Showing posts with label NGC 6611. Show all posts
Showing posts with label NGC 6611. Show all posts

Saturday, July 14, 2018

The Eagle Nebula (M16): "X"-ploring the Eagle Nebula and "Pillars of Creation"

Pillars of Creatio/M16
Credit: X-ray: NASA/CXC/INAF/M.Guarcello et al.; Optical: NASA/STScI
JPEG (797 kb) - Large JPEG (8 MB) -Tiff (15.8 MB) - More Images

Field of ViewX-ray/Optical
Credit: X-ray: NASA/CXC/INAF/M.Guarcello et al.; Optical: NASA/STScI

Optical and infrared identifications with stars were used to sort out chance interlopers in the foreground or background, and to determine that more than two-thirds of the sources are likely young stars that are members of the NGC 6611 cluster.

Chandra's unique ability to resolve and locate X-ray sources made it possible to identify hundreds of very young stars, and those still in the process of forming (known as "protostars"). Infrared observations from NASA's Spitzer Space Telescope and the European Southern Observatory indicate that 219 of the X-ray sources in the Eagle Nebula are young stars surrounded by disks of dust and gas and 964 are young stars without these disks.

Combined with the Chandra observations, the data show that X-ray activity in young stars with disks is, on average, a few times less intense that in young stars without disks. This behavior is likely due to the interaction of the disk with the magnetic field of the host star. Much of the matter in the disks around these protostars will eventually be blown away by radiation from their host stars, but, in certain cases, some of it may form into planets.

This new composite image shows the region around the Pillars, which are about 5,700 light years from Earth. The image combines X-ray data from NASA's Chandra X-ray Observatory and Hubble Space Telescope optical data. The optical image, taken with filters to emphasize the interstellar gas and dust, shows dusty brown nebula immersed in a blue-green haze, and a few stars that appear as pink dots in the image. The Chandra data reveal X-rays from hot outer atmospheres from stars. In this image, low, medium, and high-energy X-rays detected by Chandra have been colored red, green, and blue.

In the image, some of the X-ray sources appear to be located in the Pillars. However, an analysis of the absorption of X-rays from these sources indicates that almost all of these sources belong to the larger Eagle Nebula rather than being immersed in the Pillars.

Three X-ray sources appear to lie near the tip of the largest Pillar. Infrared observations show a protostar containing four or five times the mass of the Sun is located near one of these sources — the blue one near the tip of the Pillar. This source exhibits strong absorption of low-energy X-rays, consistent with a location inside the Pillar. Similar arguments show that one of these sources is associated with a disk-less star outside the Pillar, and one is a foreground object.

A paper by Mario Guarcello, currently at the National Institute for Astronomy in Italy, and colleagues describing these results appeared in The Astrophysical Journal. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.



Fast Facts for The Eagle Nebula (M16):

Scale: Image is about 2.5 arcmin (5.13 light years across) across
Category: Normal Stars & Star Clusters
Coordinates (J2000): RA 18h 18m 51.79s | Dec -13º 49' 54.93"
Constellation: Serpens
Observation Date: 07/30/2001
Observation Time: 22 hours
Obs. ID: 978
Instrument: ACIS
References: M. Guarcello et al. 2012, ApJ, 753, 117; arXiv:1205.2111
Color Code: X-ray (larger point sources): Red (0.5-1.5 keV); Green (1.5-2.5 keV); Blue (2.5-7.0 keV); Optical (diffuse emission & smaller point sources): Red, Green and Blue
Distance Estimate: About 5,700 light years



Thursday, April 30, 2015

The Pillars of Creation Revealed in 3D

3D data visualisation of the Pillars of Creation

Colour composite view of the Pillars of Creation from MUSE data

The three-dimensional view of the Pillars of Creation from MUSE
 
Messier 16 in the constellation of Serpens Cauda (The Tail of the Serpent)
 
Digitized Sky Survey Image of the Eagle Nebula 

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Videos

3D data visualisation of the Pillars of Creation
3D data visualisation of the Pillars of Creation

3D data visualisation of the Pillars of Creation
3D data visualisation of the Pillars of Creation 


New study suggests that iconic structures more aptly named the Pillars of Destruction

Using the MUSE instrument on ESO’s Very Large Telescope (VLT), astronomers have produced the first complete three-dimensional view of the famous Pillars of Creation in the Eagle Nebula, Messier 16. The new observations demonstrate how the different dusty pillars of this iconic object are distributed in space and reveal many new details — including a previously unseen jet from a young star. Intense radiation and stellar winds from the cluster’s brilliant stars have sculpted the dusty Pillars of Creation over time and should fully evaporate them in about three million years.

The original NASA/ESA Hubble Space Telescope image of the famous Pillars of Creation was taken two decades ago and immediately became one of its most famous and evocative pictures. Since then, these billowing clouds, which extend over a few light-years [1], have awed scientists and the public alike.

The jutting structures, along with the nearby star cluster, NGC 6611, are parts of a star formation region called the Eagle Nebula, also known as Messier 16 or M16. The nebula and its associated objects are located about 7000 light-years away in the constellation of Serpens (The Serpent).

The Pillars of Creation are a classic example of the column-like shapes that develop in the giant clouds of gas and dust that are the birthplaces of new stars. The columns arise when immense, freshly formed blue–white O and B stars give off intense ultraviolet radiation and stellar winds that blow away less dense materials from their vicinity.

Denser pockets of gas and dust, however, can resist this erosion for longer. Behind such thicker dust pockets, material is shielded from the harsh, withering glare of O and B stars. This shielding creates dark "tails" or “elephant trunks”, which we see as the dusky body of a pillar, that point away from the brilliant stars.

ESO's MUSE instrument on the Very Large Telescope has now helped illustrate the ongoing evaporation of the Pillars of Creation in unprecedented detail, revealing their orientation.

MUSE has shown that the tip of the left pillar is facing us, atop a pillar that is is actually situated behind NGC 6611, unlike the other pillars. This tip is bearing the brunt of the radiation from NGC 6611’s stars, and as a result looks brighter to our eyes than the bottom left, middle and right pillars, whose tips are all pointed away from our view.
Astronomers hope to better understand how young O and B stars like those in NGC 6611 influence the formation of subsequent stars. Numerous studies have identified protostars forming in these clouds — they are indeed Pillars of Creation. The new study also reports fresh evidence for two gestating stars in the left and middle pillars as well as a jet from a young star that had escaped attention up to now.
For more stars to form in environments like the Pillars of Creation, it is a race against time as intense radiation from the powerful stars that are already shining continues to grind away at the pillars.
By measuring the Pillars of Creation’s rate of evaporation, MUSE has given astronomers a time frame for when the pillars will be no more. They shed about 70 times the mass of the Sun every million years or so. Based on the their present mass of about 200 times that of the Sun, the Pillars of Creation have an expected lifetime of perhaps three million more years — an eyeblink in cosmic time. It seems that an equally apt name for these iconic cosmic columns might be the Pillars of Destruction.


Notes

[1] The left pillar, considered as a complete object from top to bottom, is estimated to be about four light-years in length. It is the longest pillar and about twice the height of the right pillar.


More Information


This research was presented in a paper entitled "The Pillars of Creation revisited with MUSE: gas kinematics and high-mass stellar feedback traced by optical spectroscopy" by A. F. McLeod et al., to appear in the journal Monthly Notices of the Royal Astronomical Society on 30 April 2015.
The team is composed of A. F. Mc Leod (ESO, Garching, Germany), J. E. Dale (Universitäts-Sternwarte München, München, Germany; Excellence Cluster Universe, Garching bei München, Germany), A. Ginsburg (ESO), B. Ercolano (Universitats-Sternwarte München,; Excellence Cluster Universe), M. Gritschneder (Universitats-Sternwarte München), S. Ramsay (ESO) and L. Testi (ESO; INAF/Osservatorio Astrofisico di Arcetri, Firenze, Italy).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.


Links

Contacts

Anna Faye Mc Leod
ESO
Garching bei München, Germany
Tel: +49 89 3200 6321
Email:
amcleod@eso.org

Richard Hook
ESO, Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email:
rhook@eso.org

Source: ESO 

Tuesday, January 06, 2015

Hubble Goes High Def to Revisit the Iconic 'Pillars of Creation'

M16, Eagle Nebula, NGC 6611
Credit for WFPC2 image: NASA, ESA, STScI, and J. Hester and P. Scowen (Arizona State University)
Credit for WFC3 image: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
 

Although NASA's Hubble Space Telescope has taken many breathtaking images of the universe, one snapshot stands out from the rest: the iconic view of the so-called "Pillars of Creation." The jaw-dropping photo, taken in 1995, revealed never-before-seen details of three giant columns of cold gas bathed in the scorching ultraviolet light from a cluster of young, massive stars in a small region of the Eagle Nebula, or M16.

Though such butte-like features are common in star-forming regions, the M16 structures are by far the most photogenic and evocative. The Hubble image is so popular that it has appeared in movies and television shows, on tee-shirts and pillows, and even on a postage stamp.

And now, in celebration of its 25th anniversary, Hubble has revisited the famous pillars, providing astronomers with a sharper and wider view. As a bonus, the pillars have been photographed in near-infrared light, as well as visible light. The infrared view transforms the pillars into eerie, wispy silhouettes seen against a background of myriad stars. That's because the infrared light penetrates much of the gas and dust, except for the densest regions of the pillars. Newborn stars can be seen hidden away inside the pillars. The new images are being unveiled at the American Astronomical Society meeting in Seattle, Washington.

Although the original image was dubbed the Pillars of Creation, the new image hints that they are also pillars of destruction. "I'm impressed by how transitory these structures are. They are actively being ablated away before our very eyes. The ghostly bluish haze around the dense edges of the pillars is material getting heated up and evaporating away into space. We have caught these pillars at a very unique and short-lived moment in their evolution," explained Paul Scowen of Arizona State University in Tempe, who, with astronomer Jeff Hester, formerly of Arizona State University, led the original Hubble observations of the Eagle Nebula.

The infrared image shows that the reason the pillars exist is because the very ends of them are dense, and they shadow the gas below them, creating the long, pillar-like structures. The gas in between the pillars has long since been blown away by the ionizing winds from the central star cluster located above the pillars.

At the top edge of the left-hand pillar, a gaseous fragment has been heated up and is flying away from the structure, underscoring the violent nature of star-forming regions. "These pillars represent a very dynamic, active process," Scowen said. "The gas is not being passively heated up and gently wafting away into space. The gaseous pillars are actually getting ionized (a process by which electrons are stripped off of atoms) and heated up by radiation from the massive stars. And then they are being eroded by the stars' strong winds (barrage of charged particles), which are sandblasting away the tops of these pillars."

When Scowen and Hester used Hubble to make the initial observations of the Eagle Nebula in 1995, astronomers had seen the pillar-like structures in ground-based images, but not in detail. They knew that the physical processes are not unique to the Eagle Nebula because star birth takes place across the universe. But at a distance of just 6,500 light-years, M16 is the most dramatic nearby example, as the team soon realized.

As Scowen was piecing together the Hubble exposures of the Eagle, he was amazed at what he saw. "I called Jeff Hester on his phone and said, 'You need to get here now,'" Scowen recalled. "We laid the pictures out on the table, and we were just gushing because of all the incredible detail that we were seeing for the very first time."

The first features that jumped out at the team in 1995 were the streamers of gas seemingly floating away from the columns. Astronomers had previously debated what effect nearby massive stars would have on the surrounding gas in stellar nurseries. "There is only one thing that can light up a neighborhood like this: massive stars kicking out enough horsepower in ultraviolet light to ionize the gas clouds and make them glow," Scowen said. "Nebulous star-forming regions like M16 are the interstellar neon signs that say, 'We just made a bunch of massive stars here.' This was the first time we had directly seen observational evidence that the erosionary process, not only the radiation but the mechanical stripping away of the gas from the columns, was actually being seen."

By comparing the 1995 and 2014 pictures, astronomers also noticed a lengthening of a narrow jet-like feature that may have been ejected from a newly forming star. The jet looks like a stream of water from a garden hose. Over the intervening 19 years, this jet has stretched farther into space, across an additional 60 billion miles, at an estimated speed of about 450,000 miles per hour.

Our Sun probably formed in a similar turbulent star-forming region. There is evidence that the forming solar system was seasoned with radioactive shrapnel from a nearby supernova. That means that our Sun was formed as part of a cluster that included stars massive enough to produce powerful ionizing radiation, such as is seen in the Eagle Nebula. "That's the only way the nebula from which the Sun was born could have been exposed to a supernova that quickly, in the short period of time that represents, because supernovae only come from massive stars, and those stars only live a few tens of millions of years," Scowen explained. "What that means is when you look at the environment of the Eagle Nebula or other star-forming regions, you're looking at exactly the kind of nascent environment that our Sun formed in."


CONTACT

Felicia Chou
NASA Headquarters, Washington, D.C.
202-358-0257

felicia.chou@nasa.gov

Donna Weaver / Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4493 / 410-338-4514

dweaver@stsci.edu / villard@stsci.edu

Source: HubbleSite


Tuesday, January 17, 2012

A New View of an Icon

Combining almost opposite ends of the electromagnetic spectrum, this composite of the Herschel in far-infrared and XMM-Newton’s X-ray images shows how the hot young stars detected by the X-ray observations are sculpting and interacting with the surrounding ultra-cool gas and dust, which, at only a few degrees above absolute zero, is the critical material for star formation itself. Both wavelengths would be blocked by Earth’s atmosphere, so are critical to our understanding of the lifecycle of stars

Credits: far-infrared: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium; X-ray: ESA/XMM-Newton/EPIC/XMM-Newton-SOC/Boulanger.

HI-RES JPEG (Size: 432 kb)

The Eagle Nebula as never seen before. In 1995, the Hubble Space Telescope's 'Pillars of Creation' image of the Eagle Nebula became one of the most iconic images of the 20th century. Now, two of ESA's orbiting observatories have shed new light on this enigmatic star-forming region.

The Eagle Nebula is 6500 light-years away in the constellation of Serpens. It contains a young hot star cluster, NGC6611, visible with modest back-garden telescopes, that is sculpting and illuminating the surrounding gas and dust, resulting in a huge hollowed-out cavity and pillars, each several light-years long.

The Hubble image hinted at new stars being born within the pillars, deeply inside small clumps known as 'evaporating gaseous globules' or EGGs. Owing to obscuring dust, Hubble's visible light picture was unable to see inside and prove that young stars were indeed forming.

This 1995 Hubble Space Telescope image of the ‘Pillars of Creation’ is probably the most famous astronomical image of the 20th Century. Taken in visible light using a combination of SII/H-alpha and OIII filters, it shows a part of the Eagle Nebula where new stars are forming. The tallest pillar is around 4 light-years high.

Credits: NASA/ESA/STScI, Hester & Scowen (Arizona State University)
HI-RES JPEG (Size: 814 kb)

The ESA Herschel Space Observatory's new image shows the pillars and the wide field of gas and dust around them. Captured in far-infrared wavelengths, the image allows astronomers to see inside the pillars and structures in the region.

In parallel, a new multi-energy X-ray image from ESA's XMM-Newton telescope shows those hot young stars responsible for carving the pillars.

XMM-Newton’s images of the Eagle Nebula region in X-rays, which here is colour-coded to show different energy levels (red: 0.3–1 keV, green: 1–2 keV and blue: 2–8 keV) is helping astronomers to investigate a theory that the Eagle Nebula is being powered by a hidden supernova remnant. The researchers are looking for signs of very diffuse emission and how far this extends around the region. They believe that an absence of this X-ray emission beyond that found by previous orbiting space telescopes (Chandra and Spitzer) would support the supernova remnant theory. The work on this is continuing.

Credits: ESA/XMM-Newton/EPIC/XMM-Newton-SOC/Boulanger

Combining the new space data with near-infrared images from the European Southern Observatory's (ESO's) Very Large Telescope at Paranal, Chile, and visible-light data from its Max Planck Gesellschaft 2.2m diameter telescope at La Silla, Chile, we see this iconic region of the sky in a uniquely beautiful and revealing way.


Messier 16 is a diffuse emission nebula that contains the young open cluster NGC6611. The iconic ‘Pillars of Creation’ image taken with the Hubble Space Telescope in 1995 is captured in near-infrared by the VLT, which penetrates straight through the obscuring gas and dust, rendering them almost invisible. The pillars are only a small portion of the extensive nebulous region imaged in far-infrared by ESA’s Herschel Space Observatory, which shows cool dust and gas tendrils being carved away by the hot stars seen in the X-ray image from XMM-Newton. The wide-field optical image from the ESO MPG telescope puts the pillars into context against the full scale of the nebula, which is over 75 light-years across.

Credits: far-infrared: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium; ESA/XMM-Newton/EPIC/XMM-Newton-SOC/Boulanger; optical: MPG/ESO; near-infrared/VLT/ISAAC/McCaughrean & Andersen/AIP/ESO.

HI-RES JPEG (Size: 769 kb)

In visible wavelengths, the nebula shines mainly due to reflected starlight and hot gas filling the giant cavity, covering the surfaces of the pillars and other dusty structures.

A movie of the Eagle Nebula at several wavelengths. A high-resolution downloadable version of the movie is available for download (19mb) in Quicktime format. Credits: far-infrared: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium; ESA/XMM-Newton/EPIC/XMM-Newton-SOC/Boulanger; optical: MPG/ESO; near-infrared/VLT/ISAAC/McCaughrean & Andersen/AIP/ESO.

At near-infrared wavelengths, the dust becomes almost transparent and the pillars practically vanish.

The 8.2m-diameter VLT’s ANTU telescope imaged the famous Pillars of Creation region and its surroundings in near-infrared using the ISAAC instrument. This enabled astronomers to penetrate the obscuring dust in their search to detect newly formed stars. The research into the ‘evaporating gaseous globules’ (EGGs), which were first detected in the Hubble images, needed the near-infrared capabilities and resolution of the VLT to peel back the layers of dust and detect the low-mass young stars cocooned within the EGG shells. The near-infrared results showed that 11 of the 73 EGGs detected possibly contained stars, and that the tips of the pillars contain stars and nebulosity not seen in the Hubble image.

Credits: VLT/ISAAC/McCaughrean & Andersen/AIP/ESO . HI-RES JPEG (Size:
996 kb)

In far-infrared, Herschel detects this cold dust and the pillars reappear, this time glowing in their own light.

Intricate tendrils of dust and gas are seen to shine, giving astronomers clues about how it interacts with strong ultraviolet light from the hot stars seen by XMM-Newton.

In 2001, Very Large Telescope near-infrared images had shown only a small minority of the EGGs were likely to contain stars being born.

However, Herschel's image makes it possible to search for young stars over a much wider region and thus come to a much fuller understanding of the creative and destructive forces inside the Eagle Nebula.

This Herschel image of the Eagle Nebula, colour coded to 70 microns for blue and 160 microns for green using the PACS (Photodetector Array Camera) and 250 microns for red using the SPIRE (Spectral and Photometric Imaging Receiver) shows the self-emission of the intensely cold nebula’s gas and dust as never seen before. Each colour shows a different temperature of dust, from around 10 degrees above absolute zero (10K) for the red, up to around 40K for the blue. In the far–infrared, the nebula shows its intricate tendril nature, with vast cavities forming an almost cave-like surrounding to the famous pillars, which take on an ethereal ghostly appearance. The gas and dust provide the material for the star formation that is still under way inside this enigmatic nebula .

Credits: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium. HI-RES JPEG (Size:
423 kb)

Earlier mid-infrared images from ESA's Infrared Space Observatory and NASA's Spitzer, and the new XMM-Newton data, have led astronomers to suspect that one of the massive, hot stars in NGC6611 may have exploded in a supernova 6000 years ago, emitting a shockwave that destroyed the pillars.

However, because of the distance of the Eagle Nebula, we won't see this happen for several hundred years yet.

Up to 1998 the ESA ISO (Infrared Space Observatory) was the most sensitive mid infrared telescope ever built. ISO observations were performed at 7 microns (and 15 microns, not shown) aiming to detect embedded sources in the pillars.

Credits: ESA/ISO/Pilbratt et al. HI-RES JPEG (Size:
192 kb)

Powerful ground-based telescopes continue to provide astonishing views of our Universe, but images in far-infrared, mid-infrared and X-ray wavelengths are impossible to obtain owing to the absorbing effects of Earth's atmosphere.

Space-based observatories such as ESA's Herschel and XMM-Newton help to peel back that veil and see the full beauty of the Universe across the electromagnetic spectrum.

With regions like the Eagle Nebula, combining all of these observations helps astronomers to understand the complex yet amazing lifecycle of stars.

Tuesday, January 04, 2011

Stellar Powerhouses in the Eagle Nebula

NGC 6611 - The Eagle Nebula
Credit: ESA/Hubble & NASA

A spectacular section of the well-known Eagle Nebula has been targeted by the NASA/ESA Hubble Space Telescope. This collection of dazzling stars is called NGC 6611, an open star cluster that formed about 5.5 million years ago and is found approximately 6500 light-years from the Earth. It is a very young cluster, containing many hot, blue stars, whose fierce ultraviolet glow make the surrounding Eagle Nebula glow brightly. The cluster and the associated nebula together are also known as Messier 16.

Astronomers refer to areas like the Eagle Nebula as HII regions. This is the scientific notation for ionised hydrogen from which the region is largely made. Extrapolating far into the future, this HII region will eventually disperse, helped along by shockwaves from supernova explosions as the more massive young stars end their brief but brilliant lives.

In this image, dark patches can also be spotted, punctuating the stellar landscape. These areas of apparent nothingness are actually very dense regions of gas and dust, which obstruct light from passing through. Many of these may be hiding the sites of the early stages of star formation, before the fledgling stars clear away their surroundings and burst into view. Dark nebulae, large and small, are dotted throughout the Universe. If you look up to the Milky Way with the naked eye from a dark, remote site, you can easily spot some huge dark nebulae blocking the background starlight.

This picture was created from images from Hubble’s Wide Field Channel of the Advanced Camera for Surveys through the unusual combination of two near-infrared filters (F775W, coloured blue, and F850LP, coloured red). The image has also been subtly colourised using a ground-based image taken through more conventional filters. The Hubble exposure times were 2000 s in both cases and the field of view is about 3.2 arcminutes across.