Invitation to Join: 2023 LSST Photo-z Virtual Symposia

2023 LSST Photo-z Virtual Symposia

The focus of these symposia will be on the development and interoperability of software related to the generation and science validation of photometric redshifts for the LSST within the context of Rubin commissioning and international in-kind contribution programs.

Registration and abstract submission form.

Dates – There will be two half-day sessions, the first on Tue June 27 and the second November (TBD), with two 90-min virtual sessions per day (8:30-10:00am and 10:30am-12:00pm US Pacific).

  • Abstract deadline: Wed May 31 2023
  • Registration deadline: None
  • First symposium: Tue June 27, 8:30 - 12:00 US Pacific

Agenda – The June symposium will start with overviews of the Rubin Data Management team’s PZ Roadmap and the DESC’s PZ-related work, followed by talks from various in-kind teams to present their components and highlight interfaces and challenges. We will discuss interoperability and set action items for collaboration which we will return to in the November symposium.

Draft agenda for the June session.
  • 8:30 - 8:35 – welcome
  • 8:35 - 8:45 – DM PZ roadmap overview
  • 8:45 - 8:55 – DESC’s PZ-related software
  • 9:00 - 10:00 – contributed talks
  • 10:00 - 10:30 – break
  • 10:30 - 11:15 – contributed talks
  • 11:15 - 11:50 – discussion, potentially in breakouts
  • 11:50 - 12:00 – action item summary

Who should submit an abstract for the June symposium? One person from each of the seven international in-kind teams with PZ-related contributions should submit an abstract, if possible; space is reserved for at least one 10 minute talk from each of these teams. Anyone else developing infrastructure or software components for PZ estimation with the LSST data is welcome to submit an abstract, but note space is limited.

Who should register for the June symposium? Everyone who is working on software related to generating LSST photometric redshifts (photo-z or PZ) is invited to register for the symposium. Registration is required in order to receive the Zoom link. The session agenda will be posted in this thread and emailed to all registered participants.

How is the Photo-z Coordination Group involved?

These symposia are being hosted in the context of the LSST Photo-z Coordination Group, which was established to help international in-kind contribution teams and their recipients (e.g., the Science Collaborations, Rubin Data Management), along with any other scientists working towards generating LSST photo-z, to communicate and collaborate.

Will there be a PZ session at the 2023 Rubin PCW?

We also anticipate hosting a science breakout session on LSST photo-z at the 2023 Rubin Community and Project Workshop, for which the focus would be less on software interoperability and more on science with photo-z. Submitted abstracts that do not fit into the June symposium will be considered for the PCW session.

If you have any questions, please reply in this thread or contact Eric Charles or Melissa Graham (@MelissaGraham).


All talks are 10 minutes +5 for questions.
All times are in US Pacific time on Tue June 27 2023 (UTC-7).

8:30 - 8:45 – Welcome & LSST DM PZ roadmap overview

8:45 - 9:00 – DESC’s PZ-related software

9:00 - 10:00 – contributed talks

  • 9:00 - 9:15 – BRA-LIN-S4: Photo-z Services for LSST. Julia Gschwend, LIneA, Brazil
  • 9:15 - 9:30 – Impact of spatial variability on photo-z for LSST. Qianjun (Ellen) Hang, University College London, UK
  • 9:30 - 9:45 – Calibrated Predictive Distributions for Photometric Redshifts. Biprateep Dey, University of Pittsburgh, USA
  • 9:45 - 10:00 – Deep learning based photometric redshifts of galaxies in Kilo-Degree survey. Anjitha John William Mini Latha, Center For Theoretical Physics, PAS, Warsaw, Poland

10:00 - 10:30 – break

10:30 - 11:15 – contributed talks

  • 10:30 - 10:45 – Computing photo-z for AGN via SED fitting. Mara Salvato, MPE, Germany
  • 10:45 - 11:00 – Implementing stellar population synthesis capabilities in RAIL. Luca Tortorelli, LMU Munich, Germany
  • 11:00 - 11:15 – Generating galaxy spectra templates. Sylvie Dagoret-Campagne, CNRS/IN2P3/IJCLab, France

11:15 - 11:20 – breakout room topics & organization

11:20 - 11:50 – breakout discussions

11:50 - 12:00 – breakout reports / action item summary

After a great set of talks, each followed with an interesting Q&A, attendees split into two breakout rooms.

Room 1 discussed photo-z for AGN. Attendees spoke about ongoing work and concerns regarding the need to take into account that the photometry uses cModel fit fluxes, different ways to select AGN, and the benefits of adding IR photometry.

Room 2 discussed the kinds of templates to use to extend spectra for use in template-fitting photo-z estimators, and related concerns regarding adopted stellar populations and the treatment of emission lines; this was related to the talk by Sylvie Dagoret-Campagne. This room also discussed how to include correlations in the error model for simulated apparent LSST magnitudes (related to the presentation by Qianjun (Ellen) Hang), and how to do this in the context of RAIL.

If you would like access to the meeting materials (abstracts, slides, Zoom recordings) please submit to the registration form and you will be automatically emailed a link.