From the five science chapters in my PhD thesis, only three had so far been published as regular papers. I submitted one of the remaining chapters as a paper last autumn, and I got word today that it’s accepted as a paper in Astronomy & Astrophysics. It’s the least chemical of the five chapters; five years ago, as an undergraduate student in chemistry, I wouldn’t have had a clue what it’s about.

The final unpublished chapter will hopefully lose its unpublished status later this year. I know how I want to convert it into an A&A paper, but that won’t happen until the summer. First I have to finish a modelling paper I’m currently writing for the “Water In Star-forming regions with Herschel” (WISH) key program on the Herschel Space Observatory. Meanwhile, I’m also co-author on a series of papers showcasing the first results from the WISH program. The first six such papers, submitted late March, are accepted by now or will be soon. The next batch (possibly containing as many as twelve papers!) is due for submission on May 31st. There’s still tons of work to be done on those, so it’s gonna be a very busy month. Then again, seeing the beautiful results makes it all worth it. Here’s a couple of highlights released this week at the Herschel First Results Conference at ESA/ESTEC:

• Herschel’s HIFI follows the trail of cosmic water
• Herschel-HIFI unveils precursors of life-enabling molecules in Orion Nebula
• Herschel unveils rare massive stars in the act of forming

My main job as a postdoc this year is to help in the analysis of data taken with the Herschel Space Observatory. This infrared telescope was launched in May of last year and offers higher sensitivity and higher accuracy than any infrared space telescope to date. The astrochemistry group here in Leiden is leading the key program “Water In Star-forming regions with Herschel” (WISH), which is looking at water and chemically related species in a large number of young stars of different masses and different ages. We want to understand the role that water plays during the formation of new stars and their planetary systems.

For the past couple of months, we have been working very hard to prepare the first set of data for publication in a special issue of the journal Astronomy & Astrophysics. The full WISH team consists of some 70 scientists from around the world, and together we have written four papers for this special issue. Today is the deadline for submission to the journal. The journal editors will then send the papers to external referees in the regular process that scientific papers always have to go through. The papers are expected to be accepted for publication by mid-May, and the special issue should appear in July or August.

My main contribution to this set of first results papers has been to construct models for one particular young star, called HH 46, which we think is similar to the Sun when it was much younger. These models allow us to disentangle the contributions of different physical components (cold gas far away from the star, hot gas close to the star, and so-called shocks) to the observed emission. With the first results papers now submitted, the next order of business is to make the models a bit more general and apply them to the full sample of young stars that we are targeting. That will keep me busy for several months at least.

One of the other three WISH first results papers focuses on NGC 7129, a young star that is more massive than HH 46, but otherwise quite alike. An even more massive young star, DR21, is the focus of the third WISH paper. The fourth WISH paper looks at L1157, a young star that is expelling a lot of material in opposite directions. As team member of the WISH project, I’m co-author on these three, but I didn’t contribute much to the actual science cases.

I am also somewhat involved with another key program, called DIGIT, or “Dust, Ice and Gas In Time”. The aim of this project is to look more generally at the evolution of… well… dust, ice and gas during star and planet formation. The DIGIT team is submitting two papers for the first results special issue, each one looking at a young star (HD100546 and DK Cha) that is a bit older than the stars we targeted with WISH. That makes for a total of six papers I can add to my resume today. Not a bad score!

Part of the Herschel data presented in these papers is under embargo until the papers are accepted in May, so I’m not posting any abstracts yet. I did, however, put the titles and (partial) author lists on my publications page. Abstracts and full-text PDFs will appear at a later date.

My tradition of visiting the United States in January continues into the new decade. As the years pass, the number of destinations increases. In 2008, the business part of the trip only included Granville, OH. Last year, I also visited Columbus, OH and Ann Arbor, MI. This time, the two Ohio destinations are replaced by four new places: Austin, TX; Pasadena, CA; Cambridge, MA; and Washington, DC. I’ll also have a day and a half in Phoenix, AZ, but no business will be done there – the result of some logistical issues in planning the whole deal.

The purpose of this trip? To present my research at some of the top US astronomy institutes, and to talk about the possibilities for a postdoc position somewhere.

I’m off to a good start, with a pleasant flight from Amsterdam to Detroit (insofar as sitting in a cramped seat for 8.5 hours is ever pleasant), a quick transfer to my hotel in Ann Arbor, and a comfortable room in that hotel. Following the Christmas incident, security prior to boarding was tighter than ever. No body scan yet, but a full pat-down for every passenger, more stringent passport control, and a brief interrogation as to the purpose of the trip. The flight itself was unremarkable, except that it struck me as odd that the window shutters were closed almost the whole time. I don’t recall that being the case in 2008 and 2009.

Once out of the airport in Detroit, it was clear that I was in the US. The half-hour drive from the airport to Ann Arbor runs through the typical urban sprawl, with an overabundance of asphalt, billboards, gas stations and food courts. The hotel (Quality Inn & Suites, just off the US23 highway) is anonymous, but the girl at the reception was friendly, the room looks fine, and there’s free wi-fi.

I’ll be at the University of Michigan for the next day and a half, with a talk scheduled for Tuesday. I had a great time at UMich last year, and I look forward to repeating that experience.

I’ve got a date for my PhD defense: Wednesday October 21st at 3pm. It’s a strange idea: in less than two months, I’ll be a doctor.

The third paper for my PhD thesis just got accepted for publication in Astronomy & Astrophysics. The initial referee report we received last month was pretty hostile and recommended “eventual publication but only after some substantial revisions.” Basically, the referee felt we had ignored some recent experimental results in constructing our model. We had strong reservations about the validity of those results, so we deliberately didn’t include them.

We reran some of our models with the new experimental data included, and fortunately our conclusions didn’t change. That allowed us to send in a new manuscript that only contained some small changes relative to the original one. The referee now felt we had done a good job discussing the experimental data in question, and had made a good case for not including them throughout the paper. That was enough for him or her to recommend publication.

So, that means three of the five science chapters of my thesis are now finished. The fourth one is approaching a first full draft, and the fifth one is still entirely to be written. That still leaves a lot of writing to do before the end of August, but with the CO paper now accepted, I’m an important step closer to my graduation.

Everything is looking good so far on the launch of the Herschel Space Observatory together with Planck. Lift-off occurred at 15:12 (Dutch time) and the module is currently at 170 km above Earth’s surface and still climbing fast. There’s still a long time to go before we know if Herschel will actually work correctly, but the first couple of minutes at least went very well.

The end of my four-year PhD contract is approaching rapidly. I hope to submit my thesis to the printer at the end of August and defend it in the second half of October. As these dates are getting closer, I thought it’d be nice to maintain some sort of progress indicator on my website. So, as of today, “thesis stats” are visible at the top of the menu bar. Yesterday was the first time I compiled all available stuff into one PDF file. Spread across 126 pages are some front matter, a table of contents, three science chapters, a list of references, and a list of my own publications. Still missing are the figures in these three chapters, two additional science chapters, an introduction, a Dutch summary, and some minor other things. It looks like the final product will be around 200 pages. I wonder who’s gonna read all of that…

Leiden Observatory is the world’s oldest university observatory. It’s currently located on the university’s science campus at the edge of the city, but for over a hundred years it occupied a building downtown. This building, called the Old Observatory, dates from 1861 (the Observatory itself was founded in 1633) and is suffering from many years of poor maintenance. Last year, our Minister of Education, Culture and Science, Ronald Plasterk, allocated 2.8 million euros to restore the Old Observatory to its former glory. Today the minister was invited to start the restoration works by lifting one of the telescope domes off the roof.

I needed a break from my uncooperative collapse model, so I went to have a look. Also, I didn’t want to miss any possible mishaps. You never know what might happen when you let a secretary of state operate a mobile crane. They’re used to running the country, not a heavy piece of construction equipment.

As it turned out, not quite surprisingly, everything went just fine. The dome did swing about a bit during its descent, but it didn’t knock into the building or against any astronomers. The dome landed safely on the right spot. A local newspaper, the Leidsch Dagblad, was on scene to film the occasion. Pictures by myself and others are gathered here.

Because I didn’t want to sit through half an hour of speeches before the main event, I arrived later than most guests. Now I had to watch from behind a fence, but this turned out to have its virtues. After Plasterk put the dome on the ground, he led the party back to the Old Observatory building. He looked around before stepping through the door and noticed a bunch of people watching (and photographing) him from behind a fence a few metres away. Of course, those people were me and a few other students.

Plasterk turned around and headed straight for us. He must have heard us talk English, because he asked (in English) whether we were tourists. When we said we were students at the university, he told us he used to study there as well. In fact, as a biology student, he spent a lot of time at the Old Observatory. (For some reason, the biology faculty held classes there for many years.) We talked briefly about the difficulty of astronomical observations in Leiden nowadays, what with the generally poor weather, and we agreed this wasn’t such a bad thing, as it means we get to go to Chile every now and then to use much bigger telescopes. He then wished us a nice day and went back inside to finish the official programme.

This impromptu chat didn’t go unnoticed by the gathered journalists, who seemed to think that anyone talking to the minister must also be noteworthy. I’ve never had so many cameras pointed at me. Now let’s see if those journalists can find out why Plasterk displayed such interest in us.

NASA scientists have found strong evidence that microbes once lived on Mars, and may still do so right now, British tabloid The Sun reports. The evidence consists of a haze of methane in the Martian atmosphere. Professor Colin Pillinger, a Mars expert from the UK, says NASA will announce this discovery later today. The methane is believed to be a waste product from microbes living—or having lived—in large underground water reservoirs. No other features on Mars are known that would produce methane in the observed quantities.

If this story is confirmed, it would be a huge find: the first strong evidence that we are not alone in the universe. Even if our neighbours are just a bunch of methane-burping microscopic lifeforms, it would be one of the biggest discoveries in history. So, keep an eye out for any news coming from NASA today…

Update: NASA did indeed report on the discovery of Martian methane, but (quite expectedly) they don’t go as far as to say that this is strong evidence for life on the Red Planet. The methane might well have a geological origin, rather than a biological one. Nevertheless, it’s an important step in our ongoing quest of finding signs of life outside the Earth.