Picture This – Astronomy Now

A rare triple active galactic nucleus

Astronomy Now — Wed, 14 Feb 2024 14:36:34 +0000

Image: ESA/Hubble and NASA/J. Dalcanton/Dark Energy Survey/DOE/FNAL/NOIRLab/NSF/AURA.

This cosmic collision is a coming together of two large spiral galaxies, but if you look carefully you might see two smaller galaxies that are also involved. The large galaxy in the top half of the picture is NGC 7734, while the other, distorted, galaxy is NGC 7733. Both have had their spiral arms unwrapped, with NGC 7733 in particular forming a warped ring galaxy with a lens or bar in the middle. On NGC 7733’s blue ring of stars is a noticeable bright knot. This is a third galaxy, NGC 7733N, which lies between us and NGC 7733. It’s interacting with NGC 7733, and may be partially to blame for the ring structure (this normally forms when a smaller galaxy passes through a larger galaxy). As for the fourth galaxy, it is the sliver of light to the lower-left.

Ultraviolet observations suggest that it is connected to NGC 7733 by a river of hot gas, although this has yet to be confirmed via redshift measurements. All four galaxies, which are 500 million light years away, are interacting and will eventually merge to form one giant elliptical galaxy. In 2021 a study published in the journal Astronomy and Astrophysics, using data from the Very Large Telescope’s MUSE (Multi Unit Spectroscopic Explorer) instrument and near-infrared observations from the South African Astronomical Observatory, indicated that NGC 7733b contains an active galactic nucleus (AGN) called a Low Ionisation Nuclear Emission-line Region (LINER), while both NGC 7734 and NGC 7733N contain Seyfert AGN. That makes this system, collectively known as Arp–Madore 2339-661, a rare triple AGN. When the galaxies all merge, the supermassive black holes at the heart of these AGN will also merge.

This image of the galaxies is a composite taken by the Hubble Space Telescope’s Advanced Camera for Surveys and the Dark Energy Camera on the Victor M. Blanco four-metre telescope in
Chile.

Webb space telescope turns its infrared eye on the Crab Nebula and its remnant pulsar

Astronomy Now — Tue, 07 Nov 2023 17:43:12 +0000

The James Webb Space Telescope recently turned its infrared eye on the Crab Nebula to learn more about the supernova that created the billowing structure. The explosion was first observed in China in 1054 and the cloud of gas and debris left behind was first seen in 1731. At the center of the image, the Crab’s remnant pulsar, spinning at 30 times per second, can be seen as a brilliant white dot surrounded by compact rings of dust and gas. Webb used its Near-Infrared Camera (NIRCam) and its Mid-Infrared Instrument (MIRI) to produce this striking image.

The Crab Nebula as seen by the James Webb Space Telescope. Image: NASA, ESA, CSA, STScI, Tea Temim (Princeton University)

Hubble images a glittering, star-studded globular cluster

Astronomy Now — Sun, 06 Aug 2023 16:02:42 +0000

The globular cluster NGC 6652 is found in the constellation Sagittarius, about 30,000 light years from Earth and just 6,500 light years from the center of the Milky Way. This star-studded image was captured by the Hubble Space Telescope’s Advanced Camera for Surveys and Wide Field Camera 3 for two studies, one focused on determining the ages of such globulars and their contribution to the gravitational potential of the galaxy and one to pin down the proportions of carbon, nitrogen and oxygen in clusters like NGC 6652. The bright blue stars of the globular are seen behind brighter foreground stars marked by diffraction spikes.

NGC 6652. Image: ESA/Hubble & NASA, A. Sarajedini, G. Piotto

Webb observes menagerie of lensed galaxies behind ‘El Gordo’ cluster

Astronomy Now — Wed, 02 Aug 2023 14:39:58 +0000

Peering at a galaxy cluster known as “El Gordo,” the James Webb Space Telescope has spotted a host of background galaxies, magnified, warped and distorted by gravitational lensing to produce a menagerie of never-before-seen star swarms. El Gordo includes hundreds of galaxies that existed when the universe was 6.2 billion years old. The most striking feature, perhaps, is a bright arc of red at upper right nicknamed El Anzuelo, or The Fishhook, a lensed galaxy dating back 10.6 billion years (labeled B in the second image below). Observers were able to correct the distortions to find the background galaxy is disk shaped but only about 26,000 light years in diameter. They were also able to determine star formation was slowing down in a process known as quenching. Another intriguing feature is a long thin line at left of center known as La Flaca, or The Thin One (labeled A in the second image below). It’s another lensed galaxy some 11 billion light years away. Numerous other gravitationally magnified galaxies are also visible. Click on the image below for a zoomed-in version.

The “El Gordo” galaxy cluster as seen by the James Webb Space Telescope. Image: NASA, ESA, CSA; image processing: Alyssa Pagan (STScI), Jake Summers (ASU), Jordan C. J. D’Silva (UWA), Anton M. Koekemoer (STScI), Aaron Robotham (UWA), Rogier Windhorst (ASU)

Image: NASA, ESA, CSA; image processing: Alyssa Pagan (STScI), Jake Summers (ASU), Jordan C. J. D’Silva (UWA), Anton M. Koekemoer (STScI), Aaron Robotham (UWA), Rogier Windhorst (ASU)

JunoCam images and expert ‘citizen-scientist’ processing provides stunning portrait of Jupiter and three of its Galilean moons

Astronomy Now — Tue, 01 Aug 2023 02:00:21 +0000

A colourful family portrait combining images of Jupiter and three of its Galilean moons – Ganymede, Europa and Io – as seen by NASA’s Juno orbiter. The images were captured by the spacecraft’s public-domain JunoCam instrument and processed by two “citizen scientists.” Kevin Gill produced the images of Jupiter (far right), Ganymede (far left) and its icy neighbour Europa while Thomas Thomopoulos processed an image of volcanic Io. Launched in August 2011, Juno has been orbiting Jupiter since July 2016. Data collected by the JunoCam imager is available to the public for processing and sharing.

Family portrait (left to right): Ganymede, Europa, Io and Jupiter. Image: NASA/JPL-Caltech/SwRI/MSSS; Image processing: Kevin M. Gill, Thomas Thomopoulos

Hubble probes merging galaxy clusters combining to form powerful gravitational lenses

Astronomy Now — Wed, 19 Jul 2023 14:59:24 +0000

While the James Webb Space Telescope is capturing headlines on a near-daily basis, its famous predecessor – the Hubble Space Telescope – remains in the forefront of optical astronomy as seen in this view of at least two galaxy clusters in the process of merging. In a project called “Monsters in the Making,” Hubble’s Wide Field Camera 3 and the Advanced Camera for Surveys studied a throng of galaxies known as eMACS J1353.7+4329, located about eight billion light years from Earth in the constellation Canes Venatici. The resulting image shows the crowded field of galaxies and the first hints of gravitational lensing, arcs of distorted light from background galaxies that are magnified by the combined gravity of the foreground cluster. The Monsters in the Making project is designed to help lay the groundwork for future gravitational lensing studies by Webb and other next-generation telescopes.

The arc-like structure to the left of the bright star at upper right is the light from a more distant background galaxy, distorted and magnified by the combined gravity of merging galaxy clusters in the foreground. Image: ESA/Hubble & NASA, H. Ebeling

Webb ‘scientific visualization’ takes viewers back in time at 200 million light years per second

Astronomy Now — Mon, 10 Jul 2023 15:55:57 +0000

Data captured by the James Webb Space Telescope as part of the ongoing Cosmic Evolution Early Release Science survey takes viewers on trip back in time to a never-before-seen galaxy that was shining just 390 million years after the Big Bang. The video is based on data from 5,000 galaxies in a vast swath between Ursa Major and Boötes that includes about 100,000 galaxies altogether. Data from Webb and earlier observations by the Hubble Space Telescope were combined to determine the distances to target galaxies, taking viewers all the way back to “Maisie’s Galaxy,” which formed about 13.4 billion years ago. Each second of the video amounts to traveling 200 million years further into the past. We recommend full-screen viewing!

https://stsci-opo.org/STScI-01H4TYWHQX17WA0HVXVTTS2Z32.mp4

Credits:

Visualization:
Frank Summers (STScI), Greg Bacon (STScI), Joseph DePasquale (STScI), Leah Hustak (STScI), Joseph Olmsted (STScI), Alyssa Pagan (STScI)

Science:
Steve Finkelstein (UT Austin), Rebecca Larson (RIT), Micaela Bagley (UT Austin)

Music
“Spring Morning,” Maarten Schellekens

Hubble provides a stunning view of a tightly packed sea of stars in globular cluster M14

Astronomy Now — Wed, 05 Jul 2023 14:38:45 +0000

Globular clusters draw gasps of wonder when viewed through even modest telescopes. But the Hubble Space Telescope’s view of Messier 14, combining visible, near infrared and ultraviolet wavelengths, is in a class by itself, a stunning sea of tightly-packed stars that defies the imagination. Discovered by comet-hunter Charles Messier in 1764, M14 features and estimated 150,000 suns located some 29,000 light years from Earth in the constellation Ophiuchus. It is well positioned for observing in July. Click into the image below for a larger view.

Messier 14, as observed by the Hubble Space Telescope. Image: NASA, ESA, and F. D’Antona (INAF, Osservatorio Astronomico di Roma); Image Processing: Gladys Kober

Webb takes a spectacular infrared look at Saturn and its brilliant rings

Astronomy Now — Fri, 30 Jun 2023 22:37:09 +0000

The James Webb Space Telescope has turned its attention to Saturn as part of a program to test the observatory’s ability to detect faint moons and subtle details in its splendid ring system. Needless to say, scientists were thrilled with the results, capturing images showing the rings virtually blazing at near-infrared wavelengths, along with three of Saturn’s moons. Deeper images are planned to reveal more details about the planet’s fainter rings, including the dim G ring and the diffuse E ring, which is fed by geysers erupted from the ice moon Enceladus. Saturn itself appears extremely dark because methane gas absorbs almost all of the light hitting the atmosphere.

Saturn and three of its moons – Dione, Enceladus and Tethys – as seen by the James Webb Space Telescope. Images: NASA, ESA, CSA, STScI, M. Tiscareno (SETI Institute), M. Hedman (University of Idaho), M. El Moutamid (Cornell University), M. Showalter (SETI Institute), L. Fletcher (University of Leicester), H. Hammel (AURA); image processing by J. DePasquale (STScI)

‘Smiling cat’ nebula blazes with newborn stars and hot, ionised gas

Astronomy Now — Tue, 27 Jun 2023 12:32:27 +0000

Fifteen thousand light years away in the constellation Monoceros, a stellar nursery known as Sh2-284 blazes with the fiery glow of young stars blasting out strong winds and torrents of radiation. The radiation is enough to ionise hydrogen gas in a 150-lightyear-wide nebula, producing billowing bright orange and red clouds that vaguely resemble the face of a smiling cat as seen from Earth. This spectacular image was captured by the VLT Survey Telescope at Paranal Observatory in Chile. The VST is mapping the southern sky with a 256-million-pixel camera optimised for wide-field images.

The “smiling cat” nebula, formally Sh2-284. Image: ESO/VPHAS+ team. Acknowledgement: CASU