10 days after returning to Earth.

TESS Spacecraft Presents Panorama of Southern Sky

The plane of our Milky Way galaxy arcs across a starry landscape in this detail of the TESS southern sky mosaic. Credit: NASA/MIT/TESS and Ethan Kruse (USRA)

The glow of the Milky Way -- our galaxy seen edgewise -- arcs across a sea of stars in a new mosaic of the southern sky produced from a year of observations by NASA's Transiting Exoplanet Survey Satellite (TESS). Constructed from 208 TESS images taken during the mission's first year of science operations, completed on July 18, the southern panorama reveals both the beauty of the cosmic landscape and the reach of TESS's cameras.

Saturday, November 9, 2019

The Most Spectacular Celestial Vision You’ll Never See

This is a simulation of HR 5183b's brightness in the night sky as compared to Venus, one of the brightest objects visible from Earth.

Contrary to previous thought, a gigantic planet in wild orbit does not preclude the presence of an Earth-like planet in the same solar system - or life on that planet. What's more, the view from that Earth-like planet as its giant neighbor moves past would be unlike anything it is possible to view in our own night skies on Earth, according to new research led by Stephen Kane, associate professor of planetary astrophysics at UC Riverside.