OULE3 - Time Domain - PowerPoint Presentation

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OULE3 - Time DomainImplementation & Validation Phase

Isobel HookJean-Philippe Beaulieu

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Euclid’s time-domain data

Euclid’s deep fields will be observed several times Of order 40

sq

deg, observed ~ 40 timesCadence TBD These may or may not be the same as the fields required for calibration of primary science goalsEuclid’s wide survey will have overlap regions between adjacent fields1% overlaps (see Red Book) of 15,000 sq deg = 150sq degImaged twice or sometimes more, time separation hours to years…Each exposure is made of 4 dithered framesTimescale between dithers ~15 minutesPossibly also dedicated time-domain surveysIf survey time/scheduling permit

2Slide3

Euclid’s time-domain science

Science goals include:Solar system Supernovae (Type

Ia

, II,

ultraluminous…)Exo-planets (detected via microlensing)Variable QSOsOther transients (GRBs…?) These are considered “legacy science”/ “secondary cosmology”They can drive goals (but not formal requirements on the mission)3Slide4

Potential dedicated surveys

SNIa cosmology: dedicated survey (6 months

or longer)

Of order 10-60 sq deg, observed ~ 40 times

Cadence of order 4-8 days Focus on Y,J,H imaging, possibly with non-standard exposure timesEuclid microlensing : dedicated survey (ideally 6-10 months)Fields observable twice a year for 1 monthContinuous 1 month observation period of 3 fields in galactic bulge (17 min cadence)Monitoring in H band, VIS images every 12 hours4Slide5

Implementation WP Summary -

Inputs [From v4.0 of WP descriptions]

Preliminary

EUCLID data on time-ordered images from OU‐EUC and OU-VIS

Preliminary versions of the EUCLID catalogues from OU‐PHO, OU-SPE and OU‐MER for object identification [comment: should include external data]Comment: Should also include simulated data!5Slide6

Implementation WP Summary -

Outputs[From v4.0 of WP descriptions]

Algorithms

to produce a catalogue of orbital, time and position parameters for transient solar

neighborhood objects Algorithms to produce a catalogue of light curves, time, redshift, magnitude parameters for transient supernovae‐like objects. A catalogue of any stellar time‐dependent variation. Algorithms to produce a catalogue of microlensing events 6Slide7

Implementation WP Summary - Deliverables

[From v4.0 of WP descriptions]

Documentation

describing the algorithms, their implementation and results on the tests.

Prototypes of the algorithms for the computation of the catalogues for solar system, stellar‐like transient and microlensing catalogues.Example simulated dataset used for the testing of the prototypes.Comment: What about verifying the LE3 data products themselves?7Slide8

Implementation WP Summary – List of tasks

[paraphrased From v4.0 of WP descriptions]

Definition, development and testing of:

[Solar system]

algorithms to detect transients algorithms for cross matching with existing catalogues [Supernovae and other stellar-like transients]algorithms to detect transients

algorithms

for

cross

matching

with existing catalogues

[

Exoplanets

]

algorithms to generate photometry catalogues (image subtraction)

Algorithms to detect microlensing events

Algorithms to detect transiting planets

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WP Summary - List of tasks [F

rom v4.0 of WP descriptions]

[Solar system]

Definition, development and testing

of algorithms to detect transients ENOs, TNOs, asteroid belts and Trojan objects) in the solar neighbourhood (goal). Definition, 

development testing

of

algorithms

for

cross

matching

of

ENOs

,

TNOs

, asteroid

belts and Trojan

objects

with existing catalogues (goal).[Supernovae]Definition, development and testing of algorithms to detect stellar‐like transients including supernovae-like transient objects, including but not limited to Type Ia  supernovae using externally observed colour and spectroscopic information for light curve fitting and redshift determination (goal).Definition, development and testing of algorithms for cross matching of detected SNe and stellar‐like transients with existing catalogues (goal).[Exoplanets]Definition, development and testing of algorithms to generate compact body and exoplanet microlensing catalogues (goal).

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Proposed sub-tasks [E

xample of SN case – based on input from the SN & transients SWG]

Start from simulated ‘raw’ data (

s

ee later slide for definition)Develop algorithms to do the following stepsCreate an oversampled stacked image as a reference (will be done by OU-MER?)Register new images to referencePSF match of new & reference image (accounting for flux ratio)Subtract imagesDetect objects on the subtracted imagesDo photometry on the detectionsSelect ‘real’ transients based on quality cutsMatch detections with previous catalogues, including other Euclid data and external dataClassify the detections based on various levels of available data

Fit light curves

Enter detection data into a database for further use (including cutouts for visual inspection)

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Proposed sub-tasks [E

xample of exoplanet case – based on input from exoplanet

SWG

very close to SN tasks]

Start from simulated ‘raw’ dataDevelop algorithms to do the following stepsCreate an oversampled stacked image as a reference (will be done by OU-MER?)Register new images to referencePSF match of new & reference image (accounting for flux ratio)Subtract images Detect objects on the subtracted imagesDo photometry on the detectionsSelect ‘real’ transients based on quality cuts

Classify the detections (

microlensing

events, variable stars, transiting planets)

Modeling of anomalous

microlensing

(fitting light curves)

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Note that there is a need for development of these image subtraction pipelines

for both Legacy SN and

exoplanets

. It is not needed for core science.Slide12

WP members – old version

Others interested : R. Carlberg

+ C.

Pritchet

(Canada – not yet in Euclid) - experience in SNeJJ Kavelaars (Canada) – experience in solar system Possibly some members of the SN & transients WG, depending on the boundary of SWG and LE3 workNameFTERelevant experience/interest

Isobel Hook

0.3

or

0.1

+ postdoc

(expected)

SNe

Alain Blanchard

0.3

Andrew Jaffe

0.1

Lucia

Pozzetti

0.3

Mark Sullivan

SNe

Remi

Cabanac

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Implementation WP members

Total FTE “committed” ~ 0.85FTE.

Others interested :

R.

Carlberg + C. Pritchet (Canada – not yet in Euclid) - experience in SNeJJ Kavelaars (Canada) – experience in solar system Possibly some members of the SN & transients WG, depending on the boundary of SWG and LE3 work(*)* Level of available effort depends on whether there is an interesting SN survey in Euclid!

Name

FTE

Relevant experience/interest

Isobel Hook

0.1

+ 0.15

postdoc (expected)

SNe

(*)

Pascal

Fouque

’

0.3

microlensing

Andrew Jaffe

0.1

Mark Sullivan

0.1?

SNe

(*)Remi Cabanac0.1microlensing on SL quasars13Slide14

Implementaton WP Summary -

List of tasks [paraphrased From v4.0 of WP descriptions]

Definition, development and testing of:

[Solar system] – 0.0 FTE

algorithms to detect transients algorithms for cross matching

with existing catalogues

[Supernovae and other stellar-like transients] ~ 0.35FTE

algorithms

to

detect

transients

algorithms

for

cross

matching

with existing catalogues

[Exoplanets] – 0.4 FTEalgorithms to generate cataloguesLow level of committed effort is a concern. 14Slide15

Required simulations

Three main scientific areas require simulations:Solar

system (moving objects

)

SNe (point-like transients on host galaxies)Include dithered exposures so that oversampled reference image can be createdSimulated SNe should have realistic lightcurves, colours, and spatial distribution on host galaxiesExo-planet microlensing (variable point sources in crowded fields) 15Slide16

Simulated data requirements

Time series of VIS and NISP Y,J,H images (2D)

Possibly with non-standard exposure times and non-standard SAA (if dedicated SN or

exoplanet

surveys are carried out)Images should have fake transients added, with realistic propertiesImages should be pre-processed (bias corrected, flat fielded and sky subtracted)Covering an area of ~1 sq deg (?)Simulated NISP spectroscopy of the field (IS THIS NEEDED?)Simulated photo-z catalogue of the field (required for SN case)16Slide17

Pipeline requirements[Summary of document sent to legacy science coordinators from SN&T SWG]

For transients, the real-time and final reductions have different requirements

Not clear whether they will be the same software

Real-time pipeline:

Mainly for triggering follow-up. Can be less precise, but must be able to filter out junk (requires colour info, z if available, vignettes for human inspection etc)Software must be rapidly adaptable. Would not be compatible with long code review processFinal reductions Precision goal of 1% relative PSF photometry[But not for the entire Euclid dataset – only repeat-imaged areas]Slide18

Validation tasks (Beaulieu et al.)

Goal : Validation of the algorithms to obtain catalogues for objects in the time domain for Euclid including solar system transients, supernovae, stellar transients and

microlensing

events.

Science working groups are setting up goals and requirements.Implementation WP is proposing a road towards these goals & requirements.Validation will use these two ingredients.Our approach will be to work closely with the implementation WP. Let’s well define the implementation first.

Sign in for implementation and/or validation WP.

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The End

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