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.