PESSTO Meeting III : Technical Meeting Oxford June 2012

PESSTO Technical Meeting Summary

We reviewed the first run from three aspects

1. Target Selection from LSQ, strategy and survey cadence

Both Stephen and Stefan T. presented their thoughts and summary of the target selection and results from classifications. We focused mostly on LSQ as this is clearly the current best feeder survey for PESSTO. The figure below shows the summary of the epochs that we caught the targets for classification. Green is good, orange would be acceptable if the transients were peculiar, red is bad. You can see that we got some young SNe Ia before peak, but many were too late. Stefan T. discussed how good the scoring was in selecting targets and selecting interesting ones. In conclusion the host properties were not as useful as one might expect, but we should indeed use them to weed out AGNs, stars etc. What was lacking was information on the prediscovery history of the transient, which would give a much better clue to the epoch and allow us to weed out the old, or potentially old, targets.

Similarly, see Stefan's summary here :

Mark's comparison with PTF

Top priority recommendations

1. LSQ to go to 2d cadence, cover approx 1500 sq degrees (twice per night to eliminate moving objects). Ideally target the southern most part of the SDSS footprint, as this provides useful contextual information for initial classification of targets e.g. galaxy host, no host etc.

2. LSQ to provide forced photometry on the images available before the first discovery - to indicate the limits on how old the SN might be

3. QUB to integrate all the information into the PESSTO Marshall - work is ongoing with PTF/Weizmann coding input

2. Lessons from the Observing logistics

Stefano presented his view from the observational side. He recommended that students who are going as the 2nd observer are well trained observers (either NTT or previous experience on other telescopes). The third observer can be new and can be trained, but there is too much for an untrained student to be left with. The development of the PESSTO marshall is essential to the future smooth running of the survey, and as much as possible should be automated through the marshall (e.g. observing lists, OBs, information for Trieste and Wizemann). The team in Europe should write the ATels and check the classifications (which should be much easier when we have the marshall). We need to agree how the european team access raw data, if they need to, as the link from the NTT is painfully slow (although ESO have a very fast link, which we can't access!!). See Stefano's slides for his full review.

3. Data products and information flow

We agreed how the data products and the science meta-data (from the PESSTO marshall) should flow. Trieste/Padova will provide a repository and searchable archive of all the data products, which are initially private for the PESSTO collaboration. WISERep will continue to serve the fast reduced spectra, as required in our commitment to ESO as a Public Survey. WISERep will also serve the final reduced spectra, which allows the value added extras that it can provide to the community. The final reduced spectra will also be available in Trieste and in the future could be released within the VO. The Phase III submission to ESO will come through the Trieste archive. A short report on the data flow logistics will be prepared soon for circulation amongst the PESSTO consortium.

June 20th

10.30 start

- Introduction and summary of project to date (S. Smartt)

- Feedback from first run. Observing strategy, exposure times, classification success, etc.. (S. Valenti and others)

- Target selection criteria and process: experiences from April (S. Taubenberger)

1pm-2pm lunch (provided)

2pm

- PESSTO marshall development (D. Young)

- A data reduction tutorial (S. Valenti)

5pm Break

Evening: Dinner at nearby restaurant

June 21st

9am

- A data reduction tutorial (S. Valenti - continued from Tuesday, if needed)

-

PESSTO data and data product storage (Weizmann and Trieste)

1pm-2pm lunch (provided)

2pm

- Any early science results from the first run (??)

- Any pressing collaboration issues (Smartt/Sullivan)

4pm end of meeting

Registrants

David Young

Kate Maguire

Avishay Gal-Yam

Cosimo Inserra

Stefan Taubenberger

Cristina Knapic

Marco Molinaro

Stephen Smartt

Ken Smith

Riccardo Smareglia

Stefano Valenti

Emma Walker

Sylvain Baumont

Iair Arcavi

Mark Sullivan

David Young

Christophe Balland

Morgan Fraser

Michel Dennefeld

Isobel Hook

Logistics and registration

You can register for the meeting here:

Meeting registration

Below are some simple logistical details below concerning travel. Please book your accommodation yourself; a map can be found here

Map of Oxford

which marks the astrophysics department, the hotels listed below, and the rail and bus stations. All the hotels listed are within walking distance to the department. June is a busy time in Oxford, so better to book hotels sooner rather than later.

Lunches and tea/coffee will be provided on both days.

Accommodation

Many hotels are now fully booked. Contact Mark Sullivan if you still need a room.

Travel

Air

Oxford is located near London and so is served by all greater London airports (Heathrow, Gatwick, Luton, Stansted) and by Birmingham Airport, although Heathrow is the most convenient.

From Heathrow or Gatwick, we recommend using the fast and frequent coach service The AirLine, which will take you Queen's Lane on the High Street from where you can easily walk to the astronomy department, or to the Oxford Bus Station ("Gloucester Green") in the centre of Oxford. From there, you can walk to just about anywhere in the centre of Oxford, take a city bus, or take a taxi. The cost for a period return (valid up to 3 months) is £27 from Heathrow, and £37 from Gatwick (one-way fares £23 and £28 respectively) although these change regularly.

At Heathrow, the coach starts from the central bus station (serving terminals 1 and 3; mostly non-BA flights with some exceptions) before calling at the new terminal 5 (mostly BA/IB flights). It does not stop at terminal 4; from there, you will need to make an inter-terminal transfer to T5 to catch the coach. Allow 20-30 minutes for this. Thus, T1,3,5 are more convenient than T4.

Pre-booking is possible on these coaches, but is rarely necessary. You can pay in cash directly to the driver, but not with large denominations (i.e., don't expect the driver to accept a £50 note or above). Euros and US dollars are apparently also accepted, doubtless at a ruinous exchange rate. Alternatively, at Heathrow central station or T5, you can buy your ticket at the National Express ticket offices with a credit/debit card, but this is slower than paying in cash to the driver.

If you absolutely require a taxi to/from Heathrow, do not take a "walk-up" black cab - this will be prohibitively expensive. We can recommend pre-booked Oxford-based taxi companies, though note that this will cost in the region of £80 one-way. Pre-booked taxis from Gatwick will be well in excess of £100.

From Gatwick, you can also travel by train to Oxford, with a change at Reading. See National Rail for timetables.

Transport from Stansted or Luton is neither as fast nor as convenient as from Heathrow/Gatwick, and it is probably a good plan to pre-book coach tickets to these airports.

Note there is a direct, approximately hourly train from Birmingham airport to Oxford rail station (journey time ~1h10m) and from Southampton airport (parkway station), journey time ~1h30m.

Train

There are regular services to/from Oxford from/to London Paddington Station which take about an hour. There are also regular links to other parts of the country via Didcot, Reading and Birmingham (including a direct train from Oxford to Birmingham international airport). The Oxford train station is at the edge of the city centre. A taxi to just about anywhere in Oxford itself should cost you less than £10.

Coach

Two reliable services operate from London: the Oxford Espress and Oxford Tube. Both leave/arrive from London Victoria Station and arrive/leave at the Oxford Bus Station (Gloucester Green) in the centre of Oxford, with several additional stops in both London and Oxford. Travel time depends on trafic condition and rush hours in London should be avoided.

Car

It is strongly recommended that you do not drive to Oxford. Parking is extremely difficult, and expensive, in the city centre. If you must drive, Oxford does have many park and ride facilities (park the car in an out-of-town car park and take a bus to the centre).