Articles tagged with Dwarf Galaxies
A new survey of 29 massive stars in extremely metal-poor galaxies reveals unexpectedly weak stellar winds, delivering the largest-ever dataset of its kind. The findings could reshape our understanding of how galaxies formed in the early universe, and provide insights into the evolution of massive stars.
The Sloan Digital Sky Survey has released its 20th data set, featuring over three million spectra of stars and galaxies, as well as 18 new value-added catalogs. This release marks a significant expansion of the survey's efforts, integrating full all-sky panoptic spectroscopy across both hemispheres.
Ultra-faint dwarf galaxies, tiny satellite galaxies of the Milky Way, can reflect conditions of the early universe, shedding light on galaxy formation and dark matter. Simulations suggest these small galaxies are sensitive to early radiation environment and can probe the universe's earliest climate.
Researchers suggest that dark matter may consist of multiple particles, whose behavior varies depending on the cosmic environment. This could explain why a signal observed at the center of our galaxy is not seen in dwarf galaxies.
Astronomers have discovered a rare second-generation star, PicII-503, in the ultra-faint dwarf galaxy Pictor II, which preserves the chemical imprint of the first stars in the Universe. The star has an extreme overabundance of carbon and the lowest iron abundance ever measured outside of the Milky Way.
A new study proposes a two-component self-interacting dark matter model that naturally reproduces observational results for dwarf galaxies and strong gravitational lensing. The model predicts mass segregation, where heavier particles sink towards galaxy centers and lighter particles diffuse outward.
Astronomers have made a groundbreaking discovery of a colossal bridge of neutral hydrogen gas linking two dwarf galaxies. The Virgo cluster plays a significant role in this phenomenon.
Astronomers have finally solved the mystery of globular clusters using detailed simulations, uncovering a new class of object that could be in our own galaxy. The study found multiple pathways for their creation and a new class of star system, “globular cluster-like dwarfs”, which sits between globular clusters and dwarf galaxies.
Astronomers discovered a greedy white dwarf star consuming its closest celestial companion at an unprecedented rate. The study found that the super-dense white dwarf is burning brightly due to the mass transfer between the two stars, potentially leading to a massive explosion visible from Earth.
A team of astrophysicists from the University of Bonn and Iran has reclassified Ursa Major III as a compact star cluster containing a black hole core. Simulations suggest that the object's high mass-to-light ratio can be explained by the presence of dark stars rather than dark matter.
A new study by Dartmouth astronomers has mapped 355 candidate satellite galaxies around dwarf galaxies, tripling the number previously surveyed. The researchers aim to understand how external conditions influence satellite formation and uncover insights into dark matter's nature.
New research predicts the existence of 80-100 additional satellite galaxies surrounding the Milky Way, orbiting at close distances. These 'orphan' galaxies are lost in most simulations but should have survived in the real Universe.
A new type of star-like object, called 'dark dwarfs', could help solve the universe's greatest mystery: dark matter. These objects are powered by dark matter and may be found at the center of our galaxy.
A new study of diffuse dwarf galaxies has revealed an exceptionally strong clustering pattern, contradicting the established understanding of galaxy clustering. The researchers propose a new model of dark matter based on the Self-Interacting Dark Matter (SIDM) theory.
A new study by the University of Oulu has directly observed the merger of star clusters in dwarf galaxies for the first time, shedding light on their formation. The observations confirm that compact star clusters form through the cannibalization of smaller globular clusters at the centers of these galaxies.
Researchers found Andromeda XXXV, the smallest and dimmest satellite galaxy to date, which challenges our understanding of galaxy formation and evolution. The discovery provides new insights into how galaxies survive different epochs of the universe.
The study reveals a dynamic ecosystem with diverse dwarf galaxies, unlike the Milky Way's smaller satellite system. Hubble's observations provide insights into how small-galaxy growth is affected by massive galaxies like Andromeda.
The Dark Energy Spectroscopic Instrument (DESI) has discovered a treasure trove of actively feeding black holes in small galaxies, revealing surprisingly few are of intermediate mass. The team identified 300 new intermediate-mass black hole candidates and 2500 active black holes in dwarf galaxies.
The Hubble Space Telescope has captured a cosmic bullseye, revealing eight visible rings and confirming a ninth using data from the W. M. Keck Observatory in Hawaii. The galaxy's unique ring structure was formed by a blue dwarf galaxy colliding with its center, creating a new generation of stars.
A team of astronomers has obtained detailed images of a small galaxy and its surroundings, revealing features typically associated with larger galaxies. The study found that the mechanisms fueling galaxy growth may be more universal than previously thought, suggesting that even dwarf galaxies can build stellar halos through accretion.
Researchers led by Kristen McQuinn used the Webb Telescope to find that Leo P formed stars early on but stopped for a few billion years during the Epoch of Reionization. The study provides insights into the growth of low-mass structures and the processes that led to star creation.
Astronomers discovered three ultra-faint dwarf galaxies in an isolated region of space, containing only very old stars. The findings support the theory that events in the early universe cut off star formation in small galaxies.
Researchers have discovered three tiny ultra-faint dwarf galaxies, dubbed 'stellar-ghost-town' galaxies, with minimal gas and old stars. This suggests that their star formation was cut off early in the universe's history due to insufficient gravity or events like reionization or supernovae explosions.
Scientists have discovered birth sites of gigantic elliptical galaxies, suggesting large gas flows and galaxy collisions created these ancient systems. The research, published in Nature, may finally unravel the enigma of how these giant galaxies formed.
Astronomers observe low-mass supermassive black hole consuming matter at over 40 times the theoretical limit, providing new insights into rapidly growing black holes. The discovery reveals a possible mechanism for black holes to exceed their Eddington limit, sparking further investigation.
A new study published in the Astrophysical Journal has found that galaxies in denser environments are up to 25% larger than isolated galaxies. Researchers used a machine learning tool to analyze millions of galaxies and found a clear trend: galaxies with more neighbors are also on average larger.
A team of astronomers used NASA's Hubble Space Telescope to create the most accurate three-dimensional understanding of stars' movements within the Draco dwarf galaxy. This allowed them to build a more precise model of dark matter distribution, which aligns with cosmological models and suggests a cusp-like structure.
Researchers confirm model predicting galaxy clusters' separation via gravity, while identifying potential new galaxies with Euclid's powerful equipment. The telescope's early release observations reveal millions of objects in a single day, opening up new possibilities for dark matter research.
Researchers have discovered three of the oldest stars in the universe, forming between 12 and 13 billion years ago. The team believes these 'Small Accreted Stellar System' (SASS) stars originated from small primitive galaxies absorbed by the Milky Way.
A Clemson astrophysicist's research offers the most stringent constraints yet on dark matter's fundamental nature. The study reveals a small hint of a signal that could be confirmed in the next decade if real.
A team of astrophysicists used simulations to track galaxy formation near the Big Bang, including interactions between gas and dark matter. The results show that tiny, bright galaxies were formed more quickly than expected, challenging current theories about dark matter.
Researchers have found a serendipitous discovery of a dwarf galaxy, PEARLSDG, that contradicts current theories on galaxy formation. The isolated quiescent galaxy has an old stellar population and doesn't form new stars, with individual stars visible in JWST images, providing clues to its distance.
The newly discovered galaxy Nube has a set of specific properties that distinguish it from previously known objects, including being ten times fainter and ten times more extended than other dwarf galaxies. Its unusual characteristics challenge the current understanding of the universe, particularly the dark matter model.
University of Michigan researchers discovered that less evolved dwarf galaxies have bigger regions of star factories with higher rates of star formation. A 10-million-year delay in blowing out gas allows these galaxies to hang on to their gas and dust, enabling more stars to coalesce and evolve.
Researchers found a 200,000-light-year-long stellar tail emanating from F8D1, suggesting recent interaction with another galaxy. The discovery provides crucial evidence for understanding the origins of ultra-diffuse galaxies.
The Hydrogen Epoch of Reionization Array (HERA) team has doubled the sensitivity of its radio telescope array, providing clues to the composition of stars and galaxies in the early universe. The data suggest that early galaxies contained few elements besides hydrogen and helium.
Researchers used the Panchromatic Hubble Andromeda Treasury Triangulum Extended Region — or PHATTER — survey to study the Triangulum galaxy. The team discovered two drastically different structures depending on the age of the stars, with younger and older stars having distinct distributions.
Researchers suggest using ancient red giant stars' winds as a potential source of material for observing the supermassive black hole. This could provide the accretion rate needed to detect the black hole, which is currently undetectable due to its low activity.
Astronomers used the Young Supernova Experiment to detect an intermediate-mass black hole in a dwarf galaxy, revealing its mass and providing insight into supermassive black hole growth. The study aims to improve understanding of black hole-galaxy relationships and inform theories on supermassive black hole formation.
Astronomers have discovered a stellar binary with an extremely short orbit of just 51 minutes, confirming a decades-old prediction. The system is believed to be a cataclysmic variable, in which a white dwarf is accreting material from its companion star.
A team of researchers at Lund University used Gaia space telescope data to study the outer disk of the Milky Way, finding large parts vibrate due to a passing dwarf galaxy. This 'galactic seismology' provides clues about Sagittarius' history and orbit around our home galaxy.
A team of researchers has discovered that gamma-ray radiation from the Sagittarius Dwarf galaxy can be explained by millisecond pulsars, ruling out dark matter annihilation as a possible explanation. The study reveals that these stellar objects are efficient accelerators of high-energy electrons and positrons.
A team of researchers has detected a small satellite galaxy of the Milky Way filled with dark matter using gamma-ray emissions. The discovery was initially thought to be indicative of dark matter annihilation, but further analysis reveals that millisecond pulsars are more likely to be the source of the emission.
Researchers from the University of Bonn found that dwarf galaxies in one of Earth's nearest galaxy clusters show signs of disturbance without dark matter halos. The study's results contradict previous models, suggesting an alternative gravity theory might be more accurate.
Scientists have discovered a new, extremely faint galaxy named Pegasus V, located on the outskirts of Andromeda. The dwarf galaxy is believed to be one of the oldest in the universe, with its stars forming over 13 billion years ago.
A team of astronomers discovered an unusual ultra-faint dwarf galaxy, Pegasus V, on the outer edge of the Andromeda Galaxy using NSF's NOIRLab facilities. The galaxy appears to be extremely deficient in heavier elements, indicating it is very old and likely a fossil of the first galaxies.
Scientists have found evidence for a young and extremely powerful neutron star, dubbed VT 1137-0337, in a dwarf galaxy 395 million light-years from Earth. The pulsar is thought to be as young as 14 years old and has the strongest magnetic field of any known object.
Researchers studied over 500 stars in a region of Andromeda called the Northeast shelf, finding conclusive evidence of an ancient collision. The findings provide insights into how material from collisions shapes a galaxy's appearance and makeup.
Researchers have discovered a new repeating fast radio burst, FRB 190520B, which exhibits extreme behavior similar to the initial discovery, FRB 121102A. The source has high ambient electron density and reliable bursting behaviors, suggesting it may be a 'newborn' with characteristics resembling a super luminous supernova.
Astrophysicists have calculated the original mass and size of a dwarf galaxy torn apart in a collision with the Milky Way billions of years ago. The reconstructed galaxy's stars now stream through the Milky Way, carrying information about its gravitational field.
Researchers have found no dark matter in the ultra-diffuse dwarf galaxy AGC 114905, which can be explained by normal matter. The discovery confirms previous measurements and raises questions about the existence of dark matter in galaxies.
Astronomers at UT Austin's McDonald Observatory have discovered a massively dense black hole at the center of dwarf satellite galaxy Leo I, revealing an unprecedented mass ratio between the galaxy and its central black hole. This finding shakes up our understanding of galaxy evolution and dark matter distribution.
Researchers used simulations to detect extended dwarf galaxies with low surface brightness, challenging previous theories. The study found that these 'quenched' UDGs originated in backsplash orbits and are isolated from their parent systems.
Researchers used detailed simulations to detect and study 'quenched' UDGs, which are rare dwarf galaxies that have stopped generating stars. They found these galaxies were not in clusters but rather isolated in voids, with unique orbits that stripped away their star-forming gas.
Researchers from IAC and STScI discovered transverse rotation in three dwarf spheroidal galaxies using Gaia satellite data, shedding light on their evolutionary history. This finding supports the idea that these galaxies may have formed through the agglomeration of smaller systems.
A team of scientists discovered that three dozen dwarf galaxies simultaneously accelerated their star birth rates, defying expectations. The galaxies, separated by up to 13 million light-years, had a synchronized decrease in stellar birth rate 6 billion years ago and an increase 3 billion years ago.
A team of researchers used stellar kinematics to study dark matter in ultra-faint dwarf galaxies, revealing a dense core and limited scattering. This challenges existing theories on self-interacting dark matter, suggesting that supernova explosions may be responsible for less dense distributions.
Researchers found that some dwarf galaxies may appear dark-matter free due to extreme tidal mass loss, challenging the LCDM cosmological model. Simulations suggest a combined solution to both the structure and low dark matter content of these ultradiffuse galaxies.
Researchers at Rensselaer Polytechnic Institute have discovered the first shell-like formations of stars in the Milky Way, created by a 2.7 billion-year-old broadside collision with a dwarf galaxy. The findings offer new insights into the ancient event and its potential implications for other stellar phenomena.
Researchers have advanced studies on galaxy formation, revealing the role of massive clumps in scattering stars and creating smooth galaxy disks. The models show that this process is robust and universal, applying to many types of galaxies.