by Ann » Mon Sep 24, 2018 5:07 pm
bystander wrote: ↑Mon Sep 24, 2018 4:50 pm
Warped and Distorted
ESA Hubble Picture of the Week | 2018 Sep 24
This NASA/ESA Hubble Space Telescope image contains a veritable mix of different galaxies, some of which belong to the same larger structure: At the middle of the frame sits the galaxy cluster SDSS J1050+0017.
The gigantic mass of this cluster creates the fascinating phenomenon of
strong gravitational lensing. The gravity of the cluster bends light coming from behind it in a similar way to how the base of a wine glass bends light. The effects of this lensing can be clearly seen as curved streaks forming a circular shape around the centre of the frame. Astronomers can use these distorted galaxies to calculate the mass of the cluster — including the mass of the dark matter within it — and to peer deeper into the Universe as otherwise possible. Gravitational lensing does not only distorts the views of galaxies, it also enlarge their appearance on the sky and magnifies their light.
Hubble has viewed
gravitational lensing many times, and produced truly stunning images. Astronomers even set up a dedicated programme to study different galaxy clusters which show a great number of lensed galaxies: The
Frontier Fields programme. This way some of the most distant galaxies in the Universe were found. With each additional cluster being observed some more distant galaxies are added to this list, slowly completing our picture of how galaxies looked and evolved in the early Universe.
I love these rich cluster and lensed galaxies images!!!
Geck, the spacetelescope.org page credits you. You have told us before that sometimes they credit you even if you have had little or nothing to do with the image, but perhaps, in this case, you know something about it? For example, do you know what filters were used for it?
I note that the blue features in the image are often sharply blue or blue-green. For example, at middle right, there is what looks like a sharply turquoise edge-on galaxy seemingly falling straight into a sedate-looking yellow disk galaxy, which is itself located to the right of a very similar sedate-looking yellow disk galaxy. That turquoise interloper looks weird. Perhaps it is a background object? Or a foreground object?
Many of the galaxies in the picture are in fact sharply blue, and others sport bright little blue sites of star formation in their yellow arms or disks. I suppose blue represents redshifted ultraviolet light. Knowing what filters were used for the image would be helpful. So if you can help, Geck, I would be grateful!
Ann
[quote=bystander post_id=286050 time=1537807856 user_id=112005]
[url=https://www.spacetelescope.org/images/potw1839a/][size=125][b][i]Warped and Distorted[/i][/b][/size][/url]
ESA Hubble Picture of the Week | 2018 Sep 24
[quote]
[float=left][img3="Image Credit: ESA/Hubble & NASA -
Acknowledgement: Judy Schmidt"]https://cdn.spacetelescope.org/archives/images/screen/potw1839a.jpg[/img3][/float]This NASA/ESA Hubble Space Telescope image contains a veritable mix of different galaxies, some of which belong to the same larger structure: At the middle of the frame sits the galaxy cluster SDSS J1050+0017.
The gigantic mass of this cluster creates the fascinating phenomenon of [url=https://en.wikipedia.org/wiki/Gravitational_lens]strong gravitational lensing[/url]. The gravity of the cluster bends light coming from behind it in a similar way to how the base of a wine glass bends light. The effects of this lensing can be clearly seen as curved streaks forming a circular shape around the centre of the frame. Astronomers can use these distorted galaxies to calculate the mass of the cluster — including the mass of the dark matter within it — and to peer deeper into the Universe as otherwise possible. Gravitational lensing does not only distorts the views of galaxies, it also enlarge their appearance on the sky and magnifies their light.
Hubble has viewed [url=http://www.spacetelescope.org/science/gravitational_lensing/]gravitational lensing[/url] many times, and produced truly stunning images. Astronomers even set up a dedicated programme to study different galaxy clusters which show a great number of lensed galaxies: The [url=https://frontierfields.org/]Frontier Fields[/url] programme. This way some of the most distant galaxies in the Universe were found. With each additional cluster being observed some more distant galaxies are added to this list, slowly completing our picture of how galaxies looked and evolved in the early Universe. [/quote]
[/quote]
I love these rich cluster and lensed galaxies images!!!
Geck, the spacetelescope.org page credits you. You have told us before that sometimes they credit you even if you have had little or nothing to do with the image, but perhaps, in this case, you know something about it? For example, do you know what filters were used for it?
I note that the blue features in the image are often sharply blue or blue-green. For example, at middle right, there is what looks like a sharply turquoise edge-on galaxy seemingly falling straight into a sedate-looking yellow disk galaxy, which is itself located to the right of a very similar sedate-looking yellow disk galaxy. That turquoise interloper looks weird. Perhaps it is a background object? Or a foreground object?
Many of the galaxies in the picture are in fact sharply blue, and others sport bright little blue sites of star formation in their yellow arms or disks. I suppose blue represents redshifted ultraviolet light. Knowing what filters were used for the image would be helpful. So if you can help, Geck, I would be grateful!
Ann