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LV-EM Open Forum Telecon - Thursday, January 25, 2018 @14:00 UTC

Telecon time: 06:00 US Pacific / 08:00 US Central / 09:00 US Eastern / 11:00 Chile / 14:00 UK / 15:00 Central Europe / 19:30 India / 22:00 Australia West, China / 23:00 Japan / 00:00 (Fri Jan 26) Australia East

The call will be one hour long.

You can connect to this telecon with either of two methods (the audio will be bridged):
  • Using the free TeamSpeak software: Download from here and install the software, preferably in advance. Please use either an anti-echo USB speakerphone (e.g. a "Phoenix box") or headphones to prevent echoes. At the beginning of the telecon, connect to the server at and use the password la$er. (Note to LVC members: this is not the usual LVC telecon server.) Once you are connected to the server, drag your name down to the "LV-EM Forum" channel. For more details and usage advice, see TeamSpeakInfo.
  • Telephone: Dial the access numbers 1-800-704-9804 (toll free in the US; possibly accessible toll-free via skype from outside the US too) and internationally 1-404-920-6604 with participant code 8295093# . To mute/unmute your line, press *6 .Please note this telecon, agenda, and minutes are not password-protected.


  • Announcements/ establishing monthly LV-EM telecons (All, 5') telecon is being recorded
  • Status of the LIGO-Virgo instruments (Lisa Barsotti 5' + 5' discussion) - slides (backup link for slides)
  • Update from the LIGO-Virgo EM follow-up group (10') - slides (backup link)
  • Updates and feedback from astronomer partners (20')
  • Planning GW multi-messenger town hall meeting(s) (10') - slides (backup link)
  • LIGO-Virgo O2 publications on EM operations (5')
  • Technical aspects of the GW alert implementation (5')
  • AOB


LV-EM forum now open:
Today's call agenda:
OpenLVEM Telecons on 3rd Thu of the month.
Motion to anchor it at 7AM Pacific US Time-- passed.
Next call on Thursday, February 15th @7AM Pacific US Time.
Motion to have Australia/Asia friendly calls.
Proposal to hold companion telecon at 8AM Central European Time on 3rd Thursday.
Proposal is to be confirmed.

Telecon to be recorded:
The Road to O3 (Lisa Barsotti presenting)

O3: 1 calendar year run with the two LIGOs @120Mpc (min), Virgo @65Mpc (min)
Work in progress, goal is to be ready to commence O3 by end of 2018
pre-O3, at least 1 month-long engineering run (ER) in the Oct/Nov 2018 time frame
possible additional engineering runs over the summer, but not more to say on at this point

Mandeep: will there be EM alerts over the ERs?
Lisa/Erik/Peter: emphasis of ERs is system integration and testing of (among other
things) the EM infrastructure. Alerts will go out on a best effort basis. The system
may be up and down, while being tested. Latency may not be as low as we are
targeting for O3.

Update from the LV EM follow-up group (Erik Katsavounidis presenting)

LVC will issue Open Public Alerts (let's call them OPAs) starting with O3 and beyond.
No MOUs will be involved for such OPAs.

Key policy, specification and requirements for the program are being discussed with LVC.
Technical aspects are being worked on. Invitation to the EM community to participate. Some top level questions addressed to all: how prompt OPAs should be/what level of
purity (contamination from false alerts), what is the event information that will be
shared promptly (and later on).

GW events beyond the "detection candidate": what is the science driver for sharing such
alerts? How to share them: as OPAs, through MOUs agreements, or not make them available
at all? Possibility of collaborative way of analyzing such "sub-prime" alerts involving
GW and EM observers?

Are there science topics/measurements that will be best addressed by joint teams of GW-EM
partners and via MOU agreements specific to such topics?

Work under way on the technical aspects of the infrastructure for OPAs; invitation to
participate in identifying the needs, reviewing the plans.

Mandeep: release alerts with minimal restrictions; even with "bad" FARs. People observing
the whole sky won't mind receiving and following-up such events. The O1/O2 rate (and higher)
should be fine.

Edo: need purity vs S/N ratio; this will help quantifying what observers want.

Peter: what level of purity makes sense for a public alert? Different opinions on that.
Knowing your input on this is important. Also need to have some quantifiable science

Erik (summary): So, there is wish by observers to receive more alerts and then use their
own criteria.

Mansi: using O1/O2 as starting point for rates of OPAs, the EM community is fine with it.
As long as the event info includes some measure of the significance. The EM community will
do the filtering. The point of departure should be O1/O2. But, what is the information
envisioned to be shared for each event?

Peter: there is a lot of discussion on this within LIGO-Virgo. Starting point: what we did
(released) in O2. Obviously: time, significance, distance info, classification (kind
of binary). Concerns on the ability of LIGO-Virgo to participate in areas of research,
e.g., cosmology. Things are not decided within the collaborations.

Graham: support rate and info of alerts at the O2 level. What is the publication policy
for such OPAs.

Erik: point of departure is for OPAs to come with no publication rules or restrictions.

Steven: support release low significance events. Information on events at least at the level
of O2. Distance is essential.

Marcos: what is the expected latency for O3?

Erik: preliminary alerts with few minutes.

Peter: few minutes without vetting.

Edo: releasing events at O(1) month might impact access to "expensive" facilities with
limited availability. Will probably need more event information w/r/t O2. For example,
information on masses, spins, EOS will play the definitive factor in selecting event to
take on to such "expensive" facilities.

Peter: we have limited ability to have info on masses/spins/EOS at low latency. It takes
weeks, months for such information to be obtained. What and how any of that will affect
observing strategies? Can you be more specific?

Edo: these are important things to know. Knowing, for example, as close to t=0 that there
is a chance for non-zero spin, this might be enough to trigger HUbble. Will be helpful
to know the timeline of what information will become available when and with what error

Mandeep: wasn't this available within days or so during O2?

Peter: there are degeneracies between measurements-- it takes time and for many quantities
there won't be resolved.

Edo: is there a plan of making public the full scale of results for measured quantities
of the detections? Even for GW170817, final posterior distrib function were not released.

Erik: LIGO-Virgo has not released PDFs for any of the detections.

Edo: we need to discuss this next time and understand when the collab intends to release
this information.

Marco: how will MOU partners have access to the full error budgets?

Marica: we need to work with the astronomers how the O3 MOUs will work

Mandeep: the vision was that by O3 all was going to be open. What is the value in secrecy?
Need to make everything available publicly.

Peter: we do intend to release confident detections; we are not strategically secretive.

Vicky: all alerts for detections will be shared. But making every quantity and measurement
immediately available is a different story and not the rule in astronomy.

Peter: LIGO-Virgo thinks data need to be analyzed carefully.

Mandeep: most astronomy data everybody can process and reduce. GW data can not be processed
easily by non-GW people

Ryan: what will happen with non-CBC alerts? will they be included in such releases?

Erik: yes

Leo: are there qualitative pieces of information that will help prompt follow-up? Need to
identify them in the GCNs. For example, Need a statement there is 90% probability the inclination of
an event is <20deg?

Mandeep: will need a sample event profile on the table and discuss over what we need.

Edo: +1

Planning GW multi-messenger town hall meeting(s) (Marica Branchesi presenting)

Town Hall meetings, one in US and another one in Europe

Boston or Atlanta (16-17 March or 29-30 March)
Cascina (March 12-17, 27-30 and April 11-13)
Doodle to maximize participation

LIGO-Virgo O2 publications on EM operations
The GCNs of the triggers sent in O2 will be publicly released with the O2 BBH catalog paper.
Not before April/May.
LVC EM follow-up team is writing an O2 LVC paper to provide the O2 EM infrastructure/program
(to be submitted at the same time of O2 BBH catalog paper)

-- ErikKatsavounidis - 23 Jan 2018
Topic attachments
I Attachment Action Size Date Who Comment
20180125-LVEM-status.pdfpdf 20180125-LVEM-status.pdf manage 54 K 2018-01-25 - 14:19 UnknownUser 20180125-LVEM-state
G1800136-v3.pdfpdf G1800136-v3.pdf manage 109 K 2018-01-25 - 13:53 UnknownUser LIGO-Virgo road to O3
JointTelecon25_TownHallPublication.pdfpdf JointTelecon25_TownHallPublication.pdf manage 101 K 2018-01-25 - 14:04 UnknownUser  
ts3_recording_18_01_25_9_3_38.mp3mp3 ts3_recording_18_01_25_9_3_38.mp3 manage 9 MB 2018-01-28 - 01:57 UnknownUser Telecon recording
Topic revision: r14 - 2018-11-13,
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