Category Astronomy/Space

Fermi-LAT sky map with the celestial neighborhood of the newly discovered pulsar PSR J1906+0722 featuring several other gamma-ray pulsars (not labeled). The color scale shows the gamma-ray intensity. The dashed square at the centre encloses the position of the pulsar and the part of the sky shown in more detail in the figure below. Credit: Knispel/AEI/NASA/DOE/Fermi LAT Collaboration Read more at: http://phys.org/news/2015-08-scientists-elusive-gamma-ray-pulsar.html#jCp

Gamma-ray pulsars are remnants of explosions that end the lives of massive stars. They are highly-magnetized and rapidly rotating compact neutron stars. Like a cosmic lighthouse they emit gamma-ray photons in a characteristic pattern that repeats with every rotation...

Astronomers have uncovered a unique process for how the universe’s largest elliptical galaxies continue making stars long after their peak years of star birth. Hubble Space Telescope’s exquisite high resolution and UVlight sensitivity allowed the astronomers to see brilliant knots of hot, blue stars forming along the jets of active black holes found in the centers of giant elliptical galaxies.

Combining Hubble data with observations from a suite of ground-based and space telescopes, 2 independent teams found that that the black hole, jets, and newborn stars are all parts of a self-regulating cycle. High-energy jets shooting from the black hole heat a halo of surrounding gas, controlling the rate at which the gas cools and falls into the galaxy.

“Think of the gas surrounding a galaxy ...

The polarized light reflected from the leaf contains a footprint of the leaf’s biopigments. These biosignatures can be detected with a polarization filter, shown here as a pair of sunglasses. Credit: Illustration: Svetlana Berdyugina

Biopigments of plants, so-called biological photosynthetic pigments, leave behind unique traces in the light they reflect, an international team has discovered. The scientists studied these biosignatures with the help of polarization filters: If biopigments were present as a sign of life on a planet, they would leave behind a detectable polarized signature in the reflected light.

Eg Chlorophyll pigments in plant leaves, absorb blue to red light but reflect a small part of green in the visible spectrum and thus appear green...

A rock fulgurite revealed that lightning strikes alter quartz’s crystal structure on the atomic level.

Researchers once believed only meteorites could do so. At a rock outcropping in southern France, a jagged fracture runs along the granite. The surface in and around the crevice is discolored black, as if wet or covered in algae. But the real explanation for the rock’s unusual features is more dramatic: a powerful bolt of lightning.

Using extremely high-resolution microscopy, Prof Gieré et al found that not only had the lightning melted the rock’s surface, resulting in a distinctive black “glaze,” but had transferred enough pressure to deform a thin layer of quartz crystals beneath the surface, resulting in distinct atomic-level structures called shock lamellae...