Artist rendering of the James Webb Space Telescope. Credit: NASA GSFC/CIL/Adriana Manrique Gutierrez
Web Space Telescope Team keep working in myself commissioning It is the last step before scientific operations begin in the summer. We recently saw the amazing photo of The black hole at the center of our Milky Way galaxytaken by event horizon telescope. One of the mysteries of modern astronomy is the size of each one galaxy He came to have a giant centrality Black holeAnd how surprisingly large some of these black holes are even in the early universe. We asked Webb’s Near Infrared Spectrometer (NIRSpec) team member Roberto Maiolino to tell us how Webb will help answer some of these questions.
“One of the most exciting areas of discovery that Webb is about to unlock is the search for primordial black holes in the early universe. These are the seeds of the most massive black holes that astronomers have found at the heart of the galaxy. Most (perhaps all) galaxies host black holes at their centers, and their masses range from Millions to billions of times the mass of our sun, these supermassive black holes have grown to become very large by devouring the matter around them as well as merging even smaller black holes.
“The latest interesting discovery is the discovery of supermassive black holes, with masses up to several billion solar masses, which already existed when the universe was only about 700 million years old, a fraction of its current age of 13.8 billion years. This is an intriguing result. Therefore, because at such early ages there was not enough time for such massive black holes to evolve, according to standard theories, some scenarios have been proposed to solve this mystery.
One possibility is that black holes, caused by the death of the first generation of stars in the early universe, accumulated material at exceptionally high rates. Another scenario is that primordial gas clouds, which are not yet enriched with chemical elements heavier than helium, could collapse directly to form[{” attribute=””>black hole with a mass of a few hundred thousand solar masses, and subsequently accrete matter to evolve into the hyper-massive black holes observed at later epochs. Finally, dense, nuclear star clusters at the centers of baby galaxies may have produced intermediate mass black hole seeds, via stellar collisions or merging of stellar-mass black holes, and then become much more massive via accretion.
This illustration shows the populations of known black holes (large black dots) and the candidate black hole progenitors in the early universe (shaded regions). Credit: Roberto Maiolino, University of Cambridge
“Webb is about to open a completely new discovery space in this area. It is possible that the first black hole seeds originally formed in the ‘baby universe,’ within just a few million years after the big bang. Webb is the perfect ‘time machine’ to learn about these primeval objects. Its exceptional sensitivity makes Webb capable of detecting extremely distant galaxies, and because of the time required for the light emitted by the galaxies to travel to us, we will see them as they were in the remote past.
“Webb’s NIRSpec instrument is particularly well suited to identify primeval black hole seeds. My colleagues in the NIRSpec Instrument Science Team and I will be searching for their signatures during ‘active’ phases, when they are voraciously gobbling matter and growing rapidly. In these phases the material surrounding them becomes extremely hot and luminous and ionizes the atoms in their surroundings and in their host galaxies.
“NIRSpec will disperse the light from these systems into spectra, or ‘rainbows.’ The rainbow of active black hole seeds will be characterised by specific ‘fingerprints,’ features of highly ionized atoms. NIRSpec will also measure the velocity of the gas orbiting in the vicinity of these primeval black holes. Smaller black holes will be characterized by lower orbital velocities. Black hole seeds formed in pristine clouds will be identified by the absence of features associated with any element heavier than helium.
“I look forward to using Webb’s unprecedented capabilities to search for these black hole progenitors, with the ultimate goal of understanding their nature and origin. The early universe and the realm of black holes seeds is a completely uncharted territory that my colleagues and I are very excited to explore with Webb.”
— Roberto Maiolino, professor of experimental astrophysics and director of the Kavli Institute for Cosmology, University of Cambridge
Written by:
- Jonathan Gardner, Webb deputy senior project scientist, NASA’s Goddard Space Flight Center
- Stefanie Milam, Webb deputy project scientist for planetary science, NASA’s Goddard Space Flight Center
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