Archive for the ‘ESA’ Category

Herschel has an App!

May 25, 2011

You can now browse Herschel’s online image showcase OSHI using an App on your iPhone, iPod or iPad.

More details available from the Apple App Store:

http://itunes.apple.com/us/app/esa-oshi/id429660006?mt=8

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Herschel Views Andromeda

January 5, 2011

We’ve been sitting on this image since just before Christmas so that it could be unveiled during the BBC Stargazing Live show last night, but I’ve been aching to get this onto the blog ever since I saw it.

This is a Herschel image of our nearest neighbour galaxy, the Andromeda galaxy, also known as M31, along with comparison images at other wavelengths.

Andromeda Galaxy

The Herschel data shows where stars are forming and where starlight is absorbed by dust. Images in the optical show us where stars are now, and the complementary X-ray data from XMM, ESA’s X-ray space telescope, show us where stars have died. The different locations picked out by these different wavelengths give hints as to how the Andromeda Galaxy has changed and evolved over its lifetime.

More information available from ESA, and from the BBC.

No, we’ve not gone asleep…

October 18, 2010

… but instead, we’re swamped with a combination of SPIRE-related technical work, miscellaneous activities for our home institute (such as teaching, and the list goes on) and bottom of the pile, finding time to do some actual science. The various science teams are retrenching/reorganising to produce new papers/results now that the hectic Science Demonstration paper era has now passed – so expect to see a whole new slew of results over the next few months on here.

In the meantime, you can read the full Astronomy & Astrophysics Herschel special addition – for free!

Herschel and Planck win Grand Prix!

June 14, 2010

No, not the Monaco Grand Prix, but the Grand Prix for 2010 of the AAAF, the French Association for Aeronautics and Astronautics to acknowledge their “outstanding space endeavours”.

More information about the prize can be found from ESA and from the Planck webpages.

Press release time from the ESLAB meeting

May 6, 2010

ESA held a press conference a couple of hours ago to highlight some of the results from the ESLAB meeting. If you missed the live stream earlier, you can catch it here .

A number of major programs released some mouth-watering data to the general public, ranging from high resolution studies of massive star formation in our own Galaxy (the massive bubble RCW 120, which contains an embryonic massive Wolf-Rayet star, and huge star forming complexes in Aquila and Vulpecula) to studies of the high redshift universe (the H-ATLAS program).

The H-ATLAS field
Credits: ESA/ATLAS Consortium

A picture of the first field observed in the H-ATLAS survey, made by combining the images made with the SPIRE camera at 250, 350 and 500 microns. The colours in the image are not real but have been used to represent the different infrared wavelengths. The faint blue whisps at the top of the image show dust in our own Galaxy and the bright object just above the centre of the picture is a ‘Bok globule’, a dense cloud of gas and dust, also in our Galaxy, in which a small star may be forming. The other objects in the picture are all galaxies, at distances up to 12 billion light-years. The image shows that the survey is detecting objects in our celestial ‘backyard’ and also other, further ones that we are seeing as they were not long after the Big Bang.

Vulpecula
Credits: ESA/Hi-GAL Consortium

This image, in the constellation of Vulpecula, shows an entire assembly line of newborn stars. The diffuse glow reveals the widespread cold reservoir of raw material that our Galaxy has in stock for building stars.

Large-scale turbulence from the giant colliding Galactic flows causes this material to condense into the web of filaments that we see all over the image. These are the ‘pregnant’ entities where the material becomes colder and denser. At this point, gravitational forces take over and fragment these filaments into chains of stellar embryos that can finally collapse to form baby stars.

Aquila
Credits: ESA/Hi-GAL Consortium

At the centre and the left of the image, the two massive star-forming regions G29.9 and W43 are clearly visible. These mini-starbursts are forming, as we speak, hundreds and hundreds of stars of all sizes: from those similar to our Sun, to monsters several tens of times heavier than our Sun.

These newborn large stars are catastrophically disrupting their original gas embryos by kicking away their surroundings and excavating giant cavities in the Galaxy. This is clearly visible in the ‘fluffy chimney’ below W43.

The RCW 120 bubble
Credits: ESA/PACS/SPIRE/HOBYS Consortia

RCW 120 is a galactic bubble with a large surprise. How large? At least 8 times the mass of the Sun. Nestled in the shell around this large bubble is an embryonic star that looks set to turn into one of the brightest stars in the Galaxy.

The Galactic bubble is known as RCW 120. It lies about 4300 light-years away and has been formed by a star at its centre. The star is not visible at these infrared wavelengths but pushes on the surrounding dust and gas with nothing more than the power of its starlight. In the 2.5 million years the star has existed. It has raised the density of matter in the bubble wall so much that the quantity trapped there can now collapse to form new stars.

The bright knot to the right of the base of the bubble is an unexpectedly large, embryonic star, triggered into formation by the power of the central star. Herschel’s observations have shown that it already contains between 8-10 times the mass of our Sun. The star can only get bigger because it is surrounded by a cloud containing an additional 2000 solar masses.

Not all of that will fall onto the star, even the largest stars in the Galaxy do not exceed 150 solar masses. But the question of what stops the matter falling onto the star is a puzzle for modern astronomers. According to theory, stars should stop forming at about 8 solar masses. At that mass they should become so hot that they shine powerfully at ultraviolet wavelengths.

This light should push the surrounding matter away, much as the central star did to form this bubble. But clearly sometimes this mass limit is exceeded otherwise there would be no giant stars in the Galaxy. So astronomers would like to know how some stars can seem to defy physics and grow so large. Is this newly discovered stellar embryo destined to grow into a stellar monster? At the moment, nobody knows but further analysis of this Herschel image could give us invaluable clues.

The press release (which this post is based upon quite heavily!), and high-res JPEGS of these images can be found at the ESA Herschel web site.

Additional First Science press releases – which we’ll return to later – can also be found here.

HERITAGE survey of the Large Magellanic Cloud

May 4, 2010

The first results on an extragalactic object here at ESLAB were presented this afternoon on the HERITAGE survey of the Large Magellanic Cloud – a follow-up program to a major Spitzer program to study the effects of star formation on the surrounding gas and dust in an environment that differs quite significantly from our own Galactic neighbourhood at high spatial resolution.

The HERITAGE team presented results from a central strip through the LMC that was observed as part of the Science Demonstration phase – one of the central results to emerge from this is the need for refinement of standard dust models when applied to environments such as the LMC. The harsh radiation environment, plus comparative lack of dust in the LMC leaves traditional dust models predicted too much dust – a different approach, based on modelling with amorphous carbon seems allow better constraints on the overall spectral energy distribution, especially as we move to longer wavelengths – too much dust can lead to an over-estimate of the amount of very, very cold dust (temperatures ~ 5-10 K!). There’s also tantalising hints of an over-abundance of polycyclic aromatic hydrocarbons (PAHs – basically soot, or the stuff burnt on an overdone hamburger) co-incident with the stellar bar in the LMC – for more details, sadly, I’ll have to talk to the presenter…

First Herschel Science!

December 16, 2009

Lots of new Herschel science will be released over the next few days by ESA. The first new result is an image of a region in Acquilla (not the Eagle Nebula as I originally stated – apologies!) taken with the PACS and SPIRE instruments.

The Eagle Nebula image reveals the dust and young stars obscured from observation by telescopes, such as HST, working at shorter wavelengths. Much structure is seen in this image, revealing the complex turbulent interactions behind star and planet formation.

More images and science results are coming. There should be several more releases over the next few days, coinciding with the early Herschel science meeting currently underway in Madrid (I’m not there so can’t report live). ESA have set up a central resource for all new Herschel images – the OSHI – online showcase of Herschel images. There’s not much there at the moment, but it’ll soon be filling up!

SPICA: The Next Step

December 2, 2009

While data has only just started to flow from Herschel, since these space missions take more than a decade to build, we’re already working on the next steps. These are all being done in the context of the ESA ‘Cosmic Visions’ programme.

There was an important meeting yesterday in Paris where the six remaining candidates had their chance in the spotlight.

The Herschel successor mission, SPICA, seems to be doing rather well, as it is the only one of the six missions whose budget is well within the limits.

A report on the meeting is available at BBC News Online.

First look at Herschel Spectroscopy

November 27, 2009

ESA put out a major release today showing the first results from the spectrographs on Herschel. The release includes data on the Orion star formation region, on nearby and distant galaxies, on a massive star about to become a supernova and on a comet in our own solar system. The latter set of data was taken with HIFI before the technical fault that has left it shut down, awaiting a restart early next year.

These spectroscopic observations show the huge potential of Herschel to show us the physical and chemical processes going on inside dusty objects, be they star formation regions in our own galaxy, or in luminous interacting galaxies like Arp220 and Mrk231. My own research interests are more focussed on the distant luminous objects, and the data shown here from two archetypical ULIRGs (Ultraluminous Infrared Galaxies) are really spectacular. Never before have we seen the rich range of spectral lines that PACS and SPIRE have revealed in these objects.

PACS also holds out the hope of examining the velocity structure of some of these lines. This is particularly interesting in Mrk231 which hosts not only a massive burst of star formation but also a supermassive black hole powering a hugely luminous active galactic nucleus (AGN). The relationship between galaxy interactions and mergers in triggering both starbursts and AGNs is a hot topic, and Mrk231 makes an ideal testbed.

Finally, for sheer spectral richness and complexity, the PACS spectrum of the massive star VYCMa takes some beating. There’s a huge amount of physics and chemistry in this spectrum of a star deep into its old age and soon to become a supernova. Unfortunately this isn’t my area, so hopefully someone will add comments describing what the data means for this object.

For more information and coverage of these results see the ESA web release, BBC News Online, and the SPIRE website at Cardiff University.

Stunning new Herschel Images of the Milky Way

October 2, 2009

ESA released new images form the Herschle telescope today. This shows a two degree square region of our galaxy at wavelengths and resolutions that have never before been achieved.

5 Colour Herschel Image of part of our own galaxy

The images show intricate filamentary structures made from cold interstellar material. This matter feeds galactic star formation, and this image provides new insights into these highly turbulent processes. This is also the first image released from Herschel’s ‘parallel mode’ that allows it’s two imaging instruments, PACS and SPIRE, to work together. This observing mode is immensely powerful as it allows 5 colour images such as this to be produced which might otherwise have had to be pieced together from separate observations. It’s a critically important mode for many of Herschel’s large area surveys, including the HIGAL project which will observe the entire galactic plane with sensitivity and resolution matching the 2 degree by 2 degree image shown here.

Further information about Herschel can be found from ESA, the SPIRE instrument team, the UK’s STFC and the BBC.