Chandra takes an X-ray look at early Webb infrared observations

Chandra's X-ray vision of the Cartwheel Galaxy
Chandra’s X-ray view of the Cartwheel Galaxy

Webb's view of the Cartwheel Galaxy
Webb’s infrared view of the Cartwheel Galaxy
Click for full image.

Hubble's optical view of the Cartwheel Galaxy
Hubble’s optical view of the Cartwheel Galaxy. Click for original image.

Astronomers have now taken X-ray images using the orbital Chandra X-ray Observatory of four of the first Webb Space Telescope observations. The four targets were the Cartwheel Galaxy, Stephan’s Quintet, galaxy cluster SMACS 0723.3–7327, and the Carina Nebula.

The three images to the right illustrate the importance of studying astronomy across the entire electromagnetic spectrum. Each shows the Cartwheel Galaxy as seen by three of the world’s most important space-based telescopes, each looking at the galaxy in a different wavelength.

The top picture is Chandra’s new X-ray observations. As the press release notes,

Chandra data generally show higher-energy phenomena (like superheated gas and the remnants of exploded stars) than Webb’s infrared view. … X-rays seen by Chandra (blue and purple) come from superheated gas, individual exploded stars, and neutron stars and black holes pulling material from companion stars.

The middle picture was produced by Webb, shortly after the start of its science operations. It looks at the galaxy in the infrared.

In this near- and mid-infrared composite image, MIRI data are colored red while NIRCam data are colored blue, orange, and yellow. Amidst the red swirls of dust, there are many individual blue dots, which represent individual stars or pockets of star formation. NIRCam also defines the difference between the older star populations and dense dust in the core and the younger star populations outside of it.

The bottom picture was taken by the Hubble Space Telescope in 1995. I have rotated the image to match the others. It looks at the galaxy in optical wavelengths, the wavelengths that our eyes perceive.

Note how bright the central galactic region is in the infrared and optical, but is invisible in X-rays. Chandra is telling us that all the most active regions in the Cartwheel are located in that outer ring, not in its center.

First Webb infrared image of Cartwheel Galaxy

Webb's view of the Cartwheel Galaxy
Click for full image.

Scientists today have released a new infrared image of the Cartwheel Galaxy, taken by two instruments on the James Webb Space Telescope. That image is to the right, reduced to post here. From the caption:

In this near- and mid-infrared composite image, MIRI data are colored red while NIRCam data are colored blue, orange, and yellow. Amidst the red swirls of dust, there are many individual blue dots, which represent individual stars or pockets of star formation. NIRCam also defines the difference between the older star populations and dense dust in the core and the younger star populations outside of it.

The galaxy, located about a half billion light years away, is one of the more well known astronomical objects due to its unusual shape, believed caused by a collision with a smaller galaxy sometime in the past. Earlier this year for example astronomers discovered a supernovae had exploded in the galaxy sometime in 2021. To see a 1995 Hubble optical image, go here.

This Webb image reveals many new details previously obscured by dust.

Supernova discovered in Cartwheel galaxy

Cartwheel Galaxy, before and after supernova
Click for full image.

Cool image time! In reviewing a December 2021 image of the Cartwheel Galaxy taken by the New Technology Telescope in Chile, astronomers noticed something that was not there in earlier images, a new supernovae.

The photo above, reduced to post here, compares a 2014 image, taken by the Very Large Telescope, with the 2021 photo. In the lower left of the new image is a bright object not in the previous photo.

This event, called SN2021afdx, is a type II supernova, which occurs when a massive star reaches the end of its evolution. Supernovae can cause a star to shine brighter than its entire host galaxy and can be visible to observers for months, or even years — a blink of an eye on astronomical timescales. Supernovae are one of the reasons astronomers say we are all made of stardust: they sprinkle the surrounding space with heavy elements forged by the progenitor star, which may end up being part of later generations of stars, the planets around them and life that may exist in those planets.

Cartwheel is about 500 million light years away, and because of its bright outer ring is one one of the more unusual nearby galaxies.