Herschel Telescope Peers into the Glow of Cygnus X

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In infrared, Cygnus-X is a glowing star nursery, and the Herschel space observatory has captured this beautiful new view showing an extremely active region of big-baby stars. It is located about 4,500 light-years from Earth in the constellation of Cygnus, the Swan. The image highlights the unique capabilities of Herschel to probe the birth of large stars and their influence on the surrounding interstellar material.

The bright white areas are where large stars have recently formed out of turbulent clouds, especially evident in the chaotic network of filaments seen in the right-hand portion of the image. The dense knots of gas and dust collapse to form new stars; the bubble-like structures are carved by the enormous radiation emitted by these stars.

In the center of the image, fierce radiation and powerful stellar winds from stars undetected at Herschel’s wavelengths have partly cleared and heated interstellar material, which then glows blue. The threads of compact red objects scattered throughout the image shows where future generations of stars will be born.

See larger versions of this image at ESA’s website.

Supernova Primo – Out To Far Frontiers

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Its nickname is SN Primo and it’s the farthest Type Ia supernova to have its distance spectroscopically confirmed. When the progenitor star exploded some 9 billion years ago, Primo sent its brilliant beacon of light across time and space to be captured by the Hubble Space Telescope. It’s all part and parcel of a three-year project dealing specifically with Type Ia supernovae. By splitting its light into constituent colors, researchers can verify its distance by redshift and help astronomers better understand not only the expanding Universe, but the constraints of dark energy.

“For decades, astronomers have harnessed the power of Hubble to unravel the mysteries of the Universe,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “This new observation builds upon the revolutionary research using Hubble that won astronomers the 2011 Nobel Prize in Physics, while bringing us a step closer to understanding the nature of dark energy which drives the cosmic acceleration.”

Type Ia supernovae are theorized to have originated from white dwarf stars which have collected an excess of material from their companions and exploded. Because of their remote nature, they have been used to measure great distances with acceptable accuracy. Enter the CANDELS+CLASH Supernova Project… a type of census which utilizes the sharpness and versatility of Hubble’s Wide Field Camera 3 (WFC3) to aid astronomers in the search for supernovae in near- infrared light and verify their distance with spectroscopy. CANDELS is the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and CLASH is the Cluster Lensing and Supernova Survey with Hubble.

“In our search for supernovae, we had gone as far as we could go in optical light,” said Adam Riess, the project’s lead investigator, at the Space Telescope Science Institute and The Johns Hopkins University in Baltimore, Md. “But it’s only the beginning of what we can do in infrared light. This discovery demonstrates that we can use the Wide Field Camera 3 to search for supernovae in the distant Universe.”

However, discovering a supernova like Primo just doesn’t happen overnight. It took the research team several months of work and a huge amount of near-infrared images to locate the faint signature. After capturing the elusive target in October 2010, it was time to employ the WFC3’s spectrometer to validate SN Primo’s distance and analyze the spectra for confirmation of a Type Ia supernova event. Once verified, the team continued to image SN Primo for the next eight months – collecting data as it faded away. By engaging the Hubble in this type of census, astronomers hope to further their understanding of how such events are created. If they should discover that Type Ia supernova don’t always appear the same, it may lead to a way of categorizing those changes and aid in measuring dark energy. Riess and two other astronomers shared the 2011 Nobel Prize in Physics for discovering dark energy 13 years ago, using Type Ia supernova to plot the Universe’s expansion rate.

“If we look into the early Universe and measure a drop in the number of supernovae, then it could be that it takes a long time to make a Type Ia supernova,” said team member Steve Rodney of The Johns Hopkins University. “Like corn kernels in a pan waiting for the oil to heat up, the stars haven’t had enough time at that epoch to evolve to the point of explosion. However, if supernovae form very quickly, like microwave popcorn, then they will be immediately visible, and we’ll find many of them, even when the Universe was very young. Each supernova is unique, so it’s possible that there are multiple ways to make a supernova.”

Original Story Source: Hubble Site News Release.

First (of many) Gorgeous Pictures from the New VISTA

Well, the WISE infrared all-sky satellite may be delayed until Monday, but the new infrared southern sky survey telescope VISTA (Visible and Infrared Survey Telescope for Astronomy) right here on Earth has gone online and released its first few gorgeous pictures.

This first one is of the Flame Nebula (NGC 2024), a star-forming region in the constellation Orion. The bright star in the image is the blue supergiant Alnitak, which is the easternmost star in Orion’s belt. Also shown is the reflected glow of NGC 2023 just below center, and the outline of the Horsehead Nebula in the far lower right (it looks a little different than you might normally see it because VISTA is operating in the visible and near-infrared). This image is about half the area of the full VISTA field of view, and is measures about 40 x 50 arcminutes – that’s about half a square degree on the sky , or twice the area of the full Moon.

The VISTA telescope is operated by the European Southern Observatory, and is part of their Paranal Observatory in the Atacama Desert of Northern Chile. It’s sitting just one peak over from the Very Large Telescope, also operated by the ESO. The main mirror on VISTA is a whopping 4.1 meters across (13.5 feet), and has 16 different detectors and a 3-ton camera for a total output of 67 million pixels. This allows for some very detailed images.

Since it’s a near-infrared telescope, it detects heat, and would detect its own heat signature, so the camera is housed in a cooler that keeps it at a chilly -200 degrees Celsius (-328 degrees Fahrenheit), and it’s sealed with the largest infrared-transparent window ever made. VISTA is charged with surveying the southern sky in the visible and near-infrared, and it will do so at a sensitivity that is forty times that of other infrared sky surveys, such as the Two Micron All-Sky Survey. It will be taking in enormous amounts of data to be processed: 300 gigabytes each night, or more than 100 terabytes per year.

Here’s a few more links to the first images released from the observatory to whet your appetite. Click on the links for a zoomable, hi-resolution image. You can be sure to see more like these in the future!

The Fornax Galaxy Cluster. Image Credit: ESO

The Fornax Galaxy Cluster, including the barred-spiral galaxy NGC 1365 in the lower right, and the elliptical galaxy NGC 1399 to the left of it.A mosaic image of over one million stars near the center of the Milky Way, in the constellation Sagittarius. Image Credit: ESO

This image shows a dusty region with over one million stars near the heart of the Milky Way. The dust normally obscures the stars in visible light, but these stars are visible with the infrared eyes of VISTA.

Source: ESO

Ring of Stars in Centaurus A Uncovered

Centaurus A (NGC 5128) is one of the most studied objects in the Southern sky, because it is the giant elliptical galaxy with the closest proximity to our own Milky Way. It lies 11 million light years away from the Milky Way, and is believe to have merged with another gaseous galaxy about 200 to 700 million years ago. The result of this galactic mashup: the birth of hundreds of thousands of stars in a kiloparsec-spanning ring near the core.

This is the first time that the inner structure of the galaxy has been resolved in such detail. Using the SOFI large field Infra-Red (1-2.5 micron) spectro-imager at the ESO New Technology Telescope, a research team led by Jouni Kainulainen of the University of Helsinki and Max Planck Institute for Astronomy was able to image a large ring of stars that have formed – and are still continuing to form – near the center of the galaxy. The brightest sources in the ring are red supergiants, or low-mass star clusters.

“It is important to note that it is not decisively the instrument (the telescope or the instrument attached to it) that enables us to see through dust, but the data analysis technique that is used to analyze the images taken with it. Of course, the instrument plays a big role in a sense that adequately high-quality images are needed to perform the analysis,” Dr. Kainulainen said in an email interview.

“There is a fundamental difference between the images we use in our paper and the Spitzer images: the wavelength that the images cover. In the images we used in our work, the dust lane of Centaurus A shows itself as “a shadow”, or more precisely, as an absorption feature (the wavelength is 1-2 micrometers). The Spitzer images represent somewhat longer wavelengths, and show the radiation emitted by the dust itself. As a concrete example, the most famous Spitzer image of Centaurus A … shows a parallelogram-like structure, but the image describes radiation mainly from dust, not from stars,” he said.

There is a large, S- or bar-shaped dust lane straight through the center of Centaurus A that obscures observations in the visible light spectrum. As shown in the image below, the ring structure of star formation is obscured by dust, but visible in the near-infrared.A comparison of Centaurus A in the visible and near-infrared spectra. Image Credit:ESO

Centaurus A is believe to house a supermassive black hole that has the mass of 200 million Suns at its core, evidenced by the radio emissions streaming out from the galaxy. Previous images of the galaxy from the Spitzer Space Telescope, the ESA’s Infrared Space Observatory and the Hubble Space Telescope revealed some aspects of the structure of the galaxy. The infrared eyes of Spitzer peered partway through the dust to show a warped parallelogram, the cause of which is the gravitational disturbance caused by the merger of Centaurus A with a smaller spiral galaxy.

The presence of rings such as the one seen in Centaurus A is probably not common among other elliptical galaxies, but other such galaxies are known to exist. It’s possible that they are present during only certain periods of an elliptical galaxy’s formation after it merges with another galaxy.

Dr. Kainulainen commented on this possiblity: “One should consider that seeing so bright ring structure is probably quite time-critical. The rings are believed to be induced by “a violent event” of merging galaxies, and they may evolve rather quickly to something that no longer looks like a clear, bright ring. Therefore, they might actually be quite common for merging galaxies, but they “last” only such a short time that we don’t see them in so many galaxies.”

The analysis technique used by the team could be applied to other galaxies to resolve formation structures previously hidden by dust, and provide more information about how violent events alter the formation of elliptical galaxies.

“Potentially, the technique can be applied to any relatively nearby galaxy showing prominent dust features. Such targets could be M31, M83, M51, Fornax A, or any similarly large, bright, dust containing galaxy. Due to geometrical reasons, Centaurus A was a very suitable target for applying the method. It will be more challenging in the case of, for example, normal Spiral galaxies. However, we have already experimented with such galaxies and feel positive about the possibilities they give,” said Dr. Kainulainen.

The striking image of Centaurus A’s ring of star formation was a somewhat surprising result of the imaging that the astronomers took of the galaxy, though there were hints from images taken by other telescopes that stellar formation was present in the obscured, dusty core.

Dr. Kainulainen said, “It was very surprising that the structure contained so much stars and star-forming activity, and that we could reveal it in such great detail. However, it was expected that a structure of this kind exists there, and contains at least some star formation. This was evident, for example, from the earlier Spitzer images. But when I first saw our result, “The Naked Picture of Centaurus A”, on my computer screen, it really was a big WOW-feeling!”

Further observations of Centaurus A are definitely in order to further explore the structure of the stellar ring, and the gravitational dynamics that allowed for its formation.

“Our plans include observations with the Very Large Telescope (European Southern Observatory) and the Hubble Space Telescope. In that work, the information we got about the dust lane in our published Letter will play a significant role. The planned observations aim particularly at determining how long, and in what magnitude, the structure has been forming stars in the past. Such information will help to understand galaxy-merging process, which is not an uncommon event in the Universe.

Dr. Kainulainen and his team published their results in a letter to Astronomy & Astrophysics, published online July 2nd, 2009. The full text of the letter is available here.

Source: ESO, Astronomy and Astrophysics, email interview with Jouni Kainulainen