star formation Archives

November 6, 2023November 9, 2023 by Matt Williams

Supermassive Black Holes Shut Down Star Formation During Cosmic Noon

Artist’s impression of a quasar. These all have supermassive black holes at their hearts. Credit: NOIRLab/NSF/AURA/J. da Silva

Since it became operational almost two years ago, the James Webb Space Telescope (JWST) has produced countless breathtaking images of the Universe and enabled fresh insights into how it evolved. In particular, the telescope’s instruments are optimized for studying the cosmological epoch known as Cosmic Dawn, ca. 50 million to one billion years after the Big Bang when the first stars, black holes, and galaxies in the Universe formed. However, astronomers are also getting a better look at the epoch that followed, Cosmic Noon, which lasted from 2 to 3 billion years after the Big Bang.

During this time, the first galaxies grew considerably, most stars in the Universe formed, and many galaxies with supermassive black holes (SMBHs) at their centers became incredibly luminous quasars. Scientists have been eager to get a better look at galaxies dated to this period so they can see how SMBHs affected star formation in young galaxies. Using near-infrared data obtained by Webb, an international team of astronomers made detailed observations of over 100 galaxies as they appeared 2 to 4 billion years after the Big Bang, coinciding with Cosmic Noon.

October 25, 2023October 25, 2023 by Evan Gough

Astronomers Want JWST to Study the Milky Way Core for Hundreds of Hours

This overview of the Milky Way's Galactic Center (GC) shows the region of the proposed JWST survey. Image Credit: NASA/JPL-Caltech/S. Stolovy (Spitzer Science Center/Caltech)

To understand the Universe, we need to understand the extreme processes that shape it and drive its evolution. Things like supermassive black holes (SMBHs,) supernovae, massive reservoirs of dense gas, and crowds of stars both on and off the main sequence. Fortunately there’s a place where these objects dwell in close proximity to one another: the Milky Way’s Galactic Center (GC.)

October 12, 2023October 12, 2023 by Evan Gough

Feast Your Eyes on this Star-Forming Region, Thanks to the JWST

The JWST cast its infrared gaze at NGC 346, a young open cluster in the Small Magellanic Cloud. It's the largest and brightest star forming region in the SMC. Image Credit: ESA/CSA/NASA N. Habel (JPL), P. Kavanagh (Maynooth University)

Nature is stingy with its secrets. That’s why humans developed the scientific method. Without it, we’d still be ignorant and living in a world dominated by superstitions.

Astrophysicists have made great progress in understanding how stars form, thanks to the scientific method. But there’s a lot they still don’t know. That’s one of the reasons NASA built the James Webb Space Telescope: to coerce Nature into surrendering its deeply-held secrets.

October 11, 2023October 11, 2023 by Evan Gough

Compare Images of a Galaxy Seen by Both Hubble and JWST

NGC 5068 is a barred spiral galaxy about 20 million light-years away. The Hubble captured this image of NGC 5068 in ultraviolet, visible, and near-infrared light. Image Credits: NASA, ESA, R. Chandar (University of Toledo), and J. Lee (Space Telescope Science Institute); Processing: Gladys Kober (NASA/Catholic University of America)

The James Webb Space Telescope is widely considered to be better than the Hubble Space Telescope. But the JWST doesn’t replace its elder sibling; it’s the Hubble’s successor. The Hubble is nowhere near ready to retire. It’s still a powerful science instrument with lots to contribute. Comparing images of the same object, NGC 5068, from both telescopes illustrates each one’s value and how they can work together.

September 19, 2023September 19, 2023 by Evan Gough

Galaxies Breathe Gas, and When They Stop, No More Stars Form

Artist concept of how a galaxy might accrete mass from rapid, narrow streams of cold gas. These filaments provide the galaxy with continuous flows of raw material to feed its star-forming at a rather leisurely pace. Credit: ESA–AOES Medialab

For most of the history of astronomy, all we could see were stars. We could see them individually, in clusters, in nebulae, and in fuzzy blobs that we thought were clumps of stars but were actually galaxies. The thing is, most of what’s out there is much harder to see than stars and galaxies. It’s gas.

Now that astronomers can see gas better than ever, we can see how galaxies breathe it in and out. When they stop breathing it, stars stop forming.

September 6, 2023September 6, 2023 by Evan Gough

JWST Gazes into the Dark Molecular Clouds at the Heart of the Milky Way

The Central Molecular Zone; the Heart of the Milky Way. Image Credit: Henshaw / MPIA

There’s an unusual object near the Milky Way’s heart that astronomers call “The Brick.” It’s a massive cloud of gas called an infrared dark cloud (IDC). The Brick is dense and turbulent like others of its type, but for some reason, it shows few signs of star formation.

Why?

August 12, 2023August 12, 2023 by Matt Williams

Astronomers Find a Newly-Forming Quadruple-Star System

This artist’s impression shows the orbits of the objects in the HR 6819 triple system. Credit: ESO/L. Calçada

In a surprising find, the international ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP) team recently observed a young quadruple star system within a star-forming region in the Orion constellation. The discovery was made during a high-resolution survey of 72 dense cores in the Orion Giant Molecular Clouds (GMCs) using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. These observations provide a compelling explanation for the origins and formation mechanisms of binary and multiple-star systems.

July 20, 2023July 20, 2023 by Evan Gough

Star Factories Haven’t Changed Much Over the Entire Age of the Universe

“Sh 2-209” is a rare and large-scale star-forming region in the outer region of the Milky Way Galaxy. It's notable for its low metallicity, a characteristic it shares with the early Universe. Image Credit: NAOJ/Subaru Telescope

The ancient Universe is weird and secretive. Scientists have made laudable progress in uncovering more and more information on how the Universe began and what conditions were like all those billions of years ago. Powerful infrared telescopes, especially the ground-breaking James Webb Space Telescope, have let astronomers study the ancient light from the early Universe and remove some of the secrecy.

One of the mysteries astronomers want to untangle concerns star formation. Has it changed much since the Universe’s early days?

May 31, 2023May 31, 2023 by Matt Williams

Here's How You Could Get Impossibly Large Galaxies in the Early Universe

The galaxy cluster SMACS0723, with the five galaxies selected for closer study. Credit: NASA, ESA, CSA, STScI / Giménez-Arteaga et al. (2023), Peter Laursen (Cosmic Dawn Center).

One of the most interesting (and confounding) discoveries made by the James Webb Space Telescope (JWST) is the existence of “impossibly large galaxies.” As noted in a previous article, these galaxies existed during the “Cosmic Dawn,” the period that coincided with the end of the “Cosmic Dark Age” (roughly 1 billion years after the Big Bang). This period is believed to hold the answers to many cosmological mysteries, not the least of which is what the earliest galaxies in the Universe looked like. But after Webb obtained images of these primordial galaxies, astronomers noticed something perplexing.

The galaxies were much larger than what the most widely accepted cosmological model predicts! Since then, astronomers and astrophysicists have been racking their brains to explain how these galaxies could have formed. Recently, a team of astrophysicists from The Hebrew University of Jerusalem Jerusalem published a theoretical model that addresses the mystery of these massive galaxies. According to their findings, the prevalence of special conditions in these galaxies (at the time) allowed highly-efficient rates of star formation without interference from other stars.

May 12, 2023May 12, 2023 by Matt Williams

New Images Reveal the Magnetic Fields in the Horsehead Nebula

Magnetic field detections overlaid on a two-color composite of Hubble Space Telescope image taken at two near-IR wavelengths (Mikulski Archive for Space Telescopes). Black and orange segments show magnetic field orientations inferred from JCMT and Palomar Observatory. Credit: Hwang et al. 2023.

Located near the summit of Maunakea, Hawaii, the 15-meter (~49 ft) James Clerk Maxwell Telescope (JCMT) at the East Asia Observatory (EAO) is the largest telescope in the world designed to operate exclusively in the submillimetre-wavelength. In 2018, Molokai’i High School alumna Mallory Go was awarded time with the JCMT under the Maunakea Scholars program. With the assistance of EAO astronomer Dr. Harriet Parsons, Go obtained unique images of the Horsehead Nebula in polarized light, which revealed the nebula’s magnetic fields.