Workshop attendees shared the following resources related to the workshop topic (listed in no particular order):
There are four hands-on sessions, split into two broad topics: Comparison of JWST Data with High-resolution Data from Ground-based Telescopes (Sessions I and II) and Atmospheric Modeling (Sessions III and IV).
Group projects are based on the hands-on sessions. Attendees are encouraged to select one of the group projects to work on during the week and make informal group presentations at the end of the workshop. Please read this document for full descriptions of each Group Project, which are summarized below.
Click on the links below navigate this page.
The hands-on session activities will use Python notebooks. You can choose to either install Python and associated software packages on your computer and use Jupyter notebooks, or download and use Google Colaboratory (Colab) notebooks. The latter runs in your Google Drive using a virtual machine and does not require a Python installation, therefore they provide the easiest way to work on the activities. No prior Python experience is required to participate in the hands-on sessions.
Here are the instructions:
JWST observations offer the potential for amazing advancements in the field of exoplanet atmospheric characterization. However, the raw data produced by JWST first needs careful processing to be able to perform such measurements. The goal of this first hands-on session is to teach you how to go from raw JWST data to spectroscopic light curves for a transiting planet; a process called “data reduction”. During the session, you will reduce real observations from the JWST Transiting Exoplanet Community Early Release Science (JTEC ERS) program with your choice of working on NIRSpec/G395H transit observations of WASP-39b or MIRI/LRS eclipse observations of WASP-43b.
Topics covered in the session will include:
In this hands-on session, you will learn how to fit light curves to measure the transmission (or emission) spectra of transiting exoplanets. In particular, you will learn how to fit real spectroscopic lightcurves from JWST using the open-source Eureka! package. This session will build on the spectroscopic light curves produced during Session I, but all of the data files required for this session will be available for those who do not attend Session I or struggle to get a good reduction themselves.
Topics covered in the session will include:
In this hands on session you will learn how to conduct the steps taken to create a small grid of atmospheric models, similar to those used in the analysis of the JWST Transiting Exoplanet Early Release Science Team's WASP-39b observation (see Ahrer et al., Rustamkulov et al., Alderson et al., and Feistein et al., 2003). Then, you will learn how to use grid models to conduct basic fits to data in order to make physical inferences of a planet's atmosphere. In all the process will be composed of:
In this session you will learn how to use petitRADTRANS (pRT) to calculate atmospheric spectra for JWST retrievals. An input spectrum will be provided.
The following points will be covered:
More specifically this will include the following steps:
Please read this document for full descriptions of each Group Project, which are summarized below.
This group project entails reducing and analyzing WASP-39b data from the JWST Transiting Exoplanet Community Early Release Science (JTEC ERS) program (#1366). There are 3 possible datasets to choose from:
Participants may already be familiar with the NIRSpec/G395H NRS2 dataset from tutorials earlier in the week. This is an opportunity for participants to apply lessons learned from the tutorials in generating a transmission spectrum with clear spectroscopic features.
This group project entails reducing and analyzing WASP-43b data from the JWST Transiting Exoplanet Community Early Release Science (JTEC ERS) program (#1366). Here, MIRI/LRS obtained a full-orbit phase curve observation of the hot Jupiter WASP-43b. Participants may already be familiar with the MIRI/LRS dataset from fitting a secondary eclipse during tutorials earlier in the week. This is an opportunity for participants to apply lessons learned from the tutorials in fitting the full, white-light phase curve.
During the hands-on session you learned how to compute grid models including radiative-convective climate modeling and cloud modeling. That will enable you to create a grid of models for any kind of planet. However, in order to compare grids to data you must also understand how to use basic grid fitting tools that yield a best fit model. For the group project, we take this more quantitative approach to grid fitting by compute the single best fit model, which has the least chi squared. In this notebook, we show how to use the PICASO-formatted grid models to interpret data. We continue focusing on the ERS WASP-39b result. For the hands on session, we started by using the results of the JWST Transiting Exoplanet Community Early Release Science Team's first look analysis of WASP-39 b, which used the NIRSpec Prism data. However, as part of that team, there were four other analyses using four instruments. One benefit of JWST is its broad wavelength coverage. This often means you will be stringing together multiple instruments as part of a single planet analysis. Therefore, in this group project we will focus on this. We will take these grid fitting tools in order to analyze the reduced spectra from:
In this group exercise you will run a retrieval on the atmospheric properties of WASP-77 Ab, which is a hot Jupiter (Teq~1700 K) in orbit around a sun-like star. WASP-77 Ab's atmosphere has been found to be depleted in metals when compared to solar, both based on high- resolution ground based data (Line et al. 2021) and JWST observations. Here you will try to reproduce this result, using the JWST data of August et al. (2023). Similar to the transmission spectrum retrieval example of the hands-on session, we will be using NIRSpec G395H data here.
Both in-person and remote attendees will give short, informal presentations with their group on their chosen project from Thursday. This is a great way to get experience giving a presentation in front of a friendly audience!
We will post notebooks with some answers to the group projects here after the workshop.
Questions? Sagan_Workshop@ipac.caltech.edu
(last updated July 31st, 2023 14:06:22)
The NASA Exoplanet Science Institute is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program.
