Massive Disk-Shaped Dead Galaxy Discovered

Astronomers have detected a first-of-its kind compact yet massive, fast-spinning, disk-shaped galaxy that stopped making stars only a few billion years after the Big Bang.

Finding such a galaxy early in the history of the universe challenges the current understanding of how massive galaxies form and evolve, the researchers said.

The finding, published in the the journal Nature, was possible with the capability of NASA’s Hubble space telescope.

When Hubble photographed the galaxy, astronomers expected to see a chaotic ball of stars formed through galaxies merging together.

Instead, they saw evidence that the stars were born in a pancake-shaped disk.

This was the first direct observational evidence that at least some of the earliest so-called “dead” galaxies – where star formation stopped – somehow evolve from a Milky Way-shaped disk into the giant elliptical galaxies we see today.

“This new insight may force us to rethink the whole cosmological context of how galaxies burn out early on and evolve into local elliptical-shaped galaxies,” said study leader Sune Toft from University of Copenhagen, Denmark.

Massive Disk-Shaped Dead Galaxy Discovered“Perhaps we have been blind to the fact that early ‘dead’ galaxies could in fact be disks, simply because we haven’t been able to resolve them,” Toft said.

The remote galaxy was three times as massive as the Milky Way but only half the size.

Rotational velocity measurements made with the European Southern Observatory’s Very Large Telescope (VLT) showed that the disk galaxy was spinning more than twice as fast as the Milky Way.

Using archival data from the Cluster Lensing And Supernova survey with Hubble (CLASH), Toft and his team were able to determine the stellar mass, star-formation rate, and the ages of the stars.

Why this galaxy stopped forming stars was still unknown. It might be the result of an active galactic nucleus, where energy was gushing from a supermassive black hole.

This energy inhibits star formation by heating the gas or expelling it from the galaxy. Or it might be the result of the cold gas streaming onto the galaxy being rapidly compressed and heated up, preventing it from cooling down into star-forming clouds in the galaxy’s centre.

But how do these young, massive, compact disks evolve into the elliptical galaxies we see in the present-day universe?

“Probably through mergers,” Toft said.

How to choose a successful dietary weight loss strategy

London: While trying to lose weight, one size approach may not fit all. Instead, selecting a right diet strategy based on fasting blood sugar and fasting insulin levels may lead to a six- to seven-fold greater weight loss, researchers say.

The specific diets based on these biomarkers will work differently whether a patient has normal blood sugar, has prediabetes or is living with diabetes, the researchers said.

“Our research shows that weight loss strategies should be customised based on an individual’s biomarkers, which is a big step forward in using personalised nutrition to help people achieve greater weight loss success,” said Professor Arne Astrup from the University of Copenhagen in Denmark.

“These findings are particularly important as they allow us to provide those with prediabetes a custom strategy to help them lose weight, which can ultimately prevent or delay the development of Type 2 diabetes,” Astrup added.

For most people with prediabetes, a fibre-rich diet without calorie restriction will be very effective and has been shown to improve diabetes markers. In this population, carbohydrates or fats should be adjusted based on fasting insulin levels.

How to choose a successful dietary weight loss strategyFor people with Type 2 diabetes, a diet rich in healthy, plant-based fats such as from olive oil, nuts and avocados will be effective to achieve weight loss.

“Remarkably, for many patients, use of these biomarkers can lead to a six-to-seven-fold greater weight loss,” Astrup said.

“Going forward, we can educate patients when a diet they planned to follow would actually make them gain weight, and redirect them to a strategy that we know will work for them,” Astrup noted.

The researchers acknowledged that no one solution will work for every patient, but for many these strategies are likely to be more effective than a generic ‘one size fits all’ approach.

The results were presented at the American Diabetes Association’s 77th Scientific Sessions held in San Diego, California.