Tag Archives: spiral

Hubble captures the stunning collision of two spiral galaxies in Arp 122

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This cosmic encounter is known as Arp 122, and here: NASA/ESA Hubble Space Telescope.

Two spiral galaxies, NGC 6040 and NGC 6039, have merged on the right side of this Hubble image. NGC 6039 is circular when viewed from the front. NGC 6040 appears to be before the first one. In the lower left corner of the frame, elliptical galaxy NGC 6041, the central member of the galaxy cluster in which Arp 122 resides, is visible as light emanating from a point. This color image was created in both the visible and infrared regions of the spectrum using Hubble's Altitude Survey Camera (ACS) and the Dark Energy Camera mounted on NSF's Victor M. Blanco 4-meter Telescope at Cerro Tololo Inter. Created from separate exposures taken in the area. -American Observatory of Chile. Four filters were used to sample different wavelengths. Color is obtained by assigning different hues to each monochromatic image associated with an individual filter. Image credits: NASA / ESA / Hubble / J. Dalcanton / Dark Energy Survey / DOE / FNAL / DECam / CTIO / NOIRLab / NSF / AURA / L. Shatz.

Alp 122 It is located in the constellation Hercules, approximately 570 million light years from Earth.

This system consists of two galaxies: a tilted and distorted spiral galaxy; NGC6040 and the spiral galaxy in front of me NGC6039.

“Galaxy collisions and mergers are highly energetic and dramatic events, but they occur on very slow timescales,” Hubble astronomers said in a statement.

“For example, our Milky Way galaxy is on a colliding orbit with its nearest galactic neighbor, the Andromeda galaxy, but it will still be four billion years before these two galaxies actually meet. ”

“The process of collision and fusion will not end soon either; it may take hundreds of millions of years to unfold.”

“These collisions take a very long time because they have very long distances.”

“Galaxies are composed of stars and their solar systems, dust and gas,” the researchers added.

“Over time, the structures of two (or more) colliding galaxies may change completely, eventually forming a single, merged galaxy.”

“That could be the result of the collision seen in this image.”

“Galaxies resulting from mergers are thought to have regular or elliptical structures because the merger process destroys more complex structures (such as those observed in spiral galaxies).”

“It will be interesting to see what Arp 122 will look like once this collision is complete, but that won't happen for a long time.”

Source: www.sci.news

ALMA discovers earthquake-like ripples in the disk of an old barred spiral galaxy

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astronomer using Atacama Large Millimeter/Submillimeter Array ALMA observed disk bending waves in BRI 1335-0417, the oldest known spiral galaxy, more than 12 billion years old. This unprecedented observation reveals the galaxy’s dynamic growth pattern, showing the motion of a vertically oscillating disk similar to ripples in a pond. This study is the first time such a phenomenon has been detected in an early galaxy.

This simulation shows how the galactic disk is disturbed and seismic ripples propagate throughout the disk. Image credit: Brand-Hawthorne & Tepper-Garcia, University of Sydney.

Bar structures play an important role in driving galaxy evolution and forming disk structures.

In galaxies, axisymmetric stellar bars exert a gravitational torque on the gas, driving it toward the galactic center and forming concentrated stellar structures such as bulges and core disks.

This process may also promote the accretion of gas onto black holes, which are observed as active galactic nuclei.

Bars can also cause radial migration of gas and stars, which is essential for explaining the stellar kinematics observed in galaxies similar to the Milky Way.

“Thanks to a cutting-edge telescope called ALMA, we have been able to observe the ancient galaxy BRI 1335-0417 in greater detail,” said lead author Dr Takafumi Tsukui, an astronomer at the Australian National University.

“In particular, we were interested in how gas moves within and across galaxies.”

“Gas is a key component for star formation and provides important clues about how galaxies actually drive star formation.”

In this case, Dr. Tsukui and his colleagues were not only able to capture the movement of gas around BRI 1335-0417, but also revealed the formation of seismic waves, a first for this type of early galaxy.

The galaxy’s disk moves similar to the ripples in a pond after a stone is thrown into it.

ALMA detected emission from carbon ions in the galaxy BRI 1335-0417. Image credit: ALMA / ESO / NAOJ / NRAO / T. Tsukui & S. Iguchi, doi: 10.1126/science.abe9680.

“The vertical oscillatory motion of the disk is due to external factors, such as new gas flowing into the galaxy or contact with other small galaxies,” Tsukui said.

“Both possibilities would bombard the galaxy with new fuel for star formation.”

“Furthermore, our study revealed rod-like structures within the disk.”

“The galactic rods can destroy gas and transport it towards the center of the galaxy.”

“The bar discovered at BRI 1335-0417 is the most remote known structure of its kind.”

“Taken together, these results point to the dynamic growth of young galaxies.”

“We know that early galaxies formed stars at much faster rates than modern galaxies,” said co-author Dr Emily Wisnioski, also from the Australian National University.

“This is also true for BRI 1335-0417, which has a similar mass to our Milky Way galaxy but forms stars hundreds of times faster.”

“We wanted to understand how gas is supplied to keep up with this rapid rate of star formation.”

“Spiral structures are rare in the early Universe, and exactly how they form remains unknown.”

“This study also provides important information about the most likely scenario.”

“While it is impossible to directly observe the evolution of galaxies, our observations only provide snapshots, so computer simulations can help piece together the story.”

of findings will appear in Royal Astronomical Society Monthly Notices.

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Takafumi Tsukui other. 2024. Disk bending waves detected in a barred spiral galaxy at redshift 4.4. MNRAS 527 (3): 8941-8949; doi: 10.1093/mnras/stad3588

Source: www.sci.news

Astrophysicists uncover the reason behind the absence of spiral galaxies in our supergalactic plane

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Astrophysicists have discovered why spiral galaxies like the Milky Way are rare in the supergalactic plane, a dense region of our local universe. The study, led by Durham University and the University of Helsinki, used simulations on the SIBELIUS supercomputer to show that dense galaxy clusters on a plane frequently merge, transforming spiral galaxies into elliptical galaxies. The discovery is consistent with telescope observations, supports the Standard Model of the Universe, and helps explain long-standing cosmic anomalies in the distribution of galaxies.

Astrophysicists say they have found the answer to why spiral galaxies are similar to our galaxy

This image showing an elliptical galaxy (left) and a spiral galaxy (right) includes near-infrared light from the James Webb Space Telescope and ultraviolet and visible light from the Hubble Space Telescope. Credits: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS team, Alyssa Pagan (STScI)

Evolution of galaxies in dense star clusters

In dense galaxy clusters in supergalactic planes, galaxies frequently experience interactions and mergers with other galaxies. This transforms the spiral galaxy into an elliptical galaxy (a smooth galaxy with no obvious internal structure or spiral arms), leading to the growth of a supermassive black hole.

In contrast, away from the plane, galaxies can evolve in relative isolation, which helps maintain their spiral structure.

Innovative simulations and important discoveries

Research results will be published in a magazine natural astronomy.

The Milky Way is part of a supergalactic plane that includes several giant galaxy clusters and thousands of individual galaxies. Most of the galaxies found here are elliptical galaxies.

The research team used the SIBELIUS (Simulations Beyond the Local Universe) supercomputer simulation, which tracks the evolution of the universe over 13.8 billion years, from the beginning of the universe to the present.

Distribution of the brightest galaxies in the local universe. observed in the 2MASS survey (left panel) and reproduced in the SIBELIUS simulation (right panel). Both panels show projections in supergalactic coordinates down to about 100 megaparsecs (Mpc). The nearly vertical stripes of the sky represent the region of the sky hidden behind our Milky Way galaxy. The simulation accurately reproduces the structure seen in the local universe.Credit: Dr. Thiru Sawala

While most cosmological simulations consider random patches of the universe and cannot be directly compared to observations, SIBELIUS aims to accurately reproduce observed structures, including supergalactic planes. . The final simulation is in remarkable agreement with telescopic observations of the universe.

Contribution and significance of research

Study co-author Professor Carlos Frenk, Ogden Professor of Fundamental Physics at Durham University’s Institute of Computational Cosmology, said:

“This is rare, but not a complete anomaly. Our simulations reveal details of galaxy formation, such as the change from spirals to ellipses due to galaxy mergers.”

“Furthermore, the simulations show that the Standard Model of the Universe, which is based on the idea that most of the mass of the Universe is cold dark matter, is one of the most remarkable structures in the Universe, including the magnificent structure of which the Milky Way Galaxy forms part. This shows that the structure can be reproduced.”

The unusual separation of spiral and elliptical galaxies in the local universe has been known since the 1960s and was included in a recent list of “cosmic anomalies” compiled by renowned cosmologist and 2019 Nobel Prize winner Professor Jim Peebles. prominently mentioned.

Study lead author Dr Thiru Sawala, a postdoctoral fellow at Durham University and the University of Helsinki, said: lecture.

“Then we realized that simulations had already been completed that might contain the answer. Our research shows that the known mechanisms of galaxy evolution also work in this unique cosmic environment. Masu.”

Reference: “A distinct distribution of elliptical and disk galaxies across local superclusters as a ΛCDM prediction” by Til Sawalha, Carlos Frenk, Jens Jachet, Peter H. Johansson, and Guillem Laveau, 2023. 11 20th of the month, natural astronomy.
DOI: 10.1038/s41550-023-02130-6

The supercomputer simulations were run on the Cosmology Machine (COSMA 8) supercomputer hosted by Durham University’s Institute for Computational Cosmology on behalf of the UK’s DiRAC high-performance computing facility, and on CSC’s Mahti supercomputer in Finland. .

This research was funded by the European Research Council, the Academy of Finland, and the UK Science and Technology Facilities Council.

Source: scitechdaily.com