Tag Archive for 'Halo'

This image shows the spiral galaxy 2MASX J23453268-0449256 and its giant radio jets. Image credit: Bagchi et al. / Giant Metrewave Radio Telescope.

Cosmic Anomaly: Massive Spiral Galaxy is Ejecting Colossal Pair of Relativistic Jets

Mar 24, 2025 by News Staff

2MASX J23453268-0449256 (J2345-0449 for short), an extremely massive, rapidly rotating, jet-launching spiral galaxy approximately 947 million light-years...

GD-1 exhibits spur and gap structures that may result from a close encounter with a dense substructure. Image credit: University of California, Riverside.

Study: GD-1 Stellar Stream’s Distinctive Features Caused by Self-Interacting Dark Matter Subhalo

Jan 7, 2025 by News Staff

A core-collapsing self-interacting dark matter subhalo is responsible for the peculiar spur and gap features observed in GD-1, a stellar stream within...

This image visualizes our Milky Way Galaxy and its surrounding halo of stars. The new Gaia data reveal that the wrinkles we see in the Milky Way were likely caused by a dwarf galaxy colliding with the Milky Way around 2.7 billion years ago. Our Galaxy’s two prominent satellite galaxies -- the Large and Small Magellanic Clouds -- are visible to the lower right, Image credit: ESA / Gaia / DPAC / Donlon et al. / Stefan Payne-Wardenaar.

Milky Way’s Last Major Merger Occurred Billions of Years Later than Previously Thought

Jun 7, 2024 by News Staff

This discovery was made possible by ESA’s Gaia spacecraft, which is mapping more than a billion stars throughout the Milky Way Galaxy and beyond, tracking...

An artist’s conception of the Milky Way Galaxy. Image credit: Pablo Carlos Budassi / CC BY-SA 4.0.

Astronomers Find 12- to 13-Billion-Year-Old Stars in Milky Way’s Halo

May 15, 2024 by News Staff

Astronomers at MIT have discovered thee extremely ancient stars in the Milky Way’s halo, a cloud of stars that envelopes the entire main Galactic disk....

This two-part graphic shows evidence of a gaseous clump of helium in the halo surrounding galaxy GN-z11. In the top portion, at the far right, a small box identifies GN-z11 in a field of galaxies. The middle box shows a zoomed-in image of the galaxy. The box at the far left displays a map of the helium gas in the halo of GN-z11, including a clump that does not appear in the infrared colors shown in the middle panel. In the lower half of the graphic, a spectrum shows the distinct ‘fingerprint’ of helium in the halo. The full spectrum shows no evidence of other elements and so suggests that the helium clump must be fairly pristine, made of hydrogen and helium gas left over from the big bang, without much contamination from heavier elements produced by stars. Theory and simulations in the vicinity of particularly massive galaxies from these epochs predict that there should be pockets of pristine gas surviving in the halo, and these may collapse and form Population III star clusters. Image credit: NASA / ESA / CSA / Ralf Crawford, STScI.

Webb Detects Pristine Helium Clump in GN-z11’s Halo

Mar 5, 2024 by Enrico de Lazaro

GN-z11 is an exceptionally luminous galaxy that existed when our Universe was only 420 million years old, making it one of the earliest and most distant...

From a great distance, our Milky Way Galaxy would look like a thin disk of stars that orbits once every few hundred million years around its central region, where hundreds of billions of stars provide the gravitational ‘glue’ to hold it all together. But this pull of gravity is much weaker in the Galaxy’s far outer disk. There, the hydrogen atoms making up most of the Milky Way’s gas disk are no longer confined to a thin plane, instead they give the disk an S-like, or warped, appearance. Image credit: Xiaodian Chen.

Milky Way is Embedded in Tilted Dark Matter Halo, Research Suggests

Oct 12, 2023 by News Staff

The outer disk of our Milky Way Galaxy is warped and flared. Several mechanisms have been proposed to explain these phenomena, but none have reproduced...

This DEC image shows the onion-like layers of NGC 3923, a shell galaxy some 70 million light-years away in the constellation of Hydra. The image also shows the face-on spiral galaxies LEDA 744285 and ESO 440-11; and near the top of the image is the extremely large gravitational lens around the galaxy cluster PLCK G287.0+32.9. Image credit: DESI Legacy Imaging Surveys / LBNL / DOE / KPNO / CTIO / NOIRLab / NSF / AURA / T.A. Rector, University of Alaska Anchorage / NSF’s NOIRLab / M. Zamani, NSF’s NOIRLab / R. Colombari, NSF’s NOIRLab / D. de Martin, NSF’s NOIRLab.

Dark Energy Camera Captures Rare Shell Galaxy

Oct 2, 2023 by Enrico de Lazaro

Astronomers using the Dark Energy Camera (DEC) on NSF’s Víctor M. Blanco 4-m telescope at Cerro Tololo Inter-American Observatory, a Program of NSF’s...

The very massive first-generation stars with a mass range from 140 to 260 solar masses are predicted to enrich the early interstellar medium through pair-instability supernovae; decades of observational efforts, however, have not been able to uniquely identify the imprints of such very massive stars on the most metal-poor stars in the Milky Way. Image credit: NAOC.

Galactic Halo Star’s Chemical Signature Indicates Existence of Very Massive Stars in Early Universe

Jun 7, 2023 by News Staff

Early Universe’s stars had up to several hundred solar masses. The earliest stars of 140-260 solar masses became pair-instability supernovae (PISNe)....

Dey et al. uncovered striking new evidence for a mass migration of stars into the Andromeda galaxy. Image credit: KPNO / NOIRLab / AURA / NSF / Local Group Survey Team / T.A. Rector, University of Alaska Anchorage / D. de Martin / M. Zamani.

Galactic Immigration Event Occurred in Andromeda Galaxy 1-2 Billion Years Ago

Feb 8, 2023 by News Staff

The Andromeda galaxy (Messier 31), which is located 2.5 million light-years away, is the Milky Way’s nearest large galactic neighbor. By measuring the...

This illustration shows the inner and outer halos of our Milky Way Galaxy. Image credit: NASA / ESA / A. Feild, STScI.

Milky Way’s Stellar Halo is At Least Two Million Light-Years Across

Jan 16, 2023 by News Staff

Astronomers from the University of California, Santa Cruz and elsewhere have discovered 208 new RR Lyrae variable stars in the halo of our Milky Way Galaxy;...

This artist’s illustration emphasizes the shape of the stellar halo surrounding our Milky Way Galaxy. Image credit: Melissa Weiss / Harvard & Smithsonian’s Center for Astrophysics.

Milky Way’s Stellar Halo is Oblong and Tilted, Astronomers Say

Nov 21, 2022 by News Staff

Accounting for approximately 1% of the total stellar mass, the stellar halo — the diffuse cloud of stars surrounding the Galactic disk — plays...

Shown here in purple, the Magellanic Corona stretches more than 100,000 light-years from the main mass of stars, gas, and dust that make up the Magellanic Clouds, intermingling with the hotter and more extensive corona that surrounds the Milky Way. Image credit: Leah Hustak, STScI.

Magellanic Corona: Astronomers Detect Protective Shield around Small and Large Magellanic Clouds

Oct 4, 2022 by News Staff

The Small and Large Magellanic Clouds — satellite galaxies of the Milky Way Galaxy — are surrounded by a diffuse halo of hot, supercharged...

This image of a sun pillar was captured by ESA-sponsored medical doctor Hannes Hagson. Image credit: ESA / IPEV / PNRA / H. Hagson.

Antarctic Researcher Spots Rare Optical Phenomenon: Sun Pillar

Sep 26, 2022 by Enrico de Lazaro

A light pillar is an optical phenomenon where a column of light can be seen emanating from a light source. If the light comes from the Sun, the phenomenon...

Milky Way Evolved in Few Different Phases, New Research Suggests

Mar 23, 2022 by News Staff

The formation of our Milky Way Galaxy can be split up qualitatively into different assembly phases that resulted in its structurally different stellar...

This image shows the Milky Way Galaxy as seen by ESA’s Gaia spacecraft; the squares represent the location of globular clusters, the triangles the location of satellite galaxies, and the small dots are stellar streams; the dots and squares in purple are objects brought into the Milky Way by the Pontus merging galaxy. Image credit: ESA / Gaia / DPAC / CC BY-SA 3.0 IGO.

Gaia Discovers New Fossil Galaxy Hidden in Milky Way’s Halo

Feb 17, 2022 by News Staff

Using data from ESA’s Gaia spacecraft, astronomers have looked for the remains of ancient dwarf galaxies in the Milky Way’s halo, which surrounds the...

C-19 is a grouping of stars in the Milky Way halo that share a common orbital motion around the Galaxy. Image credit: Gemini Observatory / NOIRLab / NSF / AURA / J. da Silva / Spaceengine / M. Zamani.

Astronomers Find Primordial Stellar Stream in Milky Way’s Halo

Jan 6, 2022 by News Staff

Named C-19, the newly-discovered stellar stream is the remnant of an ancient globular cluster and contains stars with extremely low metallicity, with a...

This Hubble image shows Messier 104. Image credit: NASA / ESA / Hubble Heritage Team / STScI / AURA.

Giant Stellar Stream Spotted around Sombrero Galaxy

Jul 22, 2021 by Enrico de Lazaro

The Sombrero galaxy likely merged with a relatively massive galaxy several billions years ago. In a new study published in the Monthly Notices of the Royal...

The red giant star SMSS J200322.54-114203.3 (center) in the south-eastern corner of the constellation of Aquila, close to the border with Capricornus and Sagittarius. Image credit: Da Costa / SkyMapper.

Ancient Magneto-Rotational Hypernova Fuelled High Levels of Metals in Unique Star

Jul 8, 2021 by News Staff

An explosion of a fast-spinning strongly magnetized star, called a magneto-rotational hypernova, is the most likely explanation for the presence of unusually...

Color-coded map of the distribution of stars emerging from the star cluster Palomar 5 (white blob); the two long tidal tails (orange) contain 1.3 times the mass of the cluster and delineate its orbit around the Milky Way Galaxy. Image credit: SDSS.

Palomar 5 Contains More Than 100 Stellar-Mass Black Holes: Study

Jul 6, 2021 by Enrico de Lazaro

Palomar 5 is one of the sparsest star clusters in the halo of our Milky Way Galaxy and is best known for its spectacular tidal tails, spanning over 20...

The open star cluster NGC 2516. Image credit: Centre de Données astronomiques de Strasbourg / SIMBAD / DSS2.

Open Cluster NGC 2516 is at least 1,600 Light-Years Long, Study Shows

Jun 9, 2021 by Enrico de Lazaro

A young open cluster called NGC 2516 has a classical tidal radius of 10 parsecs (33 light-years) and a halo of stars spanning at least 500 parsecs (1,600...