IMAGE-1:- The Crab Nebula:
NASA's James Webb Space Telescope recently focused its lenses on the Crab Nebula, a leftover from a supernova explosion that occurred about 6,500 light-years away in the Taurus constellation. This celestial event was originally observed and recorded by astronomers in the year 1054 CE. The Crab Nebula has captivated scientists for centuries, leading to ongoing research aimed at understanding the intricate details of supernovae, their behavior, and their aftermath. Studying the Crab Nebula provides valuable insights because it is a relatively close example of a supernova remnant.
A team of researchers led by Tea Temim from Princeton University used Webb's advanced instruments, the NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument), to investigate the origins of the Crab Nebula. By utilizing Webb's exceptional sensitivity and spatial resolution, the team aimed to analyze the composition of the material ejected during the explosion, specifically focusing on iron and nickel content. This analysis could reveal crucial information about the type of explosion that created the Crab Nebula.
In the observations captured by Webb, the Crab Nebula displayed a distinctive structure. The overall shape of the remnant resembled images taken in visible light by NASA's Hubble Space Telescope in 2005. However, Webb's infrared observations revealed new details. The images showed a clear, cage-like structure formed by fluffy gaseous filaments, appearing in shades of red-orange. Additionally, for the first time, Webb mapped out emissions from dust grains in the central regions, represented in yellow-white and green hues. This groundbreaking observation provided valuable data, shedding light on the intricate features of the Crab Nebula and enhancing our understanding of supernova remnants.
Image-2 :- Color:
NASA’s James Webb Space Telescope and Hubble Space Telescope have united to study an expansive galaxy cluster known as MACS0416. The resulting panchromatic image combines visible and infrared light to assemble one of the most comprehensive views of the universe ever taken. Located about 4.3 billion light-years from Earth, MACS0416 is a pair of colliding galaxy clusters that will eventually combine to form an even bigger cluster.
“We are building on Hubble’s legacy by pushing to greater distances and fainter objects,” said Rogier Windhorst of Arizona State University, principal investigator of the PEARLS program (Prime Extragalactic Areas for Reionization and Lensing Science), which took the Webb observations.
His cluster was the first of a set of unprecedented, super-deep views of the universe from an ambitious, collaborative Hubble program called the Frontier Field, inaugurated in 2014. Hubble pioneered the search for some of the intrinsically faintest and youngest galaxies ever detected. Webb’s infrared view significantly bolsters this deep look by going even farther into the early universe with its infrared vision.
Image-3:-Extended disk:-
Theories have long proposed that icy pebbles forming in the cold, outer regions of protoplanetary disks — the same area where comets originate in our solar system — should be the fundamental seeds of planet formation. The main requirement of these theories is that pebbles should drift inward toward the star due to friction in the gaseous disk, delivering both solids and water to planets.
A fundamental prediction of this theory is that as icy pebbles enter into the warmer region within the "snowline" — where ice transitions to vapor — they should release large amounts of cold water vapor. This is exactly what Webb observed.
The two compact disks are expected to experience efficient pebble drift, delivering pebbles to well within a distance equivalent to Neptune's orbit. In contrast, the extended disks are expected to have their pebbles retained in multiple rings as far out as six times the orbit of Neptune.
The Webb observations were designed to determine whether compact disks have a higher water abundance in their inner, rocky planet region, as expected if pebble drift is more efficient and is delivering lots of solid mass and water to inner planets. The team chose to use MIRI's MRS (the Medium-Resolution Spectrometer) because it is sensitive to water vapor in disks.
The results confirmed expectations by revealing excess cool water in the compact disks, compared with the large disks.
As the pebbles drift, any time they encounter a pressure bump — an increase in pressure — they tend to collect there. These pressure traps don't necessarily shut down pebble drift, but they do impede it. This is what appears to be happening in the large disks with rings and gaps.
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