Project leads: Vivek Kumar Jha (NCRA-TIFR), Yogesh Wadadekar (NCRA-TIFR)
This work package is part of the in-kind contribution from NCRA-TIFR (India), with the Galaxies Science Collaborationn as the primary recipient.
Point of contact: Vivek Kumar Jha (vjha@ncra.tifr.res.in)
Rubin project code: IND-NCR-S1
Relevant working groups: SED fitting and Photometric Redshifts, Active Galactic Nuclei
Project status: Active
Galaxy evolution, a key area of study in astrophysics, aims to understand the formation and transformation of galaxies throughout cosmic time. Large-scale surveys, like the upcoming Legacy Survey of Space and Time (LSST), are set to revolutionise our comprehension of galaxy evolution. LSST will observe an order of a billion galaxies, leading to an unprecedented amount of data. However, extracting meaningful scientific knowledge from this vast dataset requires robust, efficient, and accurate data analysis techniques and tools. Galaxy spectral energy distribution (SED) modelling is a crucial method for analysing galaxy properties. We can infer key physical parameters such as photometric redshifts, stellar mass, star formation history (SFH), dust content, and metallicity by comparing observed galaxy SEDs with theoretical models. Our project will compare, contrast, and optimise two leading galaxy SED modelling codes: BAGPIPES (Bayesian Analysis of Galaxies for Physical Inference and Parameter EStimation) and prospector for the LSST dataset. To develop our tools, we will make use of a sample of galaxies selected from the Hyper Suprime-Cam (HSC) Survey, which can be extremely relevant with its depth and photometric coverage similar to LSST and act as a perfect testing ground. We’ll assess the strengths and limitations of the methods, determining their suitability for managing datasets on the scale of LSST. After this exercise, we will work towards scaling up the codes to deploy to the Rubin pipelines later.
TBA
2. Testing SED Fitting Tools: Galaxy Properties from Prospector and BAGPIPES in LSST era (Vivek Kumar Jha)
Talk at the Rubin Community Workshop,Tucson, AZ; USA (31 July 2025) (online).
Exploring SED Fitting for Rubin Galaxies with Bagpipes and Prospector (Vivek Kumar Jha)
Talk at LSST Galaxies SC telecon on 02 June 2025
An interactive pre computed SED grid to visualize the physical parameters and their influence. link here
Physical properties from broadband SED fitting using CIGALE.
Sky-subtraction that preserves low-surface-brightness flux.