A radio glow surrounds Plckg 287.0+32.9, seen here in a composite image with data from the X -ray telescope (Viola) of NASA and the Array Radio Meerkat (orange). Credit: X -rays: NASA/CXC/SAO/K. Rajpurohit et al.; Optical: Panstarrs; Radio: Sarao/Meerkat; Image processing: NASA/CXC/SAO/n. Wolk
When the galaxies come across each other, they often seem to merge gracely, their cores that move around the other, designed by their mutual gravitational attraction while their spiral arms extend outwards in rest and their discs dissolve in an eternal embrace.
But not in the Galaxy Plckg Cluster 287.0+32.9.
Like a high-speed multi-car accumulation in a successful film by Hollywood, with a series of eliminated and endless explosions, this epic collision between three packages of galaxies 5 billion light years away leaves the jaw astronomers for the way it continues to go and go … and go.
It is not easy to see what’s going on in the middle of this mess. But a team of astronomers has discovered new indications on how much carnage is creating the collision, including a huge light cloud that surrounds the galaxy cluster, emitting in radio wavelengths.
For almost 20 million light years, this incandescent halo “is the largest ever observed in any galaxy cluster,” said the main author of the study, Kamlesh Rajpurohit, an astronomer of Smithsonian at the Harvard-Smithsonian Center for the Astrophysicist (CFA), while presented the work in the 246th meeting of the American Astronomical Society A Anchorage, in June, in June, in June, in June, in June, June, in June, in June, in June, June, in June, in June, in June, in June, June, in June, in June, June, in June, in June, in the Goglia di Alaska, in June of Alaska, in the Goglia di Alaska. A document that covers the search is available on Arxiv; Another is in preparation.
The vast scale of the structure – or about 200 times the diameter of the galaxy of the Milky Way – is unexpected and suggests even more physical that is just outside the sight.
“Memories of our first universe”
The galaxy clusters are the most visible part of the scaffolding that underlies the whole issue in the universe. The largest structures of the universe are the filaments of the cosmic network, where gases and dust gather. From these titanic vitics, galaxies are formed, with groups of galaxies that form the intersections of these filaments.
This is part of what makes the galaxy clusters as Plckg 287.0+32.9 (pronounced “Planck 287” in short) interesting for astronomers – “bring memories of our early universe, thus opening a direct window on how it all started and evolved,” said Rajpurohit.
Plckg 287.0+32.9 is a collision during three different subclusters of galaxies that “are known to be one of the most massive and violent clusters,” said Rajpurohit. The new data that your team has analyzed, from the NASA’s X-Ray Telescope Chandra and from the ARray of RadioTelescope Meerkat in South Africa, show the carnage more in detail.
The new high resolution data of its chandra team reveal where the gas is clashing, forming a shock wave or baked by turbulence. Some of these structures are related to the jets spitted by the black food holes in the centers of the galaxies of the cluster. All these structures-in which the gas is heated at temperatures high enough to issue x-sster indications of “very violent collisions”, said Rajpurohit.
So, by combining Chandra data with the observations of Meerkat, the team was able to obtain a more complete vision of what is happening. At the radio wavelengths, the cluster seems to be what Rajpurohit has called a “beautiful mess”, with a further front of shock separated from that visible to Chandra from a distance of 12 million light years. In addition, these shocks are not smooth, but they contain a multitude of turns similar to Wiggle.
But these shocks are only “the tip of the iceberg”, said Rajpurohit, compared to the massive radio swabs that includes the entire cluster.
This raises a mystery: the emission of radio in the galaxies is often triggered by the active nutrition of supermaxicci black holes that spit winds or jets of material, but those phenomena are not powerful enough to support a bright halo as large as the one around Plckg 287.0+32.9.
This is because this radio emission requires two things: highly energy -charged particles known as cosmic rays and magnetic fields. Cosmic rays can be generated by shock waves. There, where the gas compresses, even their magnetic fields, acting as particles accelerators who can push electrons at speeds close to light. While these electrons turn through the magnetic fields, they emit the radio emission – but in the end, this unloads them of their energy.
The huge radio halo is so great that it does not seem possible for cosmic rays to maintain their energy while emitting on these vast distances. “We still don’t understand where these cosmic rays come from and how they survive there,” said Rajpurohit.
Instead, there must be some other source of energy within the galaxies cluster – perhaps invisible shocks, turbulence or other galaxies not seen by Chandra or Meerkat – which is reacting them.
Rajpurohit suspects that there may be many more galaxies in the cluster than those that can only be seen in longer wavelengths longer than existing radio structures can detect. “We just suppose they are like a ghost – they exist, but you are not yet perceived them,” he said Astronomy.
The uncertain future of Chandra
The study would not have been possible without chandra’s ability to shoot high resolution X -ray images, which are not equal from any other current or planned X -ray telescope.
Rajpurohit has multiple chandra observations of Plckg 287.0+32.9 in suspense – but the telescope may never be able to take them. Although Chandra remains one of the most requested telescopes in the NASA portfolio, the observatory was on the block for over a year due to budgetary difficulties whose roots precede the current administration. The rejection of the congress and a public awareness campaign from astronomers seemed to win the mission a recovery last year.
But under the request for the presidential budget of the Trump administration published last month – which cuts the funding for NASA science almost halfway – Chandra would have been closed forever.
If that move is approved by the congress, “we will lose our X -ray eyes”, says Jaya Maithil, an astronomer CFA that also uses Chandra, but has not been involved in the work Plckg 287.0+32.9.
At the AAS meeting, Maithil presented a jet from Quasar surprisingly strong seen by Chandra just 3 billion years after the Big Bang. “There is no other telescope that can actually solve that jet – it’s just chandra,” he said Astronomy. Even the future X -ray telescopes currently on the drawing table will not have a comparable resolution, he observed. “All these things will only be a source of points in the sky … we will never be able to know how the universe has formed as the way we see it today.”
