Archive for European Space Agency

Euclid Updates

Posted in The Universe and Stuff with tags , , , , on June 17, 2019 by telescoper

Following the Euclid Consortium Meeting in Helsinki a couple of weeks ago, here are a couple of updates.

First, here is the conference photograph so you can play Spot The Telescoper:

(The picture was taken from the roof of the Finlandia Hall, by the way, which accounts for the strange viewpoint.

The other update is that the European Space Agency has released a Press Release releasing information about the location on the sky of the planned Euclid Deep Fields. Here they are (marked in yellow):

These deep fields amount to only about 40 square degrees, a small fraction of the total sky coverage of Euclid (~15,000 square degrees), but the Euclid telescope will point at them multiple times in order to detect very faint distant galaxies at enormous look-back times to study galaxy evolution. It is expected that these fields will produce several hundred thousand galaxy images per square degree…

Selecting these fields was a difficult task because one has to avoid bright sources in both optical and infrared (such as stars and zodiacal emission) so as not to mess with Euclid’s very sensitive camera. Roberto Scaramella gave a talk at the Helsinki Meeting showing how hard it is to find fields that satisfy all the constraints. The problem is that there are just too many stars and other bits of rubbish in the sky getting in the way of the interesting stuff!

 

For much more detail see here.

 

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Notes from Euclid 2019

Posted in Biographical, Maynooth, The Universe and Stuff with tags , , , , on June 4, 2019 by telescoper

I’ve just had my breakfast so I thought I’d do a quick post before the start of play on of the 2019 Euclid Consortium Meeting in Helsinki. Previous Euclid Consortium meetings were held in: Bologna (2011); Copenhagen (2012); Leiden (2013); Marseille (2014); Lausanne (2015); Lisbon (2016); London (2017); and Bonn (2018). I’ve only attended the last two: I was non-Euclidean before that.

Finlandia Hall

The venue is the Finlandia Hall, which looks splendid from the outside. I passed it during my stroll yesterday afternoon just so I could be sure where it is. It’s easy to find as it is very central and on the edge of a lake next to a major thoroughfare (Mannerheimintie). . I arrived yesterday to beautiful sunny weather but that has changed – it is pouring down as I write this, with thunder and lightning to boot. I don’t have to leave the Hotel for an hour or so, however, so perhaps it will have passed. There’s no sign of that just yet but I brought a brolly, and it’s only 15 minutes away from the Hotel on foot.

According to the web page there are 408 participants at the last count. I expect there’ll be quite a few people I know here but I haven’t met any yet. The Euclid Consortium has well over a thousand members, but obviously they’re not all here this week. I seem still to be the only representative of Ireland.

There’s a nice webpage showing all the institutions around the world who belong to the consortium behind the European Space Agency’s Euclid Mission. Here’s a screen grab that shows all the logos of all the institutions involved in this very large Consortium:

There are so many that it’s hard to see them all, but if you look very closely about half way down, among the Ms, you will see Maynooth University among them. Ireland is a member state of the European Space Agency, by the way.

Top tips for participants include not to tip:

Here is the latest timeline for the Euclid mission: launch around June 2022 followed by six years of operations.

If you want to follow on Twitter the relevant hashtag is #Euclid2019.

The Tenth Anniversary of the Herschel/Planck Launch

Posted in Biographical, Cardiff, The Universe and Stuff with tags , , on May 14, 2019 by telescoper

A little birdie told me (via a tweet) that today is the 10th anniversary of the launch of the ESA Planck and Herschel satellite missions. Can it really be so long ago?

Anyway, both were superbly successful and both involved many friends and former colleagues from Cardiff and elsewhere, so I thought I’d reblog this post which I wrote on the day of the launch (on May 14 2009)….

In the Dark

The Big Day has finally arrived!

I’ve managed to submit my paper to the journal and the ArXiv before the little shindig we’ve been planning for the Planck and Herschel launch gets under way at 1pm. Business as usual so far, though.

Strangely, I haven’t managed to get nervous yet, although I have to say  there are many anxious faces around the department. I just keep telling people how much simpler their life is going to be if it all goes wrong, without all that messy and unnecessarily complicated data to deal with. It bothers me sometimes that I don’t often get nervous expect when watching sport. Mind you, being  a Newcastle United supporter probably makes me more nervous more often than most people.

Anyway, at times like this a  stiff upper lip is obviously called for. Anyone who cracks now is clearly not officer material. There’ll be plenty of…

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Nature After Planck…

Posted in Maynooth, The Universe and Stuff with tags , , , , , , on July 24, 2018 by telescoper

After last week’s short update about the last tranche of papers from the European Space Agency’s Planck Mission it’s time for another short update about a piece in Nature (by David Castelvecchi) that explains how researchers are moving to smaller projects studying different aspects of the cosmic microwave background.

In the spirit of gratuitous self-promotion I should also mention that there’s a little quote from me in that piece. My comment was hardly profound, but at least it gets Maynooth University a name check…

Much of Davide’s piece echoes discussions that were going on at the meeting I attended in India  last October, but things have moved on quite a bit since then at least as far as space experiments are concerned. In particular, the proposed Japanese mission Litebird has been shortlisted for consideration, though we will have to wait until next year (2019) at the earliest to see if it will be selected. An Indian mission, CMB-Bharat, has also emerged as a contender.

While the end of Planck closes one chapter on CMB research, several others will open. These are likely to focus on polarization, gravitational lensing and on cosmic reionization rather than refining the basic cosmological parameters still further.

Planck’s Last Papers

Posted in The Universe and Stuff with tags , , , , on July 17, 2018 by telescoper

Well, they’ve been a little while coming but just today I heard that the final set of a dozen papers from the European Space Agency’s Planck mission are now available. You can find the latest ones, along with the all the others, here.

This final `Legacy’ set of papers is sure to be a vital resource for many years to come and I can hear in my mind’s ear the sound of cosmologists all around the globe scurrying to download them!

I’m not sure when I’ll get time to read these papers, so if anyone finds any interesting nuggets therein please feel free to comment below!

Planck wins the Gruber Prize (and the Shaw Prize)

Posted in Science Politics, The Universe and Stuff with tags , , on May 13, 2018 by telescoper

I forgot to mention last week that the 2018 Gruber Prize for Cosmology has been awarded to the Planck team, and its Principal Investigators Nazzareno Mandolesi and Jean-Loup Puget.

For more information about the award and the citation, see here.

This annual prize is worth $500,00; the two PIs will get $125,000 each and the rest divided among the team. I’m not sure whether this means the Planck Science Team (whose membership is listed here or the entire Planck Collaboration (which numbers several hundred people) but regardless of whoever gets the actual dosh, this award provides a good excuse to send congratulations to everyone who worked on this brilliant and highly successful mission!

 

UPDATE: 14th May 2018. Jean-Loup Puget has also been awarded the Shaw Prize for Astronomy.

Gaia’s Second Data Release!

Posted in The Universe and Stuff with tags , , , on April 26, 2018 by telescoper

It seems like only yesterday that I was blogging excitedly about the first release of data (DR1) from the European Space Agency’s Gaia Mission. In fact it was way back in 2016! Anyway, yesterday came another glut of Gaia goodness in the form of the second release of data, known to its friends as DR2.

In case you weren’t aware, Gaia is an ambitious space mission to chart a three-dimensional map of our Galaxy, the Milky Way, in the process revealing the composition, formation and evolution of the Galaxy. Gaia will provide unprecedented positional and radial velocity measurements with the accuracy needed to produce a stereoscopic and kinematic census of about one billion stars in our Galaxy and throughout the Local Group. This amounts to about 1 per cent of the Galactic stellar population.

You can find links to all the DR2 science papers here, a guide to how to use the data here, and of course a link to the full Gaia Archive here.

Here’s a (brief!) list of the contents of DR2:

  • The five-parameter astrometric solution – positions on the sky (α, δ), parallaxes, and proper motions – for more than 1.3 billion (109) sources, with a limiting magnitude of G = 21 and a bright limit of G ≈ 3. Parallax uncertainties are in the range of up to 0.04 milliarcsecond for sources at G < 15, around 0.1 mas for sources with G=17 and at the faint end, the uncertainty is of the order of 0.7 mas at G = 20. The corresponding uncertainties in the respective proper motion components are up to 0.06 mas yr-1 (for G < 15 mag), 0.2 mas yr-1 (for G = 17 mag) and 1.2 mas yr-1 (for G = 20 mag). The Gaia DR2 parallaxes and proper motions are based only on Gaia data; they do no longer depend on the Tycho-2 Catalogue.
  • Median radial velocities (i.e. the median value over the epochs) for more than 7.2 million stars with a mean G magnitude between about 4 and 13 and an effective temperature (Teff) in the range of about 3550 to 6900 K. This leads to a full six-parameter solution: positions and motions on the sky with parallaxes and radial velocities, all combined with mean G magnitudes. The overall precision of the radial velocities at the bright end is in the order of 200-300 m s-1 while at the faint end the overall precision is approximately 1.2 km s-1 for a Teff of 4750 K and about 2.5 km s-1 for a Teff of 6500 K.
  • An additional set of more than 361 million sources for which a two-parameter solution is available: the positions on the sky (α, δ) combined with the mean G magnitude. These sources have a positional uncertainty at G=20 of about 2 mas, at J2015.5.
    G magnitudes for more than 1.69 billion sources, with precisions varying from around 1 milli-mag at the bright (G<13) end to around 20 milli-mag at G=20. Please be aware that the photometric system for the G band in Gaia DR2 is different from the photometric system as used in Gaia DR1.
  • GBP and GRP magnitudes for more than 1.38 billion sources, with precisions varying from a few milli-mag at the bright (G<13) end to around 200 milli-mag at G=20.
  • Full passband definitions for G, BP and RP. These passbands are now available for download.
  • Epoch astrometry for 14,099 known solar system objects based on more than 1.5 million CCD observations. 96% of the along-scan (AL) residuals are in the range -5 to 5 mas, and 52% of the AL residuals are in the range of -1 to 1 mas. The transit observations are part of Gaia DR2 and have also been delivered to the Minor Planet Center (MPC).
  • Subject to limitations (see below) the effective temperatures Teff for more than 161 million sources brighter than 17th magnitude with effective temperatures in the range 3000 to 10,000 K. For a subset of about 87 million sources also the line-of-sight extinction AG and reddening E(BP-RP) are given and for a part of this subset (around 76 million sources) the luminosity and radius are available as well.
  • Classifications for more than 550,000 variable sources consisting of Cepheids, RR Lyrae, Mira and Semi-Regular Candidates as well as High-Amplitude Delta Scuti, BY Draconis candidates, SX Phoenicis Candidates and short time scale phenomena.
  • Planned cross-matches between Gaia DR2 sources on the one hand and Hipparcos-2, Tycho-2, 2MASS PSC, SDSS DR9, Pan-STARRS1, GSC2.3, PPM-XL, AllWISE, and URAT-1 data on the other hand.

There’s much more to Gaia than pictures, but here’s a map of the stars in our galaxy to give you an idea:

I remember first hearing about Gaia about 17 years ago when I was on a PPARC advisory panel and was immediately amazed  by the ambition of its objectives. As I mentioned above, Gaia is a global space astrometry mission, which will make the largest, most precise three-dimensional map of our Galaxy by surveying more than a billion stars. In some sense Gaia is the descendant of the Hipparcos mission launched in 1989, but it’s very much more than that. Gaia monitors each of its target stars about 70 times over a five-year period. It is expected to discover hundreds of thousands of new celestial objects, such as extra-solar planets and brown dwarfs, and observe hundreds of thousands of asteroids within our own Solar System. The mission is also expected to yield a wide variety of other benefits, including new tests of the  General Theory of Relativity.

For the brighter objects, i.e. those brighter than magnitude 15, Gaia  measures their positions to an accuracy of 24 microarcseconds, comparable to measuring the diameter of a human hair at a distance of 1000 km. Distances of relatively nearby stars are measured to an accuracy of 0.001%. Even stars near the Galactic Centre, some 30,000 light-years away, have their distances measured to within an accuracy of 20%.

It’s an astonishing mission that will leave an unbelievably rich legacy not only for the astronomers working on the front-line operations of Gaia but for generations to come.