Sunday, June 11, 2023

Across The Universe, Cont. -- Jellyfish Galaxy And 45,000 More

 

(click on image to enlarge)

From NASA/ ESA, June 5, 2023: The jellyfish galaxy JO206 trails across this image from the NASA/ESA Hubble Space Telescope, showcasing a colourful star-forming disc surrounded by a pale, luminous cloud of dust. A handful of bright stars with criss-cross diffraction spikes stand out against an inky black backdrop at the bottom of the image. JO206 lies over 700 million light-years from Earth in the constellation Aquarius, and this image of the galaxy is the sixth and final instalment in a series of observations of jellyfish galaxies. Some of Hubble's other observations of these peculiar galaxies — which range from grandiose to ghostly — are available here

Jellyfish galaxies are so-called because of their resemblance to their aquatic namesakes. In this image, the disc of JO206 is trailed by long tendrils of bright star formation that stretch towards the bottom right of this image, just as jellyfish trail tentacles behind them. The tendrils of jellyfish galaxies are formed by the interaction between galaxies and the intra-cluster medium, a tenuous superheated plasma that pervades galaxy clusters. As galaxies move through galaxy clusters they ram into the intracluster medium, which strips gas from the galaxies and draws it into the long tendrils of star formation.

The tentacles of jellyfish galaxies give astronomers a unique opportunity to study star formation under extreme conditions, far from the influence of the main disc of the galaxy. Surprisingly, Hubble revealed that there are no striking differences between star formation in the discs of jellyfish galaxies and star formation in their tentacles, which suggests the environment of newly-formed stars has only a minor influence on their formation.

[Image Description: A spiral galaxy that is tilted partially toward us. Its inner disc is bright and colourful, with bluish and reddish spots of star formation throughout the arms. An outer disc of pale, dim dust surrounds it. It has many arms, which are being pulled away from the disc, down and to the right. They stretch into long, faint trails that cross the image. The background is dark and mostly empty, with three bright stars.]

Credit:  ESA/Hubble & NASA, M. Gullieuszik and the GASP team

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(click on image to enlarge)


From the James Webb Space Telescope, June 5, 2023: This infrared image from NASA’s James Webb Space Telescope (JWST) was taken for the JWST Advanced Deep Extragalactic Survey, or JADES, program. It shows a portion of an area of the sky known as GOODS-South, which has been well studied by the Hubble Space Telescope and other observatories. More than 45,000 galaxies are visible here.

Using these and other data, the JADES team has discovered hundreds of galaxies that existed when the universe was less than 600 million years old. The sheer number of these galaxies was far beyond predictions from observations made before Webb’s launch.

The team also has identified galaxies that existed during a time known as the Epoch of Reionization, when the universe underwent a transformation from opaque to transparent. Many of these galaxies shown unusually strong emission line signatures due to the creation of multitudes of hot, massive stars.

In this image, blue, green, and red were assigned to Webb’s NIRCam (Near-Infrared Camera) data at 0.9, 1.15, and 1.5 microns; 2.0, 2.77, and 3.55 microns; and 3.56, 4.1, and 4.44 microns (F090W, F115W, and F150W; F200W, F277W, and F335M; and F356W, F410M, and F444W), respectively.

Credit:  NASA, ESA, CSA, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Marcia Rieke (University of Arizona), Daniel Eisenstein (CfA);  Alyssa Pagan (STScI)  

1 comment:

rick shapiro said...

The universe was not opaque prior to the Epoch of Reionization, because neutral H does not absorb EM except at specific quantum transition wavelengths. It was opaque before
previous Epoch of Recombination, because an ionized plasma really does absorb all wavelengths. The only reason that the universe remained transparent during the Epoch of Reionization is because expansion of the universe had meanwhile caused ionized atoms to be too dispersed to absorb all light.