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Introduction
April 4th News Digest (https://www.lsst.org/news/digest )
TMA “substantially complete”
Renee Hlozek elected DESC Spokesperson
More details on PCW2023: https://project.lsst.org/meetings/rubin2023/ - including requests for sessions (and ability to browse those already suggested).
Following a Construction/Commissioning Schedule workshop held on April 6th, the updated Project completion date has been adjusted to February 2025, with System First Light forecast for October 2024. The completion date is a forecast from the detailed project plan to completion that will be updated as we progress through the challenging but rewarding next steps of system integration and test. The forecast date does not include the expected schedule contingency we will build into the plan forward as we work with the NSF and DOE on the final phases of the project.
Those with ideas for future newsletter items should contact the LSST:UK Project Managers (George Beckett and Terry Sloanlusc_pm@mlist.is.ed.ac.uk), while everyone is encouraged to subscribe to the Rubin Observatory Digest for more general news from the US observatory team.
IDACs Workshop
Website - https://project.lsst.org/meetings/rubin-idacs/welcome
Google Drive folder - https://drive.google.com/drive/folders/1Vns_hvyrWSNgwNtlam0M5qXZgJbUTW-v
Rubin’s Science Pipelines: Not just a one-trick pony
As most readers of this newsletter will already know, turning Rubin’s millions of raw exposures into useable science products is a major challenge. To address this challenge, the international LSST consortium is developing a software pipeline to perform all the calibration, coadding, detection, measuring, etc., that the astronomy community needs to turn the raw imaging data into scientific discoveries. What is perhaps less well known is that these science pipelines have been designed and developed with universality in mind, allowing other surveys to utilise the expertise and effort that has gone into developing Rubin’s Science Pipeline for their own gain.
While Rubin’s Science Pipelines have been developed with broader application in-mind, the sheer diversity of astronomical surveys mandates a flexible structure that can be adapted to different datasets taken by different telescopes/instruments with different pixel scales, filters, metadata (i.e., headers) etc. The way this adaptation is achieved is via so-called “obs packages”. As well as providing configuration data, such as detector size, defects, and pixel scales, an obs package dictates how the raw exposures are ingested into the data repository that is referred-to throughout data processing. Further, what steps are carried-out by the science pipelines - whether that be flat-fielding and bias subtraction, PSF-modelling, coaddition of science frames, source detection and measurement, etc. - can also be controlled by the obs package. As such, obs packages are a fundamental component of the Rubin Science Pipeline that allows it to process data from different telescopes and instruments.
Because each instrument (or, indeed, simulated dataset) requires its own obs package, a number of obs packages already exist for the various different datasets that have been processed by the Rubin Science Pipeline. Of course, the LSST camera has its own obs package, which includes adaptations to processed data from the Commissioning Camera as well as the simulated images used to create the DP0 datasets, which some of you may already have accessed. But obs packages have also been produced for other telescope and instruments, including Subaru, DECam, and CFHT. On the UK-side, Raphael Shirley has been leading the development of obs_vista, an obs package that allows the Rubin Science Pipelines to interface with and process near-infrared exposures obtained by the VISTA telescope, which formed a key part of LSST:UK’s Phase B WP3.5 (“LSST and near-infrared data fusion”). My own introduction to obs packages was while developing one for GOTO, which my former PhD student, Lydia Makrygianni, and I used to process and analyse a subset of the data obtained by the GOTO prototype. I’ve also recently been developing obs_necam (“anycam”), which is a stripped-down obs package that comes with instructions and scripts to help people get started processing data and developing their own obs package.
As we move into the era of massive multiwavelength astronomical datasets, much will be gained from being able to combine these datasets as seamlessly as possible. By developing a robust science pipeline that is flexible enough to be applied to very different datasets, the LSST consortium is making great strides to reaching this goal.
Outcome of Consortium Board Chair election process
As mentioned in the March Newsletter, Mike Watson’s current term as Consortium Board Chair is coming to a close, so, as Deputy Chair, I solicited nominations from the Board to fill that role for the next three years. The outcome of that process is that Mike will continue as LSST:UK Board Chair for another term, having been elected unopposed, which I take as a clear indication of the confidence the Board has in Mike's stewardship. LSST:UK has benefited greatly from that stewardship and we all look forward to Mike guiding us to the start of operations.
DP0 Summer School
https://dp0-2.lsst.io/dp0-delegate-resources/virtual-summer-school-2023.html - deadline June 5th
Recent LSST:UK Science Centre outputs
The LSST:UK Science Centre has recently produced the following technical reports.
Title | Author(s) | Description |
|---|---|---|
D2.1.4 LSST:UK DAC Roadmap and Integration Plan for DEV Activities (updated) | Bob Mann and George Beckett (University of Edinburgh) | This document provides an update to the “LSST:UK DAC Roadmap and Integration Plan for DEV Activities” presented in D2.1.1 in the light of current Rubin and LUSC plans. By updating the DAC Roadmap it defines the capabilities of the UK DAC that should be in place at the end of Phase B (nominally 31/MAR/23) and outlines the plans for further DAC development in the early stages of Phase C, although the latter remain somewhat uncertain due to the Rubin Construction Project’s recent decision not to perform on-sky observing with ComCam, which has implications for the timing and content of Data Preview 1 and, hence, for the UKDAC release schedule. This document also presents an updated account of the interaction between LSST:UK and IRIS, its main infrastructure provider, which has changed significantly since the publication of D2.1.1 with the advent of the Somerville cloud system. Furthermore, it presents a revised discussion of the support provided by the DAC to the Phase B DEV WP teams, although the details of these interactions are now captured in separate DAC-DEV interface documents. |
Bob Mann and George Beckett (University of Edinburgh) | In the light of the Covid-induced delay to the start of survey operations, the scope of this Deliverable was changed, from a release of documentation through the UK’s Data Access Centre (DAC) to a discussion of the requirements for such documentation in future. The areas in which UK DAC documentation is likely to be required are identified, and a set of principles – non-duplication, sufficiency, currency and use of similar format, jargon and style to Rubin documentation – for their development is outlined. These principles should inform the creation of a UK DAC documentation plan early in Phase C, which will provide a specification of each planned piece of documentation and which is intended, thereby, to aid their production. | |
D3.11.4 Report on the Preparation for Full-Scale DAC Matches | Tom J Wilson and Tim Naylor (University of Exeter) | The goal of WP3.11, Cross-Matching and Astrometry at LSST Depths, is to create a cross-match tool through which common detections can be identified between LSST objects and sources in numerous other (non-LSST) datasets. Alongside identifying matches, the generated products should be able to report on the probability of such a match (to identify unreliable assignments for users), and provide key derived secondary information such as is necessary or useful for the astronomer. Until now each WP3.11 deliverable has extended this cross-match functionality. This began with a “simple” Bayesian cross-match and we then added to the algorithms to include those needed to overcome the systematic effects such as the effects of hidden, unresolved contaminant objects on the positions of sources, or the inclusion of photometric information in the discernment of “false positive” matches. By contrast this deliverable, D3.11.4, reports the efforts of WP3.11 to accomplish the goal of performing matches, rather than making a match-capable software. This report summarises those efforts, a three-pronged work. First, the incorporation of previous testing which identified the need to increase the scope of parallelisation within the codebase to reduce total runtimes. Second, the inclusion of additional software to ensure that the matches are both precise and accurate in their reported match likelihoods. Finally the beginning of “full scale” matches, running all-sky tests and simulating the wider workflow with the DAC team in which catalogues are generated, matched, and the consolidated results ingested into the UK DAC for access by in the community the UK RSP. |
Forthcoming meetings of interest
A reminder of a date for your diary for the LSST@Europe 5 meeting, which will be held in Poreč, Croatia, during 25th--29th September 2023. Registration information is expected to be published in the next couple of weeks. The dates have also been confirmed for the Rubin Project and Community Workshop 2023: it will be held on 7th--11th August in Tucson, Arizona.
Other meetings of potential interest for the coming months include:
12th-14th June: LSST Galaxies Collaboration meeting, Paris
20th–22nd June: The Transient and Variable Universe, held at University of Urbana Champaign, Illinois, USA
3rd-7th July: The National Astronomy Meeting 2023, held in Cardiff, with a three-part session on “UK involvement in the Vera C. Rubin Observatory: Legacy Survey of Space and Time”
24th–28th July: DESC Collaboration Meeting (SLAC), California, USA
Members of the Consortium (not in receipt of travel funding through one of the Science Centre grants) may apply for travel support for meetings of this kind via the the LSST:UK Pool Travel Fund. Details are available at Forthcoming LSST-related Meetings .
Note that the current list of forthcoming meeting is always available on the Relevant Meetings page. You may also wish to check information held on the LSST organisation website LSST-organised events and the LSST Corporation website.
Announcements
If you have significant announcements that are directly relevant to LSST:UK and would like to share the announcement in a future newsletter, please contact the LSST:UK project managers.