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  • Cosimo Q - for Stephen regarding spetroscopic spectroscopic addition to Lasair but , confused about the various projects. 4most tides does not do targetted opportunities. So it might be 20 to 100 days after the LSST discusoverydiscovery. Can understand how SOXS can be contributebut contribute but not so much 4MOST/ . So how much can these spectra actually controibuteSS contribute. What spectra information will be available and in what format?

  • StephenS A - correct that 4MOST pointing cannot control the poiniting but likley be controlled but it is likely to follow the LSST footprints. Can It is possible to control the fibre poiting withing pointing within the fields of 4MOST. any thing Anything brighter that than magnitude 22 in the foiedl field of 4MOST will have a fiber fibre put on it. Speatra oif Spectra of 20K to 30K transiernts transients plus 30K host glaxies. Cannot galaxies are expected but cannot control exactly when that the spectra will be collected. The challenge is to get objects out of alrte the alert stream and onto the the 4MOST schedule. If fibre can be put the fiber on them then when an object is 4MOST obesveredobserved, then the then UK WP will reconginsed fiber is LSST:UK UK WP3.3 will recognise that the fibre is in place, make esitamate estimates and the information will then go back to LAsair Lasair as a annotation. All of the data will be public in ESO archives. We will get information back asap into the broker.

  • Cosim Cosimo Q - do you plan the same same thing for SOXS.

  • SJS Stephen S A - yes, there will be some link from LasairtLasair

  • Jakob Q - How well defined is the UK programme . Have the spectra discussed what they require in terms of triggering from LSST? To what degree has the UK:LSST community specified their LSST plans, such that these can be sued as Lasair requirements

  • SJS - yes these discussions are happending at cocneptaual level. Triger are classsified as supernovae by sherlock( not an agn, not a variable star…). Essentially if bright enough for 4MOST to take a spectra then put a fibre on it.

  • Jakob - sounds like UK will only do supernvoa?

  • SJS - actually mean extragalactic transients

  • Question from JulienP - Funding context was highlighted, but the focus was on PI/developers. What about the hardware funding status and plan ?

  • Stephen S - This will be discussed in afternoon. Top level funding is secured. Lasair is a small part of the UK computing. LSSTUK is a small part of UK IRIS. So overall Lasair are not the dominant partner and hence we believe Lasair is safe. Andy agrees and explained that the plan for UK expected requirements is being put in to UKRI. This is for the 10 years operation and includes Lasair.

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  • query, filter and stream are all the same in Lasair

  • Sherlock - cross-matches location of transient with other catalogs

  • Q Julien - screen annotation - what is the feedback on this?

  • Roy - have not built the system yet. Micheal will talk later about one of the classifications. would like to share classifications from other brokers eg FINK if acceptable.

  • Sara Q - stream annotation - are there plans to create a collaboation so people are not competing on the same follow-ups?

  • Roy - Mrashall refers to a fgroupo of peole able to submit opinions on transients and make decisions

  • Andy - Mrashall building byeond scope to solve this. Omn assumption that ouitside world then wnat to know what pepople need to build their own marshalls.

  • Jakob - annotatins are hard. Decided instead tobe flexible so people can do what they want but they then have the responsibility to maintain and make useful. On 2nd slide, no arrow to/from Rubin Science platform. Have you thought about jhow this ealates tp the DB contens

  • Andy - grimly aware need to think about this but not yet solved.

  • Jakob Q to Eric - how frequently can we expect updates and show seriosly to take these

  • Eric says let discuss during talk

Science experience with ZTF (Matt Nicholl)

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Differences between ZTF and LSST (Eric Bellm)

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(need slides from Eric - have messaged)

  • ZTF is on telescope that is almost 75 years old

  • Slide 3 shows physical differences with Rubin. Only advantage for ZTF is in field of view. Total number of exposures per night will be similar on both telescopes.

  • Major difference is ZTF only processes the data once i.e. as live data comes off the telescope.

  • Q Julien on chat - Cutouts to be transmitted for LSST are template and difference. Why choosing template over science? The science one is probaby what I look first to judge quality.

  • A- The reason lost to pre-history. aim was to get 2 out of 3. Aim to go to 3 cut-outs.

  • Question: (Roy W asked) Can Lasair get awayt with using the LSST cutout service instead of saving them in our own database? How many can we fetch per day?

  • Answer: Do not think Lasair should use US cutout service. Capacity limits are not clear at moment, but cut-outs won’t become available until after the underlying images, which means a 3-day delay (in line with Government requirements).

  • Q Jakob - Regarding upper limits on forced photometry, will there always be 12 month limits on alerts with varying limits for forced photometry.?

  • A: Not built rigourously in pipelines, so remains conceptual. Should have history of every time observe a reason, and provide upper limit on noise estimate where don’t have forced photometry. This can change from night to night.

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  • Davy asked to clarify that forced photometry in alerts in one epoch behind actrual allert. Eric confirmed this was case. Getting triggering DSRs, but will. Eric will make a note and hope anomoly can be achieved without significant effort.

Session-3: Architecture and Technology (chair: Andy Lawrence)
Lasair-LSST Architecture (Roy Williams)

  • Roy will also explain why the architecture is what it is.

  • Platform maintains ~1-week cache of alerts from ZTF stream

  • Cassandra and Galera are both scalable. Aim to be able to dynamically scale to deal with changing load

  • New feature - external annotator - can receive a stream from Lasair and then query DB to draw conclusions. This might be a classifier – e.g., Zooniverse.

  • Lasair user interface is SQL-based (specifically, simple SELECT), but supports both on-demand and streaming queries

  • Supports community contributions (queries, classifications, etc.)

  • Architecture based on scale-up of low-power VMs

1445: Kafka processing (Gareth Francis/Roy Williams)
1455: Hardware implementation (Roy Williams)
1505: Light curve classification (Michael Fulton)
1515: Discussion