Tag Archives: galaxies

The Hubble Telescope uncovers countless faraway galaxies in the constellation Cetus

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New infrared images taken with wide field camera 3 (WFC3) onboard the NASA/ESA Hubble Space Telescope shows dozens of galaxies in the constellation Cetus, including SDSS J020941.27+001558.4, SDSS J020941.23+001600.7, and HerS J020941.1+001557. Masu.

This Hubble image shows a variety of distant galaxies in the constellation Cetus. Most galaxies are very small, but there are also some larger galaxies and some stars that can be seen in detail. At its center is an elliptical galaxy with a bright nucleus and a wide disk. A reddish, distorted ring of light surrounds its center, thicker on one side. Small galaxies intersect the rings as bright spots. Image credits: NASA / ESA / Hubble / H. Nayyeri / L. Marchetti / J. Lowenthal.

“What are we looking at when we study this image?” Hubble astronomers said in a statement.

“A distant galaxy 19.5 billion light-years away from Earth? Or a much closer (relatively) tiny glowing red galaxy 2.7 billion light-years away? Or a third galaxy that appears to be much closer to the second galaxy? Is not it?”

“The answer, perhaps confusingly, is that we are considering all three.”

“More precisely, we see light emitted from all of these galaxies, even though the farthest galaxy from Earth is directly behind the first.”

“In fact, it's that very alignment that makes the particular visuals of this image possible.”

“The bright spot in the center of this image is one of our closest galaxies, known by a long (but informative) name. SDSS J020941.27+001558.4,” they said.

“Another bright spot above it appears to be intersected by a curved crescent of light, SDSS J020941.23+001600.7, is the second closest galaxy. ”

“And finally, that curved crescent of light itself is 'lensed' light from a very distant galaxy. Girlfriend J020941.1+001557”

Her J020941.1+001557 light was bent by the gravity of the foreground galaxy and expanded into a circular shape called an Einstein ring.

“Einstein rings occur when light from a very distant object bends around a large intermediate object,” the astronomers said.

“This is possible because the fabric of the universe itself, spacetime, is bent by mass, and so is light traveling through spacetime.”

“This is too subtle to observe at a local level, but when dealing with the curvature of light on large astronomical scales, for example when light emitted from a galaxy bends around another galaxy or galaxy cluster, , may become clearly observable.”

“When the lensed object and the lensed object are aligned in such a way, the result is a unique Einstein ring shape, with a complete or partial ring around the lensed object, depending on the precision of the alignment. A circle of light appears.

“This partial Einstein ring is of particular interest because it was identified thanks to a citizen science project. space warp — means that the public made the discovery of this object possible. ”

Source: www.sci.news

Unexpected star formation driven by dwarf galaxies discovered

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A University of Michigan astronomer, Sally Ooi, led a study on the star-forming regions of the host galaxy NGC 2366, a typical dwarf irregular galaxy. This study was credited to the Observatorio de Calar Alto, J. van Eymeren (AIRUB, ATNF), and Á.R. López Sánchez. As it turns out, dwarf galaxies such as NGC 2366 experience a delay in expelling gas, which allows for the star-forming regions to hold onto gas and dust longer, promoting the formation and development of more stars. This delays the onset of strong superwinds by 10 million years, resulting in more active star formation. This discovery was published in the Astrophysical Journal.

This delay offers astronomers a unique opportunity to study a scenario similar to the dawn of the universe, when ultraviolet light begins to ionize hydrogen, changing the universe from opaque to transparent. By observing low-metallicity dwarf galaxies with large amounts of ultraviolet radiation, scientists can gain insight into these early stages of the universe. The use of new technology from the Hubble Space Telescope allows researchers to observe the light of triple ionized carbon in these galaxies. This observational evidence supports the delayed onset of strong superwinds and a greater amount of ultraviolet radiation in these galaxies.

Thanks to these discoveries, scientists may gain a better understanding of the nature of galaxies seen at the dawn of the universe. This information could be important for the upcoming James Webb Space Telescope. The study was published in the Astrophysical Journal and the Astrophysics Journal Letter. The research team involved in these studies included Michelle C. Jecmen, MS Oey, Amit N. Sawant, Ashkviz Danekar, Sergiy Silic, Linda J. Smith, Jens Melinder, Klaus Reiter, Matthew Hayes, Anne E. Jascott, Daniela Calzetti, Yu-Hua Chu, and Bethan L. James. Ultimately, these findings provide valuable insight into the formation and development of stars in low-metallicity dwarf galaxies.

Source: scitechdaily.com

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