Crystallization, Convection, and a Magnetic White Dwarf Mystery

A white dwarf shines brightly at the center of this Hubble Space Telescope image. Credit: NASA, ESA, P. McGill (Univ. of California, Santa Cruz and University of Cambridge), K. Sahu (STScI), J. Depasquale (STScI); CC BY 4.0

Most stars in the Milky Way will evolve into white dwarfs: ultra-hot, crystallized stellar cores, some of which have magnetic fields millions of times stronger than Earth’s. Could the crystallization of white dwarf interiors explain why some of these stars have such strong magnetic fields?

When a super-hot white dwarf illuminates the diffuse shells of gas that surround it, we see a glowing planetary nebula. The central white dwarf is visible in this image of the Ring Nebula. Credit: NASA, ESA and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration

Magnetic Mystery

Roughly 5–6 billion years from now, the Sun will cease all nuclear fusion in its core and cast off the outer layers of its atmosphere. Left behind will be a blazingly hot, Earth-sized core of carbon and oxygen wreathed in a colorful and ephemeral planetary nebula. This carbon–oxygen core — a white dwarf — will slowly cool over trillions of years and fade from view. Such is the fate of more than 95% of the stars in our galaxy.

Some white dwarfs have extremely strong magnetic fields, and the origin of these fields isn’t yet clear. Though the magnetic fields in question are a million times stronger than Earth’s, they might form in similar ways, as new research from José Rafael Fuentes (University of Colorado Boulder) and collaborators shows.

The composition flux, τ, as a function of time for a 0.9-solar-mass white dwarf. Convection of the white dwarf’s liquid layer is only efficient while the composition flux is large. Credit: Fuentes et al. 2024

Creating Crystal Interiors

Many magnetic fields in the universe, including Earth’s, form in liquids that have three properties: they’re electrically conductive, they rotate, and they convect — rising and falling like the globs of wax in a lava lamp. As white dwarfs begin to cool, a process begins by which their liquid interiors may achieve all three criteria necessary to generate a magnetic field.

When first formed, white dwarfs are filled with a hot quantum liquid of carbon and oxygen. As they cool, their centers crystallize into a solid, with a layer of quantum liquid surrounding the crystal core. Crystallization changes the composition of the interior, as oxygen tends to be pulled into the crystal core and carbon tends to remain in the liquid. The difference in chemical makeup causes the electrically conductive, rotating fluid to convect — setting the stage for magnetic-field creation.

To probe whether crystallization could help create the million-Gauss magnetic fields seen in some white dwarfs, Fuentes and collaborators modeled the interiors of white dwarfs as they crystallize. The team used the Modules for Experiments in Stellar Astrophysics (MESA) stellar evolution model to show that during a brief, 10-million-year period, strong convection could generate magnetic fields of 1–100 million Gauss.

Comparison of the magnetic field strengths obtained though modeling (blue line) with the observed magnetic fields of white dwarfs (symbols). The filled symbols show white dwarfs that are expected to be crystallizing, given their ages, while the open symbols show white dwarfs that are likely not yet crystallizing. Adapted from Fuentes et al. 2024

Short Phase, Lasting Consequences

While the period of strong convection that creates magnetic fields is short lived, the magnetic field is likely to be long lasting; it takes a long time for magnetic fields to dissipate in a white dwarf, especially once it crystallizes completely.

The models used by Fuentes and coauthors reproduce some observed properties of white-dwarf magnetic fields, such as the lack of a dependence of the field strength on the rotation rate. However, the models also predict that magnetic fields should be stronger for more massive white dwarfs, which observations don’t support. Extending the modeling forward in time may reveal how the magnetic fields evolve and diffuse as the star cools, helping to make sense of these magnetic crystalline stars.

By Kerry Hensley

Source: American Astronomical Society/AAS-Nova

---

Citation

“A Short Intense Dynamo at the Onset of Crystallization in White Dwarfs,” J. R. Fuentes et al 2024 ApJL 964 L15.
doi:10.3847/2041-8213/ad3100

---

Astronomers discover 49 new galaxies in under three hours

The 49ers – the 49 new gas-rich galaxies detected by the MeerKAT radio telescope in South Africa. Each detection is shown as coloured contours, with redder colours indicating more distant gas from us, and bluer colours as closer gas. The background image comes from the optical PanSTARRS survey. Credit: Glowacki et al 2024.

Four nearby galaxies as part of the set of 49 found by MeerKAT, shown by the white contours. Three of the galaxies are connected together by their gas content. The largest galaxy is stealing gas from two neighbouring galaxies. The background colour image is from the DECaLS DR10 optical survey. Glowacki et al. 2024

---

An international team of astronomers has discovered 49 new gas-rich galaxies using the MeerKAT radio telescope in South Africa.

Dr Marcin Glowacki, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) in Western Australia, led the research, which aimed to study the star-forming gas in a single radio galaxy.  Although the team didn’t find any star-forming gas in the galaxy they were studying, Dr Glowacki instead discovered other galaxies while inspecting the data.

In total, the gas of 49 galaxies was detected. Dr Glowacki said this was a great example of how fantastic an instrument like MeerKAT is for finding the star-forming gas in galaxies.

The observations, which lasted less than three hours and were facilitated by IDIA (Inter-University Institute for Data Intensive Astronomy), made this discovery possible.

“I did not expect to find almost fifty new galaxies in such a short time,” he said. “By implementing different techniques for finding galaxies, which are used for other MeerKAT surveys, we were able to detect all of these galaxies and reveal their gas content.”

The new galaxies have been informally nicknamed the 49ers, a reference to the 1849 California gold rush miners. Dr Glowacki views the 49 new galaxies as valuable as gold nuggets in our night sky. Many galaxies are near each other, forming galaxy groups, with several identified in one observation.

Three galaxies are directly connected by their gas.

Dr Glowacki said, “These three are particularly interesting, as by studying the galaxies at other wavelengths of light, we discovered the central galaxy is forming many stars. It is likely stealing the gas from its companion galaxies to fuel its star formation, which may lead the other two to become inactive.”

Professor Ed Elson, from the University of the Western Cape and a co-author of the paper, said, “This discovery highlights the raw power of the MeerKAT telescope as an imaging instrument.  The methods we developed and implemented to study the 49ers will be useful for MeerKAT large science surveys and smaller observing campaigns such as ours.”

Dr Glowacki has recently discovered more gas-rich galaxies with the help of Jasmine White, an ICRAR summer student, who worked with him and analysed short observations made by MeerKAT.

“We hope to continue our studies and share even more discoveries of new gas-rich galaxies with the wider community soon,” Dr Glowacki said.

The research was published overnight in Monthly Notices of the Royal Astronomical Society.

Source: International Center for Radio Astronomy Research (ICRAR)/News

---

Publication

‘A serendipitous discovery of HI-rich galaxy groups with MeerKAT’, ‘published in Monthly Notices of Royal Astronomical Society – March 2024.

Multimedia

Multimedia assets available here.

---

Three-Year Study of Young Stars with NASA's Hubble Enters New Chapter

ULLYSES

The ULLYSES program studied two types of young stars: super-hot, massive, blue stars and cooler, redder, less massive stars than our Sun.
The top panel is a Hubble Space Telescope image of a star-forming region containing massive, young, blue stars in 30 Doradus, the Tarantula Nebula. Located within the Large Magellanic Cloud, this is one of the regions observed by ULLYSES.
The bottom panel shows an artist's concept of a cooler, redder, young star that's less massive than our Sun.This type of star is still gathering material from its surrounding, planet-forming disk.

Credits: Image: NASA, ESA, STScI, Francesco Paresce (INAF-IASF Bologna), Robert O'Connell (UVA), SOC-WFC3, ESO

Images

---

In the largest and one of the most ambitious Hubble Space Telescope programs ever executed, a team of scientists and engineers collected information on almost 500 stars over a three-year period. This effort offers new insights into the stars' formation, evolution, and impact on their surroundings.

This comprehensive survey, called ULLYSES (Ultraviolet Legacy Library of Young Stars as Essential Standards), was completed in December 2023, and provides a rich spectroscopic dataset obtained in ultraviolet light that astronomers will be mining for decades to come. Because ultraviolet light can only be observed from space, Hubble is the only active telescope that can accomplish this research.

"I believe the ULLYSES project will be transformative, impacting overall astrophysics – from exoplanets, to the effects of massive stars on galaxy evolution, to understanding the earliest stages of the evolving universe," said Julia Roman-Duval, Implementation Team Lead for ULLYSES at the Space Telescope Science Institute (STScI) in Baltimore, Maryland. "Aside from the specific goals of the program, the stellar data can also be used in fields of astrophysics in ways we can’t yet imagine."

The ULLYSES team studied 220 stars, then combined those observations with information from the Hubble archive on 275 additional stars. The program also included data from some of the world's largest, most powerful ground-based telescopes and X-ray space telescopes. The ULLYSES dataset is made up of stellar spectra, which carry information about each star's temperature, chemical composition, and rotation.

One type of stars studied under ULLYSES is super-hot, massive, blue stars. They are a million times brighter than the Sun and glow fiercely in ultraviolet light that can easily be detected by Hubble. Their spectra include key diagnostics of the speed of their powerful winds. The winds drive galaxy evolution and seed galaxies with the elements needed for life. Those elements are cooked up inside the stars' nuclear fusion ovens and then injected into space as a star dies. ULLYSES targeted blue stars in nearby galaxies that are deficient in elements heavier than helium and hydrogen. This type of galaxy was common in the very early universe. "ULLYSES observations are a stepping stone to understanding those first stars and their winds in the universe, and how they impact the evolution of their young host galaxy," said Roman-Duval.

The other star category in the ULLYSES program is young stars less massive than our Sun. Though cooler and redder than our Sun, in their formative years they unleash a torrent of high-energy radiation, including blasts of ultraviolet light and X-rays. Because they are still growing, they are gathering material from their surrounding planet-forming disks of dust and gas. The Hubble spectra include key diagnostics of the process by which they acquire their mass, including how much energy this process releases into the surrounding planet-forming disk and nearby environment. The blistering ultraviolet light from young stars affects the evolution of these disks as they form planets, as well as the chances of habitability for newborn planets. The target stars are located in nearby star-forming regions in our Milky Way galaxy.

The ULLYSES concept was designed by a committee of experts with the goal of using Hubble to provide a legacy set of stellar observations. "ULLYSES was originally conceived as an observing program utilizing Hubble's sensitive spectrographs. However, the program was tremendously enhanced by community-led coordinated and ancillary observations with other ground- and space-based observatories," said Roman-Duval. "Such broad coverage allows astronomers to investigate the lives of stars in unprecedented detail and paint a more comprehensive picture of the properties of these stars and how they impact their environment."

To that end, STScI hosted a ULLYSES workshop March 11–14 to celebrate the beginning of a new era of research on young stars. The goal was to allow members of the astronomical community to collaborate on the data, so that they could gain momentum in the ongoing analyses, or kickstart new ideas for analysis. The workshop was one important step in exploiting this legacy spectral library to its fullest potential, fulfilling the promise of ULLYSES.

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, Colorado, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

Source: HubbleSite/News

---

About This Release

Credits:

Release: NASA, ESA, STScI

Media Contact:

Ann Jenkins
Space Telescope Science Institute, Baltimore, Maryland

Ray Villard
Space Telescope Science Institute, Baltimore, Maryland

Science Contact:

Julia Roman-Duval
Space Telescope Science Institute, Baltimore, Maryland

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• NASA's Hubble Portal
• Hubble's ULLYSES Program

---

Astronomers unveil strong magnetic fields spiraling at the edge of Milky Way’s central black hole

PR Image eso2406a
A view of the Milky Way supermassive black hole Sagittarius A* in polarised light

PR Image eso2406b
M87* and Sgr A* side-by-side in polarised light

PR Image eso2406c
First image of our black hole

PR Image eso2406d
A view of the M87 supermassive black hole in polarised light

PR Image eso2406e
Comparison of the sizes of two black holes: M87* and Sagittarius A*

PR Image eso2406f
Locations of the telescopes that make up the EHT array

PR Image eso2406g
Wide-field view of the centre of the Milky Way

PR Image eso2406h
Sagittarius A* in the constellation of Sagittarius

---

Videos

 

PR Video eso2406abh
A new view of our black hole | ESO News

 

PR Video eso2406bbh
Zoom in to view the black hole at the Milky Way centre in a new light

---

A new image from the Event Horizon Telescope (EHT) collaboration has uncovered strong and organised magnetic fields spiraling from the edge of the supermassive black hole Sagittarius A* (Sgr A*). Seen in polarised light for the first time, this new view of the monster lurking at the heart of the Milky Way galaxy has revealed a magnetic field structure strikingly similar to that of the black hole at the centre of the M87 galaxy, suggesting that strong magnetic fields may be common to all black holes. This similarity also hints toward a hidden jet in Sgr A*. The results were published today in The Astrophysical Journal Letters.

In 2022 scientists unveiled the first image of Sgr A* at press conferences around the world, including at the European Southern Observatory (ESO). While the Milky Way’s supermassive black hole, which is roughly 27 000 light-years away from Earth, is more than a thousand times smaller and less massive than M87’s, the first-ever black hole imaged, the observations revealed that the two look remarkably similar. This made scientists wonder whether the two shared common traits outside of their looks. To find out, the team decided to study Sgr A* in polarised light. Previous studies of light around the M87 black hole (M87*) revealed that the magnetic fields around it allowed the black hole to launch powerful jets of material back into the surrounding environment. Building on this work, the new images have revealed that the same may be true for Sgr A*.

>“What we’re seeing now is that there are strong, twisted, and organised magnetic fields near the black hole at the centre of the Milky Way galaxy,” said Sara Issaoun, NASA Hubble Fellowship Program Einstein Fellow at the Center for Astrophysics | Harvard & Smithsonian, US, and co-lead of the project. “Along with Sgr A* having a strikingly similar polarisation structure to that seen in the much larger and more powerful M87* black hole, we’ve learned that strong and ordered magnetic fields are critical to how black holes interact with the gas and matter around them.”

Light is an oscillating, or moving, electromagnetic wave that allows us to see objects. Sometimes, light oscillates in a preferred orientation, and we call it ‘polarised’. Although polarised light surrounds us, to human eyes it is indistinguishable from ‘normal’ light. In the plasma around these black holes, particles whirling around magnetic field lines impart a polarisation pattern perpendicular to the field. This allows astronomers to see in increasingly vivid detail what’s happening in black hole regions and map their magnetic field lines.

“By imaging polarised light from hot glowing gas near black holes, we are directly inferring the structure and strength of the magnetic fields that thread the flow of gas and matter that the black hole feeds on and ejects,” said Harvard Black Hole Initiative Fellow and project co-lead Angelo Ricarte. “Polarised light teaches us a lot more about the astrophysics, the properties of the gas, and mechanisms that take place as a black hole feeds.”

But imaging black holes in polarised light isn’t as easy as putting on a pair of polarised sunglasses, and this is particularly true of Sgr A*, which is changing so fast that it doesn’t sit still for pictures. Imaging the supermassive black hole requires sophisticated tools above and beyond those previously used for capturing M87*, a much steadier target. EHT Project Scientist Geoffrey Bower from the Institute of Astronomy and Astrophysics, Academia Sinica, Taipei said, “Because Sgr A* moves around while we try to take its picture, it was difficult to construct even the unpolarised image,” adding that the first image was an average of multiple images owing to Sgr A*’s movement. “We were relieved that polarised imaging was even possible. Some models were far too scrambled and turbulent to construct a polarised image, but Nature was not so cruel.”

Mariafelicia De Laurentis, EHT Deputy Project Scientist and professor at the University of Naples Federico II, Italy, said, “With a sample of two black holes — with very different masses and very different host galaxies — it’s important to determine what they agree and disagree on. Since both are pointing us toward strong magnetic fields, it suggests that this may be a universal and perhaps fundamental feature of these kinds of systems. One of the similarities between these two black holes might be a jet, but while we’ve imaged a very obvious one in M87*, we’ve yet to find one in Sgr A*.”

To observe Sgr A*, the collaboration linked eight telescopes around the world to create a virtual Earth-sized telescope, the EHT. The Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, and the ESO-hosted Atacama Pathfinder Experiment (APEX), both in northern Chile, were part of the network that made the observations, conducted in 2017.

"As the largest and most powerful of the telescopes in the EHT, ALMA played a key role in making this image possible,” says ESO’s María Díaz Trigo, European ALMA Programme Scientist. “ALMA is now planning an ‘extreme makeover’, the Wideband Sensitivity Upgrade, which will make ALMA even more sensitive and keep it a fundamental player in future EHT observations of Sgr A* and other black holes."

The EHT has conducted several observations since 2017 and is scheduled to observe Sgr A* again in April 2024. Each year, the images improve as the EHT incorporates new telescopes, larger bandwidth, and new observing frequencies. Planned expansions for the next decade will enable high-fidelity movies of Sgr A*, may reveal a hidden jet, and could allow astronomers to observe similar polarisation features in other black holes. Meanwhile, extending the EHT into space would provide sharper images of black holes than ever before.

Source: ESO/News

---

More information

This research was presented in two papers by the EHT Collaboration published today in The Astrophysical Journal Letters: "First Sagittarius A* Event Horizon Telescope Results. VII. Polarization of the Ring" (doi:10.3847/2041-8213/ad2df0) and "First Sagittarius A* Event Horizon Telescope Results. VIII.: Physical interpretation of the polarized ring" (doi:10.3847/2041-8213/ad2df1).

The EHT collaboration involves more than 300 researchers from Africa, Asia, Europe, and North and South America. The international collaboration is working to capture the most detailed black hole images ever obtained by creating a virtual Earth-sized telescope. Supported by considerable international investment, the EHT links existing telescopes using novel systems — creating a fundamentally new instrument with the highest angular resolving power that has yet been achieved.

The individual telescopes involved in the EHT in April 2017, when the observations were conducted, were: the Atacama Large Millimeter/submillimeter Array (ALMA), the Atacama Pathfinder EXperiment (APEX), the Institut de Radioastronomie Millimetrique (IRAM) 30-meter Telescope, the James Clerk Maxwell Telescope (JCMT), the Large Millimeter Telescope Alfonso Serrano (LMT), the Submillimeter Array (SMA), the UArizona Submillimeter Telescope (SMT), and the South Pole Telescope (SPT). Since then, the EHT has added the Greenland Telescope (GLT), the IRAM NOrthern Extended Millimeter Array (NOEMA) and the UArizona 12-meter Telescope on Kitt Peak to its network.

The EHT consortium consists of 13 stakeholder institutes: the Academia Sinica Institute of Astronomy and Astrophysics, the University of Arizona, the University of Chicago, the East Asian Observatory, Goethe-Universitaet Frankfurt, Institut de Radioastronomie Millimétrique, Large Millimeter Telescope, Max Planck Institute for Radio Astronomy, MIT Haystack Observatory, National Astronomical Observatory of Japan, Perimeter Institute for Theoretical Physics, Radboud University and the Smithsonian Astrophysical Observatory.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

---

Links

• Research paper VII
• Research paper VIII
• Photos of ALMA
• Photos of APEX
• ESO EHT Milky Way page (focusing on the previous Sgr A* results)
• For journalists: subscribe to receive our releases under embargo in your language
• For scientists: got a story? Pitch your research

---

Contacts

Sara Issaoun
Center for Astrophysics | Harvard & Smithsonian
USA
Email: sara.issaoun@cfa.harvard.edu

Angelo Ricarte
Center for Astrophysics | Harvard & Smithsonian
USA
Email: angelo.ricarte@cfa.harvard.edu

Geoffrey Bower
EHT Project Scientist
Institute of Astronomy and Astrophysics, Academic Sinica, Taiwan
Email: gbower@asiaa.sinica.edu.tw

Mariafelicia De Laurentis
EHT Deputy Project Scientist, University of Naples Federico II
Italy
Email: mariafelicia.delaurentis@unina.it

María Diaz Trigo
ALMA Programme Scientist, European Southern Observatory
Garching bei München, Germany
Email: mdiaztri@eso.org

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Tel: +49 89 3200 6670
Cell: +49 151 241 664 00
Email: press@eso.org

---

No zoom

NGC 1651

A spherical collection of stars, which fills the whole view. The stars merge into a bright, bluish core in the centre, and form a sparse band around that out to the edges of the image. A few stars lie in front of the cluster, with visible diffraction spikes. The background is dark black. Credit: ESA/Hubble & NASA, L. Girardi, F. Niederhofer

---

This image shows a globular cluster known as NGC 1651. Like the object in another recent Picture of the Week, it is located about 162 000 light-years away in the largest and brightest of the Milky Way’s satellite galaxies, the Large Magellanic Cloud (LMC). A notable feature of this image is that the globular cluster almost fills the entire image, even though globular clusters are only about 10 to 300 light-years in diameter (NGC 1651 has a diameter of roughly 120 light-years). In contrast, there are numerous Hubble Pictures of the Week that feature entire galaxies — which can be tens or hundreds of millions of light-years in diameter — that also more or less fill the whole image.

A common misconception is that Hubble and other large telescopes manage to observe wildly differently sized celestial objects by zooming in on them, as one would with a specialised camera here on Earth. However, whilst small telescopes might have the option to zoom in and out to a certain extent, large telescopes do not. Each telescope’s instrument has a fixed ‘field of view’ (the size of the region of sky that it can observe in a single observation). For example, the ultraviolet/visible light channel of Hubble’s Wide Field Camera 3 (WFC3), the channel and instrument that were used to collect the data used in this image, has a field of view roughly one twelfth the diameter of the Moon as seen from Earth. Whenever WFC3 makes an observation, that is the size of the region of sky that it can observe.

The reason that Hubble can observe objects of such wildly different sizes is two-fold. Firstly, the distance to an object will determine how big it appears to be from Earth, so entire galaxies that are relatively far away might take up the same amount of space in the sky as a globular cluster like NGC 1651 that is relatively close by. In fact, there's a distant spiral galaxy lurking in this image, directly left of the cluster — though undoubtedly much larger than this star cluster, it appears small enough here to blend in with foreground stars! Secondly, multiple images spanning different parts of the sky can be mosaiced together to create single images of objects that are too big for Hubble’s field of view. This is a very complex task and is not typically done for Pictures of the Week, but it has been done for some of Hubble’s most iconic images.

Source: ESA/Hubble/potw

---

Hubble sees new star proclaiming its presence with cosmic light show

PR Image heic2406a
FS Tau

---

Videos

PR Video heic2406a
Pan: FS Tau

---

Jets emerge from the cocoon of a newly forming star to blast across space, slicing through the gas and dust of a shining nebula, in this new image from the NASA/ESA Hubble Space Telescope.

FS Tau is a multi-star system made up of FS Tau A, the bright star-like object near the middle of the image, and FS Tau B (Haro 6-5B), the bright object to the far right that is partially obscured by a dark, vertical lane of dust. These young objects are surrounded by the softly illuminated gas and dust of this stellar nursery. The system is only about 2.8 million years old, very young for a star system. Our Sun, by contrast, is about 4.6 billion years old.

FS Tau B is a newly forming star, or protostar, and is surrounded by a protoplanetary disc, a pancake-shaped collection of dust and gas left over from the formation of the star that will eventually coalesce into planets. The thick dust lane, seen nearly edge-on, separates what are thought to be the illuminated surfaces of the disc.

FS Tau B is likely in the process of becoming a T Tauri star, a type of young variable star that hasn’t begun nuclear fusion yet but is beginning to evolve into a hydrogen-fueled star similar to our Sun. Protostars shine with the heat energy released as the gas clouds from which they are forming collapse, and from the accretion of material from nearby gas and dust. Variable stars are a class of star whose brightness changes noticeably over time.

FS Tau A is itself a T Tauri binary system, consisting of two stars orbiting each other.

Protostars are known to eject fast-moving, column-like streams of energised material called jets, and FS Tau B provides a striking example of this phenomenon. The protostar is the source of an unusual asymmetric, double-sided jet, visible here in blue. Its asymmetrical structure may be because mass is being expelled from the object at different rates.

FS Tau B is also classified as a Herbig-Haro object. Herbig–Haro objects form when jets of ionised gas ejected by a young star collide with nearby clouds of gas and dust at high speeds, creating bright patches of nebulosity.

FS Tau is part of the Taurus-Auriga region, a collection of dark molecular clouds that are home to numerous newly forming and young stars, roughly 450 light-years away in the constellations of Taurus and Auriga. Hubble has previously observed this region, whose star-forming activity makes it a compelling target for astronomers. Hubble made these observations as part of an investigation of edge-on dust discs around young stellar objects.

Source: ESA/Hubble/News

---

More information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Image credit: NASA, ESA, and K. Stapelfeldt (NASA JPL), G. Kober (NASA/Catholic University of America)

---

Links

• Release on NASA website

---

Contacts

Bethany Downer
ESA/Hubble Chief Science Communications Officer
Email: Bethany.Downer@esahubble.org

---

H1821+643: NASA's Chandra Identifies an Underachieving Black Hole

H1821+643
Credit: X-ray: NASA/CXC/Univ. of Nottingham/H. Russell et al.; Radio: NSF/NRAO/VLA;

 Image Processing: NASA/CXC/SAO/N. Wolk

JPEG (66.3 kb) - Large JPEG (783 kb) - Tiff (32.9 MB) - More Images

A Tour of H1821+643 - More Videos

---

This image shows a quasar, a rapidly growing supermassive black hole, which is not achieving what astronomers would expect from it, as reported in our latest press release. Data from NASA’s Chandra X-ray Observatory (blue) and radio data from the NSF’s Karl G. Jansky’s Very Large Array (red) reveal some of the evidence for this quasar’s disappointing impact on its host galaxy.

Known as H1821+643, this quasar is about 3.4 billion light-years from Earth. Quasars are a rare and extreme class of supermassive black holes that are furiously pulling material inwards, producing intense radiation and sometimes powerful jets. H1821+643 is the closest quasar to Earth in a cluster of galaxies.

Quasars are different than other supermassive black holes in the centers of galaxy clusters in that they are pulling in more material at a higher rate. Astronomers have found that non-quasar black holes growing at moderate rates influence their surroundings by preventing the intergalactic hot gas from cooling down too much. This regulates the growth of stars around the black hole.

The influence of quasars, however, is not as well known. This new study of H1821+643 that quasars — despite being so active — may be less important in driving the fate of their host galaxy and cluster than some scientists might expect.

To reach this conclusion the team used Chandra to study the hot gas that H1821+643 and its host galaxy are shrouded in. The bright X-rays from the quasar, however, made it difficult to study the weaker X-rays from the hot gas. The researchers carefully removed the X-ray glare to reveal what the black hole’s influence is, which is reflected in the new composite image showing X-rays from hot gas in the cluster surrounding the quasar. This allowed them to see that the quasar is actually having little effect on its surroundings.

Using Chandra, the team found that the density of gas near the black hole in the center of the galaxy is much higher, and the gas temperatures much lower, than in regions farther away. Scientists expect the hot gas to behave like this when there is little or no energy input (which would typically come from outbursts from a black hole) to prevent the hot gas from cooling down and flowing towards the center of the cluster.

A paper describing these results has been accepted into the Monthly Notices of the Royal Astronomical Society and is available online. The authors are Helen Russell (University of Nottingham, UK), Paul Nulsen (Center for Astrophysics | Harvard & Smithsonian), Andy Fabian (University of Cambridge, UK), Thomas Braben (University of Nottingham), Niel Brandt (Penn State University), Lucy Clews (University of Nottingham), Michael McDonald (Massachusetts Institute of Technology), Christopher Reynolds (University of Maryland), Jeremy Saunders (Max Planck Institute for Extraterrestrial Research), and Sylvain Veilleux (University of Maryland).

NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.

Quick Look: NASA's Chandra Identifies an Underachieving Black Hole

Source: NASA's Chandra X-Ray Observatory

---

Visual Description:

This composite image shows a quasar, a rare and extreme class of supermassive black hole, that's located about 3.4 billion light-years from Earth.

At the center of the image is a bright, white, circular light, similar to the beam of a flashlight if it was pointed directly toward you. A fuzzy, bar-shaped structure of red-colored radio light, slightly larger than the width of the white light, surrounds the circular structure. The red bar also extends above and below the white light, stretching in a somewhat straight line from about the one o'clock position to the seven o'clock position on a clock face.

On either side of the red bar, X-ray light is present as blue, wispy clouds of hot gas that are brighter closer to the red and white features. The brighter clouds represent more dense gas.

---

Fast Facts for H1821+643:

Scale: Image is about 1.1 arcmin (960,000 light-years) across.
Category: Black Holes, Groups & Clusters of Galaxies
Coordinates (J2000): RA 18h 21m 57.40s | Dec +64° 20´ 37.0"
Constellation: Draco
Observation Dates: 11 observations Oct 7, 2019 to Jul 15, 2020
Observation Time: 93 hours 44 minutes (3 days 21 hours 44 minutes)
Obs. ID: 22105-22108, 21558-21561, 23054, 23211, 23240
Instrument: ACIS
References: Russell, H.R. et al., 2024, MNRAS, 528, 1863; arXiv:2401.03022.
Color Code: X-ray: blue; Radio: red
Distance Estimate: About 3.4 billion light-years (z=0.296)

---

Scientists find one of the most ancient stars that formed in another galaxy

Identification of low-metallicity member stars in the LMC. Credit: Nature Astronomy (2024)
DOI: 10.1038/s41550-024-02223-w

The first generation of stars transformed the universe. Inside their cores, simple hydrogen and helium fused into a rainbow of elements. When these stars died, they exploded and sent these new elements across the universe. The iron running in your veins and the calcium in your teeth and the sodium powering your thoughts were all born in the heart of a long-dead star.

No one has been able to find any of those first generation of stars, but scientists have announced a unique finding: a star from the second generation that originally formed in a different galaxy from ours.

"This star provides a unique window into the very early element-forming process in galaxies other than our own," said Anirudh Chiti, a University of Chicago postdoctoral fellow and first author on a paper announcing the findings. "We have built up an idea of the how these stars that were chemically enriched by the first stars look like in the Milky Way, but we don't yet know if some of these signatures are unique, or if things happened similarly across other galaxies."

The paper was published March 20 in Nature Astronomy.

'Fishing needles out of haystacks'

Chiti specializes in what is called stellar archaeology: Reconstructing how the earliest generations of stars changed the universe. "We want to understand what the properties of those first stars were and what were the elements they produced," said Chiti.

But no one has yet managed to directly see these first-generation stars, if any remain in the universe. Instead, Chiti and his colleagues look for stars that formed from the ashes of that first generation.

It's hard work, because even the second generation of stars is now incredibly ancient and rare. Most stars in the universe, including our own sun, are the result of tens to thousands of generations, building up more and more heavy elements each time.

"Maybe fewer than one in 100,000 stars in the Milky Way is one of these second-gen stars," he said. "You really are fishing needles out of haystacks."

But it's worth it to get snapshots of what the universe looked like back in time. "In their outer layers, these stars preserve the elements near where they formed," he explained. "If you can find a very old star and get its chemical composition, you can understand what the chemical composition of the universe was like where that star formed, billions of years ago.

"Elemental abundance trends of stars in the LMC versus the Milky Way and the Sculptor dwarf galaxy. Credit: Nature Astronomy (2024). DOI: 10.1038/s41550-024-02223-w

---

An intriguing oddity

For this study, Chiti and his colleagues aimed their telescopes at an unusual target: the stars that make up the Large Magellanic Cloud.

The Large Magellanic Cloud is a bright swath of stars visible to the naked eye in the Southern Hemisphere. We now think it was once a separate galaxy that was captured by the Milky Way's gravity just a few billion years ago. This makes it particularly interesting because its oldest stars were formed outside the Milky Way—giving astronomers a chance to learn about whether conditions in the early universe all looked the same, or were different in other places.

The scientists searched for evidence of these particularly ancient stars in the Large Magellanic Cloud and catalogued ten of them, first with the European Space Agency's Gaia satellite and then with the Magellan Telescope in Chile.

One of these stars immediately One of these stars immediately umped out as an oddity. It had much, much less of the heavier elements in it than any other star yet seen in the Large Magellanic Cloud. This means it was probably formed in the wake of the first generation of stars—so it had not yet built up heavier elements over the course of repeated star births and deaths

Mapping out its elements, the scientists were surprised to see that it had a lot less carbon than iron compared to what we see in Milky Way stars.

"That was very intriguing, and it suggests that perhaps carbon enhancement of the earliest generation, as we see in the Milky Way, was not universal," Chiti said. "We'll have to do further studies, but it suggests there are differences from place to place.

"I think we're filling out the picture of what the early element enrichment process looked like in different environments," he said.

Their findings also corroborated other studies that have suggested that the Large Magellanic Cloud made much fewer stars early on compared to the Milky Way.

Chiti is currently leading an imaging program to map out a large portion of the southern sky to find the earliest stars possible. "This discovery suggests there should be many of these stars in the Large Magellanic Cloud if we look closely," he said. "It's really exciting to be opening up stellar archaeology of the Large Magellanic Cloud, and to be able to map out in such detail how the first stars chemically enriched the universe in different regions."

Source: Phys.org

---

More information:

Anirudh Chiti et al, Enrichment by extragalactic first stars in the Large Magellanic Cloud, Nature Astronomy (2024). DOI: 10.1038/s41550-024-02223-w

Provided by University of Chicago

---

Explore further

• Discovery of unusual star may change our picture of how stars explode and elements are made

---

Modeling a Conversation Between a Black Hole and Its Galaxy

The massive, dusty elliptical galaxy Centaurus A, shown here in an image from the Hubble Space Telescope, contains the nearest active galactic nucleus to Earth. Cropped from NASA, ESA, and the Hubble Heritage (STScI/AURA)–ESA/Hubble Collaboration; Acknowledgment: R. O'Connell (University of Virginia) and the WFC3 Scientific Oversight Committee]

A new modeling method allows black holes and the gas that surrounds them to “talk” back and forth, painting a more realistic picture of how black holes collect material and churn out energy.

A Problem of Scale

Black holes at the centers of galaxies across the universe consume gas, dust, and even stars from their surroundings. In exchange for this feast, accreting black holes emit powerful jets and radiation that disrupt and heat nearby gas. This process, known as feedback, cements the link between a black hole and its home galaxy.

Supermassive black holes, though enormous, are tiny compared to their host galaxies — the Milky Way’s central black hole’s event horizon stretches roughly 15 million miles, just a minuscule fraction of our galaxy’s half-quintillion-mile diameter. Despite this size mismatch, supermassive black holes are so powerful that they can influence entire galaxies, leaving researchers with the enormous challenge of modeling the complex processes of accretion and feedback across a wide range of spatial scales.

Composite image of Centaurus A, a galaxy whose appearance is dominated by the large-scale jets powered by the supermassive black hole at its center. Credit: ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray); CC BY 4.0

 

Building a Two-Way Radio

Typically, models of hungry black holes handle the spatial scale issue by nesting simulations spanning different scales within each other and running them in sequence, starting far from the black hole and spiraling in toward it. This strategy helps the model communicate to the black hole what’s going on around it — how much gas there is to snack on, for example — but it needs to let the black hole talk back, too. That’s where a new technique from a team led by Hyerin Cho (조혜린), Center for Astrophysics | Harvard & Smithsonian and the Black Hole Initiative, comes in.

This new technique uses general relativistic magnetohydrodynamics to model black hole accretion and feedback across seven orders of magnitude in spatial scale. The key advance is that the model spirals from large scales down to small scales — and back — hundreds of times, allowing the black hole to chat freely with its surroundings.

Maps of plasma beta (β; the ratio of thermal pressure to magnetic pressure within a plasma) and plasma density (ρ) across eight orders of magnitude in spatial scale. Adapted from Cho et al. 2023

Focusing on Feedback

To demonstrate the new method’s capabilities, Cho and collaborators first showed that they could reproduce the standard analytical solution for a black hole accreting unmagnetized gas. Then, they moved on to a more realistic system that includes magnetic fields. Unlike the unmagnetized case, where gas swirls toward the black hole in a smooth and orderly way, the magnetized case is chaotic: random, turbulent movements as the gas is pulled toward the black hole make the accretion rate vary wildly.

Where does the turbulence come from? Cho’s team found that magnetic field lines close to the black hole are constantly rearranging, relaxing into new configurations that convert pent-up magnetic energy into kinetic energy. In other words, the reconfiguring of the magnetic field heats and accelerates the surrounding gas, prompting large-scale motions that transport energy away from the black hole — and this outward transport of energy signals that black hole feedback is actually taking place!

Importantly, Cho’s team’s results mesh with what researchers have seen for the black holes they’ve observed closely, especially the central supermassive black holes of the Milky Way and the massive elliptical galaxy Messier 87. While this two-way communication represents a huge advance in the modeling of black hole accretion and feedback, there’s more work to be done; future investigations will tackle spinning black holes surrounded by rotating gas.

By Kerry Hensley

Citation

“Bridging Scales in Black Hole Accretion and Feedback: Magnetized Bondi Accretion in 3D GRMHD,” Hyerin Cho et al 2023 ApJL 959 L22. doi:10.3847/2041-8213/ad1048

Source: American Astronomical Society/AAS-Nova

---

NASA's Hubble Finds that Aging Brown Dwarfs Grow Lonely

Hubble Brown Dwarf Survey Illustration
Credits: Artwork: NASA, ESA, Joseph Olmsted (STScI)

Images

---

It takes two to tango, but in the case of brown dwarfs that were once paired as binary systems, that relationship doesn't last for very long, according to a recent survey from NASA's Hubble Space Telescope.

Brown dwarfs are interstellar objects larger than Jupiter but smaller than the lowest-mass stars. They are born like stars – out of a cloud of gas and dust that collapses – but do not have enough mass to sustain the fusion of hydrogen like a normal star.

Astronomers using Hubble confirm that companions are extremely rare around the lowest-mass and coldest brown dwarfs. Hubble can detect binaries as close to each other as a 300-million-mile separation – the approximate separation between our Sun and the asteroid belt. But they didn't find any binary pairs in a sample of brown dwarfs in the solar neighborhood. This implies that a binary pair of dwarfs is so weakly linked by gravity that they drift apart over a few hundred million years due to the pull of bypassing stars.

"Our survey confirms that widely separated companions are extremely rare among the lowest-mass and coldest isolated brown dwarfs, even though binary brown dwarfs are observed at younger ages. This suggests that such systems do not survive over time," said lead author Clémence Fontanive of the Trottier Institute for Research on Exoplanets, Université de Montréal, Canada.

In a similar survey Fontanive conducted a couple of years ago, Hubble looked at extremely young brown dwarfs and some had binary companions, confirming that star-forming mechanisms do produce binary pairs among low-mass brown dwarfs. The lack of binary companions for older brown dwarfs suggests that some may have started out as binaries, but parted ways over time.

The new Hubble findings published in The Monthly Notices of the Royal Astronomical Society further support the theory that brown dwarfs are born the same way as stars, through the gravitational collapse of a cloud of molecular hydrogen. The difference being that they do not have enough mass to sustain nuclear fusion of hydrogen for generating energy, whereas stars do. More than half of the stars in our galaxy have a companion star that resulted from these formation processes, with more massive stars more commonly found in binary systems. "The motivation for the study was really to see how low in mass the trends seen among multiple stars systems hold up," said Fontanive.

"Our Hubble survey offers direct evidence that these binaries that we observe when they're young are unlikely to survive to old ages, they're likely going to get disrupted. When they're young, they're part of a molecular cloud, and then as they age the cloud disperses. As that happens, things start moving around and stars pass by each other. Because brown dwarfs are so light, the gravitational hold tying wide binary pairs is very weak, and bypassing stars can easily tear these binaries apart," said Fontanive.

The team selected a sample of brown dwarfs previously identified by NASA's Wide-Field Infrared Survey Explorer. It sampled some of the coldest and lowest-mass old brown dwarfs in the solar neighborhood. These old brown dwarfs are so cool (a few hundred degrees warmer than Jupiter in most cases) that their atmospheres contain water vapor that condensed out.

To find the coolest companions, the team used two different near-infrared filters, one in which cold brown dwarfs are bright, and another covering specific wavelengths where they appear very faint due to water absorption in their atmospheres.

"This is the best observational evidence to date that brown dwarf pairs drift apart over time," said Fontanive. "We could not have done this kind of survey and confirmed earlier models without Hubble's sharp vision and sensitivity."

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. Goddard also conducts mission operations with Lockheed Martin Space based in Denver, Colorado. The Space Telescope Science Institute in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

Source: HubbleSite/News

---

About This Release:

Credits:

Media Contact:

Ray Villard
Space Telescope Science Institute, Baltimore, Maryland

Science Contact:

Clémence Fontanive
Trottier Institute for Research on Exoplanets at Université de Montréal

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• Science Paper: The science paper by C. Fontanive/Trottier Inst. for Research on Exoplanets-U. Montreal), PDF (1.88 MB) 
•  NASA's Hubble Portal
• ESA/Hubble's Release
• iREx, Université de Montréal's Release

---

Using Polarization to Improve Quantum Imaging

A stained slice of a mouse brain, as imaged with classical imaging (left) and using the Wang group's ICE method (right). The difference in resolution between the two techniques is clear in the side-by-side comparison focused on an area of detail highlighted in boxes E and F.

A zebrafish is shown classically imaged (left) and using the ICE technique (right), in the presence of unwanted, or stray light, that could interfere with the quality of an image. The black dots in the classical image are imperfections caused by stray light.

Since quantum entanglement allows paired photons to be linked no matter how far apart they might be, Wang is already imagining how his new system could be used to make birefringence measurements in space.

---

Quantum imaging is a growing field that takes advantage of the counterintuitive and "spooky" ability of light particles, or photons, to become linked, or entangled, under specialized circumstances. If the state of one photon in the entangled duo gets tweaked, so does the other, regardless of how far apart the two photons might be.

Caltech researchers demonstrated last May how such entanglement could double the resolution of classical light microscopes while also preventing an imaging system's light from damaging fragile biological samples. Now the same team has improved upon the technique, making it possible to quantum image whole organ slices and even small organisms.

Led by Lihong Wang, the Bren Professor of Medical Engineering and Electrical Engineering, the new work uses entanglement—what Albert Einstein once famously described as "spooky action at a distance"— to control not only the color and brightness of the light hitting a sample, but also the polarization of that light.

"Our new technique has the potential to pave the way for quantum imaging in many different fields, including biomedical imaging and potentially even remote space sensing," says Wang, who is also the Andrew and Peggy Cherng Medical Engineering Leadership Chair and executive officer for medical engineering.

Like wavelength and intensity, polarization is a fundamental property of light and represents which direction the electric component of a light wave is oriented with respect to the wave's general direction of travel. Most light, including sunlight, is unpolarized, meaning that its electromagnetic waves move and travel in all directions. However, filters called polarizers can be used to create light beams with one specific polarization. A vertical polarizer, for example, only allows photons with vertical polarization to pass through. Those with horizontal polarization (meaning that the electric component of the light wave is oriented horizontally with respect to the direction of travel) will be blocked. Any light with other polarization angles (between vertical and horizontal), will partially pass through. The outcome is a stream of vertically polarized light.

This is how polarized sunglasses reduce glare. They use a vertically polarizing chemical coating to block sunlight that has become horizontally polarized by reflecting off a horizontal surface, such as a lake or snowy field. This means that the wearer only observes vertically polarized light.

When changes in light intensity or color are not enough to give scientists quality images of certain objects, controlling the polarization of the light in an imaging system can sometimes provide more information about the sample and offer a different way to identify contrast between a sample and its background. Detecting the changes in polarization caused by certain samples can also give researchers information about the internal structure and behavior of those materials.

Wang's newest microscopy technique, dubbed quantum imaging by coincidence from entanglement (ICE), takes advantage of entangled photon pairs to obtain higher-resolution images of biological materials, including thicker samples, and to make measurements of materials that have what scientists call birefringent properties.

Rather than consistently bending incoming light waves in the same way, as most materials do, birefringent materials bend those waves to different degrees depending on the light's polarization and the direction in which it is traveling. The most common birefringent materials studied by scientists are calcite crystals. But biological materials, such as cellulose, starch, and many types of animal tissue, including collagen and cartilage, are also birefringent.

If a sample with birefringent properties is placed between two polarizers oriented at 90-degree angles to each other, some of the light going through the sample will be altered in its polarization and will therefore make it through to the detector, even though all the other incoming light should be blocked by the two polarizers. The detected light can then provide information about the structure of the sample. In materials science, for example, scientists use birefringence measurements to get a better understanding of the areas where mechanical stress builds up in plastics.

In Wang's ICE setup, light is passed first through a polarizer and then through a pair of special barium borate crystals, which will occasionally create an entangled photon pair; about one pair is produced for every million photons that pass through the crystals. From there, the two entangled photons will branch off and follow one of the system's two arms: one will travel straight ahead, following what is called the idler arm, while the other traces a more circuitous path called the signal arm that causes the photon to pass through the object of interest. Finally, both photons go through an additional polarizer before reaching two detectors, which record the time of arrival of the detected photons. Here, though, occurs a "spooky" quantum effect because of the entangled nature of the photons: the detector in the idler arm can act as a virtual "pinhole" and "polarization selector" on the signal arm, instantly affecting the location and polarization of the photon incident on the object in the signal arm.

"In the ICE setup, the detectors in the signal and idler arms function as 'real' and 'virtual' pinholes, respectively," says Yide Zhang, lead author of the new paper and a postdoctoral scholar fellowship trainee in medical engineering at Caltech. "This dual pinhole configuration enhances the spatial resolution of the object imaged in the signal arm. Consequently, ICE achieves higher spatial resolution than conventional imaging that utilizes a single pinhole in the signal arm."

"Since each entangled photon pair always arrives at the detectors at the same time, we can suppress noises in the image caused by random photons," adds Xin Tong, co-author of the study and a graduate student in medical and electrical engineering at Caltech.

To determine the birefringent properties of a material with a classical microscopy setup, scientists typically switch through different input states, illuminating an object separately with horizontally, vertically, and diagonally polarized light, and then measuring the corresponding output states with a detector. The goal is to measure how the birefringence of the sample alters the image that the detector receives in each of those states. This information informs scientists about the structure of the sample and can provide images that would not otherwise be possible.

Since quantum entanglement allows paired photons to be linked no matter how far apart they might be, Wang is already imagining how his new system could be used to make birefringence measurements in space. Consider a situation where something of interest, perhaps an interstellar medium, is located light years away from Earth. A satellite in space might be positioned such that it could emit entangled photon pairs using the ICE technique, with two ground stations acting as detectors. The large distance to the satellite would make it impractical to send any kind of signal to adjust the device's source polarization. However, due to entanglement, changing the polarization state in the idler arm would be equivalent to changing the polarization of the source light before the beam hits the object. "Using quantum technology, nearly instantaneously, we can make changes to the polarization state of the photons no matter where they are," Wang says. "Quantum technologies are the future. Out of scientific curiosity, we need to explore this direction."

A paper describing the work, "Quantum imaging of biological organisms through spatial and polarization entanglement," appears in the March 8 issue of the journal Science Advances. In addition to Wang, Zhang, and Tong, the paper's co-authors are medical engineering graduate student David Garrett, postdoctoral scholar research associate Rui Cao, and former postdoctoral scholar research associate Zhe He, who is now at the Shandong Institute of Advanced Technology. The work was supported by funding from Caltech's Center for Sensing to Intelligence and the National Institutes of Health.

Written by Kimm Fesenmaier

Source: Caltech

---

Contact:

Kimm Fesenmaier

(626) 395‑1217

kfesenma@caltech.edu

---