Friday, September 30, 2022

Bright Galaxies Blowing Bubbles


An artist's impression of galaxies during the epoch of reionization, which occurred less than a billion years after the Big Bang. Credit: ESO/M. Kornmesser; CC BY 4.0

Title: CLEAR: Boosted Lyα Transmission of the Intergalactic Medium in UV-bright Galaxies
Authors: Intae Jung et al.
First Author’s Institution: The Catholic University of America and NASA’s Goddard Space Flight Center
Status: Published in ApJ

Sometimes the things we don’t see can still give us insight. This strategy of getting clues from both detections and non-detections is common in astronomy, and the non-detections studied in today’s article are used to understand the process of reionization. Sometime during the first billion or so years of the universe, a period of transition called the epoch of reionization took place. During this epoch, the first stars and galaxies formed and began emitting high-energy light that ionized the then mostly neutral hydrogen gas filling the universe. Ionizing radiation can kick off electrons from neutral hydrogen atoms, and in the epoch of reionization this occurred enough to ionize the universe’s gas nearly completely.

A Whodunit Mystery

Early galaxies are a major source of ionizing photons and perhaps the main drivers of this ionization process, so the properties of early galaxies and how they evolved over the first billion years of the universe have great implications for processes within the epoch of reionization. However, understanding how many photons were produced during this epoch and whether they escaped their galaxies and ionized the neutral gas around them is highly dependent on the physical conditions of each galaxy, and it’s therefore challenging to constrain and predict these factors. These challenges lead to more challenges in determining precisely when and where reionization occurred, as well as what kinds of galaxies were primarily responsible.

Tracing the strength of emission from the Lyman-α (n=2 to n=1) transition of hydrogen from early galaxies can give us a sense of the who and where: what sorts of galaxies produced more of the ionizing photons, and were they clustered together or spread out? This line of questioning corresponds to the spatial evolution of reionization. By tracking the fraction of gas that was ionized over time, we can also constrain the temporal evolution of reionization.

Today’s article seeks to get at the whodunit of reionization, focusing on galaxies in the epoch of reionization. More specifically, the authors of today’s article aim to distinguish between brighter and fainter galaxies, particularly within the ultraviolet (UV) range where photons have enough energy to ionize hydrogen. By determining trends between a galaxy’s capacity to emit ionizing photons and the reionization near that galaxy, the authors can test the idea that UV-bright galaxies sit within highly ionized bubbles of gas, and that reionization is accelerated in bubbles containing large numbers of galaxies (illustrated in Figure 1).


Figure 1: Representation of the varied processes during reionization, with the more UV-bright galaxies (larger symbols) sitting in larger ionized bubbles (black) within the neutral gas (white). The ionized bubbles create an environment for the Lyman-α photons to escape and ionize the surrounding gas more easily. More UV-faint galaxies likely exist in the galaxy overdensities within the bubbles but are too faint to be detected with the current dataset. Credit: Jung et al. 2022


Inequivalent Equivalent Widths

The article seeks to answer one main question: is there any evolution of Lyman-α emission in epoch of reionization galaxies with respect to the UV brightness of those galaxies? To help answer this, the authors measure the strength of Lyman-α emission with a quantity called equivalent width as function of both redshift and the intrinsic UV brightness of the galaxy. Their sample contained a few hundred galaxies with detailed spectroscopic observations as well as new data from the Hubble Space Telescope. With these data, the team searched for any signal (continuum) or Lyman-α emission lines, but they found no convincing Lyman-α emission or continuum-detected galaxies.

Still, these non-detections can help constrain the strength of Lyman-α emission coming from the galaxies. Given the sensitivity of the observations, the authors could (or even should) have detected galaxies if there is no redshift evolution of equivalent width before and after the end of the epoch of reionization (redshift z ~ 6). This basically rules out the existence of strong Lyman-α emission (in other words, high equivalent widths) in this sample, which included more UV-faint galaxies than the sample detected in previous work.

By comparing the detected and non-detected sources and running simulations of mock observations, the authors find some evidence that the Lyman-α emission line strength evolves differently for bright and faint galaxies through the epoch of reionzation. Their analysis is consistent with a picture where reionization is spatially inhomogeneous with large ionized bubbles made by bright galaxies with boosted Lyman-α transmission (Figure 1). The authors note that reionization is probably fairly complicated, with large spatial and temporal variations. Nonetheless, while we can learn something from what we don’t see, the now-operating JWST and other next-generation telescopes will be sensitive to fainter and more distant galaxies, allowing us to get a clearer picture of the epoch of reionization.

Original astrobite edited by Evan Lewis

By
Astrobites





About the author, Olivia Cooper:

I’m a third-year grad student at UT Austin studying the evolution of massive galaxies in the first two billion years. In undergrad at Smith College, I studied astrophysics and climate change communication. Besides doing science with pretty pictures of distant galaxies, I also like driving to the middle of nowhere to take pretty pictures of our own galaxy!



Thursday, September 29, 2022

Potential First Traces of the Universe’s Earliest Stars

PR Image noirlab2222a
Massive, Population III Star in the Early Universe
Population III Star Explodes as a Pair-Instability Supernova

PR Image noirlab2222c
Quasar May Hold the Chemical Fingerprint of a Population III Star

PR Image noirlab2222d
Step by Step Story to Find Potential First Traces of the Universe’s Earliest Stars



Videos

Cosmoview Episode 53: Potential First Traces of the Universe’s Earliest Stars
Cosmoview Episode 53: Potential First Traces of the Universe’s Earliest Stars 
 
CosmoView Episodio 53: Descubren evidencias de las primeras estrellas del Universo
CosmoView Episodio 53: Descubren evidencias de las primeras estrellas del Universo




Gemini observation of distant quasar uncovers evidence of first-generation star that died in ‘super-supernova’ explosion

Astronomers may have discovered the ancient chemical remains of the first stars to light up the Universe. Using an innovative analysis of a distant quasar observed by the 8.1-meter Gemini North telescope on Hawai‘i, operated by NSF’s NOIRLab, the scientists found an unusual ratio of elements that, they argue, could only come from the debris produced by the all-consuming explosion of a 300-solar-mass first-generation star.

The very first stars likely formed when the Universe was only 100 million years old, less than one percent its current age. These first stars — known as Population III — were so titanically massive that when they ended their lives as supernovae they tore themselves apart, seeding interstellar space with a distinctive blend of heavy elements. Despite decades of diligent searching by astronomers, however, there has been no direct evidence of these primordial stars, until now. 

By analyzing one of the most distant known quasars [1] using the Gemini North telescope, one of the two identical telescopes that make up the International Gemini Observatory, operated by NSF’s NOIRLab, astronomers now think they have identified the remnant material of the explosion of a first-generation star. Using an innovative method to deduce the chemical elements contained in the clouds surrounding the quasar, they noticed a highly unusual composition — the material contained over 10 times more iron than magnesium compared to the ratio of these elements found in our Sun.

The scientists believe that the most likely explanation for this striking feature is that the material was left behind by a first-generation star that exploded as a pair-instability supernova. These remarkably powerful versions of supernova explosions have never been witnessed, but are theorized to be the end of life for gigantic stars with masses between 150 and 250 times that of the Sun.

Pair-instability supernova explosions happen when photons in the center of a star spontaneously turn into electrons and positrons — the positively charged antimatter counterpart to the electron. This conversion reduces the radiation pressure inside the star, allowing gravity to overcome it and leading to the collapse and subsequent explosion.

Unlike other supernovae, these dramatic events leave no stellar remnants, such as a neutron star or a black hole, and instead eject all their material into their surroundings. There are only two ways to find evidence of them. The first is to catch a pair-instability supernova as it happens, which is a highly unlikely happenstance. The other way is to identify their chemical signature from the material they eject into interstellar space.

For their research, the astronomers studied results from a prior observation taken by the 8.1-meter Gemini North telescope using the Gemini Near-Infrared Spectrograph (GNIRS). A spectrograph splits the light emitted by celestial objects into its constituent wavelengths, which carry information about which elements the objects contain. Gemini is one of the few telescopes of its size with suitable equipment to perform such observations.

Deducing the quantities of each element present, however, is a tricky endeavor because the brightness of a line in a spectrum depends on many other factors besides the element’s abundance.

Two co-authors of the analysis, Yuzuru Yoshii and Hiroaki Sameshima of the University of Tokyo, have tackled this problem by developing a method of using the intensity of wavelengths in a quasar spectrum to estimate the abundance of the elements present there. It was by using this method to analyze the quasar’s spectrum that they and their colleagues discovered the conspicuously low magnesium-to-iron ratio.

It was obvious to me that the supernova candidate for this would be a pair-instability supernova of a Population III star, in which the entire star explodes without leaving any remnant behind,” said Yoshii. “I was delighted and somewhat surprised to find that a pair-instability supernova of a star with a mass about 300 times that of the Sun provides a ratio of magnesium to iron that agrees with the low value we derived for the quasar.

Searches for chemical evidence for a previous generation of high-mass Population III stars have been carried out before among the stars in the halo of the Milky Way and at least one tentative identification was presented in 2014. Yoshii and his colleagues, however, think the new result provides the clearest signature of a pair-instability supernova based on the extremely low magnesium-to-iron abundance ratio presented in this quasar.

If this is indeed evidence of one of the first stars and of the remains of a pair-instability supernova, this discovery will help to fill in our picture of how the matter in the Universe came to evolve into what it is today, including us. To test this interpretation more thoroughly, many more observations are required to see if other objects have similar characteristics. 

But we may be able to find the chemical signatures closer to home, too. Although high-mass Population III stars would all have died out long ago, the chemical fingerprints they leave behind in their ejected material can last much longer and may still linger on today. This means that astronomers might be able to find the signatures of pair-instability supernova explosions of long-gone stars still imprinted on objects in our local Universe.

We now know what to look for; we have a pathway,” said co-author Timothy Beers, an astronomer at the University



Notes 
 
[1] Light from this quasar has been traveling for 13.1 billion years, meaning astronomers are observing this object as it appeared when the Universe was only 700 million years old. This corresponds to a redshift of 7.54.



More Information

Yoshii, Y., Sameshima, H., Tsujimoto, T., Shigeyama, T., Beers, T. C., and Peterson, B. A. (2022) “Potential signature of Population III pair-instability supernova ejecta in the BLR gas of the most distant quasar at z = 7.54∗.” Published in the Astrophysical Journal. DOI: https://doi.org/10.3847/1538-4357/ac8163

NSF’s NOIRLab, the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory (operated in cooperation with the Department of Energy’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O'odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.



Links



Contacts:

Yuzuru Yoshii
University of Tokyo
Email:
yoshii@ioa.s.u-tokyo.ac.jp

Timothy Beers
University of Notre Dame
Email:
tbeers@nd.edu

Charles Blue
Public Information Officer
NSF’s NOIRLab
Tel: +1 202 236 6324
Email:
charles.blue@noirlab.edu




Wednesday, September 28, 2022

Hubble Detects Protective Shield Defending a Pair of Dwarf Galaxies

Using Quasars to Map the Magellanic Corona
Credits: Illustration: NASA, ESA, Leah Hustak (STScI)

Release Images

For billions of years, the Milky Way’s largest satellite galaxies – the Large and Small Magellanic Clouds – have followed a perilous journey. Orbiting one another as they are pulled in toward our home galaxy, they have begun to unravel, leaving behind trails of gaseous debris. And yet – to the puzzlement of astronomers – these dwarf galaxies remain intact, with ongoing vigorous star formation.

“A lot of people were struggling to explain how these streams of material could be there,” said Dhanesh Krishnarao, assistant professor at Colorado College. “If this gas was removed from these galaxies, how are they still forming stars?”

With the help of data from NASA’s Hubble Space Telescope and a retired satellite called the Far Ultraviolet Spectroscopic Explorer (FUSE), a team of astronomers led by Krishnarao has finally found the answer: the Magellanic system is surrounded by a corona, a protective shield of hot supercharged gas. This cocoons the two galaxies, preventing their gas supplies from being siphoned off by the Milky Way, and therefore allowing them to continue forming new stars.

This discovery, which was just published in Nature, addresses a novel aspect of galaxy evolution. “Galaxies envelope themselves in gaseous cocoons, which act as defensive shields against other galaxies,” said co-investigator Andrew Fox of the Space Telescope Science Institute in Baltimore, Maryland.

Astronomers predicted the corona’s existence several years ago. “We discovered that if we included a corona in the simulations of the Magellanic Clouds falling onto the Milky Way, we could explain the mass of extracted gas for the first time," explained Elena D'Onghia, a co-investigator at the University of Wisconsin–Madison. “We knew that the Large Magellanic Cloud should be massive enough to have a corona.”

But although the corona stretches more than 100,000 light-years from the Magellanic clouds and covers a huge portion of the southern sky, it is effectively invisible. Mapping it required scouring through 30 years of archived data for suitable measurements.

Researchers think that a galaxy’s corona is a remnant of the primordial cloud of gas that collapsed to form the galaxy billions of years ago. Although coronas have been seen around more distant dwarf galaxies, astronomers had never before been able to probe one in as much detail as this.

“There’re lots of predictions from computer simulations about what they should look like, how they should interact over billions of years, but observationally we can't really test most of them because dwarf galaxies are typically just too hard to detect,” said Krishnarao. Because they are right on our doorstep, the Magellanic Clouds provide an ideal opportunity to study how dwarf galaxies interact and evolve.

In search of direct evidence of the Magellanic Corona, the team combed through the Hubble and FUSE archives for ultraviolet observations of quasars located billions of light-years behind it. Quasars are the extremely bright cores of galaxies harboring massive active black holes. The team reasoned that although the corona would be too dim to see on its own, it should be visible as a sort of fog obscuring and absorbing distinct patterns of bright light from quasars in the background. Hubble observations of quasars were used in the past to map the corona surrounding the Andromeda galaxy.

By analyzing patterns in ultraviolet light from 28 quasars, the team was able to detect and characterize the material surrounding the Large Magellanic Cloud and confirm that the corona exists. As predicted, the quasar spectra are imprinted with the distinct signatures of carbon, oxygen, and silicon that make up the halo of hot plasma that surrounds the galaxy.

The ability to detect the corona required extremely detailed ultraviolet spectra. “The resolution of Hubble and FUSE were crucial for this study,” explained Krishnarao. “The corona gas is so diffuse, it’s barely even there.” In addition, it is mixed with other gases, including the streams pulled from the Magellanic Clouds and material originating in the Milky Way.

By mapping the results, the team also discovered that the amount of gas decreases with distance from the center of the Large Magellanic Cloud. “It’s a perfect telltale signature that this corona is really there,” said Krishnarao. “It really is cocooning the galaxy and protecting it.”

How can such a thin shroud of gas protect a galaxy from destruction?

“Anything that tries to pass into the galaxy has to pass through this material first, so it can absorb some of that impact,” explained Krishnarao. “In addition, the corona is the first material that can be extracted. While giving up a little bit of the corona, you're protecting the gas that's inside the galaxy itself and able to form new stars.”

The Hubble Space Telescope 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. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

The Far Ultraviolet Spectroscopic Explorer (FUSE) was a project of international cooperation between NASA, CSA (Canadian Space Agency), and CNES (French Space Agency), and was in operation between 1999 and 2007.



Credits:


Media Contact:

Margaret W. Carruthers
Space Telescope Science Institute, Baltimore, Maryland

Ray Villard
Space Telescope Science Institute, Baltimore, Maryland

Science Contact:

Dhanesh Krishnarao
Colorado College, Colorado Springs, Colorado

Andrew Fox
Space Telescope Science Institute, Baltimore, Maryland


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Tuesday, September 27, 2022

Hubble Spies a Stately Spiral Galaxy

NGC 5495
Credit: ESA/Hubble & NASA, J. Greene / Acknowledgement: R. Colombari

The stately sweeping spiral arms of the spiral galaxy NGC 5495 are revealed by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 in this image. NGC 5495, which lies around 300 million light-years from Earth in the constellation Hydra, is a Seyfert galaxy, a type of galaxy with a particularly bright central region. These luminous cores — known to astronomers as active galactic nuclei — are dominated by the light emitted by dust and gas falling into a supermassive black hole.

This image is drawn from a series of observations captured by astronomers studying supermassive black holes lurking in the hearts of other galaxies. Studying the central regions of galaxies can be challenging: as well as the light created by matter falling into supermassive black holes, areas of star formation and the light from existing stars all contribute to the brightness of galactic cores. Hubble’s crystal-clear vision helped astronomers disentangle the various sources of light at the core of NGC 5495, allowing them to precisely weigh its supermassive black hole.

As well as NGC 5495, two stellar interlopers are visible in this image. One is just outside the centre of NGC 5495, and the other is very prominent alongside the galaxy. While they share the same location on the sky, these objects are much closer to home than NGC 5495: they are stars from our own Milky Way. The bright stars are surrounded by criss-cross diffraction spikes, optical artefacts created by the internal structure of Hubble interacting with starlight.





Monday, September 26, 2022

Runaway Star Might Explain Black Hole's Disappearing Act More About the Missions


This illustration shows a black hole surrounded by a disk of gas. In the left panel, a streak of debris falls toward the disk. In the right panel, the debris has dispersed some of the gas, causing the corona (the ball of white light above the black hole) to disappear.Credits: NASA/JPL-Caltech


The telltale sign that the black hole was feeding vanished, perhaps when a star interrupted the feast. The event could lend new insight into these mysterious objects.

At the center of a far-off galaxy, a black hole is slowly consuming a disk of gas that swirls around it like water circling a drain. As a steady trickle of gas is pulled into the gaping maw, ultrahot particles gather close to the black hole, above and below the disk, generating a brilliant X-ray glow that can be seen 300 million light-years away on Earth. These collections of ultrahot gas, called black hole coronas, have been known to exhibit noticeable changes in their luminosity, brightening or dimming by up to 100 times as a black hole feeds.

But two years ago, astronomers watched in awe as X-rays from the black hole corona in a galaxy known as 1ES 1927+654 disappeared completely, fading by a factor of 10,000 in about 40 days. Almost immediately it began to rebound, and about 100 days later had become almost 20 times brighter than before the event.

The X-ray light from a black hole corona is a direct byproduct of the black hole's feeding, so the disappearance of that light from 1ES 1927+654 likely means that its food supply had been cut off. In a new study in the Astrophysical Journal Letters, scientists hypothesize that a runaway star might have come too close to the black hole and been torn apart. If this was the case, fast-moving debris from the star could have crashed through part of the disk, briefly dispersing the gas.

"We just don't normally see variations like this in accreting black holes," said Claudio Ricci, an assistant professor at Diego Portales University in Santiago, Chile, and lead author of the study. "It was so strange that at first we thought maybe there was something wrong with the data. When we saw it was real, it was very exciting. But we also had no idea what we were dealing with; no one we talked to had seen anything like this."

Nearly every galaxy in the universe may host a supermassive black hole at its center, like the one in 1ES 1927+654, with masses millions or billions of times greater than our Sun. They grow by consuming the gas encircling them, otherwise known as an accretion disk. Because black holes don't emit or reflect light, they can't be seen directly, but the light from their coronas and accretion disks offers a way to learn about these dark objects.

The authors' star hypothesis is also supported by the fact that a few months before the X-ray signal disappeared, observatories on Earth saw the disk brighten considerably in visible-light wavelengths (those that can be seen by the human eye). This might have resulted from the initial collision of the stellar debris with the disk.

Digger Deeper

The disappearing event in 1ES 1927+654 is unique not only because of the dramatic change in brightness, but also because of how thoroughly astronomers were able to study it. The visible-light flare prompted Ricci and his colleagues to request follow-up monitoring of the black hole using NASA's Neutron star Interior Composition Explorer (NICER), an X-ray telescope aboard the International Space Station. In total, NICER observed the system 265 times over 15 months. Additional X-ray monitoring was obtained with NASA's Neil Gehrels Swift Observatory – which also observed the system in ultraviolet light – as well as NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) and the ESA (the European Space Agency) XMM-Newton observatory (which has NASA involvement).

When the X-ray light from the corona disappeared, NICER and Swift observed lower-energy X-rays from the system so that, collectively, these observatories provided a continuous stream of information throughout the event.

Although a wayward star seems the most likely culprit, the authors note that there could be other explanations for the unprecedented event. One remarkable feature of the observations is that the overall drop in brightness wasn't a smooth transition: Day to day, the low-energy X-rays NICER detected showed dramatic variation, sometimes changing in brightness by a factor of 100 in as little as eight hours. In extreme cases, black hole coronas have been known to become 100 times brighter or dimmer, but on much longer timescales. Such rapid changes occurring continuously for months was extraordinary.

"This dataset has a lot of puzzles in it," said Erin Kara, an assistant professor of physics at the Massachusetts Institute of Technology and a coauthor of the new study. "But that's exciting, because it means we're learning something new about the universe. We think the star hypothesis is a good one, but I also think we're going to be analyzing this event for a long time."

It's possible that this kind of extreme variability is more common in black hole accretion disks than astronomers realize. Many operating and upcoming observatories are designed to search for short-term changes in cosmic phenomena, a practice known as "time domain astronomy," which could reveal more events like this one.

"This new study is a great example of how flexibility in observation scheduling allows NASA and ESA missions to study objects that evolve relatively quickly and look for longer-term changes in their average behavior," said Michael Loewenstein, a coauthor of the study and an astrophysicist for the NICER mission at the University of Maryland College Park and NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Maryland. "Will this feeding black hole return to the state it was in before the disruption event? Or has the system been fundamentally changed? We're continuing our observations to find out."

More About the Missions

NICER is an Astrophysics Mission of Opportunity within NASA's Explorer program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas.
NuSTAR recently celebrated eight years in space, having launched on June 13, 2012. 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 GSFC. ASI provides the mission's ground station and a mirror data archive. Caltech manages JPL for NASA.

ESA's XMM-Newton observatory was launched in December 1999 from Kourou, French Guiana. NASA funded elements of the XMM-Newton instrument package and provides the NASA Guest Observer Facility at GSFC, which supports use of the observatory by U.S. astronomers.

GSFC manages the Swift mission in collaboration with Penn State in University Park, Pennsylvania, the Los Alamos National Laboratory in New Mexico and Northrop Grumman Innovation Systems in Dulles, Virginia. Other partners include the University of Leicester and Mullard Space Science Laboratory of the University College London in the United Kingdom, Brera Observatory in Italy, and the Italian Space Agency.

Editor: Tony Greicius



For more information on NuSTAR, visit: https://www.nasa.gov/mission_pages/nustar/main/index.html / https://www.nustar.caltech.edu/

For more information on NICER, visit: https://www.nasa.gov/nicer / https://nicer.gsfc.nasa.gov

For more information on Swift, visit:
https://www.nasa.gov/mission_pages/swift/main / https://swift.gsfc.nasa.gov/

For more information on XMM-Newton, visit: 
https://www.nasa.gov/xmm-newton
 

Source: NASA/Nustar


Saturday, September 24, 2022

How (S)low Can You Go: Pulsar Edition

An artist’s impression of an accreting neutron star
Credit:
NASA/Goddard Space Flight Center/Dana Berry

Pulsars are one of the most complex and mysterious objects in the universe; astronomers thought they had an answer to how and why pulsars lose energy and spin slower over time…but recent discoveries have made them rethink their current theories.


An example of a pulsar in a supernova remnant; the Crab pulsar emits energy that lights up the Crab Nebula, both of which were formed in a supernova that occurred in the year 1054. Credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)


A Lack of Long-Period Pulsars

Deep inside the gas and dust of some supernova remnants, you’ll find a pulsar: a neutron star with a magnetic fields 100 million times Earth’s and a density so high that a teaspoon of matter would weigh as much as Mount Everest. Pulsars emit radio radiation and rotate rapidly; their spin periods generally fall between 2 milliseconds and 12 seconds. Puzzled by the lack of pulsars with rotation periods longer than 12 seconds, some astronomers have hypothesized that pulsars can no longer emit radio radiation when their rotation periods exceed a certain limit. Other researchers believe that our observing methods are biased toward pulsars with shorter periods.

However, recent discoveries of long-period pulsars with spin periods of 14 seconds, 23 seconds, and 76 seconds (and also a radio transient with a period of 1,091 seconds) have challenged these ideas and made astronomers rethink their models. How were these pulsars with long spin periods formed? A team led by Michele Ronchi at Spain’s Institute of Space Sciences and the Institute of Space Studies of Catalonia has proposed that it may have something to do with accretion from their parent supernovae.

The period and age of pulsars plotted for different initial magnetic field strengths and supernova disk fallback rates
Credit: Ronchi et al. 2022


The Low-Down on the Slow-Down

After their births in supernovae explosions, pulsars “spin down” over time as they lose energy through magnetic dipole radiation and their magnetic fields decay. However, it’s not clear that these processes alone can account for the few pulsars we see with very long spin periods. The team postulates that the long rotation periods seen in these pulsars might have been caused by material from the supernova falling back onto the neutron star and forming a disk, which will affect the spin rate of the pulsar. This would happen soon after a neutron star’s formation, and the amount of mass and the accretion rate would depend on the progenitor star’s mass and the dynamics of the supernova.


An example of the time evolution of the period of a pulsar. The two shaded boxes represent different phases of the accretion process. Credit: Adapted from Ronchi et al. 2022


Age Affects Accretion

The team performed simulations to understand how the spin period of a pulsar evolves over time, varying the initial magnetic field of the pulsar and the accretion rate to see if periods as long as 76 seconds are obtainable. They found that for newborn neutron stars with magnetic fields on the order of 1014–1015 G and moderate accretion rates, young long-period pulsars are possible. In neutron stars with lower initial magnetic fields, on the order of 1012 G, accretion from a fallback disk, if it is present, would have little effect. Therefore, the spin-down would be caused by magnetic dipole radiation alone, and the resulting pulsar’s period would be no longer than ~12 seconds.

Studying the mechanisms that lead to long-period pulsars could also help us understand other periodic transient events, like fast radio bursts. New radio surveys with powerful instruments such as the Low Frequency Array (LOFAR) and MeerKAT may find more of these long-period objects and put the team’s theories to the test.

Citation

“Long-period Pulsars as Possible Outcomes of Supernova Fallback Accretion,” Michele Ronchi et al 2022 ApJ 934 184. doi:10.3847/1538-4357/ac7cec

By Haley Wahl



Friday, September 23, 2022

An Enigmatic Astronomical Explosion

IRAS 05506+2414
Credit:ESA/Hubble & NASA, R. Sahai

A bright young star is surrounded by a shroud of thick gas and dust in this image from the NASA/ESA Hubble Space Telescope. Hubble’s Wide Field Camera 3 inspected a young stellar object, over 9000 light years away in the constellation Taurus, to help astronomers understand the earliest stages in the lives of massive stars. This object — which is known to astronomers as IRAS 05506+2414 — is thought to be an example of an explosive event caused by the disruption of a massive young star system. If so, it would only be the second such example known.

Usually the swirling discs of material surrounding a young star are funnelled into twin outflows of gas and dust from the star. In the case of IRAS 05506+2414, however, a fan-like spray of material travelling at velocities of up to 350 kilometres per second is spreading outwards from the centre of this image.

Astronomers turned to Hubble’s Wide Field Camera 3 to measure the distance to IRAS 05506+2414. While it is possible to measure the velocity of material speeding outwards from the star, astronomers cannot tell how far from Earth the star actually is from a single observation. However, by measuring the distance that the outflow travels between successive images, they will be able to infer the distance to IRAS 05506+2414. This will allow astronomers to determine how bright the star is and how much energy it is emitting, and hence to estimate its mass — all vital information that will help to understand the origin of this bright young star’s unusual outflow.

Link





Thursday, September 22, 2022

Astronomers detect hot gas bubble swirling around the Milky Way’s supermassive black hole

PR Image eso2212a
The orbit of the hot spot around Sagittarius A*

PR Image eso2212b
First image of our black hole

PR Image eso2212c
The Milky Way and the location of its central black hole as viewed from the Atacama Large Millimeter/submillimeter Array

PR Image eso2212d
Wide-field view of the centre of the Milky Way

PR Image eso2212e
Sagittarius A* in the constellation of Sagittarius




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Hot Gas Bubble Swirling Around our Supermassive Black Hole (ESOcast 256 Light) 
PR Video eso2212a
Hot Gas Bubble Swirling Around our Supermassive Black Hole (ESOcast 256 Light)

Sagittarius A* and animation of the hot spot around it
Sagittarius A* and animation of the hot spot around it



Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have spotted signs of a ‘hot spot’ orbiting Sagittarius A*, the black hole at the centre of our galaxy. The finding helps us better understand the enigmatic and dynamic environment of our supermassive black hole.

We think we're looking at a hot bubble of gas zipping around Sagittarius A* on an orbit similar in size to that of the planet Mercury, but making a full loop in just around 70 minutes. This requires a mind blowing velocity of about 30% of the speed of light!” says Maciek Wielgus of the Max Planck Institute for Radio Astronomy in Bonn, Germany, who led the study published today in Astronomy & Astrophysics.

The observations were made with ALMA in the Chilean Andes — a radio telescope co-owned by the European Southern Observatory (ESO) — during a campaign by the Event Horizon Telescope (EHT) Collaboration to image black holes. In April 2017 the EHT linked together eight existing radio telescopes worldwide, including ALMA, resulting in the recently released first ever image of Sagittarius A*. To calibrate the EHT data, Wielgus and his colleagues, who are members of the EHT Collaboration, used ALMA data recorded simultaneously with the EHT observations of Sagittarius A*. To the team's surprise, there were more clues to the nature of the black hole hidden in the ALMA-only measurements.

By chance, some of the observations were done shortly after a burst or flare of X-ray energy was emitted from the centre of our galaxy, which was spotted by NASA’s Chandra Space Telescope. These kinds of flares, previously observed with X-ray and infrared telescopes, are thought to be associated with so-called ‘hot spots’, hot gas bubbles that orbit very fast and close to the black hole. 

What is really new and interesting is that such flares were so far only clearly present in X-ray and infrared observations of Sagittarius A*. Here we see for the first time a very strong indication that orbiting hot spots are also present in radio observations,” says Wielgus, who is also affiliated with the Nicolaus Copernicus Astronomical Centre, Poland and the Black Hole Initiative at Harvard University, USA.

Perhaps these hot spots detected at infrared wavelengths are a manifestation of the same physical phenomenon: as infrared-emitting hot spots cool down, they become visible at longer wavelengths, like the ones observed by ALMA and the EHT,” adds Jesse Vos, a PhD student at Radboud University, the Netherlands, who was also involved in this study.

The flares were long thought to originate from magnetic interactions in the very hot gas orbiting very close to Sagittarius A*, and the new findings support this idea. “Now we find strong evidence for a magnetic origin of these flares and our observations give us a clue about the geometry of the process. The new data are extremely helpful for building a theoretical interpretation of these events,” says co-author Monika Mościbrodzka from Radboud University.

ALMA allows astronomers to study polarised radio emission from Sagittarius A*, which can be used to unveil the black hole’s magnetic field. The team used these observations together with theoretical models to learn more about the formation of the hot spot and the environment it is embedded in, including the magnetic field around Sagittarius A*. Their research provides stronger constraints on the shape of this magnetic field than previous observations, helping astronomers uncover the nature of our black hole and its surroundings.

The observations confirm some of the previous discoveries made by the GRAVITY instrument at ESO’s Very Large Telescope (VLT), which observes in the infrared. The data from GRAVITY and ALMA both suggest the flare originates in a clump of gas swirling around the black hole at about 30% of the speed of light in a clockwise direction in the sky, with the orbit of the hot spot being nearly face-on.

In the future we should be able to track hot spots across frequencies using coordinated multiwavelength observations with both GRAVITY and ALMA — the success of such an endeavour would be a true milestone for our understanding of the physics of flares in the Galactic centre,” says Ivan Marti-Vidal of the University of València in Spain, co-author of the study.

The team is also hoping to be able to directly observe the orbiting gas clumps with the EHT, to probe ever closer to the black hole and learn more about it. “Hopefully, one day, we will be comfortable saying that we ‘know’ what is going on in Sagittarius A*,” Wielgus concludes.




More Information

This research was presented in the paper “Orbital motion near Sagittarius A* – Constraints from polarimetric ALMA observations” to appear in Astronomy Astrophysics (https://www.aanda.org/10.1051/0004-6361/202244493).

The team is composed of M. Wielgus (Max-Planck-Institut für Radioastronomie, Germany [MPIfR]; Nicolaus Copernicus Astronomical Centre, Polish Academy of Sciences, Poland; Black Hole Initiative at Harvard University, USA [BHI]), M. Moscibrodzka (Department of Astrophysics, Radboud University, The Netherlands [Radboud]), J. Vos (Radboud), Z. Gelles (Center for Astrophysics | Harvard Smithsonian, USA and BHI), I. Martí-Vidal (Universitat de València, Spain), J. Farah (Las Cumbres Observatory, USA; University of California, Santa Barbara, USA), N. Marchili (Italian ALMA Regional Centre, INAF-Istituto di Radioastronomia, Italy and MPIfR), C. Goddi (Dipartimento di Fisica, Università degli Studi di Cagliari, Italy and Universidade de São Paulo, Brazil), and H. Messias (Joint ALMA Observatory, Chile).

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 Ministry of Science and Technology (MOST) 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.

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration in astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates APEX and ALMA on Chajnantor, two facilities that observe the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society.



Links



Contacts:

Maciek Wielgus
Max Planck Institute for Radio Astronomy
Bonn, Germany
Tel: +48 602417268
Email:
maciek.wielgus@gmail.com

Monika Mościbrodzka
Radboud University
Nijmegen, The Netherlands
Tel: +31-24-36-52485
Email:
m.moscibrodzka@astro.ru.nl

Ivan Martí Vidal
University of Valencia
Valencia, Spain
Tel: +34 963 543 078
Email:
i.marti-vidal@uv.es

Jesse Vos
Radboud University
Nijmegen, The Netherlands
Cell: +31 6 34008019
Email:
jt.vos@astro.ru.nl

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

Source:ESO/News


Wednesday, September 21, 2022

New Webb Image Captures Clearest View of Neptune’s Rings in Decades

Neptune (NIRCam) Labeled
Credits: Image: NASA, ESA, CSA, STScI / Image Processing: Joseph DePasquale (STScI)

Neptune Close Up (NIRCam)
Credits: Image: NASA, ESA, CSA, STScI / Image Processing: Joseph DePasquale (STScI) 
 
Neptune Wide Field (NIRCam)
Credits: Image: NASA, ESA, CSA, STScI / Image Processing: Joseph DePasquale (STScI)




NASA’s James Webb Space Telescope shows off its capabilities closer to home with its first image of Neptune. Not only has Webb captured the clearest view of this distant planet’s rings in more than 30 years, but its cameras reveal the ice giant in a whole new light.

Most striking in Webb’s new image is the crisp view of the planet’s rings – some of which have not been detected since NASA’s Voyager 2 became the first spacecraft to observe Neptune during its flyby in 1989. In addition to several bright, narrow rings, the Webb image clearly shows Neptune’s fainter dust bands.

“It has been three decades since we last saw those faint, dusty bands, and this is the first time we’ve seen them in the infrared,” notes Heidi Hammel, a Neptune system expert and interdisciplinary scientist for Webb. Webb’s extremely stable and precise image quality permits these very faint rings to be detected so close to Neptune.

Neptune has fascinated researchers since its discovery in 1846. Located 30 times farther from the Sun than Earth, Neptune orbits in the remote, dark region of the outer solar system. At that extreme distance, the Sun is so small and faint that high noon on Neptune is similar to a dim twilight on Earth.

This planet is characterized as an ice giant due to the chemical make-up of its interior. Compared to the gas giants, Jupiter and Saturn, Neptune is much richer in elements heavier than hydrogen and helium. This is readily apparent in Neptune’s signature blue appearance in Hubble Space Telescope images at visible wavelengths, caused by small amounts of gaseous methane.

Webb’s Near-Infrared Camera (NIRCam) images objects in the near-infrared range from 0.6 to 5 microns, so Neptune does not appear blue to Webb. In fact, the methane gas so strongly absorbs red and infrared light that the planet is quite dark at these near-infrared wavelengths, except where high-altitude clouds are present. Such methane-ice clouds are prominent as bright streaks and spots, which reflect sunlight before it is absorbed by methane gas. Images from other observatories, including the Hubble Space Telescope and the W.M. Keck Observatory, have recorded these rapidly evolving cloud features over the years.

More subtly, a thin line of brightness circling the planet’s equator could be a visual signature of global atmospheric circulation that powers Neptune’s winds and storms. The atmosphere descends and warms at the equator, and thus glows at infrared wavelengths more than the surrounding, cooler gases.

Neptune’s 164-year orbit means its northern pole, at the top of this image, is just out of view for astronomers, but the Webb images hint at an intriguing brightness in that area. A previously-known vortex at the southern pole is evident in Webb’s view, but for the first time Webb has revealed a continuous band of high-latitude clouds surrounding it.

Webb also captured seven of Neptune’s 14 known moons. Dominating this Webb portrait of Neptune is a very bright point of light sporting the signature diffraction spikes seen in many of Webb’s images, but this is not a star. Rather, this is Neptune’s large and unusual moon, Triton.

Covered in a frozen sheen of condensed nitrogen, Triton reflects an average of 70 percent of the sunlight that hits it. It far outshines Neptune in this image because the planet’s atmosphere is darkened by methane absorption at these near-infrared wavelengths. Triton orbits Neptune in an unusual backward (retrograde) orbit, leading astronomers to speculate that this moon was originally a Kuiper belt object that was gravitationally captured by Neptune. Additional Webb studies of both Triton and Neptune are planned in the coming year.

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.



Credits:

Release: NASA, ESA, CSA, STScI

Media Contact:

Hannah Braun
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland


Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.



Tuesday, September 20, 2022

Put a Ring On It: How Gravity Gives Astronomers a Powerful Lens On the Universe

The first image of an Einstein Ring
It was captured by the VLA in 1987. Credit: NRAO/AUI/NSF



ALMA’s highest resolution image ever reveals the dust glowing inside the distant galaxy SDP.81. The ring structure was created by a gravitational lens that distorted the view of the distant galaxy into a ring-like structure. Credit: ALMA (NRAO/ESO/NAOJ)

In 1919 astronomers Arthur Eddington and Andrew Crommelin captured photographic images of a total solar eclipse. The Sun was in the constellation Taurus at the time, and a handful of its stars could be seen in the photographs. But the stars weren’t quite in their expected place. The tremendous gravity of the Sun had deflected the light of these stars, making them appear slightly out of place. It was the first demonstration that gravity could change the path of light, just as predicted by Albert Einstein in 1915.

The bending of light by the mass of a star or galaxy is one of the central predictions of general relativity. Although Einstein first predicted the deflection of light from a single star, others such as Oliver Lodge argued that a large mass could act as a gravitational lens, warping the path of light similar to the way a glass lens focuses light. By 1935, Einstein demonstrated how light from a distant galaxy could be warped by a galaxy in front of it to create a ring of light. Such an Einstein Ring, as it came to be known, would make the distant galaxy appear as a ring or arc of light around the closer galaxy. But Einstein thought this effect would never be observed. These arcs of light would be too faint for optical telescopes to capture. Einstein was right until 1998 when the Hubble Space Telescope captured a ring around the galaxy B1938+666. This was the first optical ring to be observed, but it wasn’t the first Einstein Ring. The first ring was seen in radio light, and it was captured by the Very Large Array (VLA).

In 1987, a team of students at the MIT Research Lab in Electronics under Prof. Bernard Burke, and led by PhD student Jackie Hewitt, used the VLA to make detailed images of known radio-emitting objects. One of them, known as MG1131+0456, showed a distinct oval shape with two bright lobes. Hewitt and her team considered several models to explain the unusual shape, but only an Einstein Ring matched the data. Einstein’s galactic prediction was finally observed.

Radio astronomy is particularly good at capturing lensed galaxies. They have become a powerful tool for radio astronomers. Just as a glass lens focuses light to make an object appear brighter and larger, so does a gravitational lens. By observing lensed galaxies radio astronomers can study galaxies that would be too distant and faint to see on their own. Einstein rings can be used to measure the mass of the closer galaxy or galactic cluster since the amount of gravitational lensing depends on the mass of the foreground galaxy.

One of the more interesting aspects of gravitational lensing is that it can be used to measure the rate at which the universe expands. Light from a distant galaxy can take many different paths as it passes the foreground galaxy. Each of these paths can have different distances, which means the light can reach us at different times. We might see a burst of light from the galaxy multiple times, each from a different path. Astronomers can use this to calculate galactic distance, and thus the scale of the cosmos.

Since the first detection of an Einstein ring by the VLA, radio astronomers have found more of them, and have captured them in more detail. In 2015, for example, the Atacama Large Millimeter/submillimeter Array (ALMA) made a detailed image of the lensed arcs from a distant galaxy named SDP.81. The image was sharp enough that astronomers could trace the arcs back to their source to study how stars formed within the galaxy.

Einstein rings are now commonly seen in astronomical images, particularly in deep field images, such as those of the James Webb Space Telescope and others. As radio astronomy has shown, they are more than just beautiful. They give us a new lens on the cosmos.

About the Author:

Brian Koberlein is a science writer for NRAO. He has a Ph.D. in Physics from the University of Connecticut, and has published research in physics and astrophysics. Together with David Meisel, he is the author of Astrophysics Through Computation, published by Cambridge University Press.



Monday, September 19, 2022

Dark Energy Camera Captures Bright, Young Stars Blazing Inside Glowing Nebula

Dark Energy Camera Captures Bright, Young Stars Blazing Inside Glowing Nebula 
 


Videos


CosmoView Episodio 52: Dark Energy Camera Captures Bright, Young Stars Blazing Inside Glowing Nebula
CosmoView Episodio 52: Dark Energy Camera Captures Bright, Young Stars Blazing Inside Glowing Nebula 
 
Zoom-in to DECam Image of Lobster Nebula
Zoom-in to DECam Image of Lobster Nebula 
 
Pan of DECam image of the Lobster Nebula
Pan of DECam image of the Lobster Nebula 
 
CosmoView Episodio 52: Tololo celebra 10 años de la Cámara de Energía Oscura con impresionante imagen
CosmoView Episodio 52: Tololo celebra 10 años de la Cámara de Energía Oscura con impresionante imagen




To celebrate 10 years of discovery, the DOE-built DECam unveils thousands of stars shining in and around the Lobster Nebula

The 570-megapixel US Department of Energy-fabricated Dark Energy Camera at NOIRLab’s Cerro Tololo Inter-American Observatory in Chile is one of the most powerful tools in astronomy and astrophysics. To commemorate its first decade of discovery and exploration, NOIRLab has released a stunning image of the Lobster Nebula, a brilliant star-forming region located 8000 light-years from Earth in the direction of the constellation Scorpius. The image was unveiled at a conference highlighting DECam’s breakthrough science results.

The Dark Energy Camera (DECam) mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab, is celebrating 10 years as one of the highest-performance, wide-field CCD imagers in the world. 

To help commemorate DECam’s first decade of operation, NOIRLab has released a breathtaking image of the star-forming Lobster Nebula (NGC 6357), which is located about 8000 light-years from Earth in the direction of the constellation Scorpius. This image reveals bright, young stars surrounded by billowing clouds of dust and gas. 

At the center of the nebula, which spans about 400 light-years, resides the open star cluster Pismis 24 — a collection of dazzlingly bright, massive stars. Surrounding this cluster is a region brimming with newborn stars, protostars still wrapped in their cocoons of star-forming material, and dense cores of gas and dust that will eventually become new stars. The twisting braids of dark clouds and complex structures inside the nebula are formed by the tumultuous pressure of interstellar winds, radiation, and powerful magnetic fields. 

One of the most striking things about this image is the beautifully detailed color palette selected to highlight different aspects of the nebula. This wide-field, high-resolution image showcases the power of DECam and its ability to produce stunning images while helping astronomers study the fundamental properties of the Universe.

This image was constructed using some of a new range of very special DECam narrowband filters, which isolate very specific wavelengths of light. They make it possible to infer the physics of distant objects, including important details about their inner motions, temperatures, and complex chemistry, which is especially important when examining star-forming regions like the Lobster Nebula.

In order to create a colorful image such as this one, the same celestial object is observed multiple times using different filters. Each observation provides a single-color image, which encompases a specific range of light waves. Imaging specialists then take these individual images and assign a corresponding color to each of them. The images can then be stacked on top of one another to create a composite that closely approximates what objects might look like if they were far brighter.

The image was unveiled at the DECam at 10 years: Looking Back, Looking Forward conference, which highlighted the outstanding DECam science results of the past 10 years and the exciting opportunities with DECam as astronomy looks to the future with Vera C. Rubin Observatory, currently under construction on Cerro Pachón in Chile. DECam has just passed the remarkable milestone of taking one million individual exposures, delivering on average 400 to 500 images per night.

DECam was operated by the DOE and NSF between 2013 and 2019. DECam was funded by the DOE and was built and tested at DOE's Fermilab. Currently, DECam is used for programs covering a huge range of science.

The image was obtained by NOIRLab’s Communication, Education & Engagement team as part of the NOIRLab Legacy Imaging Program.



More Information

NSF’s NOIRLab (National Optical-Infrared Astronomy Research Laboratory), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O'odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

NCSA at the University of Illinois at Urbana-Champaign provides supercomputing and advanced digital resources for the nation’s science enterprise. At NCSA, University of Illinois faculty, staff, students, and collaborators from around the globe use advanced digital resources to address research grand challenges for the benefit of science and society. NCSA has been advancing one-third of the Fortune 50® for more than 30 years by bringing industry, researchers, and students together to solve grand challenges at rapid speed and scale. 

Fermilab is America’s premier national laboratory for particle physics and accelerator research. A US Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and operated under contract by the Fermi Research Alliance LLC, a joint partnership between the University of Chicago and the Universities Research Association, Inc. 

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.




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Contacts:

Travis Rector
NSF's NOIRLab & University of Alaska
Tel: +1 907 786 1242
Email:
tarector@alaska.edu

Charles Blue
Public Information Officer
NSF’s NOIRLab
Tel: +1 202 236 6324
Email:
charles.blue@noirlab.edu

Source: NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab)/News