Science and technology

The spectacle of the cosmos

19 spiral galaxies: the mesmerizing new images from the Webb telescope

Unpublished details that tell the story of the formation of stars and their evolution.

“Stunning images even for scientists who have studied these galaxies for decades”

01/30/2024

NASA, ESA, CSA

The questions have been the same for a long time:

how are stars born,

how do they evolve,

how do they interact

with galaxies in their formation process?

But

the level of detail

in the images and data that the

James Webb Space Telescope

now makes available to astronomers as they search for answers

is truly astounding

.

This is said, among others, by

Janice Lee

, researcher at the Space Telescope Science Institute in Baltimore, commenting on the

19 spiral galaxies

depicted by Webb with unprecedented precision: "Webb's new images are

stunning even for researchers

who have studied these same galaxies for decades.

Bubbles and filaments are resolved down to the smallest scales ever observed and

tell a story about the star formation cycle

."

Galaxies are

part of the universe closest to us

and are rich in previously unseen details of stars, gas and dust.

Details that promise to provide scientists

with valuable information

on the structure of galaxies and the

processes of stellar evolution

.

This spectacular

gallery of cosmic portraits “painted” by Webb

is part of a large project that has been going on for some time, the

Physics at High Angular resolution in Nearby Galaxies (PHANGS)

program , supported by over

150 astronomers

from around the world.

Before Webb's advent, the PHANGS project already had a wealth of data from observations from

NASA's Hubble Space Telescope

, the Very Large Telescope Multi-Unit Spectroscopic Explorer, and the

Atacama Large Millimeter/submillimeter Array

.

"The objective of the project",

Francesco Belfiore of the INAF of Arcetri,

the only researcher of the National Institute of Astrophysics involved in the project, explains to Ansa, "is to study the process of star formation, how this is influenced by the surrounding environment and vice versa, how star formation in turn influences it through

so-called feedback processes

”.

The meticulous "brush strokes"

that make up these hypnotic images are the result of the combination of data obtained in the near and medium infrared thanks to various instruments on board Webb:

the NIRCam (Near-InfraRed Camera) immortalized millions of stars visible in shades of blue,

some of which are scattered in the spiral arms of galaxies or grouped in star clusters.

Data from the Miri instrument,

however, highlights the incandescent dust, showing the areas where it is located around and between the stars.

At these wavelengths,

stars that have not yet formed completely

and remain enveloped in the gas and dust that fuel their growth are also visible in shades of red. 

Another thing that has amazed astronomers is the presence in Webb's images of

large spherical shells

in the gas and dust.

“These holes could have been created

by one or more stars that exploded

, gouging giant holes in the interstellar material,” explains

Adam Leroy,

a professor of astronomy at Ohio State University in Columbus.

There is evidence that galaxies

grow from the inside out:

star formation begins in the core of galaxies and spreads along their arms, spiraling away from the center.

The further a star is from the galaxy's core, the younger it is likely to be.

In contrast, the areas near the nuclei that appear illuminated by a blue spotlight are populations of older stars.

And how can the nuclei of galaxies that are

flooded with pink and red diffraction peaks

be explained? 

“It's a clear sign that there could be

an active supermassive black hole

,” says Eva Schinnerer, a scientist at the Max Planck Institute for Astronomy in Heidelberg, Germany.

“Or, the star clusters towards the center are so bright that they have saturated that area of ​​the image.”

Starting from the

unprecedented number of stars

captured by Webb, several research avenues are opened that scientists can follow

by cross-referencing the PHANGS data

.

“By precisely cataloging all types of stars,” says Leroy, “we can build

a holistic and more reliable view of their life cycles

.”

In addition to releasing these images, the PHANGS team also released

the largest catalog yet of approximately 100,000 star clusters.