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  • Science telecons - Second Wednesday of the month
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Dec. 20 2012

Agenda 
1. New wiki
2. Target selection, TAT and marshall - comments and duties for Dec/Jan 
3. Active TAT members getting added to Monthly duty rota (and authorship reward) 
4. EFOSC2 throughput
5. ESO Phase III plans 

Nov. 28 2012

QUB (Stephen, Morgan, Dave, Cosimo) ; MPA (Wolfgang, Stefano) ; Southampton (Mark) ; Oxford (Kate); Stefan Haschinger ; Padova (Enrico, Massimo, Stefano, Andrea), Trieste (Riccardo+) Chile (Joe, Francsico, Steve, Franz), Yale (Charlie, Ellie); Barcelona (Nancy, Antonia)

1.December run - personnel

  • Dave Young will look after selecting the targets for classification (input from QUB) - but all are welcome to put comments in the marshall
  • Mark Sullivan's group (with Yen-Chen and Rob ; PhD students) and Paris group (LPHNE) shall look after the data reduction, classification and alerts.
  • Kate Maguire and Laurent Le Guillou are at the NTT. Kate for first sub-run and Laurent for the three.
2. Target and Alerts and follow-up'

  • Charlie presented ideas to get on SNe earlier - SWOPE 1m is likely to start imaging the Yale classified "SNe nice" as soon as it can. PESSTO will look at these as soon as possible. Yale + Mark looking at ways to improve the LSQ photometry with local sequence stars in the difference imaging. Media:LSQ-target-early-SNe.pdf‎.
  • Richard Scalzo has been doing a great job at clearing the marshall inbox.
  • TAT team should be more pro-active in providing input to the marshall for picking classifications. Andrea and Stefan to identify a person at each institute as the TAT members who will ensure this happens each month
  • Key Science Targets : observers needing more input from the PIs regarding which followup tagerts to prioritize on any given night. Stephen to come up with some urgency criteria/requests that PIs should use to inform observers of their priorities
  • Scheduling prioritization can be somewhat automated for the followup targets, but will always heavily rely on directions given by the PIs of the objects. Hence all science PIs must use the marshall for comments. This is essential, detailed comments on requests for Key Science targets are needed, from the Science PIs
  • Stephen, Mark and Andrea will continue to keep an eye on the followup targets to make sure that telescope time is used wisely.

3. Low signal-to-noise classification spectra
  • Some feeling that there are more low S/N classification spectra than we expected. But it's not clear if this is systematic or anecdotal. We might be using too short exposure times, or targets have faded, or conditions were not optimal. Follow-up spectra quality seem fine.
  • Slightly more worrying is the possibility that the slit position is not stable - the acquisition OB that we use as standard relies on the slit position being known and being stable. If it moves (either due to flexure, or between runs) then a 2 pixel shift would loose ~50% of the light or more. The TOs do measure the slit, but then assume stability over a night and a run.
  • Stefan has found with spec-pol observations that the slit position can slip up to 2 pixel (~.5") - not sure how this occurs. Not sure it's due to the filter inserted in the beam, or if it's more of a wide-spread problem. He found this problem by taking through-slit images.
  • In December we will also take some through slit images on first night to check ; aswell as the acquisition images. Kate and Stephen to check.

4, Data reduction and pipeline - standards
  • Morgan found that that EG21 does not give a good flux calibration in the red for EFOSC2+Gr#16 - it has been removed from the list of pessto standards.

5. SOFI OBs
  • All seem OK now. Apart from the fact that p2pp underestimates the duration of the OBs. Am extra 35% needs to be added to the p2pp estimate. Stephen to add this to the Handbook

6. PESSTO Science Telecons
  • Suggestion to also have parallel PESSTO Science Telecons - Mark offered to organise

7. Phase III - plans and timescales
  • QUB had skype with Stefano just after the telecon
  • Stefano has drawn up a list of the (very few) keywords left to be included in the final reduction image headers to comply with ESO Phase III standards. A new version of the pipeline (hopefully the last major release) will be released soon. QUB (Morgan) will run some data through this and Stephen/Stefano will check with ESO if this is compatible. We think we are close. Aim to send to ESO in December.

June 25, 2012

Oxford Meeting

See this page
  • Reviewed 1st months operations. See what can be improved. Data reduction tutorial with Stefano.
  • SJS and ST reviewed targets. Plot of Ia SNe from ST.
  • Room for squeezing period between discovery and classification
  • MS added plot of comparison between PTF + LSQ PESSTO.
  • Agreed a plan of how the data should flow. Written on a blackboard but translated into a diagram by Iair.
Recommendations
  • sacrifice older phase targets. Sacrifice numbers for quality early ones.
  • Encourage LSQ to go to two day cadence (originally around 4-5 days) & do forced photometry to tie down the discovery epoch better. Several science drivers - e.g. to get Ia SNe as soon as possible. SJS and MS to contact Charlie Baltay to discuss.
  • "We did OK, but we could do better."
Lessons from observing
  • 2nd observer should have been observing before and have some experience. Quite a lot to do if they are being left on the mountain on their own.
  • NW asked if web access to (e.g.) Marshall will be available locally in Chile. E.g. slow ESO link for graphics intensive pages/finders.
  • NW mentioned again the possibility of installing server at ESO - or even having a Mac Mini that can be taken with the observers. (Issue with portable machine is passing from one set of observers to the next.)
Observing
  • Still need to cover October fairly urgently. (Also January & April). 3 Slots to fill.
  • Some institutes yet to volunteer.
  • Reminder that ESO pays for 2 observers. 3rd observer must be funded by institutions.
  • NW asked whether a wiki page could be setup for the observing runs. (And what to do between the runs!)
Marshall
  • PESSTO marshall s/w hope to have something running by end of July.
Phase 3
  • SJS and SV still have a few Phase 3 issues to tie up.
Barcelona meeting
  • Reminded to get accommodation booked ASAP because this will become difficult to book soon.
  • Agenda still to be decided. SJS will setup a skeleton agenda by end of week.
NO GENERAL TELECONS IN THE NEXT FEW WEEKS. Will probably just have internal software telecons in the meantime.

June 11, 2012

Padova/Trieste Collaborations
  • Data base structure coming from SV pipeline.
  • Will discuss user requirements at the Oxford meeting.
  • The database is to collect all of the specs as to how the pipeline was run.
  • All of the pipeline data is sent to Trieste.
  • Not all of the data from the pipeline goes to ESO Phase III, and this will be a selected sub-set from the Trieste dataset.
Suggested Pipeline workflow : pipeline --> trieste database --> quality control --> clean sub-sets of data to eso & WISeREP (via a selection form webpage).
  • The main problem for the pipeline is that unique naming is required for the treiste database, but identical naming is required by WISeREP.
  • The final name for the data products must be phase III compatible - the names resulting from the pipeline will be the same as the names ingested into the treiste database
  • Will discuss more with WISeREP guys at oxford.
Phase III Data Submision
  • If we are to submit photometry to ESO we will need a zeropoint for each image - this is difficult for the NTT as it has a small FOV.
  • Hopefully we can submit a zeropoint for each night at as opposed to each image.
  • Stephen to ask ESO if we have to provide a zeropoint.
  • A weight mask may be needed to be supplied for SOFI images.
  • QUB to work at ensuring that data from the pipeline is compatible with phase III and feed back to Stefano.
  • An algorithm is need to determine a median/mean value of the S/N of each spectrum.
  • Resolution to be determined from the slit width and the grism used - could possibly determine this from the skylines in the 3rd dimension of the images.

May 28, 2012

Pipeline
  • Installation manual to be updated with Ubuntu instruction - apart from that the instruction are now complete.
April Reductions
  • Stefano is working on the ESO phase 3 compatibility for the final reductions of the april run.
  • There is compatibility checking software from ESO that we can use to check our final products.
  • QUB will try and install this software - to check the ESO pages for this software.
  • Final spectra are on the pessto page but they are not yet on the WISeREP pages.
  • It is best that WISeREP team take the final 1D and 2D tarball from the pessto pages and ingest this themselves.
  • We are it keep these final data products private for the time being.
Oxford Meeting Plans
  • Stefano V. is to give a tutorial(s) on how to run the pipeline.
  • We will use this time to develop the pipeline users manual.
Science Targets
  • SNHUNT121 - is now gone.
  • SN12ac - the last spectrum from the 13th May. May need another spectrum with Genini S. We have 11–12 imaging epochs with swift (UV and visible). Object still being observer with skymapper
  • LSQ12qbw - still awaiting data.
August Run
  • There are phase 2 template for the OBs - stefano to send to QUB.
  • The OBs are on the machine in La SIlla, there is a directory called PESSTO with all of the products required.
  • Stefano/Andrea will place template OBs in a tarball on the pessto wiki for all observers to access.
Marshall
  • Dave Y has developed the plan for the PESSTO Marshall.
  • Awaiting Weismann team to send some code if possible.

May 14, 2012

Pipeline status and issues
  • Stefano has help Stephen to install the pipeline on his SNow Leopard machine (tsh).
  • Stephen has written/is writing a recipe for installation and usage.
  • Ken is to attempt to install the pipeline on Mac OS Lion (bash).
  • A final manual is to be produced for installation on various OSs (Lion, Snow Leopard and Centos), and instructions on usage.
  • Ongoing discussion on how we distribute the pipeline - probably a single tarball that can be downloaded from an SVN repository at QUB.
  • Stephen to attempt to reduce some of the April data from scratch to see if he can get similar results to stefano).
  • Need to iterate a few items to make sure the data products produced by the pipeline are ESO phase 3 compatible.
Final reductions from the April Run
  • The final reductions from the april run are on the private PESSTO.org pages (linked from the bottom of the data page)
  • ID and 2D spectra (with intermediate data products) are available.
LSQ update
  • The SN factory is looking at a few of the targets coming from LSQ
  • Focusing on finding TNOs for the next few months - back to SN focus August.
Filters for photometry

There are no good sloan matching filters on EFOSC. We can:
  1. Stick with the poor sloan matching filters
  2. Buy our own sloan matching filters (PS1, SDSS, Skymapper etc using Sloan type filters).
  3. Move to Bessel filters - DEFAULT FAVOURED.
Followup status of science targets
  • SNHunt121: faint Ic. Stefano has obtained an xshooter spectrum of the object - not reduced yet. Need to schedule observations and a few months to possibly try and get a nebular spectrum.
  • LSQ12btw : Dave Rabinovich is to send Andrea the archived imaging of 2006jc
  • 2012ac: Type IIn. Spectrum obtained last week with Gemini south. Possibly decent photometric followup with Skymapper.
Oxford Meeting
  • QUB people will try and install and use the pipeline before meeting.
  • All people going to meeting to try and install the pipeline BEFORE coming to Oxford.
  • Stefano will give tutorials on how to use the pipeline.

May 8th 2012

Pipeline status and issues
Stefano indicated that the pipeline prerequisites are:
  • pyraf
  • pyfits
  • pylab
  • numpy

If these packages are installed, the pipeline should run, though Stephen (on Snow Leopard) has had problems with pylab (which could be a 32bit/64bit library issue). Stefano also noted some issues with installing the virtual machine on an Ubuntu system.

Data access - raw data dump, detrended data

Stefano has uploaded raw data (which Ken or Dave will make available via a pessto.org link before the next audio) which can be used to test the pipeline.

EFOSC2 g-filter - do we stick with it or buy a new one, better matched to SDSS/PS1/SkyMapper

g-r colour correction ~ 0.25. If someone has the money, it might be useful to purchase an SDSS-like g-filter. Mark indicated that this level of accuracy might not be required.

Updates from science targets - which might progress to papers ?
  • 06jc-like object. If pre-outburst data found, object *would* be interesting immediately for a paper, otherwise no further follow-up.
  • Faint Ic-pec (SNHUNT121) : Stefano Valenti leading, spectra taken (incl. xshooter), lightcurve ongoing.
  • Luminous type Ia. Mark has Keck data, though LSQ mag estimate of -21 may be out. z ~ 0.35. Uncertain of nature.
  • IIn 97cy-like object (2012ac?). V bright so get spectroscopic & lightcurve coverage up to August. Being lead by Cosimo Inserra and Richard Sczalzo
  • Type II object (Master survey) z ~ 0.12?? Similar to 2009kf (Botticella et al., luminous II-P, UV luminous) - unlikely for further follow-up
Plans for Oxford meeting

Agenda to be organised by Stephen & Mark. Has everyone signed up? If not, go here: Meeting registration Those coming to the meeting should make sure they have the pipeline installed and running (with notes stating what problems they had). Stefano or Ken will update next week on from where to download the software.

Observers and data reduction teams for rest of 2012 : see Observing Runs

Still to be planned. Issues are that exact dates not available yet (and may be 2 months before they are).

Initial archive plans for Trieste

Plans afoot to make an easily queryable (via web) archive of all data in Trieste. (Can already go to WISERep for reduced data and ESO for raw data.)

April 30, 2012 - Debrief on April 2012 Observing Run

Targets : did we get targets young enough ?
  • There’s a summary on the wiki of the 68 objects we classified - see here.
  • We seemed to find quite a few pre-maximum objects.
  • We found 5 objects that were interesting enough for ‘pessto science’.
  • Peter Nugent: LSQ is working with the data that we got from this run to retrain their filters to flag the more interesting objects with hight priorities. Josh Bloom is reprogramming a few of his filtering algorithms.
  • The success rate of the LSQ candidates was ~90%. We are happy for this % to drop a little when gambling with less data to try and classify objects earlier.
Targets : five possible science targets for follow-up. How to manage these.

Typically we are looking to follow 4–5 objects/month to followup. These are the types of objects that we would hope to follow when in full survey mode:
  1. One classified object was like 06jc (LSQ12btw)
  • in historical LSQ images there seems to be a pre-SN outburst at very low significance.
  • the lightcurve of the object had a sharp decline much like 06jc - now at 20.5mag ( April 30, 2012 )
  • we didn’t get great amount of spectrophotometric followup coverage.
  • Dave R. will pull the historic images off tape and run the images through their subtraction code to see if they find a source at the location of LSQ12btw.
    2. One early SNhunt121 (CRTS)
  • very peculiar SNIc, nearby but intrinsically v. faint.
  • Stefano is perusing.
    3. Very luminous SNIa (LSQ12byu)
  • Abs mag –21
  • V. noisy NTT spectrum - require a higher s/n spectrum.
  • Mark S. to decide if this is worth following up.
  • P. Nugent: Spectrum taken at Keck last night of this object.
    4. Very bright SNIIn (PSNJ18410706–4147374)
  • At 14.5 mag currently.
  • Like SN07cy
  • This would be a candidate for pessto followup if we in full survey mode.
  • QUB possibly to get few followup spectra (SJS to keep N. Patat informed)
    5. Bright SNII - MASTER134201–023856
  • looks like a bright SNII (noisy spectrum)
  • would have been a candidate for pessto followup if we in full survey mode.
  • Andrea not convinced of SNII classification - possibly bright SNIIn. The redshift is very uncertain.
  • We may get a spectrum of this object tonight ( April 30, 2012 ).
Classification and ATel announcements
  • Padova handle most of the ATels - all seemed to run smoothly.
  • The objects used for comparison are good - usually only 1 or 2 objects every night requiring a little more detail work to classify.
Spectra delivery to WISeREP
  • The name of WISEASS has now changed to WISeREP.
  • There were initial teething problems to get data into WISeREP - but now things are generally running smoothly.
  • The main challenge now is to automate the delivery of data to WISeREP. S. Valenti’s pipeline can be updated to export nightly data in the format required by WISeREP ingestion and place this in some kind of staging disk.
  • QUB to host an external staging disk for WISeREP to access.
Plans for archiving the final reduced spectra
  • Data needs to be pushed to ESO.
  • A. Galyam: suggestion to release the final spectra to the public as soon as they are available - we many not gaining much by releasing the fast reduced spectra but holding back the final spectra.
LSQ - most recent non-detection of transients.
  • LSQ have added a column to their archive that shows an upper limit for the age of the transients - this is populated with the date of the most recent non-detection at the location of the transient.

Notes from 2012-04-16

Target selection
  • Many targets are normal type Ia’s, need to try and refine selection criteria to try and classify more peculiar/interesting objects. David R. to provide info on when was earliest detection.
  • Would be much easier for PESSTO observers if targets were in sexegesimal format - this should be changed on the target list, as ESO OB input is manual. David R. to implement on LSQ target page : DONE
  • We should select LSQ candidates that have only been observed once or twice to increase the likelihood of classifying objects early.
  • LSQ now back to taking duplicate images each night to filter out moving objects.
  • We are willing to trade off wasting time trying to classify spurious objects in order to increase the likelihood of classifying real transients as early as possible.
  • LSQ group to work on reducing the latency of getting candidates and finders to their webpages: Peter to link with David to get the finders linked from LSQ page automatically : DONE

First Observing Run Notes
  • Finder charts for some standard stars are needed - due to proper motions. Stefano to compile list of problems.
  • There is a small amount of second order contamination on grism 13. Probably best to use a red standard to mitigate the effect. There is currently no second order correction in Stefano’s reduction pipeline. i.e. for flux calibration. Blue standards have problems.
  • A set of ‘pessto standards’ should be defined for each grism. Stefano and Stephen to look at a PESSTO standards list.
  • Telluric corrections - Stefano suggesting to go down the spectral model route for removal
Pipeline Issues
  • The pipeline is to be updated automatically input zeropoint into header of g'-band acquisition images (from SDSS) to get the magnitude of the candidate.
Spectral info on WISEASS
  • There will always be objects for which we will be uncertain about the extraction/reduction:
  • The fast reduction is to be released publicly from WISEASS (regardless of the quality of the reduction)
  • The 2D frame (wavelength and flux calibrated, with average sensitivity curve) can be associated with the WISEASS spectra, so that the spectra could be re-reduced by a user (either PESSTO or Public).
  • The final reduction will replace this fast reduction - but we never do two releases of fast reductions.
  • Fast reductions of galaxy spectra are also to be released publicly via WISEASS.
  • WISEASS should include finder charter for LSQ objects : Ofer to talk to David about getting them automatically i.e. bypass PESSTO observer, and make automatic
  • WISEASS will soon have unique links for groups of objects, and direct links without a login e.g. recent pessto data.
  • Final data package should include the g'-band acqusition images. Not needed for fast data release.
Classification and ATels
  • Future ATels will run with the shorter version of the template text (see second ATel), and the author list for April will be the active people. In future the Board will come up with the Builders list.
  • In the future we should be careful to define responsibilities. Stefano's experience was that target selection, data reduction, and classification was a lot to do in one night, even for 2 observers. Suggested breakdown was
  • Observing Team concentrates on doing fast reductions (inspection of spectra for basic quality control)
  • Data reduction team take over in morning to classify objects, update the webpages and send out the ATel.
  • If there are uncertain objects then send to "expert classification team" : we will define an email list for this.

The next telecon will be on Friday 27th April : usual time 15.30 UK time

Notes from 2012-4-02

1. More discussion of access to PESSTO datastore - Trieste happy to store and serve intermediate PESSTO data products.
2. 6 April NTT nights - will be used predominantly for classification (unless a very interesting object surfaces). We can potentially classify ~50-100 transients in this time. Targets will come from LSQ and PS1.
3. ATels - default text to be drafted by M. Sullivan
  • Discussion of who is to be named on ATels: observers, those involved in the reduction team, the pessto sub-team interested in the candidate(s) in question and the initial discovery team.
  • Generally we should aim for one ATel per night (not one per object).
4. LSQ candidate pages -
  • LSQ will append a column into their candidate pages detailing the redshifts of probably host galaxies.
  • New LSQ candidates generally make it to their candidate pages ~24-36hrs after observation.
  • Discussion of the information displayed on the LSQ individual candidate pages:
  • Blue point light curve details magnitudes of the objects *only when detected* by their subtraction program.
  • Red point light curve details magnitudes of the sources sextractor detects at the location of the candidate when run on *all of the LSQ images* acquired at that location.
  • To access & edit the the LSQ followup pages, a NERSC login and pwd are required - S. Smartt and M. Sullivan to contact P. Nugent about possibly acquiring a PESSTO group username for NERSC. In the meantime PESSTO members/observers can email the LSQ email address to communicate which LSQ candidates we have classified.

Notes from 2012-3-26

    1. Discussion of access to PESSTO datastore - WISEASS can serve spectra, but not full archive server. Padova suggested Italian centre (Trieste) as a solution. Stephen to follow-up with Massimo Turatto. The concept of data storage and access needs redefined as the "ETABASE" concept and model is vague. Stephen to redesign.
    
    2. PESSTO pipleline - Stefano raised some concerns :
  • flux calibrations in the pipeline
  • ZPT for imaging : per night rather than each image
  • Stephen and Stefano to take up issues offline
    3. Target and alerts - coming now from LSQ and soon from PS1. Stephen to set up telecon with Charlie, Anderea, Stefan and Stefano, Mark.
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