One of the key things that happened last year was the formation of the GALAH survey and team. GALAH stands for GALactic Archaeology with HERMES. I wrote about HERMES in a previous post. GALAH is the survey team that will use the HERMES instrument to carry out a million star survey of the Milky Way. Using HERMES spectra the team will measure over 15 chemical elements in each star, as well as information about the stars properties (temperature, gravity and velocity). Its is the first time such a large survey is being carried out and we expect lots of science will result with such a dataset. The primary science goal of the survey is to identify the building blocks of the Milky Way using their chemical fingerprint – the work that I started since my PhD. HERMES is being built as we speak and survey plans are coming together with the formation of working groups and development of data handling software. Both HERMES and GALAH plan to take flight in 2013!! Click on the logo to see the GALAH survey website.

Other highlights of last year was winning two awards.

1. I won the Louise Webster Prize from the Astronomical Society of Australia. It is awarded in “recognition of outstanding research by a scientist early in their post-doctoral career”, which I was extremely pleased and honored to have received.

2. I was granted an Innovation Scholarship Award by the Australian Government Department of Innovation. I will use the grant of $20K to host an International workshop on Galactic Archaeology Surveys here in Sydney. The meeting is timed for the GALAH survey, so that we can learn about the latest research in this field and also tips on successful surveys in terms of technicalities of running a major survey. Here is the link to the survey website: http://physics.mq.edu.au/astronomy/ga-surveys/

Speaking of meetings, there are plenty coming up over this year – several major ones right here in Australia.

In addition to “my” workshop on Galactic Archaeology Surveys, there is a meeting on Multi-Wavelength surveys in the Hunter valley in June. I hope to attend this meeting to talk about HERMES and the GALAH survey.

There is also the Nuclei in the Cosmos (NIC) meeting in Carins in August. NIC 2012 is a major gathering of International physicists, bridging the fields of nuclear physics and astrophysics, with expected participants of over 300 people!   I am part of the organizing committee helping out the team with their many tasks, and also planning to attend and make a presentation.

This year is also the year of the International Astronomical Union (IAU) General Assembly – hosted in Beijing, China. While I would have liked to attend, the number of meetings already in Aus and ramping up of work towards the finishing HERMES is going to keep me busy well into the next year.

Having missed the first talk, because I really had to be a parent helper at Year 1 Maths groups, I got there in time to hear the talk by Nicole McKenna from the National Foundation for Australian Women. The point that struck me most was the ‘unconscious bias’ against female achievers, by both genders. She mentioned a study where students were asked to comment about a story involving the career of Heidi / Howard. The story was the same, but some students were told it was Heidi, and others were told it was Howard. All other aspects were identical. But at the end, students founds Howard more like-able than Heidi??? Why?? This made me consider occasions where I may have had similar unconscious biases – I ended up thinking about our Julia Gillard…

After tea, we heard from several different female astronomers about their careers. This was the only time at a meeting, did I hear about the effort that goes on behind the scenes by mummy astronomers. The few mummy astronomers I know chat about this kind of thing privately – about juggling research, sick children, grumpy husbands, traveling, and in-laws… but it was so good hear about it at an official meeting!

I didn’t get to attend the session after lunch because I had to pick up my older son from school. I came back with him to the last discussion session. But alas, the WiFi in the conference room was too slow and I could not find any way to keep a 6yr old amused and had to leave… Made me realize how much I depend on the internet to babysit kids!!

The 2dF robot placing fibers on the plate to observe. This system will feed light into HERMES. Photo: Barnaby Norris

I introduced my role as HERMES project scientist in the earlier post, but didn’t get around to explain what it is and why we are doing it. HERMES stands for High Efficiency and Resolution Multi-Element Spectrograph. It is the next major new instrument for the 4m Anglo-Australian Telescope (AAT), located at Siding Spring Observatory in the middle of New South Wales. HERMES will make use of existing fiber positioning facilities at the AAT (shown in the picture on the right) to provide high-resolution spectra of ~400 stars simultaneously covering four different spectral wavelength ranges in one go. It will certainly be a unique instrument!

The design of HERMES was selected such that we can use it to undertake a large scale survey of stars in our Milky Way galaxy, that is currently not possible. With so many stars observable in one go, we are proposing a large observing program to target over a million stars! The goal of this ambitious project is to chemically tag each of these million stars and identifying the original “building blocks” of the Galactic disk. This field of research is usually referred to as Galactic Archaeology. I posted earlier about the idea behind the chemical tagging technique and my work on dispersing star clusters. Now the plans are in place to carry out large scale reconstruction.

A region of the Sun's spectrum showing several chemical element lines.

For this Galactic Archaeology survey, HERMES will provide spectra in four different wavelength regions. Different chemical element are measurable from different parts of the stellar spectrum. The image on the left is a small region of the Sun’s absorption spectrum. The different absorption lines are due to different chemical elements present in the star’s atmosphere. By measuring the depth of the lines we can estimate the abundance (i.e how much) of that element is in that star. We are working here in the optical part of the spectrum, and HERMES is designed to get spectra in regions where the chemical elements needed to carry out ‘chemical tagging’ will appear. The aim is to measure more than 25 chemical elements! These lines need to be sufficiently resolved (i.e. not blended with other lines) in order to make an accurate measurement. HERMES will provide a nominal resolution of 30,000 which is exactly what we need (it will also have a higher resolution option of 50,000 for other projects).

Also, we need to have sufficient signal to make accurate measurements of the chemical content of the stars. The typical ratio of signal required over the noise that we need is 100. HERMES is deemed high-efficiency, because we aim to get this 100 signal-to-noise in 1 hour of observing (for the experts: on a 4m telescope for V~14mag star, using a fiber-system – that is pretty good efficiency).

The four channel design showing the light path from Slit and ending at the Cameras.

A model of what we expect HERMES to look like once all the components are assembled.

When I arrived at the AAO last year, my immediate task was to sort out the science requirements for HERMES as the project was at the Preliminary design stages. Since this was my first time getting involved with instrumentation, it was both interesting and challenging at the same time. Deriving a set of requirements is easy, but then you need to deal with the practicalities of it regarding the engineering, time, costs, etc. There are many things that an astronomer (esp. a naive one like me) doesn’t think about, which the engineers are quick to point out. It is interesting working in a cross-disciplinary team where some cannot understand why I am so adamant about a certain specification, while I don’t exactly feel strongly about a different requirement which the engineers see as a major problem. So much of my time last year was discussing things with the wonderful engineering team here at the AAO, learning about the complexity of building a new instrument (from optics, mechanics, electronics to software and data handling and everything in between) and the team’s give-and-take needed to make it all happen.

Last December the HERMES team put a massive effort and we passed our Final design review! So now things are relatively smooth rolling with many of the instrument parts being put together. The next major step is when we are ready to assemble it part by part and then put it up on the telescope! HERMES first light is expect in early 2013 and that will be the moment of truth!  :)

I am back!! So where to start on all the crazy things that have happened since January…

Well, I am now blogging from Sydney, Australia. Since March, I am a research astronomer at the AAO (which stands for Anglo-Australian Observatory, but from July 1st it will change to Australian Astronomical Observatory). With the offer for this position coming in mid January, I had to unfortunately pull the plug on the Marie-Curie fellowship in Lund, Sweden. So I immediately changed our plans. Flights to Sweden were canceled, school enrollments from my kids in Lund and childcare was canceled, stopped our bid for housing in Lund and instead our household goods were sent from Melbourne to Sydney. Then we needed to find accommodation, schools, childcare etc in Sydney within a matter of weeks.

It was a very very busy period the last month or so. The fact that I knew the Australian system and not having a language barrier helped alot. Although I was on my own with the kids for about 2 months getting them settled in schools and house hunting until my husband moved to Sydney. Finally we found a house, car, etc and life is (almost) back into a steady routine. And I got a restful break in Namibia – more on that in a future post.

I am really happy to get the position at AAO. The premises are small and in a bush surrounding which suites me well. I am also the Project Scientist of the HERMES instrument currently being built at the AAO. In summary, HERMES is a spectrograph to be commissioned on the AAT that will be able to provide high-resolution spectra of 400 stars at once. How cool is that!

One of the many tasks of being the project scientist is to supervise the design and performance of the instrument, to make sure we get the best possible outcome once we actually go online at the telescope. Its a new role for me, certainly challenging but even more so exciting. Its amazing the insight I have got just over the past 2months working with the engineers into the teamwork that goes in to getting a concept design on paper into an actual physical instrument. We wont have the final instrument for a couple of years yet, but now we are investigating what that instrument would be made up of, component by component. Did I say was excited about all this?

I will try to blog regularly from now on. Stay tuned for more

http://2010eclipse.blogspot.com/

http://thilinaheenatigala.blogspot.com/2010/01/expedition-to-northern-sri-lanka.html

This will be a historical moment as it will be the first time most of them are traveling to North Sri Lanka. It is a perfect opportunity to celebrate Peace in Sri Lanka through this natural phenomenon – Annular Solar Eclipse 2010

Note I am still blogging under ESO but I will not be at ESO after the end of February. So where to next? I do have a Marie Curie fellowship to work at Lund University in Sweden. Its prestigious and hard to get and may well be a turning point in my professional life, but again we will be far from home and right now we (especially my kids) are enjoying living in Melbourne so much to even consider moving overseas again. Add to that my husband recently got a permanent job here. So going to Sweden would mean splitting the family up between the opposite ends of the planet! The family vs. career battle continues on in 2010!

This is my last day at ESO, even though I would still be employed during the vacation. I am leaving here with lots of fond memories, both personally and professionally. The experience I gained in ESO-Chile is unforgetable, working at the Paranal Observatory. I will never forget the crispy clear skies at Paranal, both the pitch black dark nights with a glowing Milkyway as well as those nights brightly lit by the full moon.

And Munich will always be special to me since my second son was born here. We have made several good friends during the last year or so and I am sorry to have to say good-bye to them. Professionally the past year has been my most productive since my thesis days. Working at the USD gave me insight into ESO as a whole organization and I will surely miss the highly active science life in and around the Garching campus with the all the neighboring institutes. I highly recommend working here.

So only 3 more days to go, which will be busy with the usual chaos of relocating (I should be used to this by now). The office is cleared now. Data backed up. Now I am off to say good-bye to colleagues and then the farewell party at my son’s school. The furniture packers are coming tomorrow, then the painters, then to settle the house bills, sign off the car sale and we are off to the hotel for the last nights.

Then comes the long-haul flight from Munich to Melbourne, with two little ones. Wish me luck!

This data set was one that was given to me by a colleague in 2007. It was always on the back burner because it was a lot of data and required a careful high accuracy analysis. The science goals is to see if we can detect the very subtle effects of planet engulfment (ie. can we detect any changes to the chemical makeup of a star if it has swallowed a planet?).

The abundance analysis is finally finished. I have analysed and re-analyzed it over and over again to check every possible reason (that I could think of) for some offsets that showed up in the first results. The data are on some cool stars (in stellar astronomical terms!). They are known to be problematic with respect to getting the correct theoretical models. Basically I have had troubling getting an exact match between the observations (the stellar spectra) and the theoretical model stellar atmospheres. Even now, I cannot get a perfect agreement, but having searched the past literature and tried all the different possibilities, we have to accept that this offset is also part of the ‘result’. So I have now finished doing all the computations and the results were sent to my colleague. Disregarding the offset, I see no obvious signs of any planet engulfment, but my colleague will have the final word on that armed with statistical calculations.

Since this is not my own data, my colleagues would lead the paper writing and deal with getting it published. I am just happy to have it all finished and out of my hands.

Commenced in 2004, as the primordial observation competition is South Asia, STAR PARTY is a competition where students from different parts of Sri Lanka compete to win the competition that is focused on the fields of Astronomy, Astrophysics, Cosmology and Rocketry. Since then it has been held annually and has seen reputation as an Observation Competition and Astronomy Workshop over the years.

STAR PARTY 2009 will be the largest IYA 2009 project of Sri Lanka, taking place at the premises of University of Peradeniya, Kandy, Sri Lanka from 6.00 pm (local time) (12:30 UTC/GMT or 08:30 EDT) onwards on 25th September 2009. The project will last for more than 12 hours and already 500+ participants confirmed for Star Party. The event is organized by the Anandian Astronomical Association, of Ananda College and Astronomical Society of Mahamaya Girls’ College, Kandy as an affiliated project.

This year they will provide a live feed of the event via http://starparty2009.com/sp-09-live/. You may also find custom information and archives of past events at the official site at http://starparty2009.com/. The live feed is especially aimed at educating the global community about the event and enabling everyone to better understand the universe, following the IYA general theme “Universe is Yours to Discover”.

Well done to all who made this possible!

Luckily I already have a job lined up: I got a Marie-Curie fellowship earlier in the year which is granted by the European Commission for a duration of 2 years. I am hoping to take the funds to work with a research group in Lund, Sweden. Earlier in May we visited Lund to get an idea of the research institute, plus domestic matters like schools, housing etc.

This is all good and I am very happy to have the Marie-Curie fellowship, but with a growing family, and the kids reaching school age, and having already relocated several times to vastly different places around the world (Australia -> Chile -> Germany), there is a need to settle in one place. At the beginning it was very exciting to travel and experience new languages, cultures etc, but remember this is not touristic travel – its a relocation and it is stressful for family to have everything around them change and to loose a sense of home…my eldest son would ask: which home are we going to?

Plus, if you are in a committed relationship, you would have to have a partner who is happy with all this globetrotting, which can be jeopardising to their careers. Again, I have been lucky enough to have a husband give up his permanent job in Australia to accompany me. But I cannot ask for too much more and have to achieve a balance. We both agree that Australia would be the best place to settle. So now we are focusing on making that a reality.

The problem is there are no permanent posts in Australia that I can get anytime soon. There are however fixed term post-docs which may lead into a permanent position. This is what I am keeping an eye out for. With 4 years experience at ESO and with a Marie-Curie fellowship coming up, I am hoping to get a permanent post within the next two years. I will of course have to work hard to get enough publications and develop a contact network to make this come true. But even then nothing is guaranteed…!!