The Hubble Space Telescope has discovered a galaxy hidden behind a distant star formation

the Astronomy scientists They usually notice Galaxies This is thanks to the light emanating from these bright objects made up of billions of stars.

But there are some galaxies that are difficult to observe, because they require a different approach to viewing. using NASA Hubble Space Telescope, A team of astronomers used an unusual technique to discover… A galaxy far, far away 11 billion years. Instead of noticing the light this world emits, they noticed the light it absorbs.

In general, just as we see a light bulb by the light it emits, astronomers typically observe galaxies using the light emitted by their stars. Galaxies emit light waves that are found all over the world. Electromagnetic fieldDifferent telescopes can observe these cosmic objects with different wavelengths of light to form a complete picture.

But when the galaxy is in the same line of sight with another, more distant source of bright light, there is another way to make these galactic observations. when Light passes through the galaxy Toward the foreground galaxy, for example, some of the wavelengths of the background galaxy will be absorbed by the gas and dust in the foreground galaxy.

And because Chemical elements absorb light At specific wavelengths, looking for gaps in the light output (or spectra) of a background source can tell astronomers why this light passes through on its way to our telescopes. In other words, the light in those “spaces” has been absorbed by a foreground object on the way to our view.

A potential background source useful for this technique is quasars, which are extremely bright galactic cores powered by supermassive black holes that spew out jets of radiation and matter as they feed on surrounding matter.

“To find absorbing galaxies, we first look for quasars that are particularly red. Because stardust tends to absorb blue light but not red light, if there is a dusty galaxy in the foreground, the quasar will turn red.” He said in a statement johan fynbo, Astronomer at the Cosmic Dawn Center.

The expert and his team were able to discover several absorbing galaxies by analyzing the light from red quasars, but once they did that, they faced a much more difficult task: searching for the light emitted by the absorbing galaxy itself.

The team’s research has been accepted for publication in the journal Astronomy and astrophysics. In the meantime, a pre-peer review version is available on the website arXiv research repository.

When quasars are located just behind a galaxy, they tend to change Our view of galaxies in the foreground Because they are so cool. So much so that it essentially drowns out the combined light of every star in the entire galaxy.

This makes detecting an absorbing galaxy with its own light emission similar to trying Spotting a firefly perched on a lighthouse lamp While on Earth. Unfortunately, scientists have not yet identified the light coming from the recently discovered 11 billion-year-old absorbing galaxy, but the absorption patterns revealed by this object are remarkable.

The galaxy, seen as it was when our 13.8 billion-year-old universe was only about 3 billion years old, absorbs more light than other similar galaxies, meaning it is likely to be a more mature galaxy like the Milky Way.

“The features we found in the missing light tell us something about the dust in the foreground galaxy. In fact, the dust appears to be similar to the dust we see locally in the Milky Way and in one of our neighboring galaxies,” he said in the statement. Liz Christensen, Member of the discovery team and astronomer at the Cosmic Dawn Center.

The team was also able to determine that the galaxy has a bright counterpart. This galaxy, which appears to be generating stars at an intense rate, is so close to the absorbing galaxy that the team also believes the two are likely gravitationally linked. This means that at some point after their observation, the two galaxies likely formed a cluster of galaxies Galaxies similar to the Local Group in which the Milky Way is located.

Finbo intends to revisit this region of space using other instruments, including the Northern Optical Telescope on La Palma, to search for other members of this galaxy group in the hopes of seeing the absorbing galaxy emitting its own light. “This makes the study of galaxies much more interesting,” the astronomer concluded.