Volume 1 Issue 3, March 2017

A phenomenon recently studied in theoretical physics may hold considerable interest for astronomers: the explosive decay of primordial black holes through quantum tunnelling. Their detection would be of major theoretical importance.

As part of the dark matter Insight, Joshua Frieman, co-founder and director of the Dark Energy Survey collaboration, tells us about the ambitious project aiming to probe the origin of cosmic acceleration.

Black holes present a profound challenge to our current foundations of physics, and an exciting era of astronomy is just opening in which gravitational-wave observation and very-long-baseline interferometry may provide important hints about the new principles of physics needed.

Millimetre-wavelength interferometry and gravitational-wave detectors currently provide the most stringent tests for the existence of cosmic black holes. Complementary measurements of magnetic fields near their event horizon would be decisive.

Spectroscopic and imaging data for low metallicity galaxies observed during the peak epoch of star formation offer detailed insights into the most distant galaxies discovered to date.

The destruction of stars by supermassive black holes appears to be rarer than predicted. A candidate stellar disruption in a kind of galaxy that is usually obscured may explain why.

From the first hints of unseen matter in the Universe to the present body of evidence for dark matter, James Peebles outlines the significant developments in observation and theory in the 1970s in this Insight Perspective.

The acceptance of dark matter came slowly despite its abundance. Jaco de Swart and colleagues reconstruct the history of how dark matter brought astronomers to cosmology in their Review Article, which is part of the Insight on dark matter.

An uncharacteristically long stellar disruption from a supermassive black hole has been unravelling over the last decade. Spectral information implies very efficient accretion but recent observations hint at a transition to a less extreme accretion mode.

A binary system containing a ‘polluted’ white dwarf must host a stable, rocky, circumbinary debris disk, argue Farihi and colleagues. Therefore large planetesimal formation, and potentially terrestrial planet formation, must be robust and common in such systems.

The roughly spherical outer regions and aspherical inner regions of protoplanetary nebulae — here imaged by ALMA — are explained in terms of an embedded binary system with stars on eccentric orbits.

Environments where stars are abundantly formed are more conducive to stellar tidal disruption events, as evidenced by the detection of the remains of a star being accreted by a supermassive black hole within a starburst galaxy.

A selected group of intermediate-redshift galaxies appear similar to primeval galaxies. Analysing spectra of these nearer analogues for chemical abundances and ionization levels gives an improved understanding of galaxies that are too faint to study well.

The authors find that a nearby planetary system has two terrestrial planets that transit in front of their star (from our perspective). Transiting terrestrial planets are sought after, as they can be characterized in detail, including their atmospheres. Having two in the same system is very rare.

From near-Earth asteroids to superluminous supernovae and gravitational wave counterparts, the Zwicky Transient Facility will soon scan for transient phenomena, explain Eric Bellm and Shrinivas Kulkarni.