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NASA’s Hubble Provides Bird’s-Eye View of Andromeda Galaxy’s Ecosystem

Located 2.5 million light-years away, the majestic Andromeda galaxy appears to the naked eye as a faint, spindle-shaped object roughly the angular size of the full Moon. What backyard observers don’t see is a swarm of nearly three dozen small satellite galaxies circling the Andromeda galaxy, like bees around a hive.

These satellite galaxies represent a rambunctious galactic “ecosystem” that NASA’s Hubble Space Telescope is studying in unprecedented detail. This ambitious Hubble Treasury Program used observations from more than a whopping 1,000 Hubble orbits. Hubble’s optical stability, clarity, and efficiency made this ambitious survey possible. This work included building a precise 3D mapping of all the dwarf galaxies buzzing around Andromeda and reconstructing how efficiently they formed new stars over the nearly 14 billion years of the universe’s lifetime.

In the study published in The Astrophysical Journal, Hubble reveals a markedly different ecosystem from the smaller number of satellite galaxies that circle our Milky Way. This offers forensic clues as to how our Milky Way galaxy and Andromeda have evolved differently over billions of years. Our Milky Way has been relatively placid. But it looks like Andromeda has had a more dynamic history, which was probably affected by a major merger with another big galaxy a few billion years ago. This encounter, and the fact that Andromeda is as much as twice as massive as our Milky Way, could explain its plentiful and diverse dwarf galaxy population.

Surveying the Milky Way’s entire satellite system in such a comprehensive way is very challenging because we are embedded inside our galaxy. Nor can it be accomplished for other large galaxies because they are too far away to study the small satellite galaxies in much detail. The nearest galaxy of comparable mass to the Milky Way beyond Andromeda is M81, at nearly 12 million light-years.

This bird’s-eye view of Andromeda’s satellite system allows us to decipher what drives the evolution of these small galaxies. “We see that the duration for which the satellites can continue forming new stars really depends on how massive they are and on how close they are to the Andromeda galaxy,” said lead author Alessandro Savino of the University of California at Berkeley. “It is a clear indication of how small-galaxy growth is disturbed by the influence of a massive galaxy like Andromeda.”

“Everything scattered in the Andromeda system is very asymmetric and perturbed. It does appear that something significant happened not too long ago,” said principal investigator Daniel Weisz of the University of California at Berkeley. “There’s always a tendency to use what we understand in our own galaxy to extrapolate more generally to the other galaxies in the universe. There’s always been concerns about whether what we are learning in the Milky Way applies more broadly to other galaxies. Or is there more diversity among external galaxies? Do they have similar properties? Our work has shown that low-mass galaxies in other ecosystems have followed different evolutionary paths than what we know from the Milky Way satellite galaxies.”

For example, half of the Andromeda satellite galaxies all seem to be confined to a plane, all orbiting in the same direction. “That’s weird. It was actually a total surprise to find the satellites in that configuration and we still don’t fully understand why they appear that way,” said Weisz.

The brightest companion galaxy to Andromeda is Messier 32 (M32). This is a compact ellipsoidal galaxy that might just be the remnant core of a larger galaxy that collided with Andromeda a few billion years ago. After being gravitationally stripped of gas and some stars, it continued along its orbit. Galaxy M32 contains older stars, but there is evidence it had a flurry of star formation a few billion years ago. In addition to M32, there seems to be a unique population of dwarf galaxies in Andromeda not seen in the Milky Way. They formed most of their stars very early on, but then they didn’t stop. They kept forming stars out of a reservoir of gas at a very low rate for a much longer time.

“Star formation really continued to much later times, which is not at all what you would expect for these dwarf galaxies,” continued Savino. “This doesn’t appear in computer simulations. No one knows what to make of that so far.”

“We do find that there is a lot of diversity that needs to be explained in the Andromeda satellite system,” added Weisz. “The way things come together matters a lot in understanding this galaxy’s history.”

Hubble is providing the first set of imaging where astronomers measure the motions of the dwarf galaxies. In another five years Hubble or NASA’s James Webb Space Telescope will be able to get the second set of observations, allowing astronomers to do a dynamical reconstruction for all 36 of the dwarf galaxies, which will help astronomers to rewind the motions of the entire Andromeda ecosystem billions of years into the past.

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, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

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Media Contact:

Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight Center, Greenbelt, Maryland

Ray Villard
Space Telescope Science Institute, Baltimore, Maryland

Science Contact:

Alessandro Savino
University of California, Berkeley, California

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Hubble Space Telescope

Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.

Galaxy Details and Mergers

Reshaping Our Cosmic View: Hubble Science Highlights

Hubble’s Night Sky Challenge

Where is all the water that may form oceans on distant planets and moons? The SPHEREx astrophysics mission will search the galaxy and take stock.

Every living organism on Earth needs water to survive, so scientists searching for life outside our solar system, are often guided by the phrase “follow the water.” Scheduled to launch no earlier than Thursday, Feb. 27, NASA’s SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) mission will help in that quest.

After its ride aboard a SpaceX Falcon 9 from Vandenberg Space Force base in California, the observatory will search for water, carbon dioxide, carbon monoxide, and other key ingredients for life frozen on the surface of interstellar dust grains in the clouds of gas and dust where planets and stars eventually form.

While there are no oceans or lakes floating freely in space, scientists think these reservoirs of ice, bound to small dust grains, are where most of the water in our universe forms and resides. Additionally, the water in Earth’s oceans as well as those of other planets and moons in our galaxy likely originated in such locations.

The mission will focus on massive regions of gas and dust called molecular clouds. Within those, SPHEREx will also look at some newly formed stars and the disks of material around them from which new planets are born.

Although space telescopes such as NASA’s James Webb and retired Spitzer have detected water, carbon dioxide, carbon monoxide, and other compounds in hundreds of targets, the SPHEREx observatory is the first to be uniquely equipped to conduct a large-scale survey of the galaxy in search of water ice and other frozen compounds.

Rather than taking 2D images of a target like a star, SPHEREx will gather 3D data along its line of sight. That enables scientists to see the amount of ice present in a molecular cloud and observe how the composition of the ices throughout the cloud changes in different environments.

By making more than 9 million of these line-of-sight observations and creating the largest-ever survey of these materials, the mission will help scientists better understand how these compounds form on dust grains and how different environments can influence their abundance.  

Tip of the Iceberg

It makes sense that the composition of planets and stars would reflect the molecular clouds they formed in. However, researchers are still working to confirm the specifics of the planet formation process, and the universe doesn’t always match scientists’ expectations.

For example, a NASA mission launched in 1998, the Submillimeter Wave Astronomy Satellite (SWAS), surveyed the galaxy for water in gas form — including in molecular clouds — but found far less than expected.

“This puzzled us for a while,” said Gary Melnick, a senior astronomer at the Center for Astrophysics | Harvard & Smithsonian and a member of the SPHEREx science team. “We eventually realized that SWAS had detected gaseous water in thin layers near the surface of molecular clouds, suggesting that there might be a lot more water inside the clouds, locked up as ice.”

The mission team’s hypothesis also made sense because SWAS detected less oxygen gas (two oxygen atoms bound together) than expected. They concluded that the oxygen atoms were sticking to interstellar dust grains, and were then joined by hydrogen atoms, forming water. Later research confirmed this. What’s more, the clouds shield molecules from cosmic radiation that would otherwise break those compounds apart. As a result, water ice and other materials stored deep in a cloud’s interior are protected.

As starlight passes through a molecular cloud, molecules like water and carbon dioxide block certain wavelengths of light, creating a distinct signature that SPHEREx and other missions like Webb can identify using a technique called absorption spectroscopy.

In addition to providing a more detailed accounting of the abundance of these frozen compounds, SPHEREx will help researchers answer questions including how deep into molecular clouds ice begins to form, how the abundance of water and other ices changes with the density of a molecular cloud, and how that abundance changes once a star forms.

Powerful Partnerships

As a survey telescope, SPHEREx is designed to study large portions of the sky relatively quickly, and its results can be used in conjunction with data from targeted telescopes like Webb, which observe a significantly smaller area but can see their targets in greater detail.

“If SPHEREx discovers a particularly intriguing location, Webb can study that target with higher spectral resolving power and in wavelengths that SPHEREx cannot detect,” said Melnick. “These two telescopes could form a highly effective partnership.”

More About SPHEREx

SPHEREx is managed by NASA’s Jet Propulsion Laboratory in Southern California for the Astrophysics Division within the Science Mission Directorate at NASA Headquarters in Washington. BAE Systems (formerly Ball Aerospace) built the telescope and the spacecraft bus. The science analysis of the SPHEREx data will be conducted by a team of scientists located at 10 institutions in the U.S., two in South Korea, and one in Taiwan. Data will be processed and archived at IPAC at Caltech, which manages JPL for NASA. The mission principal investigator is based at Caltech with a joint JPL appointment. The SPHEREx dataset will be publicly available at the NASA/IPAC Infrared Science Archive.

For more information about the SPHEREx mission visit:

https://www.jpl.nasa.gov/missions/spherex/

News Media Contact

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

2025-020

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A bouquet of thousands of stars in bloom has arrived. This composite image contains the deepest X-ray image ever made of the spectacular star forming region called 30 Doradus.

By combining X-ray data from NASA’s Chandra X-ray Observatory (blue and green) with optical data from NASA’s Hubble Space Telescope (yellow) and radio data from the Atacama Large Millimeter/submillimeter Array (orange), this stellar arrangement comes alive.

Otherwise known as the Tarantula Nebula, 30 Dor is located about 160,000 light-years away in a small neighboring galaxy to the Milky Way known as the Large Magellanic Cloud (LMC). Because it one of the brightest and populated star-forming regions to Earth, 30 Dor is a frequent target for scientists trying to learn more about how stars are born.

With enough fuel to have powered the manufacturing of stars for at least 25 million years, 30 Dor is the most powerful stellar nursery in the local group of galaxies that includes the Milky Way, the LMC, and the Andromeda galaxy.

The massive young stars in 30 Dor send cosmically strong winds out into space. Along with the matter and energy ejected by stars that have previously exploded, these winds have carved out an eye-catching display of arcs, pillars, and bubbles.

A dense cluster in the center of 30 Dor contains the most massive stars astronomers have ever found, each only about one to two million years old. (Our Sun is over a thousand times older with an age of about 5 billion years.)

This new image includes the data from a large Chandra program that involved about 23 days of observing time, greatly exceeding the 1.3 days of observing that Chandra previously conducted on 30 Dor. The 3,615 X-ray sources detected by Chandra include a mixture of massive stars, double-star systems, bright stars that are still in the process of forming, and much smaller clusters of young stars.

There is a large quantity of diffuse, hot gas seen in X-rays, arising from different sources including the winds of massive stars and from the gas expelled by supernova explosions. This data set will be the best available for the foreseeable future for studying diffuse X-ray emission in star-forming regions.

The long observing time devoted to this cluster allows astronomers the ability to search for changes in the 30 Dor’s massive stars. Several of these stars are members of double star systems and their movements can be traced by the changes in X-ray brightness.

A paper describing these results appears in the July 2024 issue of The Astrophysical Journal Supplement Series. NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

Read more from NASA’s Chandra X-ray Observatory.

Learn more about the Chandra X-ray Observatory and its mission here:

https://www.nasa.gov/chandra

https://chandra.si.edu

Visual Description

This release features a highly detailed composite image of a star-forming region of space known as 30 Doradus, shaped like a bouquet, or a maple leaf.

30 Doradus is a powerful stellar nursery. In 23 days of observation, the Chandra X-ray telescope revealed thousands of distinct star systems. Chandra data also revealed a diffuse X-ray glow from winds blowing off giant stars, and X-ray gas expelled by exploding stars, or supernovas.

In this image, the X-ray wind and gas takes the shape of a massive purple and pink bouquet with an extended central flower, or perhaps a leaf from a maple tree. The hazy, mottled shape occupies much of the image, positioned just to our left of center, tilted slightly to our left. Inside the purple and pink gas and wind cloud are red and orange veins, and pockets of bright white light. The pockets of white light represent clusters of young stars. One cluster at the heart of 30 Doradus houses the most massive stars astronomers have ever found.

The hazy purple and pink bouquet is surrounded by glowing dots of green, white, orange, and red. A second mottled purple cloud shape, which resembles a ring of smoke, sits in our lower righthand corner.

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Lane Figueroa
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
lane.e.figueroa@nasa.gov

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A supernova and its host galaxy are the subject of this NASA/ESA Hubble Space Telescope image. The galaxy in question is LEDA 132905 in the constellation Sculptor. Even at more than 400 million light-years away, LEDA 132905’s spiral structure is faintly visible, as are patches of bright blue stars.

The bright pinkish-white dot in the center of the image, between the bright center of the galaxy and its faint left edge, is a supernova named SN 2022abvt. Discovered in late 2022, Hubble observed SN 2022abvt about two months later. This image uses data from a study of Type Ia supernovae, which occur when the exposed core of a dead star ignites in a sudden, destructive burst of nuclear fusion. Researchers are interested in this type of supernova because they can use them to measure precise distances to other galaxies.

The universe is a big place, and supernova explosions are fleeting. How is it possible to be in the right place at the right time to catch a supernova when it happens? Today, robotic telescopes that continuously scan the night sky discover most supernovae. The Asteroid Terrestrial-impact Last Alert System, or ATLAS, spotted SN 2022abvt. As the name suggests, ATLAS tracks down the faint, fast-moving signals from asteroids close to Earth. In addition to searching out asteroids, ATLAS also keeps tabs on objects that brighten or fade suddenly, like supernovae, variable stars, and galactic centers powered by hungry black holes.

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Media Contact:

Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight Center, Greenbelt, MD

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Hubble Space Telescope

Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.

Hubble’s Night Sky Challenge

Reshaping Our Cosmic View: Hubble Science Highlights

Hubble’s 35th Anniversary

Shaped like a megaphone, the upcoming mission will map the entire sky in infrared light to answer big questions about the universe.

Expected to launch no earlier than Thursday, Feb. 27, from Vandenberg Space Force Base in California, NASA’s SPHEREx space observatory will provide astronomers with a big-picture view of the cosmos like none before. Short for Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer, SPHEREx will map the entire celestial sky in 102 infrared colors, illuminating the origins of our universe, galaxies within it, and life’s key ingredients in our own galaxy. Here are six things to know about the mission.

1. The SPHEREx space telescope will shed light on a cosmic phenomenon called inflation.

In the first billionth of a trillionth of a trillionth of a second after the big bang, the universe increased in size by a trillion-trillionfold. Called inflation, this nearly instantaneous event took place almost 14 billion years ago, and its effects can be found today in the large-scale distribution of matter in the universe. By mapping the distribution of more than 450 million galaxies, SPHEREx will help scientists improve our understanding of the physics behind this extreme cosmic event.

2. The observatory will measure the collective glow from galaxies near and far.

Scientists have tried to estimate the total light output from all galaxies throughout cosmic history by observing individual galaxies and extrapolating to the trillions of galaxies in the universe. The SPHEREx space telescope will take a different approach and measure the total glow from all galaxies, including galaxies too small, too diffuse, or too distant for other telescopes to easily detect. Combining the measurement of this overall glow with other telescopes’ studies of individual galaxies will give scientists a more complete picture of all the major sources of light in the universe.

3. The mission will search the Milky Way galaxy for essential building blocks of life.

Life as we know it wouldn’t exist without basic ingredients such as water and carbon dioxide. The SPHEREx observatory is designed to find these molecules frozen in interstellar clouds of gas and dust, where stars and planets form. The mission will pinpoint the location and abundance of these icy compounds in our galaxy, giving researchers a better sense of their availability in the raw materials for newly forming planets.

4. It adds unique strengths to NASA’s fleet of space telescopes.

Space telescopes like NASA’s Hubble and Webb have zoomed in on many corners of the universe to show us planets, stars, and galaxies in high resolution. But some questions — like how much light do all the galaxies in the universe collectively emit? — can be answered only by looking at the big picture. To that end, the SPHEREx observatory will provide maps that encompass the entire sky. Objects of scientific interest identified by SPHEREx can then be studied in more detail by targeted telescopes like Hubble and Webb.

5. The SPHEREx observatory will make the most colorful all-sky map ever.

The SPHEREx observatory “sees” infrared light. Undetectable to the human eye, this range of wavelengths is ideal for studying stars and galaxies. Using a technique called spectroscopy, the telescope can split the light into its component colors (individual wavelengths), like a prism creates a rainbow from sunlight, in order to measure the distance to cosmic objects and learn about their composition. With SPHEREx’s spectroscopic map in hand, scientists will be able to detect evidence of chemical compounds, like water ice, in our galaxy. They’ll not only measure the total amount of light emitted by galaxies in our universe, but also discern how bright that total glow was at different points in cosmic history. And they’ll chart the 3D locations of hundreds of millions of galaxies to study how inflation influenced the large-scale structure of the universe today.

6. The spacecraft’s cone-shaped design helps it stay cold and see faint objects.

The mission’s infrared telescope and detectors need to operate at around minus 350 degrees Fahrenheit (about minus 210 degrees Celsius). This is partly to prevent them from generating their own infrared glow, which might overwhelm the faint light from cosmic sources. To keep things cold while also simplifying the spacecraft’s design and operational needs, SPHEREx relies on an entirely passive cooling system — no electricity or coolants are used during normal operations. Key to making this feat possible are three cone-shaped photon shields that protect the telescope from the heat of Earth and the Sun, as well as a mirrored structure beneath the shields to direct heat from the instrument out into space. Those photon shields give the spacecraft its distinctive outline.

More About SPHEREx

SPHEREx is managed by NASA’s Jet Propulsion Laboratory for the agency’s Astrophysics Division within the Science Mission Directorate at NASA Headquarters in Washington. BAE Systems (formerly Ball Aerospace) built the telescope and the spacecraft bus. The science analysis of the SPHEREx data will be conducted by a team of scientists located at 10 institutions in the U.S., two in South Korea, and one in Taiwan. Data will be processed and archived at IPAC at Caltech, which manages JPL for NASA. The mission principal investigator is based at Caltech with a joint JPL appointment. The SPHEREx dataset will be publicly available at the NASA/IPAC Infrared Science Archive.

For more information about the SPHEREx mission visit:

https://www.jpl.nasa.gov/missions/spherex

News Media Contact

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

2025-011

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Astronomers have taken a crucial step in showing that the most massive black holes in the universe can create their own meals. Data from NASA’s Chandra X-ray Observatory and the Very Large Telescope (VLT) provide new evidence that outbursts from black holes can help cool down gas to feed themselves.

This study was based on observations of seven clusters of galaxies. The centers of galaxy clusters contain the universe’s most massive galaxies, which harbor huge black holes with masses ranging from millions to tens of billions of times that of the Sun. Jets from these black holes are driven by the black holes feasting on gas.

These images show two of the galaxy clusters in the study, the Perseus Cluster and the Centaurus Cluster. Chandra data represented in blue reveals X-rays from filaments of hot gas, and data from the VLT, an optical telescope in Chile, shows cooler filaments in red.

The results support a model where outbursts from the black holes trigger hot gas to cool and form narrow filaments of warm gas. Turbulence in the gas also plays an important role in this triggering process.

According to this model, some of the warm gas in these filaments should then flow into the centers of the galaxies to feed the black holes, causing an outburst. The outburst causes more gas to cool and feed the black holes, leading to further outbursts.

This model predicts there will be a relationship between the brightness of filaments of hot and warm gas in the centers of galaxy clusters. More specifically, in regions where the hot gas is brighter, the warm gas should also be brighter. The team of astronomers has, for the first time, discovered such a relationship, giving critical support for the model.

This result also provides new understanding of these gas-filled filaments, which are important not just for feeding black holes but also for causing new stars to form. This advance was made possible by an innovative technique that isolates the hot filaments in the Chandra X-ray data from other structures, including large cavities in the hot gas created by the black hole’s jets.

The newly found relationship for these filaments shows remarkable similarity to the one found in the tails of jellyfish galaxies, which have had gas stripped away from them as they travel through surrounding gas, forming long tails. This similarity reveals an unexpected cosmic connection between the two objects and implies a similar process is occurring in these objects.

This work was led by Valeria Olivares from the University of Santiago de Chile, and was published Monday in Nature Astronomy. The study brought together international experts in optical and X-ray observations and simulations from the United States, Chile, Australia, Canada, and Italy. The work relied on the capabilities of the MUSE (Multi Unit Spectroscopic Explorer) instrument on the VLT, which generates 3D views of the universe.

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

Read more from NASA’s Chandra X-ray Observatory.

Learn more about the Chandra X-ray Observatory and its mission here:

https://www.nasa.gov/chandra

https://chandra.si.edu

Visual Description

This release features composite images shown side-by-side of two different galaxy clusters, each with a central black hole surrounded by patches and filaments of gas. The galaxy clusters, known as Perseus and Centaurus, are two of seven galaxy clusters observed as part of an international study led by the University of Santiago de Chile.

In each image, a patch of purple with neon pink veins floats in the blackness of space, surrounded by flecks of light. At the center of each patch is a glowing, bright white dot. The bright white dots are black holes. The purple patches represent hot X-ray gas, and the neon pink veins represent filaments of warm gas. According to the model published in the study, jets from the black holes impact the hot X-ray gas. This gas cools into warm filaments, with some warm gas flowing back into the black hole. The return flow of warm gas causes jets to again cool the hot gas, triggering the cycle once again.

While the images of the two galaxy clusters are broadly similar, there are significant visual differences. In the image of the Perseus Cluster on the left, the surrounding flecks of light are larger and brighter, making the individual galaxies they represent easier to discern. Here, the purple gas has a blue tint, and the hot pink filaments appear solid, as if rendered with quivering strokes of a paintbrush. In the image of the Centaurus Cluster on the right, the purple gas appears softer, with a more diffuse quality. The filaments are rendered in more detail, with feathery edges, and gradation in color ranging from pale pink to neon red.

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Lane Figueroa
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
lane.e.figueroa@nasa.gov

Jan. 24, 2025

NASA’s NICER Continues Science Operations Post Repair

NASA crew aboard the International Space Station installed patches to the agency’s NICER (Neutron star Interior Composition Explorer) mission during a spacewalk on Jan. 16. NICER, an X-ray telescope perched near the station’s starboard solar array, resumed science operations later the same day.

The patches cover areas of NICER’s thermal shields where damage was discovered in May 2023. These thin filters block sunlight while allowing X-rays to pass through. After the discovery, the NICER team restricted their observations during the station’s daytime to avoid overwhelming the mission’s sensitive detectors. Nighttime observations were unaffected, and the team was able to continue collecting data for the science community to make groundbreaking measurements using the instrument’s full capabilities.

The repair went according to plan. Data since collected shows the detectors behind the patched areas are performing better than before during station night, and the overall level of sunlight inside NICER during the daytime is reduced substantially.

While NICER experiences less interference from sunlight than before, after analyzing initial data, the team has determined the telescope still experiences more interference than expected. The installed patches cover areas of known damage identified using astronomical observations and from photos taken by both external robotic cameras and astronauts inside the space station. Measurements collected since the repair and close-up, high-resolution photos obtained during the spacewalk are providing new information that may point the way toward further daytime data collection.

In the meantime, NICER continues operations with its full measurement capabilities during orbit night to enable further trailblazing discoveries in time domain and multimessenger astrophysics.

Media contact: Alise Fisher, NASA Headquarters / Claire Andreoli, NASA Goddard

June 8, 2023

Sunlight ‘Leak’ Impacting NASA’s NICER Telescope, Science Continues

On Tuesday, May 22, NASA’s NICER (Neutron Star Interior Composition Explorer), an X-ray telescope on the International Space Station, developed a “light leak,” in which unwanted sunlight enters the instrument. While analyzing incoming data since then, the team identified an impact to daytime observations. Nighttime observations seem to be unaffected.

The team suspects that at least one of the thin thermal shields on NICER’s 56 X-ray Concentrators has been damaged, allowing sunlight to reach its sensitive detectors.

To mitigate the effects on measurements, the NICER team has limited daytime observations to objects far away from the Sun’s position in the sky. The team has also updated commands to NICER that automatically lower its sensitivity during the orbital day to reduce the effects from sunlight contamination. The team is evaluating these changes and assessing additional measures to reduce the impact on science observations.

To date, more than 300 scientific papers have used NICER observations, and the team is confident that NICER will continue to produce world-class science.

Media contact: Alise Fisher, NASA Headquarters / Claire Andreoli, NASA Goddard

4 Min Read

Hubble Reveals Surprising Spiral Shape of Galaxy Hosting Young Jet

The night sky has always played a crucial role in navigation, from early ocean crossings to modern GPS. Besides stars, the United States Navy uses quasars as beacons. Quasars are distant galaxies with supermassive black holes, surrounded by brilliantly hot disks of swirling gas that can blast off jets of material. Following up on the groundbreaking 2020 discovery of newborn jets in a number of quasars, aspiring naval officer Olivia Achenbach of the United States Naval Academy has used NASA’s Hubble Space Telescope to reveal surprising properties of one of them, quasar J0742+2704.

“The biggest surprise was seeing the distinct spiral shape in the Hubble Space Telescope images. At first I was worried I had made an error,” said Achenbach, who made the discovery during the course of a four-week internship.

“We typically see quasars as older galaxies that have grown very massive, along with their central black holes, after going through messy mergers and have come out with an elliptical shape,” said astronomer Kristina Nyland of the Naval Research Laboratory, Achenbach’s adviser on the research.

“It’s extremely rare and exciting to find a quasar-hosting galaxy with spiral arms and a black hole that is more than 400 million times the mass of the Sun — which is pretty big — plus young jets that weren’t detectable 20 years ago,” Nyland said.

The unusual quasar takes its place amid an active debate in the astronomy community over what triggers quasar jets, which can be significant in the evolution of galaxies, as the jets can suppress star formation. Some astronomers suspect that quasar jets are triggered by major galaxy mergers, as the material from two or more galaxies mashes together, and heated gas is funneled toward merged black holes. Spiral galaxy quasars like J0742+2704, however, suggest that there may be other pathways for jet formation.

While J0742+2704 has maintained its spiral shape, the Hubble image does show intriguing signs of its potential interaction with other galaxies. One of its arms shows distortion, possibly a tidal tail.

“Clearly there is something interesting going on. While the quasar has not experienced a major disruptive merger, it may be interacting with another galaxy, which is gravitationally tugging at its spiral arm,” said Nyland.

Another galaxy that appears nearby in the Hubble image (though its location still needs to be spectroscopically confirmed) has a ring structure. This rare shape can occur after a galaxy interaction in which a smaller galaxy punches through the center of a spiral galaxy. “The ring galaxy near the quasar host galaxy could be an intriguing clue as to what is happening in this system. We may be witnessing the aftermath of the interaction that triggered this young quasar jet,” said Nyland.

Both Achenbach and Nyland emphasize that this intriguing discovery is really a new starting point, and there will be additional multi-wavelength analysis of J0742+2704 with data from NASA’s Chandra X-ray Observatory and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. It’s also a case for keeping our eyes on the skies, said Achenbach.

“If we looked at this galaxy 20 years, or maybe even a decade ago, we would have seen a fairly average quasar and never known it would eventually be home to newborn jets,” said Achenbach. “It goes to show that if you keep searching, you can find something remarkable that you never expected, and it can send you in a whole new direction of discovery.”

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, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

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Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight Center, Greenbelt, MD

Leah Ramsay, Ray Villard
Space Telescope Science Institute, Baltimore, MD

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An effort to find some of the biggest, most active black holes in the universe provides a better estimate for the ratio of hidden to unhidden behemoths.

Multiple NASA telescopes recently helped scientists search the sky for supermassive black holes — those up to billions of times heavier than the Sun. The new survey is unique because it was as likely to find massive black holes that are hidden behind thick clouds of gas and dust as those that are not.

Astronomers think that every large galaxy in the universe has a supermassive black hole at its center. But testing this hypothesis is difficult because researchers can’t hope to count the billions or even trillions of supermassive black holes thought to exist in the universe. Instead they have to extrapolate from smaller samples to learn about the larger population. So accurately measuring the ratio of hidden supermassive black holes in a given sample helps scientists better estimate the total number of supermassive black holes in the universe.

The new study published in the Astrophysical Journal found that about 35% of supermassive black holes are heavily obscured, meaning the surrounding clouds of gas and dust are so thick they block even low-energy X-ray light. Comparable searches have previously found less than 15% of supermassive black holes are so obscured. Scientists think the true split should be closer to 50/50 based on models of how galaxies grow. If observations continue to indicate significantly less than half of supermassive black holes are hidden, scientists will need to adjust some key ideas they have about these objects and the role they play in shaping galaxies.

Hidden Treasure

Although black holes are inherently dark — not even light can escape their gravity — they can also be some of the brightest objects in the universe: When gas gets pulled into orbit around a supermassive black hole, like water circling a drain, the extreme gravity creates such intense friction and heat that the gas reaches hundreds of thousands of degrees and radiates so brightly it can outshine all the stars in the surrounding galaxy.

The clouds of gas and dust that surround and replenish the bright central disk may roughly take the shape of a torus, or doughnut. If the doughnut hole is facing toward Earth, the bright central disk within it is visible; if the doughnut is seen edge-on, the disk is obscured.

Most telescopes can rather easily identify face-on supermassive black holes, though not edge-on ones. But there’s an exception to this that the authors of the new paper took advantage of: The torus absorbs light from the central source and reemits lower-energy light in the infrared range (wavelengths slightly longer than what human eyes can detect). Essentially, the doughnuts glow in infrared.

These wavelengths of light were detected by NASA’s Infrared Astronomical Satellite, or IRAS, which operated for 10 months in 1983 and was managed by NASA’s Jet Propulsion Laboratory in Southern California. A survey telescope that imaged the entire sky, IRAS was able to see the infrared emissions from the clouds surrounding supermassive black holes. Most importantly, it could spot edge-on and face-on black holes equally well.

IRAS caught hundreds of initial targets. Some of them turned out to be not heavily obscured black holes but galaxies with high rates of star formation that emit a similar infrared glow. So the authors of the new study used ground-based, visible-light telescopes to identify those galaxies and separate them from the hidden black holes.

To confirm edge-on, heavily obscured black holes, the researchers relied on NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array), an X-ray observatory also managed by JPL. X-rays are radiated by some of the hottest material around the black hole. Lower-energy X-rays are absorbed by the surrounding clouds of gas and dust, while the higher-energy X-rays observed by NuSTAR can penetrate and scatter off the clouds. Detecting these X-rays can take hours of observation, so scientists working with NuSTAR first need a telescope like IRAS to tell them where to look.

“It amazes me how useful IRAS and NuSTAR were for this project, especially despite IRAS being operational over 40 years ago,” said study lead Peter Boorman, an astrophysicist at Caltech in Pasadena, California. “I think it shows the legacy value of telescope archives and the benefit of using multiple instruments and wavelengths of light together.”

Numerical Advantage

Determining the number of hidden black holes compared to nonhidden ones can help scientists understand how these black holes get so big. If they grow by consuming material, then a significant number of black holes should be surrounded by thick clouds and potentially obscured. Boorman and his coauthors say their study supports this hypothesis.

In addition, black holes influence the galaxies they live in, mostly by impacting how galaxies grow. This happens because black holes surrounded by massive clouds of gas and dust can consume vast — but not infinite — amounts of material. If too much falls toward a black hole at once, the black hole starts coughing up the excess and firing it back out into the galaxy. That can disperse gas clouds within the galaxy where stars are forming, slowing the rate of star formation there.

“If we didn’t have black holes, galaxies would be much larger,” said Poshak Gandhi, a professor of astrophysics at the University of Southampton in the United Kingdom and a coauthor on the new study. “So if we didn’t have a supermassive black hole in our Milky Way galaxy, there might be many more stars in the sky. That’s just one example of how black holes can influence a galaxy’s evolution.”

More About NuSTAR

A Small Explorer mission led by Caltech and managed by NASA’s Jet Propulsion Laboratory in Southern California for the agency’s Science Mission Directorate in Washington, NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corp. in Dulles, Virginia. NuSTAR’s mission operations center is at the University of California, Berkeley, and the official data archive is at NASA’s High Energy Astrophysics Science Archive Research Center at NASA’s Goddard Space Flight Center. ASI provides the mission’s ground station and a mirror data archive. Caltech manages JPL for NASA.

For more information on NuSTAR, visit:

www.nustar.caltech.edu

News Media Contact

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

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International teams of astronomers monitoring a supermassive black hole in the heart of a distant galaxy have detected features never seen before using data from NASA missions and other facilities. The features include the launch of a plasma jet moving at nearly one-third the speed of light and unusual, rapid X-ray fluctuations likely arising from near the very edge of the black hole.

The source is 1ES 1927+654, a galaxy located about 270 million light-years away in the constellation Draco. It harbors a central black hole with a mass equivalent to about 1.4 million Suns.

“In 2018, the black hole began changing its properties right before our eyes, with a major optical, ultraviolet, and X-ray outburst,” said Eileen Meyer, an associate professor at UMBC (University of Maryland Baltimore County). “Many teams have been keeping a close eye on it ever since.”

She presented her team’s findings at the 245th meeting of the American Astronomical Society in National Harbor, Maryland. A paper led by Meyer describing the radio results was published Jan. 13 in The Astrophysical Journal Letters.

After the outburst, the black hole appeared to return to a quiet state, with a lull in activity for nearly a year. But by April 2023, a team led by Sibasish Laha at UMBC and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, had noted a steady, months-long increase in low-energy X-rays in measurements by NASA’s Neil Gehrels Swift Observatory and NICER (Neutron star Interior Composition Explorer) telescope on the International Space Station. This monitoring program, which also includes observations from NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) and ESA’s (European Space Agency) XMM-Newton mission, continues.

The increase in X-rays triggered the UMBC team to make new radio observations, which indicated a strong and highly unusual radio flare was underway. The scientists then began intensive observations using the NRAO’s (National Radio Astronomy Observatory) VLBA (Very Long Baseline Array) and other facilities. The VLBA, a network of radio telescopes spread across the U.S., combines signals from individual dishes to create what amounts to a powerful, high-resolution radio camera. This allows the VLBA to detect features less than a light-year across at 1ES 1927+654’s distance.

Radio data from February, April, and May 2024 reveals what appear to be jets of ionized gas, or plasma, extending from either side of the black hole, with a total size of about half a light-year. Astronomers have long puzzled over why only a fraction of monster black holes produce powerful plasma jets, and these observations may provide critical clues.

“The launch of a black hole jet has never been observed before in real time,” Meyer noted. “We think the outflow began earlier, when the X-rays increased prior to the radio flare, and the jet was screened from our view by hot gas until it broke out early last year.”

A paper exploring that possibility, led by Laha, is under review at The Astrophysical Journal. Both Meyer and Megan Masterson, a doctoral candidate at the Massachusetts Institute of Technology in Cambridge who also presented at the meeting, are co-authors.

Using XMM-Newton observations, Masterson found that the black hole exhibited extremely rapid X-ray variations between July 2022 and March 2024. During this period, the X-ray brightness repeatedly rose and fell by 10% every few minutes. Such changes, called millihertz quasiperiodic oscillations, are difficult to detect around supermassive black holes and have been observed in only a handful of systems to date. 

“One way to produce these oscillations is with an object orbiting within the black hole’s accretion disk. In this scenario, each rise and fall of the X-rays represents one orbital cycle,” Masterson said.  

If the fluctuations were caused by an orbiting mass, then the period would shorten as the object fell ever closer to the black hole’s event horizon, the point of no return. Orbiting masses generate ripples in space-time called gravitational waves. These waves drain away orbital energy, bringing the object closer to the black hole, increasing its speed, and shortening its orbital period.

Over two years, the fluctuation period dropped from 18 minutes to just 7 — the first-ever measurement of its kind around a supermassive black hole. If this represented an orbiting object, it was now moving at half the speed of light. Then something unexpected happened — the fluctuation period stabilized.

“We were shocked by this at first,” Masterson explained. “But we realized that as the object moved closer to the black hole, its strong gravitational pull could begin to strip matter from the companion. This mass loss could offset the energy removed by gravitational waves, halting the companion’s inward motion.”

So what could this companion be? A small black hole would plunge straight in, and a normal star would quickly be torn apart by the tidal forces near the monster black hole. But the team found that a low-mass white dwarf — a stellar remnant about as large as Earth — could remain intact close to the black hole’s event horizon while shedding some of its matter. A paper led by Masterson summarizing these results will appear in the Feb. 13 edition of the journal Nature.

This model makes a key prediction, Masterson notes. If the black hole does have a white dwarf companion, the gravitational waves it produces will be detectable by LISA (Laser Interferometer Space Antenna), an ESA mission in partnership with NASA that is expected to launch in the next decade.

By Francis Reddy
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Media Contacts:
Claire Andreoli
301-286-1940
claire.andreoli@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Jill Malusky
304-456-2236
jmalusky@nrao.edu
National Radio Astronomy Observatory, Charlottesville, Va.

This NASA/ESA Hubble Space Telescope image reveals a tiny patch of sky in the constellation Hydra. The stars and galaxies depicted here span a mind-bending range of distances. The objects in this image that are nearest to us are stars within our own Milky Way galaxy. You can easily spot these stars by their diffraction spikes, lines that radiate from bright light sources, like nearby stars, as a result of how that light interacts with Hubble’s secondary mirror supports. The bright star that sits just at the edge of the prominent bluish galaxy is only 3,230 light-years away, as measured by ESA’s Gaia space observatory.

Behind this star is a galaxy named LEDA 803211. At 622 million light-years distant, this galaxy is close enough that its bright galactic nucleus is clearly visible, as are numerous star clusters scattered around its patchy disk. Many of the more distant galaxies in this frame appear star-like, with no discernible structure, but without the diffraction spikes of a star in our galaxy.

Of all the galaxies in this frame, one pair stands out: a smooth golden galaxy encircled by a nearly complete ring in the upper-right corner of the image. This curious configuration is the result of gravitational lensing that warps and magnifies the light of distant objects. Einstein predicted the curving of spacetime by matter in his general theory of relativity, and galaxies seemingly stretched into rings like the one in this image are called Einstein rings.

The lensed galaxy, whose image we see as the ring, lies incredibly far away from Earth: we are seeing it as it was when the universe was just 2.5 billion years old. The galaxy acting as the gravitational lens itself is likely much closer. A nearly perfect alignment of the two galaxies is necessary to give us this rare kind of glimpse into galactic life in the early days of the universe.

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Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight Center, Greenbelt, MD

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