Tag

Globular Clusters

All articles tagged with #globular clusters

science6 days ago•39 min saved

Gaia Uncovers a Black-Hole Swarm in Palomar 5, Destined to Dissolve

Gaia data reveal Palomar 5, a Milky Way globular cluster with an extensive tidal stream, may host over 100 stellar-mass black holes, making up about 20% of the cluster’s mass. Detailed simulations that include these black holes show they can eject stars into the cluster’s tidal tails, hastening its dissolution into a stream of black holes that will orbit the galactic center in around a billion years. The finding suggests such black-hole-rich clusters may be common and could be important for understanding black-hole mergers.

via Yahoo|

#black-holes #gaia #globular-clusters

space7 days ago•5 min saved

A Galaxy Nearly All Dark Matter, Revealed by Four Star Clusters

Astronomers have confirmed CDG-2, a faint galaxy in the Perseus cluster detected only through four globular clusters that provide about 16% of its light; by combining data from Hubble, Euclid, and Subaru, they estimate the galaxy’s total luminosity at roughly 6 million suns and a mass composed of 99.94%–99.98% dark matter, making it one of the most dark-matter–dominated galaxies and a valuable natural laboratory for studying dark matter and galaxy formation.

via WIRED|

#astronomy #cdg-2 #dark-matter

astronomy8 days ago•53 min saved

Hubble Reveals CDG-2, a Galaxy 99% Dark Matter

Astronomers using Hubble, with Euclid and Subaru, identified CDG-2 in the Perseus cluster as an extremely dark-matter–dominated galaxy—about 245 million to 300 million light-years away—where 99% of its mass is dark matter. The galaxy was detected indirectly by tracing four tightly packed globular clusters, which reveal a faint glow around them. Its normal matter is estimated at roughly 6 million sun-like stars, with about 16% accounted for by the globular clusters, suggesting past star formation that has since been stripped away by gravitational interactions. The discovery, highlighting a “dark galaxy” category, was reported in The Astrophysical Journal Letters.

via Space|

#astronomy #cdg-2 #dark-matter

space-and-spaceflight9 days ago•16 min saved

Galaxy Cloaked in Darkness Hints at 99% Dark Matter

Astronomers using the Hubble Space Telescope identified CDG-2, a very dim galaxy in the Perseus cluster that appears to be 99% dark matter, with most of its normal matter stripped away by the crowded environment; the galaxy is inferred from a surrounding globular cluster population, marking it as one of the most dark-matter–dominated galaxies and a test bed for theories of dark matter and star formation.

via Gizmodo|

#cdg-2 #dark-galaxies #dark-matter

science9 days ago•4 min saved

Hubble Reveals One of the Universe’s Darkest Galaxies Hidden in Globular Clusters

NASA’s Hubble identified CDG-2, a remarkably dark matter–dominated, low-surface-brightness galaxy in the Perseus cluster, by spotting a small group of globular clusters and a faint surrounding glow. Four tightly bound clusters signal an underlying galaxy whose luminosity is about 6 million Sun-like stars, with about 99% of its mass in dark matter and most normal matter stripped away by gravitational interactions. Confirmed through combined data from Hubble, the Euclid mission, and the Subaru Telescope, this is the first galaxy detected primarily via its globular clusters, illustrating how upcoming surveys and machine-learning methods will uncover more such faint systems.

via NASA Science (.gov)|

#dark-matter #globular-clusters #hubble-space-telescope

science5 months ago•4 min saved

Webb Telescope Uncovers New Star System Types and Solves Cosmic Mysteries

A new study using computer simulations suggests the existence of a new class of star systems called globular cluster-like dwarfs (GCDs), which bridge the gap between traditional globular clusters and dwarf galaxies, forming without dark matter and potentially observable in nearby galaxies like Reticulum II with the James Webb Space Telescope.

via Earth.com|

#dark-matter #globular-clusters #james-webb-space-telescope

astronomy5 months ago•22 min saved

Revolutionary Simulations Reveal Ancient Star Systems and the Universe’s First Galaxies

The article reviews the formation, properties, and significance of globular clusters and globular-cluster-like dwarfs in galaxy formation, highlighting their roles in understanding dark matter, galaxy evolution, and the early universe.

via Nature|

#astronomy #dark-matter #dwarf-galaxies

science1 year ago•2 min saved

Astronomers Investigate VCC 615's Globular Clusters

Astronomers using the Hubble Space Telescope have studied the globular cluster system of the ultra-diffuse galaxy VCC 615, located in the Virgo Cluster. The study identified 22 globular cluster candidates and estimated the total globular cluster population to be 25.1, indicating a high specific frequency compared to similar dwarf galaxies. The findings suggest a large mass-to-light ratio for VCC 615, with a total mass between 90 and 160 billion solar masses. The galaxy's compact nucleus may eventually form a new ultracompact dwarf galaxy.

via Phys.org|

#astronomy #globular-clusters #hubble-space-telescope

science1 year ago•2 min saved

Study Reveals Dual Stellar Populations in Globular Cluster Gran 5

Astronomers using the Gemini-South telescope have discovered that the globular cluster Gran 5, located near the Galactic center, contains two distinct stellar populations with different metallicities. This finding, based on high-resolution near-infrared spectroscopy of seven stars, marks the first detection of such diversity in a low-mass globular cluster. The study suggests that Gran 5 is not linked to the Gaia–Enceladus–Sausage structure but is part of the Galactic bulge or disk, with its metallicity variation possibly due to different evolutionary processes or mass loss.

via Phys.org|

#astronomy #galactic-structure #globular-clusters

science1 year ago•4 min saved

3D Insights into Globular Cluster Formation and Evolution

A groundbreaking study published in Astronomy & Astrophysics provides the first 3D kinematic analysis of multiple stellar populations in 16 globular clusters, revealing key insights into their formation and evolution. Conducted by researchers from INAF, the University of Bologna, and Indiana University, the study shows that globular clusters formed through multiple star formation events, with stars exhibiting distinct kinematic properties based on their chemical composition. This research, utilizing data from the ESA Gaia telescope and ESO VLT, offers a new framework for understanding these ancient cosmic structures.

via Phys.org|

#3d-kinematics #astronomy #gaia-telescope

science1 year ago•2 min saved

"Intermediate-Mass Black Holes Born in Dense Globular Clusters"

Researchers led by Michiko Fujii from the University of Tokyo have used star-by-star simulations to demonstrate a potential mechanism for the formation of intermediate-mass black holes in globular clusters. These simulations show that dense molecular clouds can lead to the formation of very massive stars through repeated stellar collisions, which then evolve into intermediate-mass black holes. The findings align with observational data and provide new insights into the birth of such black holes in star clusters.

via Phys.org|

#astrophysics #black-holes #globular-clusters

astronomy2 years ago•4 min saved

"NASA's Roman Mission: Hunting for Dark Matter in Interstellar Gaps"

NASA's upcoming Nancy Grace Roman Space Telescope will use its advanced imaging capabilities to search for signs of dark matter by studying the gaps between elongated groups of stars, known as tidal streams, pulled from globular clusters orbiting the Andromeda galaxy. The telescope's wide field instrument will allow astronomers to detect stars individually and capture detailed images of Andromeda, potentially revealing new information about the nature of dark matter and its interaction with globular cluster streams. This research could provide insights into the existence and properties of dark matter sub-halos within galaxies, ultimately redefining our understanding of the universe.

via NASA|

#andromeda-galaxy #astronomy #dark-matter

astronomy2 years ago•2 min saved

Unveiling the Secrets of Pandora's Cluster: Astronomers Peer into Billions of Years Past

Astronomers have used data from the James Webb Space Telescope to study Pandora's Cluster, a remote giant cluster of galaxies located 3.5 billion light years away. Specifically, they focused on the old, compact clusters of stars known as globular clusters within the galaxies. By examining these clusters, they can gain insights into the past history and evolution of galaxies. The James Webb Space Telescope's deep imaging capabilities have allowed them to observe features of star clusters from 3.5 billion years ago, providing new tests for theoretical predictions and enhancing our understanding of galaxy histories.

via Phys.org|

#abell-2744 #astronomy #galaxy-evolution

astronomy2 years ago•4 min saved

"Galactic Theft: The Milky Way's Pilfered Globular Clusters"

Recent research suggests that a significant number of globular clusters in the Milky Way may have been stolen from other galaxies or cannibalized by the Milky Way itself. Astronomers have identified associations between these clusters and dwarf galaxies such as the Sagittarius dwarf galaxy, as well as intact companion galaxies like the Magellanic Clouds. Studies have modeled the orbits of these galaxies and found that the percentage of clusters pulled off varied, with some galaxies more likely to lose their clusters than others. The research also identifies specific globular clusters that are likely to have been stolen from various galaxies, shedding light on the complex history of cluster formation in the Milky Way.

via Phys.org|

#astronomy #dwarf-galaxies #globular-clusters

astronomy2 years ago•4 min saved

Cosmic Heist: The Milky Way's Pilfered Globular Clusters

Recent research suggests that a significant number of globular clusters in the Milky Way may have been stolen from other galaxies or cannibalized from intact companion galaxies. Astronomers have identified associations between these clusters and various dwarf galaxies, including the Sagittarius Dwarf Galaxy, the Fornax Galaxy, and the Magellanic Clouds. Studies have found that between 12% and 93% of clusters can be separated from their host galaxies, depending on their orbits and the mass of the galaxy. The research also identifies new globular clusters associated with these dwarf galaxies, bringing the total number of known associated clusters to 29. However, further investigation is needed to fully understand the complex 3-dimensional structure of these galaxies and confirm the associations.

via Universe Today|

#astronomy #dwarf-galaxies #globular-clusters