What were the first galaxies in the Universe like? Current observations can only access a handful of these ancients. However, a new simulation has synthesized millions to better understand the galaxies of 13 billion years ago.
Although this planet is far from habitable, scientists have confirmed the presence of water vapor in the atmosphere of the WASP-12 system. What does this infer about its planetary atmosphere? Is this in agreement with other studies? The story is not as black and white as we might have thought.
Over the past decade the study of planetary debris at white dwarfs has become an increasingly exciting area. Observations of this debris have allowed us to make unique discoveries about the chemical composition of extrasolar rocky planets, as well as revealing the endpoints of the evolution of planetary systems very similar to our own…
We can measure the expansion of the universe with velocities and distances of extragalactic objects. But measuring distances is tough! The authors of this paper have developed a new technique for measure the distances of AGN using the “echo” of light from heated dust.
There’s a strange sickle-shaped object in the Carina Nebula. The authors of this paper used observations at several different wavelengths to investigate the nature of this intriguing nebula, leading to some interesting discoveries and even more questions.
Any photon with a wavelength shorter than 912 angstroms (the Lyman limit) will ionize neutral hydrogen by raising the atom’s electron from the ground state to an unbound state at infinity. From measurements of quasar absorption spectra, we know that the reionization of the intergalactic medium from its previously neutral state (at redshifts greater than 7) to the highly ionized state we observe today was complete by redshift of ~7. However, we still do not know which sources were responsible for producing the ionizing photons.