Date: 11/11/2023 19:10:03
From: mollwollfumble
ID: 2093440
Subject: Euclid, Perseus, Pandora, Quasar, Webb

Two recent Apod articles are worth reading.

https://apod.nasa.gov/apod/ap231108.html

There’s a new space telescope in the sky: Euclid. Equipped with two large panoramic cameras, Euclid captures light from the visible to the near-infrared. It took five hours of observing for Euclid’s 1.2-meter diameter primary mirror to capture, through its sharp optics, the 1000+ galaxies in the Perseus cluster, which lies 250 million light years away. More than 100,000 galaxies are visible in the background, some as far away as 10 billion light years. The revolutionary nature of Euclid lies in the combination of its wide field of view (twice the area of the full moon), its high angular resolution (thanks to its 620 Megapixel camera), and its infrared vision, which captures both images and spectra. Euclid’s initial surveys, covering a third of the sky and recording over 2 billion galaxies.

Perseus cluster from Euclid.

https://apod.nasa.gov/apod/ap231110.html

Massive cluster of galaxies Abell 2744 is known to some as Pandora’s Cluster. It lies 3.5 billion light-years away toward the constellation Sculptor. Using the galaxy cluster’s enormous mass as a gravitational lens to warp spacetime and magnify even more distant objects directly behind it, astronomers have found a background galaxy, UHZ1, at a remarkable redshift of Z=10.1. That puts UHZ1 far beyond Abell 2744, at a distance of 13.2 billion light-years, seen when our universe was about 3 percent of its current age. UHZ1 is identified in the insets of this composited image combining X-rays (purple hues) from the spacebased Chandra X-ray Observatory and infrared light from the James Webb Space Telescope. The X-ray emission from UHZ1 detected in the Chandra data is the telltale signature of a growing supermassive black hole at the center of the ultra high redshift galaxy. That makes UHZ1’s growing black hole the most distant black hole ever detected in X-rays.

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Date: 11/11/2023 20:03:11
From: mollwollfumble
ID: 2093450
Subject: re: Euclid, Perseus, Pandora, Quasar, Webb

The original press release of the Euclid images

https://www.esa.int/Science_Exploration/Space_Science/Euclid/Euclid_s_first_images_the_dazzling_edge_of_darkness

Five images.

Perseus cluster

Spiral Galaxy IC 342

Irregular galaxy NGC 6822

Globular cluster NGC 6397.

The Horsehead Nebula

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Date: 13/11/2023 12:19:51
From: mollwollfumble
ID: 2093938
Subject: re: Euclid, Perseus, Pandora, Quasar, Webb

mollwollfumble said:


The original press release of the Euclid images

https://www.esa.int/Science_Exploration/Space_Science/Euclid/Euclid_s_first_images_the_dazzling_edge_of_darkness

Five images.

Perseus cluster

Spiral Galaxy IC 342

Irregular galaxy NGC 6822

Globular cluster NGC 6397.

The Horsehead Nebula

I have always been a fan of telescopes with a wide field of view. Those with a narrow field of view such as the VLT interferometer and the James Webb are great for zooming in on distant planets around stars, but struggle to produce good images.

The data in this image were taken in just about one hour of observation. This colour image was obtained by combining VIS data and NISP photometry in Y and H bands; its size is 8800 × 8800 pixels. VIS and NISP enable observing astronomical sources in four different wavelength ranges. Aesthetics choices led to the selection of three out of these four bands to be cast onto the traditional Red-Green-Blue colour channels used to represent images on our digital screens (RGB). The blue, green, red channels capture the Universe seen by Euclid around the wavelength 0.7, 1.1, and 1.7 micron respectively. This gives Euclid a distinctive colour palette.

Zooming in full resolution.

Zooming in (rotated) with ESA Sky

Zooming out.

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Date: 16/11/2023 20:33:58
From: mollwollfumble
ID: 2094969
Subject: re: Euclid, Perseus, Pandora, Quasar, Webb

Let’s compare directly.

Horse Head nebula from Euclid above, from Hubble bottom.

Hubble’s image seems just a teensy bit better, but there’s not much in it. Euclid has a much wider field of view than Hubble.
Euclid has a field of view of 0.57 degrees squared. That’s 45 arc minutes across. Hubble has a field of view 2.7 arc minuted to a side. Webb has 2 off 2.2 arc minute fields of view, no better than Hubble.

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Date: 17/11/2023 23:54:56
From: Bubblecar
ID: 2095348
Subject: re: Euclid, Perseus, Pandora, Quasar, Webb

The full-res version of the Perseus image is magnificent.

Would be nice to see one with all Milky Way stars removed.

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