Banging the drum for ESO

It was a pleasure to welcome Rob Ivison, Director of Science at the European Southern Observatory (ESO) , to Maynooth this afternoon for a colloquium.

I was on my best behaviour introducing his talk and even refrained from pointing out that his native Lancashire is actually in the Midlands.

Ireland became a full member of ESO earlier this year and Rob has been touring Ireland giving talks to encourage Irish astronomers to make the most of the many opportunities membership presents. Having already visited Cork and Galway he passed through Maynooth today before ending up in Dublin tomorrow.

It was an enjoyable and impressive talk and very nice to chat with Rob afterwards over dinner.

Bon voyage to Rob and thanks for the visit!

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Newsflash: Ireland and ESO

Some good news was waiting for me when I got back to the office after my lecture just now, namely that Astronomy in Ireland will shortly receive an enormous boost, as the Republic has joined the European Southern Observatory (ESO).

For those of you not in the know, ESO is an intergovernmental astronomy organisation and is the world’s most productive astronomical observatory. Founded in 1962, its headquarters are in Garching (near Munich, Germany), and it currently has 15 member states. On October 1st, Ireland will become the 16th. Its main work is conducted using a variety of large optical and radio telescopes which are all located in the southern hemisphere, notably at Paranal in Chile.

ESO’s VLT telescopes at Paranal (in the Andes Mountains).

The official press release includes the following:

We are delighted to welcome Ireland as the newest member of our organisation” stated ESO’s Director General, Xavier Barcons. “Ireland’s mature and thriving astronomical community will add to the broad variety of expertise in the ESO Member States, strengthening ESO’s position at the forefront of global astronomy. Irish astronomers will gain access to a suite of the world’s most advanced ground-based astronomical telescopes and will have the opportunity to be part of the construction of the next generation of ESO instruments in partnership with other ESO Member States. We are also very much looking forward to working with Irish industrial partners to build and operate ESO’s state-of-the-art telescopes.

It was probably the industrial opportunities afforded by ESO membership that persuaded the Irish government to stump up the subscription fee, but this decision is also extremely positive news for the relatively small but vibrant community in Ireland working on observational astronomy which I’m sure will make the most of the chance to do ever more exciting research using these facilities.

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Gravitational Redshift around the Black Hole at the Centre of the Milky Way

I’ve just been catching up on the arXiv, and found this very exciting paper by the GRAVITY collaboration (see herefor background on the relevant instrumentation). The abstract of the new paper reads:

The highly elliptical, 16-year-period orbit of the star S2 around the massive black hole candidate Sgr A* is a sensitive probe of the gravitational field in the Galactic centre. Near pericentre at 120 AU, ~1400 Schwarzschild radii, the star has an orbital speed of ~7650 km/s, such that the first-order effects of Special and General Relativity have now become detectable with current capabilities. Over the past 26 years, we have monitored the radial velocity and motion on the sky of S2, mainly with the SINFONI and NACO adaptive optics instruments on the ESO Very Large Telescope, and since 2016 and leading up to the pericentre approach in May 2018, with the four-telescope interferometric beam-combiner instrument GRAVITY. From data up to and including pericentre, we robustly detect the combined gravitational redshift and relativistic transverse Doppler effect for S2 of z ~ 200 km/s / c with different statistical analysis methods. When parameterising the post-Newtonian contribution from these effects by a factor f, with f = 0 and f = 1 corresponding to the Newtonian and general relativistic limits, respectively, we find from posterior fitting with different weighting schemes f = 0.90 +/- 0.09 (stat) +\- 0.15 (sys). The S2 data are inconsistent with pure Newtonian dynamics.

Note the sentence beginning `Over the past 26 years…’!. Anyway, this remarkable study seems to have demonstrated that, although the star S2 has a perihelion over a thousand times the Schwarzschild radius of the central black hole, the extremely accurate measurements demonstrate departures from Newtonian gravity.

The European Southern Observatory has called a press conference at 14.00 CEST (13.00 in Ireland and UK) today to discuss this result.

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E-ELT: The Big Picture

Some astronomy news that made a bit of a splash over the weekend was the announcement that the UK is to invest £88 million in the European Extremely Large Telescope. This amount is to be spread over 10 years, so isn’t quite as astronomical as it sounds, but in any case it is only the UK’s contribution to a project that involves large contributions from the other countries involved in the European Southern Observatory. The UK announcement isn’t the end of the story, in fact, as not all the money needed to make the project work is yet in place.

This is all good news, especially because not long ago it seemed quite likely that the UK would have to make a choice between the E-ELT and the Square Kilometre Array. Now it looks like we’re going to be involved in both of the world’s leading ground-based observational facilities. There is a price to be paid, of course. In order to accommodate these projects within the flat-cash budget of the Science and Technology Facilities Council, difficult choices had to be made, and some things have to go. Not everyone will be happy about the outcome, but Big Science requires Big Decisions.

Anyway, it was nice to see the Observer run a piece about this story, although I was a bit baffled by the implication of the caption going with the picture used to illustrate the story:

The European Extremely Large Telescope will study the Magellanic Cloud.

I’ll avoid asking “which Magellanic Cloud (Large or Small)?” and just point out that E-ELT will study a lot more than either or both! Still, people are more likely to read web articles if they include images, so I’ll end this piece with an appropriate one.

Random Astronomical Image

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Astronomy’s Next Big Thing

I woke up this morning to hear an item about astronomy on the 7 o’clock news on BBC Radio 3. That doesn’t happen very often so I thought I’d follow it up with a short post before I head off to work.

The news item I heard followed up an announcement yesterday that the governing Council of the European Southern Observatory (ESO) had  approved the European Extremely Large Telescope (E-ELT) programme – which is to produce what will be the world’s largest ground-based optical telescope. Extremely Large is putting in mildly, of course. Its main mirror will be a colossal 39 metres in diameter (with a collecting area of almost a thousand square metres) and will have to made in bits with a sophisticated adaptive optics system to ensure that it can counter the effects of the Earth’s atmosphere and the limitations  of its own structure to  reach a phenomenal angular resolution of 0.001 arc seconds.

For more details on the telescope, see the official website here or the wikipedia article here, where you can also read more about the science to be done with E-ELT.

This telescope has been in planning for many years, of course. In fact, it began as an even more ambitious concept, a 100-metre diameter monster which I used to call the FLT. Over the years, however, for a mixture of technical and financial reasons, this was progressively de-scoped.

Yesterday’s announcement doesn’t mean that work will start immediately on building the E-ELT. That won’t happen until sufficient funding is secured and in the case of some countries, governmental approval obtained. Recent decisions by the UK Science and Technology Facilities Council to close down telescopes in Hawaii clearly anticipated the need to make some headroom in future budgets to enable this to happen. The best-case scenario is probably for E-ELT to take a decade or so to complete.

Of course the concentration of funding in ever and ever larger international facilities – such as E-ELT and the Square Kilometre Array – does create tensions within the UK astronomical community. Many scientists do excellent work with relatively small facilities, including those about to be closed down to make room for E-ELT. In the near future, the only ground-based optical facilities to which UK astronomers will have access will be operated by the European Southern Observatory. With fewer but larger (and more expensive) facilities operated by international agencies carrying out projects run by vast consortia, observational astronomy is definitely going the way of particle physics…

The problem  comes when the Next Big Thing  is too big to be built.  We might have already seen X-ray astronomy bubble burst in this way. To quote my learned friend Andy Lawrence:

Fundamentally, the problem is that X-ray astronomy has hit the funding wall. Everything gets inexorably bigger and more ambitious. Eventually its all or nothing… so when the answer is nothing … ah.

What will come after the Large Hadron Collider, or the E-ELT?  Is Big Science about to get too big?

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VISTA on Video

A chance tweet brought to my attention this video that fits well with a news story that’s been doing the rounds for a few days.   This concerns a very deep and wide survey called UltraVISTA, that has been made using the VISTA telescope at the European Southern Observatory’s Paranal Observatory in Chile. You can find the full press release from ESO that started the media interest here, where some lovely images can also be found.

VISTA is the world’s largest infra-red survey telescope, and is unusual among telescopes for having only one instrument on it, an Infra-red camera.  Technically, therefore,  it should really be called ISTA; owing to cost constraints the Visible camera that was initially proposed to accompany the Infra-red one and supply the V in its acronym,  was never built. Anyway, VISTA was designed explicitly to do survey work involving very distant and faint objects; its forte is to allow very deep images to be made with a very wide field of view, as demonstrated on the video…

Since I’m using the handle “telescoper” on this blog, I suppose I really should post about telescopes a bit more often than I do but I hope this will do for now!

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Galaxies con Alma

It’s back to School with a vengeance today, so not much time for the blog. However, I couldn’t resist mentioning the fact that the European Southern Observatory’s Atacama Large Millimetre Array, known to its friends as ALMA, has at last opened its eyes. Or at least some of them. ALMA in fact is an interferometer which eventually will comprise 66 dishes,   working together to with baselines as long 16km to synthesize a single huge aperture. The preliminary results that have just been released were obtained using just 16 dishes so they only offer a taste of what the full ALMA will do when it’s completed in 2013.

ALMA works in the millimetre wave region of the spectrum, operating at wavelengths between 0.3 and 9.6 mm. The overlap with the  wavelength range probed by the Herschel Space Observatory together with its much higher resolution than Herschel, which is a single telescope of only 3.5m diameter, makes the two very complementary: Herschel is good for surveying large parts of the sky, because it has a large field of view, whereas ALMA can do high-resolution follow-up of selected regions.

Anyway, here is ALMA’s view of the Antennae Galaxies (left) shown next to an optical image taken with the Very Large Telescope (VLT).

The system consists of two galaxies so close together that they interact strongly with each other via enormous tidal forces, hence the disturbed structure. The coloured regions in the ALMA image show radiation emanating from carbon monoxide present in huge clouds both in and between the galaxies. Altogether these clouds contain several billion solar masses worth of gas which has never been viewed before.

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