Oh, my…I was pretty much afraid that I missed the timezone or so.
I’ve a side question, since I’m not a physicist. Somebody knows what unit of measure is “Mpc”?
(I saw it from the observation runs)
IM will discuss the polarization deconvolution in my talk tomorrow
1 parsec is 3.26 lightyears
Awesome! thank you!
My question will be: how does we know from “where” the gw comes from? do we have a way to know this? (it’s a general question, no details needed. An introduction will do… ^_^)
@Ezequiel: yes. Sylvia will discuss this tomorrow.
Oh, then I will lower my hand.
Doesn't the length of the arms of the interferometer limit the observable frequency from above? So the longer the arms, the lower the upper frequency observable? Can someone verify or correct?
@Simonetta yes! That’s why our noise curve rises at higher frequewncies
Hi, just a quick one: is there any plans for multi-messenger type of detections for electromagnetic fields?
Sidharth S Nair
KAGRA is experimenting on cryogenic mirror tech afaik
@Santanu - We observed GW170817 with telescopes at all EM wavelengths. Dozens of papers were written. We look forward to doing this again!
KAGRA is cryogenic, yes.
Aweome! @Alan W. I shall look that up!
Question: why we need “observational runs”, can’t we have the interferometers at all times running? is there a huge cost in its operation or what are the factors?
There is a good deal of work in progress to attempt to detect the memory effect
why dose light is not effected by gw
Re: plotting noise curves, pygwinc in a nice tool to turn models of the interferometer into noise curves https://git.ligo.org/gwinc/pygwinc
Here’s a popular article on memory , with links to papers - https://www.space.com/gravitational-waves-memory-space-time.html
@Abhishek light is affected by gravitational waves, there’s a good explanation of why we can still use laser light to detect gravitational waves here: https://www.ligo.caltech.edu/page/faq
@Ezequiel (1) we need to periodically update our detectors to improve sensitivity. If we do this right, we win. (2) We bring the detectors down one day a week for necessary maintenance. (3) The detectors are very complex, and a bit too sensitive to environmental disturbances, like earthquakes and storms, “knocking the detectors “out of lock” (observational mode). Unfortunately, this can happen numerous times per week. Duty cycle in O2: https://www.gw-openscience.org/detector_status/O2/
Dear Professor Kanner
In terms of Machine Learning, do you use AstroML package at all? Just wondering where NOT to get lost for my own benefit :-)
may I know how Einsten @ Home works
@Santanu there are dozens of people in the LIGO Scientific Collaboration attempting to use ML to improve our analyses. They use every ML toolkit on the market!
@Alan Thanks a lot Sir!
Here’s a nice review article of all the different applications of ML to gravitational-wave data analysis https://arxiv.org/abs/2005.03745
Is the gravity spy data set tool the same as the one available at Zooniverse?
@Abhishek E@H uses BOINC to distribute chunks of LIGO data to users (hundreds of thousands of them) to look for continuous GWs.
Why the SNR data of events are changing so frecuently? LCN gratings to Professor Kanner
Thanks a lot! @Sylvia
@LUIS each event is from a source at a different distance and with different masses. More distant, lower mass sources have low SNR (and are often undetectable), and vice versa. We expect a broad spread of event SNRs
what python package do you use for getting the posterior distributions? pymc3?
Is there a way to map the gravity spy dataset to the openly strain data?
@petra Bilby uses dynesty. LALInference uses it’s own MCMC code. Sylvia will talk about it
(I saw that the GPS time is hashed, but, there is a *way*?)
What kind of information about instrumental injections in the data for every event we can find in gwosc ? Only frequencies of the injected signal or more detailed information?
(*openly available strain data)
@petra Bilby also interfaces with many other samplers including pymc3
I will cover different PSD estimation methods tomorrow
@plamen Hi! Info on hardware injections is here: https://www.gw-openscience.org/o2_inj/
Hi Alan! Thank you!
@Ezequiel gravity spy gives you a GPS time, and the open data in gw-openscience.org are listed / indexed by GPS time as well; so it should be “easy” to find the former in the latter.
Dear Alan, I am refering for the same event, exemple de g w150914 has chenched from 24 to only 19, why?
When a new detection is made, LSC announces it almost immediately for EM follow up. Is the data for the said detection put up on gwosc or elsewhere immediately as well?
if i was try to model an unmodeled signal what can i do