Cosmic cliffs and dancing galaxies: NASA’s James Webb telescope begins new era of astronomy
Science & Technology
22nd Jul, 2022
NASA releases four more images taken by James Webb Space Telescope after deep field image of SMACS 0723 shared earlier.
About James Webb:
- It is the most powerful infrared telescopeof National Aeronautics and Space Administration (NASA).
- It is also considered a successor of the Hubble Telescopeand will extend and complement its discoveries.
- JSWT will observe in near-infrared lightrather than light in the visible part of the spectrum (unlike Hubble) and thus it will have a much greater capacity to see obscure stars and galaxies
- Collaboration: It is a joint venture of NASA(US), ESA (Europe), and CSA (Canada)
- Webb was formerly known as the “Next Generation Space Telescope” (NGST)and it was renamed in 2002 after a former NASA administrator, James Webb.
IMAGES REALEASED BY JWST TILL DATE:
NASA revealed images of the following targets:
- JWST’s first image- SMACS 0723
- Carina Nebula
- WASP-96 b (spectrum data)
- Southern Ring Nebula
- Stephen’s Quintet.
JWST’s FIRST IMAGE- SMACS 0723
- NASA’s James Webb Space Telescope has delivered the deepest and sharpest infrared image of the distant universe so far. Webb’s First Deep Field is galaxy cluster SMACS 0723.
- Webb’s image covers a patch of sky approximately the size of a grain of sand held at arm’s length by someone on the ground – and reveals thousands of galaxies in a tiny sliver of vast universe.
- Webb’s sharp near-infrared view brought out faint structures in extremely distant galaxies, offering the most detailed view of the early universe to date.
- Some of the cosmic objects in the image are pictured as they were 13.1 billion years ago.
- Webb took 4 days to create the image, compared to the ten days taken by Hubble for a lower-resolution image.
- · The telescope’s NIRCam has brought distant galaxies into sharp focus, letting us see tiny, faint structures that have never been seen before, including star clusters and diffuse features.
- WASP-96b, a massive planet located nearly 1,150 light-years away from Earth.
- Discovered in 2014, the gas giant has half the mass of Jupiter and orbits its star every three to four days, meaning that it has super-hot surface temperatures.
- WASP-96b is almost entirely cloud-free and scientists predict that it has an abundance of Sodium.
WHAT JWST REVEALED?
The spectrum data of WASP-96B revealed the presence of water vapour on the distant exoplanet for the first time.
- This is the first and most detailed near-infrared transmission spectrum of an exoplanet atmosphere captured to date.
- It reveals wavelengths that haven’t been revealed before.
- The spectrum reveals tell-tale signatures of water vapour on the planet.
- WASP-96B is closer to its star than Mercury is to our sun.
- This wavelength spectrum is very sensitive to water as well as key life molecules like oxygen, methane and carbon dioxide. (these molecules could be explored in future)
- It is also known as the Southern Ring Nebula or NGC 3132. It is a well-known planetary nebula in the constellation Vela, located approximately 2,500 light-years from Earth.
- Planetary nebulae have nothing to do with planets. They are the shells of gas and dust ejected from dying stars.
WHAT JWST REVEALED:
- Webb’s powerful infrared view brings this nebula’s second star into full view, along with exceptional structures created as the stars shape the gas and dust around them.
- The images also reveal a cache of distant galaxies in the background. Most of the multi-coloured points of light seen here are galaxies – not stars.
- The dimmer star at the centre of this scene has been sending out rings of gas and dust in all directions for thousands of years, and Webb has revealed for the first time that this star is cloaked in dust.
- Webb's infrared images feature new details in the complex system of the stars – and their layers of light which are prominent in the image from Webb’s Near-Infrared Camera (NIRCam)
- While the image from Webb’s Mid-Infrared Instrument (MIRI) shows for the first time that the second star is surrounded by dust.
- The brighter star is at an earlier stage of its evolution and will probably eject its own planetary nebula in the future.
- New details like these, from the late stages of a star’s life, will help us better understand how stars evolve and transform their environments.
- Webb will allow astronomers to dig into many more specifics about planetary nebulae like this one – clouds of gas and dust expelled by dying stars.
- Understanding which molecules are present, and where they lie throughout the shells of gas and dust, will help researchers refine their knowledge of these objects.
- Stephan’s Quintet, a visual grouping of five galaxies, is best known for being prominently featured in the holiday classic film, “It’s a Wonderful Life.”
- The five galaxies of Stephan’s Quintet are also known as the Hickson Compact Group 92 (HCG 92).
- Although called a “quintet,” only four of the galaxies are truly close together and caught up in a cosmic dance.
- The fifth and leftmost galaxy, called NGC 7320, is well in the foreground compared with the other four.
- NGC 7320 resides 40 million light-years from Earth, while the other four galaxies (NGC 7317, NGC 7318A, NGC 7318B, and NGC 7319) are about 290 million light-years away.
WHAT JWST REVEALED:
- The image is an enormous mosaic of Stephan’s Quintet and the largest image taken by Webb to date. (covering about one-fifth of the Moon’s diameter)
- It covers over 150 million pixels and is constructed from 1,000 separate image files.
- It provides new insights into how galactic interactions may have driven galaxy evolution in the early universe.
- Webb captures huge shock waves as one of the galaxies, NGC 7318B, smashes through the cluster.
- Studying such ‘nearby’ galaxies like these helps scientists better understand the dynamics in a more distant universe.
- It provides astronomers a ringside seat for witnessing the merging and interactions between galaxies that are so crucial to all of galaxy evolution.
- Stephan’s Quintet is a fantastic “laboratory” for studying these processes fundamental to all galaxies.
- Combined with the most detailed infrared image ever of Stephan’s Quintet from MIRI and the Near-Infrared Camera (NIRCam), the data from Webb will provide a bounty of valuable, new information.
- For example, it will help scientists understand the rate at which supermassive black holes feed and grow.
- Webb also sees star-forming regions much more directly, and it is able to examine emission from the dust – a level of detail impossible to obtain until now.
- It is a large, complex area of bright and dark nebulosity in the constellation Carina, located in the Carina–Sagittarius Arm of the Milky Way galaxy.
- Carina Nebula is home to the Keyhole Nebula and the active, unstable supergiant star called Eta Carinae.
- The nebula is approximately 7500 light years away from Earth.
- NGC 3324 was first catalogued by James Dunlop in 1826. Visible from the Southern Hemisphere, it is located at the northwest corner of the Carina Nebula (NGC 3372), which resides in the constellation Carina.
WHAT JWST REVEALED:
- This is the last and final image released by NASA shows a star-forming region in the Carina Nebula called NGC 3324, and its “mountains” and “valleys” speckled with glittering stars.
- Captured in infrared for the first time by Webb, the new image shows previously invisible areas of star birth called as Cosmic Cliffs.
- The image resembles craggy mountains on a moonlit evening.
- Actually, it is the edge of the giant gaseous cavity within the region of the nebula and some of the tallest “peaks” in the nebula are around 7 light-years high.
- The cavernous area (cavity) in the image was carved from the nebula by the intense ultraviolet radiation and stellar winds from extremely hot young stars located in the centre of this “bubble,”
- These observations of NGC 3324 will shed light on the process of star formation.
- Star birth propagates over time, triggered by the expansion of the eroding cavity. As the bright, ionized rim moves into the nebula, it slowly pushes into the gas and dust. If the rim encounters any unstable material, the increased pressure will trigger the material to collapse and form new stars.
- Webb will address some of the great, open questions of modern astrophysics: What determines the number of stars that form in a certain region? Why do stars form with a certain mass?
- Webb will also reveal the impact of star formation on the evolution of gigantic clouds of gas and dust.
- Up to this point, scientists have had very little data about the influence of the multitude of young and more energetic low-mass stars.
- With Webb, they will be able to obtain a full census of their number and impact throughout the nebula.