Category Astronomy/Space

The Origin of the First Structures formed in Galaxies like the Milky Way identified

An example of a nearby spiral galaxy, M81, where the bulge is easily identified as the central redder part, and the disc, dotted with zones where stars are currently forming and appear as blue regions forming spiral arms. Credit: NASA/JPL-Caltech/ESA/Harvard-Smithsonian CfA.
An example of a nearby spiral galaxy, M81, where the bulge and the disc are easily identified. Credit: NASA/JPL-Caltech/ESA/Harvard-Smithsonian CfA.

An international team of scientists led from the Centre for Astrobiology (CAB, CSIC-INTA), with participation from the Instituto de Astrofísica de Canarias (IAC), has used the Gran Telescopio Canarias (GTC) to study a representative sample of galaxies, both disc and spheroidal, in a deep sky zone in the constellation of the Great Bear to characterize the properties of the stellar populations of galactic bulges. The researchers have been able to determine the mode of formation and development of these galactic structures. The results of this study were recently published in The Astrophysical Journal.

The researchers focused their study ...

Read More

Did Heat from Impacts on Asteroids provide the Ingredients for Life on Earth?

 Relationship between maximum temperature and dimensionless distance. B. Relationship between duration and dimensionless distance.
Duration is scaled by thermal diffusion (*6) time. The colors indicate different projectiles and impact speeds: PC is a polycarbonate sphere with a diameter of 4.7mm and Al is an aluminum sphere with a diameter of 2mm.

A research group from Kobe University has demonstrated that the heat generated by the impact of a small astronomical body could enable aqueous alteration (*1) and organic solid formation to occur on the surface of an asteroid. They achieved this by first conducting high-velocity impact cratering experiments using an asteroid-like target material and measuring the post-impact heat distribution around the resulting crater...

Read More

Front-row View reveals exceptional Cosmic Explosion

Artist’s impression of a relativistic jet of a gamma-ray burst (GRB), breaking out of a collapsing star, and emitting very-high-energy photons. Credit: DESY, Science Communication Lab

Observation challenges established theory of gamma-ray bursts in the universe. Scientists have gained the best view yet of the brightest explosions in the universe: A specialised observatory in Namibia has recorded the most energetic radiation and longest gamma-ray afterglow of a so-called gamma-ray burst (GRB) to date. The observations with the High Energy Stereoscopic System (H.E.S.S.) challenge the established idea of how gamma-rays are produced in these colossal stellar explosions which are the birth cries of black holes, as the international team reports in the journal Science.

“Gamma-ray bursts a...

Read More

Jets from Massive Protostars might be very different from Lower-Mass Systems

Artist’s conception of the young star Cep A HW2, showing a wide-angle wind originating close to the star and a disk of material orbiting the star (called an accretion disk), with a much narrower jet farther away.
Credit: Bill Saxton, NRAO/AUI/NSF

VLA reveals new details of protostellar jet. Astronomers studying the fast-moving jet of material ejected by a still-forming, massive young star found a major difference between that jet and those ejected by less-massive young stars. The scientists made the discovery by using the U.S. National Science Foundation’s Karl G. Jansky Very Large Array (VLA) to make the most detailed image yet of the inner region of such a jet coming from a massive young star.

Both low- and high-mass young stars, or protostars, propel jets outward perpendicular to ...

Read More