Vera C. Rubin Observatory:

Ushering a New Era of TDA

Federica Bianco

(she/her)

University of Delaware

Department of Physics and Astronomy

Biden School of Public Policy and Administration

Data Science Institute

Rubin Legacy Survey of Space and Time

Deputy Project Scientist, Rubin Construction

This is a living land acknowledgement developed in consultation with tribal leadership of Poutaxet, what is now known as the “Delaware Bay,” including: the Lenape Indian Tribe of Delaware, the Nanticoke Indian Tribe, and the Nanticoke Lenni-Lenape Tribal Nation in 2021. We thank these leaders for their generosity.

The University of Delaware occupies lands vital to the web of life for Lenni Lenape and Nanticoke, who share their ancestry, history, and future in this region. UD has financially benefited from this regional occupation as well as from Indigenous territories that were expropriated through the United States land grant system. European colonizers and later the United States forced Nanticoke and Lenni Lenape westward and northward, where they formed nations in present-day Oklahoma, Wisconsin, and Ontario, Canada. Others never left their homelands or returned from exile when they could. We express our appreciation for ongoing Indigenous stewardship of the ecologies and traditions of this region. While the harms to Indigenous people and their homelands are beyond repair, we commit to building right relationships going forward by collaborating with tribal leadership on actionable institutional steps.

slides available at

https://slides.com/federicabianco/nrhs24

This is a living land acknowledgement developed in consultation with tribal leadership of Poutaxet, what is now known as the “Delaware Bay,” including: the Lenape Indian Tribe of Delaware, the Nanticoke Indian Tribe, and the Nanticoke Lenni-Lenape Tribal Nation in 2021. We thank these leaders for their generosity.

The University of Delaware occupies lands vital to the web of life for Lenni Lenape and Nanticoke, who share their ancestry, history, and future in this region. UD has financially benefited from this regional occupation as well as from Indigenous territories that were expropriated through the United States land grant system. European colonizers and later the United States forced Nanticoke and Lenni Lenape westward and northward, where they formed nations in present-day Oklahoma, Wisconsin, and Ontario, Canada. Others never left their homelands or returned from exile when they could. We express our appreciation for ongoing Indigenous stewardship of the ecologies and traditions of this region. While the harms to Indigenous people and their homelands are beyond repair, we commit to building right relationships going forward by collaborating with tribal leadership on actionable institutional steps.

The Legacy Survey of Space and Time @

Vera C. Rubin Observatory

Site: Cerro Pachon, Chile

Funding: US NSF + DOE

LSST Science Drivers

Probing Dark Energy and Dark Matter

image credit ESO-Gaia

LSST Science Drivers

Mapping the Milky Way and Local Volume

via resolved stellar population

An unprecedented inventory of the Solar System from threatening NEO to the distant Oort Cloud

LSST Science Drivers

image credit: ESA-Justyn R. Maund

Exploring the Transients and Variable Universe

10M alerts every night shared with the world

60 seconds after observation

The immutable skies

Bartolomeu Velho, 1568 (Bibliothèque Nationale, Paris)

1549 Oronce Fine, France

From Flammarion's Astronomie Populaire (1880) Denmark

Workshop of Diebold Lauber unknown artist, ca.1450

brighter →

+

What time scales can LSST probe?

Photometric filters'	u, g, r, i, z, y
saturation limit' # visits* mag single image* mag coadd* Nominal cadence	~15, 16, 16, 16, 15, 14 53, 70, 185, 192, 168, 165 23.34, 23.2, 24.05, 23.55 22.03 25.4, 26.9, 27.0, 26.5, 25.8, 24.9 2-3 visits per night ~3 day revisit lag in any filter ~10 days revisit lag in r band

' requirement: ls.st/srd

*simulation pstn-054.lsst.io

brighter →

TED talk - Andrew Connely

Rubin Transients by the numbers

(2026)

17B stars Ivezic+19

(2026)

Rubin Transients by the numbers

SKA

(2025)

17B stars Ivezic+19

~10 million QSO Mary Loli+21

(2026)

Rubin Transients by the numbers

SKA

(2025)

17B stars Ivezic+19

~10 million QSO Mary Loli+21

∼200 quadruply-lensed quasars Minghao+19

(2026)

Rubin Transients by the numbers

SKA

(2025)

17B stars Ivezic+19

~10 million QSO Mary Loli+21

∼200 quadruply-lensed quasars Minghao+19

~50 kilonovae Setzer+19, Andreoni+19 (+ ToO)

(2026)

Rubin Transients by the numbers

SKA

(2025)

17B stars Ivezic+19

~10 million QSO Mary Loli+21

∼200 quadruply-lensed quasars Minghao+19

~50 kilonovae Setzer+19, Andreoni+19 (+ ToO)

~10k SuperLuminous Supernovae Villar+ 2018

(2026)

Rubin Transients by the numbers

SKA

(2025)

17B stars Ivezic+19

~10 million QSO Mary Loli+21

∼200 quadruply-lensed quasars Minghao+19

~50 kilonovae Setzer+19, Andreoni+19 (+ ToO)

~10k SuperLuminous Supernovae Villar+ 2018

~ 50k Tidal Disruption Events Brickman+ 2020

(2026)

Rubin Transients by the numbers

17B stars Ivezic+19

~10 million QSO Mary Loli+21

∼200 quadruply-lensed quasars Minghao+19

~50 kilonovae Setzer+19, Andreoni+19 (+ ToO)

~10k SuperLuminous Supernovae Villar+ 2018

~ 50k Tidal Disruption Events Brickman+ 2020

> 10 Interstellar Objects (aliens?)

SKA

(2025)

(2026)

Rubin Transients by the numbers

17B stars Ivezic+19

~10 million QSO Mary Loli+21

∼200 quadruply-lensed quasars Minghao+19

~50 kilonovae Setzer+19, Andreoni+19 (+ ToO)

~10k SuperLuminous Supernovae Villar+ 2018

~ 50k Tidal Disruption Events Brickman+ 2020

> 10 Interstellar Objects (aliens?)

?? things we dont know

SKA

(2025)

(2026)

Rubin Transients by the numbers

Rubin Observatory

Site: Cerro Pachon, Chile

Funding: US NSF + DOE

Status: final phases of construction - completion expected 2025

federica bianco - fbianco@udel.edu

@fedhere

September 2016

@fedhere

Fabruary 2020

@fedhere

May 2022

@fedhere

November 2022

@fedhere

March 2024

late 2024-

early 2025

mid 2025

~1.5-2 years

from now

First data release ~2.5-3y from now

ls.st/dates

alerts build up

May 2022 - Telescope Mount Assembly

18

The DOE LSST Camera - 3.2 Gigapixel

From Francisco Förster+ 2020

sensitivity

area of sky surveyed with 1 image

Resolution

10 (3.2 Gpx)

8

9

7

6

2M 3,200 Gigapixel images in 10 years -about 60 PB of data

Large FoV - High Resolution - High Sensitivity

federica bianco - fbianco@udel.edu

Rubin Field of View: 10deg square

LIGO/VIRGO GW area of localization ~100deg square

Ursa Minor: 255.86 square degrees

S190425z 18% of the sky localization

federica bianco - fbianco@udel.edu

@fedhere

At this level of precision,everything is variable, everything is blended, everything is moving.

SDSS

LSST-like HSC composite


Field of View' Image resolution' DDFs' Standard visit' Photometric precision' Photometric accuracy' Astrometric precision' Astrometric accuracy'	9.6 sq deg 0.2'' (seeing limited) 5 DDF 30 sec 5 mmag 10 mmag 10 mas 50 mas

' requirement: ls.st/srd

*simulation pstn-054.lsst.io

SDSS 2x4 arcmin sq griz

MYSUC (Gawiser 2014) 1 mag shallower than LSST coadds

federica bianco - fbianco@udel.edu

	u,g,r,i,z,y
Photometric filters' saturation limit' # visits* mag single image* mag coadd* Nominal cadence	u, g, r, i, z, y ~15, 16, 16, 16, 15, 14 53, 70, 185, 192, 168, 165 23.34, 23.2, 24.05, 23.55 22.03 25.4, 26.9, 27.0, 26.5, 25.8, 24.9 2-3 visits per night

At this level of precision,everything is variable, everything is blended, everything is moving.

' requirement: ls.st/srd

*simulation pstn-054.lsst.io

LSST time domain data products

federica bianco - fbianco@udel.edu

Alerts Images

Meta Data &

Catalog Visits

80

Pitt-Google

Broker

BABAMUL

world public!

federica bianco - fbianco@udel.edu

world public!

data right holders

Rubin Observatory LSST

federica bianco - fbianco@udel.edu

@fedhere

Rubin Transients by the number

17B stars Ivezic+19

~10 million QSO Mary Loli+21

∼200 quadruply-lensed quasars Minghao+19

~50 kilonovae Setzer+19, Andreoni+19 (+ ToO)

~10k SuperLuminous Supernovae Villar+ 2018

~ 50k Tidal Disruption Events Brickman+ 2020

> 10 Interstellar Objects (aliens?)

~1000 SN / night

LSST

federica bianco - fbianco@udel.edu

@fedhere

Rubin will see ~1000 SN every night!

Credit: Alex Gagliano University of Illinois, IAIFI fellow 2023

LSST has profoundly changed the TDA infrastructure

Discovery Engine

10M alerts/night

Community Brokers

target observation managers

the astronomy discovery chain

Pitt-Google

Broker

BABAMUL

Photometric Classification of transients

highest participation of any astronomical Kaggle challenges

Deep Drilling Fields

Kaggle PLAsTiCC challenge

AVOCADO classifier

https://arxiv.org/abs/1907.04690

Deep Drilling Fields

Kaggle PLAsTiCC challenge

AVOCADO classifier

https://arxiv.org/abs/1907.04690

Wide Fast Deep

Willow Fox Fortino

UDel grad student

When they go high, we go low

Classification power vs spectral resolution for SNe subtypes

Neural Network

classifier architectures:

- transformers
- CNNs

LSST survey strategy optimization

Operation Simulator (OpSim)

simulates the catalog of LSST observations + observation properties

Metric Analysi Framwork (MAF)

Python API to interact with OpSims specifying science performance on a science case with a metric

Lynne Jones

Peter Yoachim

~100s simulations

~1000s MAFs

Rubin LSST survey design

Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!

2017

Wide Fast Deep

5 Deep Drilling Fields

North Ecliptic spur

South Celestial Pole

+ Microsurveys

+ Targets of Opportunity

The Galactic Plane is observed differently

Rubin LSST survey design

distributions of time gaps in 76 OpSims

Bianco et al. 2021 https://iopscience.iop.org/article/10.3847/1538-4365/ac3e72

Rubin LSST survey design

https://www.lsst.org/content/charge-survey-cadence-optimization-committee-scoc

Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!

Survey Cadence Optimization Committee

Rubin LSST survey design

20+ peer review papers accepted several more under review and in preparation https://iopscience.iop.org/journal/0067-0049/page/rubin_cadence

Rubin LSST survey design

Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!

2017

Rubin LSST survey design

Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!

2019

Rubin LSST survey design

Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!

2023

Rubin LSST survey design

Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!

2024

TDA Anomalies in LSST

Presto-Color, Bianco+ 2019; Give me a few hours, Bellm+ 2019

The original survey plan didn't lead to good TDA outcomes:

2 intranight obs in same filer +

2 intranight obs in another filter ~5 day later

rate of change

# pairs of observations (1e5)

time gaps (days)

color

The original survey plan didn't lead to good TDA outcomes:

2 intranight obs in same filer +

2 intranight obs in another filter ~5 day later

Proposed 3 intranight obs

2 within 1 hour in different filters

1 at 4-8 hours separation w repeat filter

color

rate of change

Back to back images are now taken in different filters

few % of the observations will be taken in this mode

+ rolling cadence

TDA Anomalies in LSST

Presto-Color, Bianco+ 2019; Give me a few hours, Bellm+ 2019

Proposed 3 intranight obs

2 within 1 hour in different filters

1 at 4-8 hours separation w repeat filter

Ofek+ 2024

KN evolution in color vs magnitude change is distinct from the background

The original survey plan didn't lead to good TDA outcomes:

2 intranight obs in same filer +

2 intranight obs in another filter ~5 day later

TDA Anomalies in LSST

Presto-Color, Bianco+ 2019; Give me a few hours, Bellm+ 2019

Proposed 3 intranight obs

2 within 1 hour in different filters

1 at 4-8 hours separation w repeat filter

TDA Anomalies in LSST

Presto-Color, Bianco+ 2019; Give me a few hours, Bellm+ 2019

The original survey plan didn't lead to good TDA outcomes:

2 intranight obs in same filer +

2 intranight obs in another filter ~5 day later

PSTN-055 Official Rubin Cadence Recommendation 1/2023 : Rolling is recommended on the WFD, with the sky split into two 1/2-sky regions defined by declination limits and with a 0.9 rolling weight.

TDA Anomalies in LSST

newer simulations ->

<-bad good ->

2023 simulations: 62% improvement

newer simulations ->

4 – 24 hour gaps between epochs will enable kilonova parameter estimation

2017

2024

Andreoni+ 2022a

TDA Anomalies in LSST

https://lssttooworkshop.github.io

federica bianco - fbianco@udel.edu

This is a workshop: the goal of the workshop is to produce a report to be delivered to the SCOC containing recommendations for how to implement ToO responses with Rubin. There are no talks.Time is dedicated to collaboratively working toward the workshop report.