LSST Program of GRANDMA¶
Aim¶
The program aims to characterize fast transients observed by LSST, with a particular focus on phenomena associated with compact objects (neutron star, black holes). These include the characteristics of the progenitors and the associated ejectae: kilonovae , produced by the radioactive heating of heavy elements ejected during the merger of two compact objects; orphan afterglows , generated when a relativistic jet interacts with the interstellar medium and is observed off-axis; optical jets resulting from tidal disruption events , where a star is torn apart by a massive black hole; and fast blue optical transients , a class of events with still-uncertain progenitors and finally a sub-class of supernovae . The goal is to better understand the physical mechanisms behind these rapidly evolving sources and to improve theiridentification and classification within LSST data.
Members:¶
Coordinators : S. Antier (IJCLAB), M. Coughlin (UMN)
Other members can add their names here
How to:¶
Telecon : Every two weeks, Time to be defined To be defined
Slack : #LSST-group
*Wiki: https://forge.in2p3.fr/projects/lsst-group
Activities:¶
Group 1 Manage LSST (engineering)¶
Description
We will tackle how to collect and manage LSST alerts to support the follow-up and their scientific exploitation. The goal is to manage the alerts via Skyportal instances, annotate, cross match these alerts external information, transfer the info to the community internally to Skyportal or via external services
Tasks
- How to receive LSST alerts directly in SkyPortal from a specific broker ?
- How cross-correlate / compare accross multiple streams ?
- How to complement LSST alerts to other stream (ZTF, GCN) ?
- How to manage the view and management of the multiple streams based on groups and users ?
- What are the services to develop to allow users a more easy way for the scanning ?
- What are the services to develop to allow users to constructs offline / statistic studies via Skyportal ?
- What are the services to develop to capture all auto-annotations and human annotation for feedback on brokers and LLM purposes ?
- How to manage the users based on multiple annotations from different groups ?
- How to transmit any info / photometry / classification to another group of Skyportal / to a community ?
- How to manage multiple surveys and candidates register in Skyportal ?
- How to make on-going development without breaking the code ?
- How manage the accounts and data ?
- How to manage the DB that will grow expentionnally ?
Group 2 Follow-up (strategies of observations)¶
Description :
This activity focuses on defining how wide field optical alerts (with LSST) are selected, evaluated, and prioritized based our scientific goals, our observational and network constraints. It also covers how to design the protocols, scoring systems, and performance tests that will guide follow-up observations. It also covers toys models to understand where we are going
Tasks :
- How can we select alerts (one stream/multiple streams) based on different scientific topics?
- What criteria/cuts associated with each scientific objective? What are the parts we can automatize ? What are still remains on the human scanning ?
- How do we define tolerance criteria regarding telescope resources, purity versus efficiency trade-offs?
- What protocols of scanning that needs to be implemented for alert filtering, to trigger follow-up, stop obs, redirect the sources ?
- How should we orchestrate the follow-up from triggering, data collection, measurement, photometry ?
- How do we update the score of an alert for up-coming observations or based on (LSST) new alerts ?
- What criteria should be used when exploiting LSST reference data to build a consistent light curve?
- How can we test the performance of our strategy using simulations and based on previous campaign?
- How should we coordinate with external groups within the broader community ? especially when LVK is on ?
- How can we identify and write proposal for additional follow-up resources beyond GRANDMA?
Group 3 Science exploitation¶
Description
This activity focuses on scientific value of the first year of the program. It includes evaluating the performance of brokers and follow-up, and attempt to produce a first catalog of extragalactic fast transients. This catalog can use multi-messenger information and attempt to compare expected rates. We will also tackle the studies of targeted sources if any seem interesting enough to run a single paper
Tasks
Axe 1 : Performance of LSST optical survey
How do the brokers perform, individually and comparatively? What is the rate of contamination ? What are the metrics associated ?
How does our follow-up performance compare to expectations? Do we trigger enough, not ? does it provide additional value ?
What statistics can we extract from the first year of operations? What do we learn and develop in terms of tools ?
How do we transform this first set of alerts and observations into a first baseline and what are our lessons learned ?
Axe 2 : First catalog
How do we produce a first source catalog of extragalactic fast transients with LSST data?
How do we handle offline vs. online classification of the sources? Do we run all ? some ?
What are the source for Kilonova catcher
How do we build confidence in the astrophysical nature and classification of these events?
How do we derive and analyze the associated parameters and physical properties (using NMMA, other tools)?
How do we redirect events that fall outside our scientific scope offline ?
How do we evaluate the gap between alerts with partial information (e.g., lack of redshift, not sure about the time of the event, incomplete followup follow-up)?
How do we enrich the dataset through cross-matching with external catalogs and with multi-messenger observations (e.g., SVOM, Einstein Probe, gravitational-wave alerts)?
Axe 3 : Special Science cases
How do we process specific scientific cases ? and how we can organize ourselves to go fast
Axe 4 : Non Fast Transient Science
How we can help students of GRANDMA to run their own (non Fast Transient Science) studies benefiting from the GRANDMA environnement
What are the expected event rates for the catalog, and how do they compare with current theoretical and observational knowledge?