Found Images: 2018 April

[bystander]

Lights Out in the Galactic Centre
ESO Picture of the Week | 2018 Apr 30

Credit: ESO/VVV Survey/D. Minniti -- Acknowledgement: Ignacio Toledo

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A sinister smile appears amid a sea of stars in this image — a small portion of a gigantic gigapixel colour mosaic of the Milky Way’s heart. Comprised of thousands of incredibly detailed images taken by ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA), the mosaic reveals more of the stars at the Milky Way’s heart than ever before.

VISTA was chosen due to its extremely sensitive infrared camera, which can see through most of the dust that blocks our view towards the centre of the galaxy. What we see in this image is a dense patch of gas and dust — a nebula — that even VISTA’s camera cannot see through. Located near the Lagoon Nebula (not seen), it appears to wink back as it mischievously blocks out the light from background stars.

The full image contains almost nine billion pixels, and is part of the Vista Variables in the Via Lactea (VVV) survey, a project to image the Milky Way’s bulge and disc at near-infrared wavelengths. To create the colour mosaic, images at three different wavelengths were seamlessly combined. The full zoomable image can be explored online.

[bystander]

Monster in the Deep
ESA Hubble Picture of the Week | 2018 Apr 30

Credit: ESA/Hubble & NASA -- Acknowledgement: Judy Schmidt

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Though the bright, light-speckled foreground galaxy on the left is eye-catching, it is far from the most intriguing object in this NASA/ESA Hubble Space Telescope image. In the upper part of the frame, the light from distant galaxies has been smeared and twisted into odd shapes, arcs, and streaks. This phenomenon indicates the presence of a giant galaxy cluster, which is bending the light coming from the galaxies behind it with its monstrous gravitational influence.

This cluster, called SDSS J0150+2725, lies some three billion light-years away and was first documented by the Sloan Digital Sky Survey (SDSS), hence its name. The SDSS uses a 2.5-metre optical telescope located at the Apache Point Observatory in New Mexico to observe millions of objects and create detailed 3D maps of the Universe. This particular cluster was part of the Sloan Giant Arcs Survey (SGAS), which detected galaxy clusters with strong lensing properties; their gravity stretches and warps the light of more distant galaxies sitting behind them, creating weird and spectacular arcs such as those seen here.

The Hubble data on of SDSS J0150+2725 were part of a study of star formation in brightest cluster galaxies (called BCGs), lying between approximately 2 and 6 billion light-years away. This study found the star formation rate in these galaxies to be low, which is consistent with models that suggest that most stars in such galaxies form very early on. These BCGs also emit strong radio signals thought to be from active galactic nuclei (AGN) at their centers, suggesting that the activity from both the AGN and any ongoing star formation is fueled by cold gas found within the host galaxies.

[starsurfer]

LDN 810
http://afesan.es/Deepspace/slides/LDN%2 ... us%29.html
Copyright: Antonio Sánchez

[starsurfer]

Abell 23
http://members.pcug.org.au/~stevec/Abel ... 3_RC14.htm
Copyright: Steve Crouch