ORCHIDS: ORigin of the [C II] Halos In Distant Systems”, is the title of the project led by UDP academic Manuel Aravena, together with former UDP/Carnegie postdoctoral researcher Jorge González-López (now a professor at PUC).
03/13/2024
In its most recent observing time allocation cycle, the James Webb Space Telescope (JWST) granted 43.2 hours of observing time to the “ORCHIDS: ORigin of the [C II] Halos In Distant Systems” project, which is led by a professor of the Institute of Astrophysical Studies of the Diego Portales University, Manuel Aravena.
This is only the second time that projects led from Chile have obtained time on JWST. “To my knowledge, we are one of the two Chilean teams to gain time this year,” comments the academic who, together with Prof. Jorge González-López, had already obtained 17 hours of observations with JWST in 2023 with the proposal “Unveiling the interplay between the circumgalactic and interstellar media in a complex protocluster environment at z=4.5”.
The project “ORCHIDS: ORigin of the [C II] Halos In Distant Systems” seeks to take advantage of the characteristics of JWST to understand how galaxies in the early universe transport the gas by which they form stars.
In the words of Professor Manuel Aravena: “We seek to understand how galaxies form stars, how they obtain the gas to form those stars, and what happens to that gas once they have been formed, if it is returned to the galaxy or if it is recycled in the circumgalactic medium, through galactic winds, for example.”
One of the fundamental goals of extragalactic astrophysics today is to understand how galaxies are forming stars. “We can measure what the star formation of those galaxies is, but we don’t know where they are getting that gas from and what happens to that gas after that star is formed. All these gas exchange processes are what we seek to study with this project,” explains Aravena.
In addition to Professor Jorge González-López, Manuel Solimano, student of the UDP Doctorate program in Astrophysics, and the recently graduated Doctor of Astrophysics UDP, Ana Carolina Posses, will also participate.
Regarding how competitive the process of allocating observation times for the James Webb Space Telescope is, Professor Aravena comments that it is extremely difficult, because it is the most advanced and modern observatory so far, launched into space in December 2021.
“The best astronomers from around the world are proposing to do different scientific cases, and the vast majority of them are very interesting,” he says.
“Why is it so difficult? Because, for example, of the 5 thousand hours available in a year for JWST observations, around 48 thousand hours are requested. This means that there is an oversubscription of 9:1. In other words, 9 times more hours are requested than are available. You have a probability of less than 10% that they will give you time,” highlights Aravena. And, he adds, “In general, most programs ask for fewer hours, on the order of 10 to 20 hours. In our case they gave us a lot of time (43.2 hours) and that makes it very special.”
With this project, the UDP Institute of Astrophysical Studies aims to further strengthen its contribution to research in the area. For its director, José Luis Prieto, “the discoveries that are being made with JWST observations are advancing our knowledge in different areas of astrophysics. It is a tremendous achievement and immense pride that doctoral students, postdoctoral researchers, and IEA academics have obtained observation time with JWST.”
In closing, Manuel Aravena reflects on the level of astronomical research in Chile: “I would say that it is at a global level, comparable with the best universities and institutes in the world. Our skies and academic level put us in a unique position, and positions astronomy as a strategic axis of the country’s development.”
More information about this project can be found at the following link: