Radio Astronomy Archives

September 11, 2021September 10, 2021 by Paul M. Sutter

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

ALMA is an array of dishes located at the Atacama Desert in Chile. Image: ALMA (ESO/NAOJ/NRAO), O. Dessibourg

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.

August 15, 2021August 15, 2021 by Brian Koberlein

If the First Black Holes Collapsed Directly, Could we Detect Radio Signals From Those Moments?

This artist’s impression shows a possible seed for the formation of a supermassive black hole. Credit: NASA/CXC/M. Weiss

The universe is littered with supermassive black holes. There’s one a mere 30,000 light-years away in the center of the Milky Way. Most galaxies have one, and some of them are more massive than a billion stars. We know that many supermassive black holes formed early in the universe. For example, the quasar TON 618 is powered by a 66 billion solar mass black hole. Since its light travels nearly 11 billion years to reach us, TON 618 was already huge when the universe was just a few billion years old. So how did these black holes grow so massive so quickly?

June 15, 2021June 15, 2021 by Matt Williams

CHIME Detected Over 500 Fast Radio Burst in its First Year, Providing new Clues to What’s Causing Them

CHIME consists of four metal "half-pipes", each one 100 meters long. Image Credit: CHIME/Andre Renard, Dunlap Institute.

Much like Dark Matter and Dark Energy, Fast Radio Burst (FRBs) are one of those crazy cosmic phenomena that continue to mystify astronomers. These incredibly bright flashes register only in the radio band of the electromagnetic spectrum, occur suddenly, and last only a few milliseconds before vanishing without a trace. As a result, observing them with a radio telescope is rather challenging and requires extremely precise timing.

Hence why the Dominion Radio Astrophysical Observatory (DRAO) in British Columbia launched the Canadian Hydrogen Intensity Mapping Experiment (CHIME) in 2017. Along with their partners at the National Radio Astronomy Observatory (NRAO), the Massachusetts Institute of Technology (MIT), the Perimeter Institute, and multiple universities, CHIME detected more than 500 FRBs in its first year of operation (and more than 1000 since it commenced operations)!

May 16, 2021May 17, 2021 by Matt Williams

60 Years Later, is it Time to Update the Drake Equation?

The Drake Equation, a mathematical formula for the probability of finding life or advanced civilizations in the universe. Credit: University of Rochester

On November 1^st, 1961, a number of prominent scientists converged on the National Radio Astronomy Observatory in Green Bank, West Virginia, for a three-day conference. A year earlier, this facility had been the site of the first modern SETI experiment (Project Ozma), where famed astronomers Frank Drake and Carl Sagan used the Green Bank telescope (aka. “Big Ear”) to monitor two nearby Sun-like stars – Epsilon Eridani and Tau Ceti.

While unsuccessful, Ozma became a focal point for scientists who were interested in this burgeoning field known as the Search for Extraterrestrial Intelligence (SETI). As a result, Drake and Sagan were motivated to hold the very first SETI conference, wherein the subject of looking for possible extraterrestrial radio signals would be discussed. In preparation for the meeting, Drake prepared the following heuristic equation:

N = R^ x f_p x n_e x f_l x f_i x f_c x L*

This would come to be known as the “Drake Equation,” which is considered by many to be one of the most renowned equations in the history of science. On the sixtieth anniversary of its creation, John Gertz – a film producer, amateur astronomer, board-member with BreakThrough Listen, and the three-term former chairman of the board for the SETI Institute – argues in a recent paper that a factor by factor reconsideration is in order.

May 11, 2021May 11, 2021 by Andy Tomaswick

NASA is Getting Serious About a Radio Telescope on the Moon

Artist's illustration of a radio telescope inside a crater on the Moon. Credit: NASA JPL

It’s widely known by now that the “dark side” of the moon, made famous by Pink Floyd, isn’t actually dark. It gets as much sunlight as the side that is tidally locked facing Earth. However, it is dark in one very important way – it isn’t affected by radio signals emanating from Earth itself. What’s more, it’s even able to see radio waves that don’t make it down to Earth’s surface, such as those associated with the cosmic “Dark Ages” when the universe was only a few hundred million years old. Those two facts are the main reasons the far side of the moon has continually been touted as a potential location for a very large radio telescope. Now, a project sponsored by NASA’s Institute for Advanced Concepts (NIAC) has received more funding to further explore this intriguing concept.

May 2, 2021May 2, 2021 by Brian Koberlein

Breakthrough Listen Searched for Signals From Intelligent Civilizations Near the Center of the Milky Way

A view of the Green Bank Telescope. Credit: Jiuguang Wang/CC BY-SA 2.0

The Breakthrough Listen project has made several attempts to find evidence of alien civilizations through radio astronomy. Its latest effort focuses attention on the center of our galaxy.

March 8, 2021March 8, 2021 by Scott Alan Johnston

NASA is Considering a Radio Telescope on the Far Side of the Moon

The University of Colorado Boulder and Lunar Resources Inc. have just won NASA funding to study the possibility of building a radio telescope on the far side of the Moon. The project, called FarView, would harvest building materials from the Lunar surface itself, and use robotic rovers to construct a massive, intricate network of wires and antennas across 400 square kilometers. When complete, FarView would allow radio astronomers to observe the sky in low-frequency radio wavelengths with unprecedented clarity.

March 6, 2021March 6, 2021 by Brian Koberlein

Almost all High-Energy Neutrinos Come From Quasars

The IceCube Neutrino Observatory at the South Pole. It detected neutrinos and helped astronomers trace them to blazars. Credit: Emanuel Jacobi/NSF.

Buried under the ice at the South Pole is a neutrino observatory called IceCube. Every now and then IceCube will detect a particularly high-energy neutrino from space. Some of them are so high energy we aren’t entirely sure what causes them. But a new article points to quasars as the culprit.

February 24, 2021February 24, 2021 by Brian Koberlein

Cygnus X-1 was the First Black Hole Ever Found. New Measurements Show it's Much More Massive Than Previously Believed

An artist’s impression of the Cygnus X-1 system. Credit: International Centre for Radio Astronomy Research

In 1964 two Aerobee suborbital rockets were launched with the goal of mapping x-ray sources in the sky. Each rocket contained a directed Geiger counter, so that as the rocket rotated at the peak of its trajectory to measure the direction of x-ray sources. The project discovered eight x-ray sources, including a particularly bright one in the constellation Cygnus. It became known as Cygnus X-1.

Cygnus X-1 as imaged by a balloon bourne telescope. Credit: NASA/Marshall Space Flight Center

February 23, 2021February 23, 2021 by Brian Koberlein

A map of 25,000 Supermassive Black Holes Across the Universe

First results of the LOFAR LBA Sky Survey. Credit: LOFAR

The Low-Frequency Array (LOFAR) is a different kind of radio telescope. Although radio light has the longest wavelengths and lowest frequencies of the electromagnetic spectrum, much of radio astronomy has focused on the higher frequency end. Observatories such as ALMA study radio light at frequencies of hundreds of Gigahertz, and the VLA studies the fifty Gigahertz range, LOFAR captures radio signals below 250 Megahertz, which is in the range of the lowest radio frequencies that can be seen from Earth.

N = R* x fp x ne x fl x fi x fc x L

N = R^ x f_p x n_e x f_l x f_i x f_c x L*