From shriharsh at gmail.com Wed Oct 24 12:22:45 2018 From: shriharsh at gmail.com (Shriharsh Tendulkar) Date: Wed, 24 Oct 2018 09:22:45 -0700 Subject: [FRBVOEvent] FRB localization contours Message-ID: Hi all, I have been discussing FRB followup with regards to Swift and other follow up. For interferometers, the localization regions are complicated and are hard to describe with a simple position ellipse. Multiple bananas are common. One can often get positions distributions that are different than the beam shape. I propose that we add a position contour field to the FRB VOEvent standard were we can specify LIGO-like (but much smaller size) position contours. This will help follow up telescopes with small fields of views in tiling the FRB field to search for afterglows. This field should allow for multiple disjoint contours since sidelobes are complicated. The advantage of sticking to the LIGO pattern is that the machinery already exists to ingest and utilize those patterns. In order to maintain backwards compatibility and to ensure that simple position errors are easy to communicate, this field will be in addition to the beam shape ellipse. This is not hard to implement, but I would like to hear thoughts from everyone about improvements, potential downsides and pitfalls. Cheers, -- Shriharsh McGill Space Institute -------------- next part -------------- An HTML attachment was scrubbed... URL: From claw at astro.berkeley.edu Fri Oct 26 14:08:30 2018 From: claw at astro.berkeley.edu (Casey Law) Date: Fri, 26 Oct 2018 11:08:30 -0700 Subject: [FRBVOEvent] FRB localization contours In-Reply-To: References: Message-ID: This sounds like a good change. My impression was that Emily and Leon intended this protocol to be actively maintained. I suppose this could be a v2 format and the VOEvent software would know how to parse the field appropriately. Do you have an example of a LIGO-like position contour? On Fri, Oct 26, 2018 at 1:29 AM Shriharsh Tendulkar wrote: > Hi all, > > I have been discussing FRB followup with regards to Swift and other follow > up. For interferometers, the localization regions are complicated and are > hard to describe with a simple position ellipse. Multiple bananas are > common. One can often get positions distributions that are different than > the beam shape. > > I propose that we add a position contour field to the FRB VOEvent standard > were we can specify LIGO-like (but much smaller size) position contours. > This will help follow up telescopes with small fields of views in tiling > the FRB field to search for afterglows. This field should allow for > multiple disjoint contours since sidelobes are complicated. The advantage > of sticking to the LIGO pattern is that the machinery already exists to > ingest and utilize those patterns. > > In order to maintain backwards compatibility and to ensure that simple > position errors are easy to communicate, this field will be in addition to > the beam shape ellipse. > > This is not hard to implement, but I would like to hear thoughts from > everyone about improvements, potential downsides and pitfalls. > > Cheers, > -- Shriharsh > > McGill Space Institute > _______________________________________________ > Frbvoevent mailing list > Frbvoevent at lists.pulsarastronomy.net > > http://lists.pulsarastronomy.net/mailman/listinfo/frbvoevent_lists.pulsarastronomy.net > -------------- next part -------------- An HTML attachment was scrubbed... URL: From abrazier at astro.cornell.edu Fri Oct 26 14:23:55 2018 From: abrazier at astro.cornell.edu (Adam Brazier) Date: Fri, 26 Oct 2018 14:23:55 -0400 Subject: [FRBVOEvent] FRB localization contours In-Reply-To: Message-ID: An HTML attachment was scrubbed... URL: From shriharsh at gmail.com Fri Oct 26 16:09:58 2018 From: shriharsh at gmail.com (Shriharsh Tendulkar) Date: Fri, 26 Oct 2018 13:09:58 -0700 Subject: [FRBVOEvent] FRB localization contours In-Reply-To: References:

Message-ID: Hi Adam, Casey, all, When I wrote my email yesterday, I was imagining that LIGO sends ds9-like contour definitions in text coordinates. Those would have been easy to fit into the XML format. It turns out that LIGO sends entire healpix maps with the probability, distance modulus etc for different pixels on the sky. The example provided below by Charlie Kilpatrick (UCSC) is for GW170817. It is 1.5 MB in size. We could embed healpix maps as binary data in the XML or we could provide a link to a URL hosting that probability distribution file. I do worry a little bit about increasing the size of the VOEvent too much. Regards, -- Shriharsh McGill Space Institute On Fri, Oct 26, 2018 at 11:23 AM Adam Brazier wrote: > If it's an optional field, it wouldn't break backwards compatibility and > would be more like a version 1.1 > > It sounds like a good idea to me, although I would also like to see an > example? > > Cheers > > Adam > > > On Oct 26, 2018 2:08 PM, Casey Law wrote: > > This sounds like a good change. My impression was that Emily and Leon > intended this protocol to be actively maintained. I suppose this could be a > v2 format and the VOEvent software would know how to parse the field > appropriately. > Do you have an example of a LIGO-like position contour? > > > On Fri, Oct 26, 2018 at 1:29 AM Shriharsh Tendulkar > wrote: > > Hi all, > > I have been discussing FRB followup with regards to Swift and other follow > up. For interferometers, the localization regions are complicated and are > hard to describe with a simple position ellipse. Multiple bananas are > common. One can often get positions distributions that are different than > the beam shape. > > I propose that we add a position contour field to the FRB VOEvent standard > were we can specify LIGO-like (but much smaller size) position contours. > This will help follow up telescopes with small fields of views in tiling > the FRB field to search for afterglows. This field should allow for > multiple disjoint contours since sidelobes are complicated. The advantage > of sticking to the LIGO pattern is that the machinery already exists to > ingest and utilize those patterns. > > In order to maintain backwards compatibility and to ensure that simple > position errors are easy to communicate, this field will be in addition to > the beam shape ellipse. > > This is not hard to implement, but I would like to hear thoughts from > everyone about improvements, potential downsides and pitfalls. > > Cheers, > -- Shriharsh > > McGill Space Institute > _______________________________________________ > Frbvoevent mailing list > Frbvoevent at lists.pulsarastronomy.net > > http://lists.pulsarastronomy.net/mailman/listinfo/frbvoevent_lists.pulsarastronomy.net > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: LALInference_v2.fits.gz Type: application/x-gzip Size: 1528188 bytes Desc: not available URL: From claw at astro.berkeley.edu Fri Oct 26 16:18:19 2018 From: claw at astro.berkeley.edu (Casey Law) Date: Fri, 26 Oct 2018 13:18:19 -0700 Subject: [FRBVOEvent] FRB localization contours In-Reply-To: References:

Message-ID: A ds9-like region definition would be easy to support. I suppose a full spatial probability function is the most complete you would need for an interferometric localization. You could probably get away with a ds9 region definition with an annotation for the confidence level associated with a contour. The baseline assumption may be that a contour is a 50% confidence region, but someone could provide multiple contours if they like. casey On Fri, Oct 26, 2018 at 1:10 PM Shriharsh Tendulkar wrote: > Hi Adam, Casey, all, > > When I wrote my email yesterday, I was imagining that LIGO sends ds9-like > contour definitions in text coordinates. Those would have been easy to fit > into the XML format. > > It turns out that LIGO sends entire healpix maps with the probability, > distance modulus etc for different pixels on the sky. The example provided > below by Charlie Kilpatrick (UCSC) is for GW170817. It is 1.5 MB in size. > > We could embed healpix maps as binary data in the XML or we could provide > a link to a URL hosting that probability distribution file. > I do worry a little bit about increasing the size of the VOEvent too much. > > Regards, > -- Shriharsh > > McGill Space Institute > > > On Fri, Oct 26, 2018 at 11:23 AM Adam Brazier > wrote: > >> If it's an optional field, it wouldn't break backwards compatibility and >> would be more like a version 1.1 >> >> It sounds like a good idea to me, although I would also like to see an >> example? >> >> Cheers >> >> Adam >> >> >> On Oct 26, 2018 2:08 PM, Casey Law wrote: >> >> This sounds like a good change. My impression was that Emily and Leon >> intended this protocol to be actively maintained. I suppose this could be a >> v2 format and the VOEvent software would know how to parse the field >> appropriately. >> Do you have an example of a LIGO-like position contour? >> >> >> On Fri, Oct 26, 2018 at 1:29 AM Shriharsh Tendulkar >> wrote: >> >> Hi all, >> >> I have been discussing FRB followup with regards to Swift and other >> follow up. For interferometers, the localization regions are complicated >> and are hard to describe with a simple position ellipse. Multiple bananas >> are common. One can often get positions distributions that are different >> than the beam shape. >> >> I propose that we add a position contour field to the FRB VOEvent >> standard were we can specify LIGO-like (but much smaller size) position >> contours. This will help follow up telescopes with small fields of views in >> tiling the FRB field to search for afterglows. This field should allow for >> multiple disjoint contours since sidelobes are complicated. The advantage >> of sticking to the LIGO pattern is that the machinery already exists to >> ingest and utilize those patterns. >> >> In order to maintain backwards compatibility and to ensure that simple >> position errors are easy to communicate, this field will be in addition to >> the beam shape ellipse. >> >> This is not hard to implement, but I would like to hear thoughts from >> everyone about improvements, potential downsides and pitfalls. >> >> Cheers, >> -- Shriharsh >> >> McGill Space Institute >> _______________________________________________ >> Frbvoevent mailing list >> Frbvoevent at lists.pulsarastronomy.net >> >> http://lists.pulsarastronomy.net/mailman/listinfo/frbvoevent_lists.pulsarastronomy.net >> >> >> -------------- next part -------------- An HTML attachment was scrubbed... URL: