Early Massive Galaxies ran out of gas, Shutting Down Their Star Formation

Galaxies that formed within the first few billion years after the Big Bang should have lived long, healthy lives. After all, they were born with rich supplies of cold hydrogen gas, exactly the fuel needed to continue star formation. But new observations have revealed “quenched” galaxies that have shut off star formation. And astronomers have no idea why.

Continue reading “Early Massive Galaxies ran out of gas, Shutting Down Their Star Formation”

Are the Burned-Out Remnants of the First Stars all Around us?

The first stars to appear in the universe lived fast and died young. Today, none of them likely remain. But their remnants, the black holes and neutron stars, might still wander around the cosmos. Unfortunately, they’re extremely difficult to detect unless they merge, and according to new research the only way to see them would be to conduct an unprecedented survey of the local volume of the universe.

Continue reading “Are the Burned-Out Remnants of the First Stars all Around us?”

Astronomers Have a new way to Measure the Mass of Supermassive Black Holes

Even the most supermassive of the supermassive black holes aren’t very large, making it extremely difficult to measure their sizes. However, astronomers have recently developed a new technique that can estimate the mass of a black hole based on the movement of hot gas around them – even when the black hole itself it smaller than a single pixel.

Continue reading “Astronomers Have a new way to Measure the Mass of Supermassive Black Holes”

ALMA’s new Receivers Will let it see Longer Wavelengths, Peering Closer to the Beginning of the Universe

The ALMA telescope is getting a new set of receivers, enabling it to detect wavelengths down to 8.5 mm. These wavelengths are crucial for observations of the transformative epoch of reionization, when the first stars to appear in the universe unleashed a fury of radiation.

Continue reading “ALMA’s new Receivers Will let it see Longer Wavelengths, Peering Closer to the Beginning of the Universe”

There Should be More Material Left Over From Bombardment Eras. Maybe the Sun Blew it all Away?

The early solar system was an especially violent place. The terrestrial planets (Mercury, Venus, Earth, and Mars) likely formed by suffering countless collisions between planetesimals. But the material left over from all those collisions should have remained in orbit around the sun, where it would’ve eventually found itself in the asteroid belt. But the belt contains no such record of that process.

Continue reading “There Should be More Material Left Over From Bombardment Eras. Maybe the Sun Blew it all Away?”