Alec Habig: Alright, well, thank thanks a lot for the for the opportunity.
Alec Habig: And just so you know where i'm coming from is a is a graduate student I was an astrophysics student to then.
Alec Habig: ended up on the dark side of high energy physics, by being told I while you can go work in Italy.
Alec Habig: Doing cosmic rays, so I did it hit the ground sauce oh and i've been working on high energy physics experiments ever since trying to ring the astronomy out of them because that's That was my lifelong love so.
Alec Habig: When I talk about.
Alec Habig: Work that we've done with kind of a Meta experiment with many neutrino experiments.
Alec Habig: To maximize what all learn from the next galactic supernova.
Alec Habig: snooze supernova early warning system.
Alec Habig: So supernova themselves a yo yo yo you'll you'll know or astronomers know because there is the death of an old star that lights up.
Alec Habig: with as much as much light, as is in a whole galaxy but just in one star for a week or two and then and then goes away, is a great picture of one or that one star there.
Alec Habig: You know, see my mouse and I need to wave it around.
Hristova, Ivana (STFC,RAL,PPD): Yes, we have we see.
Alec Habig: Okay, so there's a there's a exploding star on the outskirts of this.
Alec Habig: This Gal to my pretty picture and astronomers divided them up in the stamp collecting phase of science into the is there, hydrogen in the in the spectrum or not Type one or Type two Type one.
Alec Habig: About 5050.
Alec Habig: It it turns out that most the one that we just saw and I think this one is well here is a white dwarf that in a close binary system that had more massacring onto it gets overshadowed sacred mass and explodes and that's a Type one day.
Alec Habig: Because it's the same thing exploding all the time they're great standard standard bombs, if you will, or a cosmology work and a.
Alec Habig: We see somewhere in the universe kind of only order one a day of these things, if you look really far out there and it's done through.
Alec Habig: A technique like this, where you just take pictures of galaxies today and tomorrow, and next week and.
Alec Habig: And just different images and where you see a sudden sudden spike their uh their vitamin A super fun, so there is a supernova Type one a next to that galaxy really, really far away right now that's not nearly as pretty as the last one.
Alec Habig: But.
Alec Habig: All the ones that we see every day that.
Alec Habig: that the people chase for cosmology or whatever they're all extract galactic and very far away.
Alec Habig: The other the other type that will spend most of the time talking about today is a core collapse supernova so the core of a massive star reaching the end of its life.
Alec Habig: Using things, all the way up to where the nuclear on the air the binding energy, nuclear on curve flips over an iron you can't get any more energy got a fusion there so.
Alec Habig: star collectors indigestible core of iron your the end of its life are very massive star that can can compress things that much to get iron.
Alec Habig: And when you get to try to take our massive that the electron degeneracy presser can't hold it up and down it goes.
Alec Habig: And how these are the five is supposed to be a almost equal to, and yet Microsoft equation editor thing.
Alec Habig: But you just do a well let's change the binding energy of something that weighs one point for solar masses from something the size of the earth a white dwarf or the core of a star.
Alec Habig: down to something held up by you're trying to generate the pressure, a neutron star the size of the city and just do the freshman physics finding energy problem there for a sphere of constant density you wind up with this.
Alec Habig: it's a lot of energy that's a astronomical units, because they like cgs Units three of the times 10 to 23 irks.
Alec Habig: That thing that is bright as a whole galaxy from before turns out to be only about point 1% of that energy.
Alec Habig: As these things explode you see them hurling across a nebula.
Alec Habig: spraying the bits of the star across a per SEC, or something like that that kinetic energy is about 1% of the total energy so that leaves 99% of the energy, you know, is there because you can do physics to account for and it turns out the neutrinos is where the rest of that goes.
Alec Habig: and
Alec Habig: Is a great plot from nakamura few years ago, which shows the whereas all that energy going versus time here is a big bright star.
Alec Habig: In terms of eric's per second one of the brightest stars in a galaxy is the bottom thing on this graph and over here is the actual explosion, which is the brightest thing in the universe for optical for weeks.
Alec Habig: But 99% of the energy is going into neutrinos which i'll explain in a minute then here's a neutrino luminosity the middle of this plot is exploded.
Alec Habig: There could also be gravitational waves if that core collapse happens asymmetrically if it happens perfectly perfectly symmetrical you won't get.
Alec Habig: gravitational waves, so that depends entirely on the asymmetry the explosion, we know they're asymmetric because we've seen neutron stars shooting across the galaxy like squid after the explosion, but the details are uncertain.
Alec Habig: and actually you see that we could get neutrinos from before the supernova as well as that core of the super giant star cool starts to go off by neutrinos and a pre supernova.
Alec Habig: what's going on and kind of a bad cartoon there is your onion skin of a big giant massive star burning things down iron at the core zoom into the core it collapses.
Alec Habig: Shutting all the electrons into neutrons and protons me making neutrons binders beta decay and spraying electron neutrinos everywhere.
Alec Habig: That actually becomes so hot and dense in the middle of the neutrinos are trapped momentarily it's actually a pig neutrinos.
Alec Habig: And the core becomes incompressible as it collapses stops collapsing rebounds and.
Alec Habig: Then a shockwave from that rebound is powered by the neutrinos streaming out of the stars, it becomes transparent in neutrinos and that explodes the details of this.
Alec Habig: are well simulated now didn't used to be and then that proton neutron star part of neutron star starts very early cools off by just pair production of neutrinos the general scheme.
Alec Habig: go into some of the details here as we, as we look at this.
Alec Habig: The thing that everyone thinks hey yeah supernovas making neutrinos.
Alec Habig: Well, because yeah because I can do that I can do that reaction right there, taking the electrons i'm shoving them into the protons and making the neutrons that's what's bringing out all the empty space.
Alec Habig: That allows the white dwarf to get earth sized city size right all the empty space for now and look electronic.
Alec Habig: turns out that's only about 1% of the neutrino total neutrino luminosity is produced this way it happens all at the beginning, when you make a neutron star.
Alec Habig: Over milliseconds so should make a very sharp spike of electron neutrinos and to the extent that a number of you might work on dune.
Alec Habig: A one of dunes goals is to be sensitive, particularly to electronic neutrinos so that we could see that spike because if you see that spike or not, you can get hit up the mass hierarchy of neutrinos.
Alec Habig: But most of the neutrinos come from our production and the same way as you pair produce any anything you start off with enough MC squared of energy, you can pair producer.
Alec Habig: But neutrinos if you grab the fireman diagram for that you're going to need a week goes on to pair producer neutrino anti-neutrinos care and that's hard right, those are other heavy don't happen very often, this is not something you generally see in an accelerator.
Alec Habig: But any of the more common reactions that you we see all the time in particle physics happened to in a neutron star.
Alec Habig: The resulting particles just don't go anywhere why because they're buried in the core of a neutron star it's really hot and really dense and the products immediately get recycled back into the super massive energy.
Alec Habig: When Mother Nature very luckily gets a neutrino anti-neutrinos pair However, they can escape because neutrinos interact weekly.
Alec Habig: And even that proton neutron stars and mostly transparent at soon after the collapse to neutrino so this sort of the leaky bucket it's, the only way the energy can get out so it does, even though on a interaction by interaction basis the interactions I list here are.
Alec Habig: So uncommon you wouldn't even look for them in your favorite accelerator.
Alec Habig: So uh and the details of this are really well model may end up being great pretty here's a here's a nice picture from bronson Messer of.
Alec Habig: Equal entropy surfaces in the proton neutron stars and splashes around had incredible temperatures and ambient katie that just makes makes yourself particles Willy nilly.
Alec Habig: The general scheme, however hasn't changed a lot that general like curve, if you will have it in neutrinos have a supernova hasn't changed in decades, even though early simulations that a hard time making next blows.
Alec Habig: And here, it is there's that very short and millisecond spike it's a log scale so that's 1% the area under the curve and a lot.
Alec Habig: Of electron neutrinos that we hope to see with.
Alec Habig: With doing and then over the next second the explosion hasn't happened yet.
Alec Habig: matter continues to rain down on that proton neutron star from the rest of the start up above it might wave around and slosh you get standing standing increasing shocks.
Alec Habig: asymmetry might result here for the gravitational wave folks and when that standing shock is a sort of ignited an accelerated by the luminosity neutrinos hitting the base of it from the star it can explode.
Alec Habig: That shockwave races out the i'm look with a star, and we see the supernova.
Alec Habig: And then from there out it's just it's just an exponential cooling curve over 10s of seconds as that proton neutron star pools by neutrino production.
Alec Habig: and
Alec Habig: Because the energies are sufficient to make yourself the arrest masses of of of neutrinos you get them and.
Alec Habig: Will will generally break them up into sort of three flavors, if you will, new end we bar and then new new a new town there antiparticles will have together as new acts or new new depending upon which whoever made the plot you'll see why in a second here.
Alec Habig: How you get that neutrino emission coming out of that star is a is neutrino opacity will go back to astrophysics lingo where you spend most of astrophysics.
Alec Habig: Doing radiated transfer problems with usually with photons and protons getting absorbed and you figure out the opacity and you see how far to the intensity goes right to astrophysics class you've done that.
Alec Habig: we're doing that, with neutrinos and neutrino opacity, we normally think of the essentially zero we're busy shining beams of them through the earth right now right but.
Alec Habig: it's so dense and so hot there that you can treat it like a regular radio, the transfer problem shine a beam of neutrinos see how many get absorbed in some D R of neutron Star and see how many make it out.
Alec Habig: And look at what neutrinos do all neutrinos, of course, the neutral current interactions wonderful current interactions are kind of weak compared to charge correct interactions that's likely.
Alec Habig: Where do you get charged current interactions electron neutrinos could do that off the neutrons and the neutron Star and there are a lot of new friends in India, trying to start.
Alec Habig: His name, and so you could get this interaction, so that is a second source of opacity that could eliminate electron neutrinos from your beam of neutron neutrinos headed towards earth from the star.
Alec Habig: Anti electron neutrinos can also see charged current, but in that case you need a proton right and protons are comparatively rare in a neutron star, although there you get the traditional and respected kit.
Alec Habig: And a new new and new TAO the energies here are 10s of them ED for these neutrinos that is not enough.
Alec Habig: kinetic energy to make the rest of massive in you or a towel, so they do not see a charge current interactions.
Alec Habig: So we turn that around, then all all six flavors of neutrinos continual current interactions but that's the only ones that new a new tlc.
Alec Habig: Anti electro neutrinos have an additional source of absorption so sort of medium and electronic trainers have the most opacity and so that results in a.
Alec Habig: temperature distribution, which is different for the three sets of neutrinos I just described, where the this is exactly like.
Alec Habig: astrophysics again with with photons say limb darkness on the sun, where do you see deepest into that proton neutron star where it is the hottest well, that would be with the new moon right because.
Alec Habig: They can get out of the middle of neutron star to you, without being absorbed they come out the hottest.
Alec Habig: The electron neutrinos have all the sources of capacity, you see, just the skin and the neutron Star and electron neutrinos so they are the coolest elektra neutrinos in the middle, so you end up with this hierarchy of.
Alec Habig: neutrino temperatures.
Alec Habig: And these days, a guy's a very old model, I will show you because it's simple it's been around.
Alec Habig: In these days, people can do the very complex calculations that are needed to to flesh out this model and show how supernovas exploded in the supercomputer.
Alec Habig: And one D models reproduce the general luminosity curves well but never really exploded, which is kind of embarrassing.
Alec Habig: But people adding general relativity all three dimensions, involving rotation Maggie do it in an excel acoustics everything explosions work now, and so there are three events models exploding.
Alec Habig: As we see stars do that's Nice.
Alec Habig: And the time profile for ministry no experiments standpoint would be that first of electron neutrinos at the very beginning and then 10s of seconds worth of exponential cooling in neutrinos with the hottest highest energy neutrinos being in the electron neutrinos.
Alec Habig: Then anytime electron neutrinos than everybody else, and this should last out to about 100 seconds, so I mean it's exponential so the signal you get goes low and for most experiments on earth will be below the noise floor after about 10 seconds.
Alec Habig: But.
Alec Habig: If a black hole forums, which the largest stars we suspect, do you would see this light curve wink out as the black hole forms of all luminosity stops and so, if you see this curve truncated suddenly you will watch the birth of a black hole.
Alec Habig: The generalities, you have neutrino experiments that are going to look for bursts of 10 1220 kind of that time range energy range of neutrinos over 10s of seconds.
Alec Habig: see a rough a rough cut off right you just saw black hole form the luminosity is roughly equal per flavor with this kind of average energy.
Alec Habig: distribution.
Alec Habig: But neutrino oscillations will of course scramble this and regular msw oscillations which are now well understood on earth and the sun.
Alec Habig: would occur, and in fact that that is the primary reason why dune claims that it would see a signal that would resolve them a neutrino mass hierarchy problem if if it deserves a supernova.
Alec Habig: Because this electron neutrinos in that initial peak would oscillate away or not, depending upon the mass hierarchy, because the matter affects the driver there's a lot of matter there would erase that peak or not depending on if it's inverted or not inverted.
Alec Habig: It could get even weirder though neutrino neutrino interactions which, again, you can happily draw a diagram for and you're never going to get a neutrino being one neutrino being collider experiment on earth, because the Cross sections would really suck.
Alec Habig: So many neutrinos I happen in a supernova.
Alec Habig: And so those collective effects, you will get a.
Alec Habig: really can scramble what the post oscillation neutrino signal would look like from this person neutrinos in a supernova.
Alec Habig: To a precision will never see on earth, and so the fine details of how the oscillation works and everything else will be a complete treasure trove of particle physics, as well as astrophysics has a probes that mass distribution and the star as that beam comes to you.
Alec Habig: To get this, however, the experiments on earth, need to be able to sort out.
Alec Habig: What are the different flavors so they can pick out the spectrums here's a sample spectrum that has been scrambled by collective oscillations to work your way backwards to what the Star and neutrinos are doing on the way out.
Alec Habig: Most experiments prefer one flavor neutrino or another, so you kind of need an ensemble experiments.
Alec Habig: We know this works in 1987.
Alec Habig: This happen right there's sort of a 1987 eight or the trash on nebula and alerts module on the cloud not in our galaxy and a very close to it only 55 little parsecs away, and so it was really well studied by everybody.
Alec Habig: And, of course, the one really super well studied one was a bizarro supernova that it was a bluetooth headset or red giant and had an odd light curve, it was kind of dim alright Murphy works in murphy's law works and observations.
Alec Habig: The important thing, it was close enough that just being one over R squared take your neutrino flux and spread it out over a sphere didn't kill the signal.
Alec Habig: All those extra galactic ones it happen every day, even the largest experiment even hyper K will only see a handful of neutrinos from something as near as andromeda.
Alec Habig: One of our scores just just kills it and neutrinos are hard to see in your detectors.
Alec Habig: Alex Friedman them, you know from doing this, one of the best ways to describe what these things are these things are gravity powered neutrino bombs.
Alec Habig: But even neutrino neutrinos are so weak that even this means you can't see it from outside the regular environment of near our galaxy best.
Alec Habig: In 1987.
Alec Habig: The four experiments claimed to have seen it the three which people most people agree really did are on this plot of a spectrum of energy of the neutrinos they saw versus time and you can see a burst of neutrinos over about 10 seconds of energy kind of 10s of them ev.
Alec Habig: And these were all small experiments looking for proton DK they all went back and looked at their tapes after people said hey a supernova went off nearby and maybe we saw hey we did.
Alec Habig: And all told there were kind of a couple dozen neutrino seen from this this event 30 years ago.
Alec Habig: To the extent where this event display from I am, be it can bring you back that you know the race race event display from the 1980s there it is there's your show recovering from a.
Alec Habig: Anti from a positron made by an inverse beta decay reaction of neutrino on water, and I am be making a shrink offering.
Alec Habig: But it worked right, you can just say all right, we saw that 24 neutrinos you know the Cross section three nodes and how big those experiments were yeah that's kind of 10 to the 53 years of the total neutrino luminosity great works.
Alec Habig: And lots of stuff happen and there's been sort of a paper per day or less than 30 years since that event, citing these results.
Alec Habig: today's detectors are much larger instead of a kiloton there are 10s of millions most supernova in and around our galaxy would happen in our galaxy not in this little a regular galaxy nearby.
Alec Habig: So one of our square to be a much larger signal and the threshold for modern detectors is down in the single digits of meds not a 10 or 20 a movie.
Alec Habig: So we would see thousands of events anyway, and each experiment for a supernova happening in the Milky Way today and more in the tomorrow asterisk that would be doing an hyper came, whatever that is and that and wps land.
Alec Habig: Well, why why we consider this right humans haven't seen a galactic supernova since kepler did, and it was a Type one a to boot, so why bother looking, the answer is you don't see much of the galaxy with human eyes in the last several hundred years.
Alec Habig: You don't see much in our galaxy until modern times when you can look at other wavelengths because the galaxy is full of crap.
Alec Habig: If you look at other galaxies and carefully plot things are related to supernova estimates are kind of one and a half per century one or 2% trends this most recent paper on that, which is quite good that uses.
Alec Habig: A range of ways to count what the Milky Way supernova rate might be.
Alec Habig: One or two per century one per sort of academic career, it pays to pace to pay attention to it.
Alec Habig: There is a map of historical supernova on the galaxy instead of a low res figure from magazine decades ago sorry about that, but they're all here in this kind of slice of the galaxy where the sun is there's the sun.
Alec Habig: There are plenty of supernova elsewhere in the galaxy, this is a good visual representation of why we haven't seen one says kepler even though they've happened people have tagged young supernova remnants elsewhere and galaxies that have happened since kepler and nobody noticed.
Alec Habig: Right, so why bother, why are we thinking about this and you know, putting it in our experimental proposals and so on, even at marginally nearby event produced such an amazing boost of progress on particle physics front and as well as astrophysics.
Alec Habig: That one closer with observation, starting from T equals zero instead of hey look something that up in the sky.
Alec Habig: And now we have the framework for neutrinos at that lab of a super dense pile of neutrinos interacting with themselves and undergoing oscillations and everything else.
Alec Habig: would really do better than anything we can imagine here on earth and the particle physics front as well.
Alec Habig: When we're looking at this, if there are two per century that happened in the Milky Way and the Milky Way is 15 phil parsecs large.
Alec Habig: that's already hundreds of supernova that have already made the neutrinos that are busy slugging their way at lightspeed across the galaxy to earth, if you want to think of it that way.
Alec Habig: Especially altruistically that's not maybe a great way of thinking about it but okay.
Right.
Alec Habig: observations from very early times.
Alec Habig: This is what that there's the star is blue giant in a in an archival picture from before the supernova and there is a after it exploded in 1987.
Alec Habig: And we don't know what happened between these two pictures, who was discovered when.
Alec Habig: an observer and telescope in Chile went out for a smoke break and looked up and said that star is not supposed to be there, went back and took pictures.
Alec Habig: observations by people, including some very good amateurs with didactic memories and that was Jones and Australia had been looking at the galaxy earlier than I did not see anything.
Alec Habig: And so there was this window of yeah nothing yet nothing yet eight or something there we don't know when the light first started to more than like an hour and a half the delta T.
Alec Habig: and
Alec Habig: The neutrinos were found later when this telegram went out around the world and the days of telegrams 1987 is that long ago yeah.
Alec Habig: All the neutrino experiments went back and pulled their tapes 6250 bpi reel to reel tapes random and said oh look neutrinos.
Alec Habig: We would like to know what goes on between these two pictures and and do it quickly, so we can we learn from the way 1987 eight worked.
Alec Habig: Sorry, so here's here's here's the scheme here, we could get observations from T equals zero in light the explosion of a star because stars are not transparent there's a picture of our star.
Alec Habig: The photos for you see is defined astronomically as we're going to start with stops becoming transparent where opacity how equals one as you look back at the sun.
Alec Habig: So whatever happens below the edge of the star of the photos fear you don't see in light.
Alec Habig: star could undergo this catastrophic core collapse and you would not notice, you would not notice until that shockwave from the rebound on the neutron star driven by neutrinos.
Alec Habig: plows its way through the radius of the star rips out through the photos here at which case we probably would see a really good burst of flopped X rays and ultraviolet as the photos forget shredded.
Alec Habig: And you'd start the clock and say astronomically from a photon standpoint.
Alec Habig: supernova but that delta T is the travel time of a shockwave oppressor radius of a star, which is a for something the size of beetlejuice typical red giant thing that we think are most likely to be a supernova progenitor would be ours.
Alec Habig: For something compact like supernova 1987 he was probably an hour and a half, Wolf or a star it might only be 10 minutes.
Alec Habig: So if you see the neutrinos which get out pronto.
Alec Habig: A you have advanced warning that a star will explode minutes to pro hopefully hours somewhere in our galaxy that would be really cool.
Alec Habig: So, now that we know we can see them supernova train, how do we do it differently and you've seen the phrase before the luck is opportunity times preparation right a.
Alec Habig: Experimental physicist would say okay it's probably opportunity cross with preparation, because you don't know what direction is going to come out and but alright.
Alec Habig: So the neutrinos come out properly upon for collapse, make a signal which is obvious and today's detectors and most because they've been preparing have an automated analysis chain that will trigger on the super open to train us.
Alec Habig: Information gets around the world, much more efficiently than telegrams these days, and so a galactic supernova would give us advance notice that we really could have good astronomical observations, starting at T equals zero.
Alec Habig: What goes on between those two pictures we don't know what we could hopefully have ringside seats and be ready to watch and do it, so this time let's do it the other way let's trigger the photon based observations, based on the neutrinos instead of vice versa.
Alec Habig: We do it.
Alec Habig: We trina experiments must be able to identify as a supernova not something else get the word out and then say hey look over there and do that all in an hour.
Alec Habig: gamma Ray bursts do this, all the time over the past couple decades at gc and friends have solved this problem of what the heck are gamma Ray burst even both types, with the help of gravitational waves, for the last killing over thing.
Alec Habig: there's about a gamma Ray bursts per day somewhere in the universe so they've had a lot of practice.
Alec Habig: snooze has been running almost as long as gcm and there hasn't been a supernova for us to work on, but this is kind of the same goal.
Alec Habig: And of course Lego and virgo and high energy neutrinos from ice cube or cam three that are all doing the same thing now getting the word out quickly so that we can get many instruments many different messengers wavelengths sensitivities.
Alec Habig: Looking at the problem as soon as possible to unravel them.
Alec Habig: Right, so the photons will be the easy stuff when they happen, what about the neutrinos you need big things because your trainers are slippery and you need a little background, which means that you're probably best going of circuit going underground.
Alec Habig: good timing energy resolution if you can point back that's great if you can see, more than one flavor neutrino that's great.
Alec Habig: Quick rundown of what we got a.
Alec Habig: simulator experiments with the most common rights is how neutrinos were discovered by a rightness and kaolin.
Alec Habig: And primarily that's the things that are circled in these in these reactions of neutrinos on things in your Center later tank and it's primarily inverse beta decay, with some neutral current.
Alec Habig: And that doesn't get you much pointing capabilities these interactions are not very forward, and in fact most simulator experiments don't even bother trying to get the direction.
Alec Habig: Because it doesn't doesn't help you too much, but lots of experiments do this because it's a great way to seem to train us.
Alec Habig: And here are four of them have which up until recently all for participating in snooze diabetes being decommissioned right now.
Alec Habig: That do this and they're all kind of on the order of a kiloton and would see hundreds of mostly new bars for a canonical supernova at the Center of our galaxy.
Alec Habig: Nova is one that I work on that is of course there's our beam line to northern Minnesota.
Alec Habig: And if you just look at the big if you just look at what that would produce in our experiment, he was he was of neutrinos anti electron neutrinos.
Alec Habig: A mostly, this is the flux going in we don't see the new ease and that Nice spike at the beginning and Nova but you see simulate away, and you can see what you would get in in in Nova and in a five millisecond data frame and Nova here's what our event display would be like with.
Alec Habig: interactions that are how yeah they're 1020 MTV there Michelle electrons mostly same same spectra.
Alec Habig: A lot of them, but kind of crappy little events spread out over the detector could we see that.
Alec Habig: No, that is, on the surface that's what we see in any random five millisecond data frame at the Nova fire detector because we're on the surface and it's all cosmic rays at 10s of killers.
Alec Habig: And we sort that out from this yeah we can and we've done that not well, but we could see most of the galaxy morally galaxy than not with our with our trigger their.
Alec Habig: Water shrink off the two largest experiments that did the saw the most neutrinos and I can add seven were cameos kinda and I envy they were water shrink off now we have super K, a people are going to build hyper K and it's mostly inverse beta decay again.
Alec Habig: With some new recurrent but elastic scattering there is really important, because electrons are light enough that even attend MTV the recoil electron from just regular scattering of.
Alec Habig: neutrinos off electrons you would be able to get a Cone back pointing to the supernova so for this kind of canonical supernova we're talking about a super K could get a Cone on the sky of about four degrees radius so supernovas over there.
Alec Habig: And super K is participating and snooze and would see thousands of us.
Alec Habig: four degrees pointing now the gadolinium is in there, they will do even better on appointing because they'll be able to tag and subtract out in verse.
Alec Habig: If you're not an imaging shrink of experiment, what if you just dangle a bunch of photo tubes and ice or water still works.
Alec Habig: Of the threshold for an event by event reconstruction is large, because these things are meant to see you know TV TV TV neutrinos, however, all those neutrinos interacting if they interact near a photo to.
Alec Habig: there's enough ice near photo tubes the dark noise rate, if you will, from these experiments which the roof inventive a supernova.
Alec Habig: And so km three net and ice cube are participating can snooze now watching their singles rate spike is their signal.
Alec Habig: And they're big enough that they would do a really thorough job of nailing the timing, just because the rate would be so high, even though, if you don't have an event the reconstruction.
Alec Habig: It says here's how it works and there's a cam three net.
Alec Habig: and doing doing much the same thing right now ice cube has more sensitivity.
Alec Habig: Having more water instrument.
Alec Habig: But they both participate.
Alec Habig: Noble liquids work great too and you're thinking dune and that's what I work on as well and and i'm doing is one of its major physics schools is see a supernova.
Alec Habig: You can get some directionality.
Alec Habig: By watching the which way the brand peak is on the as as electrons butter through the garden and it's very large or will be deep underground.
Alec Habig: But right now dark matter experiments are lux and xenon are large enough that they see supernova neutrino rates.
Alec Habig: And in fact that very little background they will see a coherent scattering a sevens events so a pure neutral current sample with essentially zero background so dark matter experiments are now in the supernova detection game as well.
Alec Habig: A a oddball that I work on in in Sudbury is HALO.
Alec Habig: A, this is what most of the experiments we've just saw do right inverse beta decay.
Alec Habig: In the lead, making more neutrons you don't need more neutrons and lead their polly blocked.
Alec Habig: And so it allows the electron neutrino on neutron interaction to proceed there also happens to be a nice set of nuclear physics between lead and beer Smith giant gamma Teller giant resonance and that's all I know about it, but it sounds cool that really jack's a cross section.
Alec Habig: And what do you have a few added proton to lead you get this myth emits thermal neutrons.
Alec Habig: piles of ladder pretty transparent and neutrons I make really bad neutron shielding right.
Alec Habig: So if you instrument, a big pile lead with neutron counters watch for supernova That way, you are actually watching for a burst of electron neutrinos.
Alec Habig: And we've done that in HALO although with small and the ensemble of experiments will let us sort it out there's out of the different kinds of experiments I mentioned, except for iron, we still haven't built a good iron supernova experiment.
Alec Habig: But for these five pie charts.
Alec Habig: You can see that the ensemble of experiments in the world have a reasonably good cross section of different types of neutrinos.
Alec Habig: Water shrink called liquid simulator is still mostly new a bar all the water from directionality can tell you more new ease or not from electron scattering as well as a direction.
Alec Habig: Very low threshold energy threshold liquid simulator experiments, I can land and works, you know, a.
Alec Habig: would be able to isolate the new bar versus neutral current basically or neutral current of low energy, you are get the protons recoiling.
Alec Habig: Lead get to new he and dune get to a lot of new he when it comes along.
Alec Habig: very, very low threshold ones like take the spin that around you get a lot more red in this picture if you're seeing on our luck's.
Alec Habig: So all the experiments that were put together will have a much more comprehensive picture of the country on luminosity by flavor by time.
Alec Habig: And let us sort out that next collective supernova.
Alec Habig: there's HALO which right now is a maybe our best chance to get a new signal and as a human scale when you see the Rack next to it it's only 77 tons of lead, and let us compact.
Alec Habig: We hope to be able to build a kiloton worth of HALO at the ground sasso as well, those are snows neutral current detectors.
Alec Habig: surplus from snow that are neutron counters and HALO.
Alec Habig: And there's where we are in HALO and it's been operational for a decade now, so dedicated supernova experiment that just waits for nutrient waits for neutrinos from supernova.
Alec Habig: and
Alec Habig: snow snow habits very deep we don't get a lot of speculation neutrons and that's why they build dark matter experiments are well for the same reasons, and so our background rate is only 150 Miller hurts.
Alec Habig: or 15 mil hurts sorry the ceiling.
Alec Habig: pile around it now it's about one neutron per minute of background and a supernova somewhere in our galaxy would give us a burst of doesn't ish.
Alec Habig: neutrons in 10 seconds so that's our that's our experiment there, the statistics will be very little bit will be very pure and electron three quarters kind of your electron neutrino.
Alec Habig: All right back to snooze why network we call it the supernova early warning system and the early warning part we talked about right compared to the light.
Alec Habig: Any single neutrino experiment, as many sources of noise even HALO deep underground.
Alec Habig: Under a few supernova none, yet that we have seen since 1987.
Alec Habig: Things that look like supernova if you're the empties flash if you have light leaks are some electronic noise solution for a good cosmic Ray we get one of those and HALO every few days to spring neutrons everywhere, is a trip to the rock nearby the detector.
Alec Habig: coins, for example, coincidences of radioactivity near your sensors and, if you look at them in an event display you can say oh yeah right, not a supernova distribution is funny.
Alec Habig: And you can even build a self an automated analysis chain with gets rid of a lot of that, but still no one experiment would feel particularly comfortable making an automated supernova announcement on its own.
Alec Habig: And, but none of these sources of noise will simultaneously occur in other experiments, at the same time, but neutrinos from real supernova will slosh across the whole earth and get all the experiments.
Alec Habig: And I have a picture of a pager there because, in the early days.
Alec Habig: that's what we did I I carried a pager for for the macro discriminate against law so for many years that if the.
Alec Habig: va Q said hey it looks like a supernova you log in fire up some histograms say.
Alec Habig: Right.
Alec Habig: That takes about an hour response time of a human to log in and look at histograms consumes most of our most of the time that is our advanced warning.
Alec Habig: It was course we're not an early warning anymore, we destroyed our chance to get astronomers out there and have this, then let them spend that hour getting their telescopes fired up and pictures taken to the sky.
Alec Habig: So we want to eliminate the human from this connection and that's what snooze does so, if the if the.
Alec Habig: neutrinos will occur occur simultaneously and currently there are seven experiments that are operational plugged into snooze looking at for supernova neutrinos in an automated way a and.
Alec Habig: With three more that are in a kind of a testing will sensitive neutrinos and.
Alec Habig: Testing their connections in the box on Nova and snow.
Alec Habig: A you would be able to say hey there is a supernova and an automated way because not only did one experiment saw it, but to did and there's Probably not.
Alec Habig: The same solution event and Japan is there isn't Italy, at the same time, or you know the photo to flashing did not occur twice in two different detectors.
Alec Habig: So it's really simple it's just a coincidence it's a network coincidence trigger.
Alec Habig: Where are the experiments if they their systems says might be a supernova it just sends a packet over the network to a computer at brookhaven have a backup computer in Bologna as well, and if two experiments do that within 10 seconds, then might be a supernova alert the world and.
Alec Habig: Two different ways that this is done now it's a big email list world's lowest traffic email list go ahead and sign up you get an email from it it's going to either be a supernova.
Alec Habig: or me saying and the 10 years since I last talked to you the lab is changed, email systems when you switch the reason, this is less a little less gets email.
Alec Habig: Also packets to gcm that's a gamma Ray bursts network so experiments which are already on the ball getting our telescopes chasing gamma Ray bursts can do that for supernova as well.
Alec Habig: experiments which would wish to trigger on the new on it to save their data which Nova will as well, because our background is as high enough, where a dark matter experiment.
Alec Habig: or legos if it's not a symmetric.
Alec Habig: They can trigger on snooze as well and in dune we are working for that capability as well because we'd really hate to miss a supernova we don't see it ourselves with our trigger primitives.
Alec Habig: We hope to be able to dump.
Alec Habig: buffers based on snooze it could be tricky because the data rate and doing as terabytes per second and we don't have we only have maybe 10 seconds worth of buffer so snooze might not be fast enough to trigger Nova are doing sorry.
Alec Habig: But we hope you can see it and do on our a lot of work is going into and you might be participating in that.
Alec Habig: So snoozes goal in 1998 we had a conference that it be you where we got a bunch of neutrino people and astronomers and got together and decided we want to be prompt yeah great vast less than an hour we don't want false alarms and we won't be able to tell you where it's at.
Alec Habig: How we've been doing on that we've been operational for most of the.
Alec Habig: Remaining 20 odd years between then.
Alec Habig: and
Alec Habig: We think we're prompt, of course, we haven't had any supernova to check this on a.
Alec Habig: But if we if we can say, based on the reaction times of the da cues involved, this is our probability distribution of getting a alarm and some amount of time.
Alec Habig: That matt straight cooked up and it's course driven by the fastest experiments in there, but he's pulled in efficiencies and things as well, certainly minutes.
Alec Habig: So we should be fast, are we prompt we so we think so right uh and we did a test early on, where we dial the thresholds down and for super case know and led and made sure that it all worked and got just put on noise coincidences and that worked.
Alec Habig: We really like to know so we'd like to be able to dial down a thresholds kind of permanently and have a chain of.
Alec Habig: High false alarm right loosen difficult things for people to play with so that all the all the machinery is tested on a more regular basis.
Alec Habig: We haven't had any false alarms in two decades flip side being haven't had any full test of the pipeline right we did an observational test back in 2003.
Alec Habig: and, interestingly, in the past two decades, what astronomers want is completely flipped in 2000, we were told, if you crazy neutrino people ever give us one false alarm will never believe you again today.
Alec Habig: yeah we get we get the false alarms all the time we're chasing gamma Ray bursts and and and X Ray transients whatnot.
Alec Habig: So long as you give us a a stream of stuff and tag it with your false alarm like we don't care what your false alarm rate it so it's a complete flip.
Alec Habig: Could we get pointing there is a plot of where the super neutrinos are coming from a supernova from super K, where the blue ones are where it came from.
Alec Habig: Mother Nature doesn't take your event display with Monte Carlo truth like that right, but that's where that four degrees comes from, we know we can do it because there's a picture of the sun in neutrinos as seen by super gay.
Alec Habig: Using the same electron scattering channel.
Alec Habig: Each pixel in there, however, is about the diameter of the signer the full moon, but the centroid of that is very well defined, of course.
Alec Habig: so soon as to point out, what are we doing two decades later to improve things we'd like to be able to provide multiple thresholds output streams that constantly exercise whatever machinery you care to plug into.
Alec Habig: A week we like experiments to be able to compare light curves real time to extract physics quickly and particular a triangulation of that second and get alerts out to all the new networks.
Alec Habig: In the way that you see gamma Ray bursts and gravitational wave chasing people do now.
Alec Habig: That original snooze code was written in C and the 90s and there's a header file from it, you know some of those if deaths don't even exist anymore, it was designed for the use of macro helping you super cold and snow some of those experiments don't even exist anymore.
Alec Habig: very old it's crunchy it's a maintenance nightmare.
Alec Habig: And plugging in new experiments is, as I mentioned before it's been hard.
Alec Habig: And yeah it's just some code management problems i'll skip over some are out of time.
Alec Habig: there's new physics, it could be seen as that star is about to explode if it's only a few hundred parsecs away that.
Alec Habig: neutrinos coming out of the hot core of the about the collapse star.
Alec Habig: We might see so Cameron does this now, could we get new experiments with low enough backgrounds to see those very low energy neutrinos plug together and sort of do a stalking experiment answers, is probably yeah.
Alec Habig: We could extend that out to a kilo per second set of a few hundred per SEC greatly increasing the number of stars, we might be able to observe about to go and then, in which case we might get days, instead of hours advance warning.
Alec Habig: and pointing unit hyper cable also have direction prevent directionality like super K super cable improve those.
Alec Habig: Maybe snooze can do this as that way front of neutrino sloshes across the earth, it will hit first one detector than the other like travel time across the Earth is three milliseconds could you.
Alec Habig: Between experiment one and experiment to just based on timing alone, you would get a disk in a ring in the sky of where could that supernova have been that would have made that timing profile and with for experiments, you can get that down to.
Alec Habig: one.
Alec Habig: point on the sky, this is the way gravitational wave experiments get their directionality and your simulations of different experiments and kind of a typical supernova and then statistics, they have.
Alec Habig: And so, you see, we might be able to protect you in the future with larger experiments that have better statistics and therefore better registration and that way front, a nail where that thing is on sky.
Alec Habig: We combine significance, can we source stack, this is the way Nova combines it's two detectors and it supernova trigger now we are plugging that into snooze 2.0 so experiments that wish to send a time series of significance and some time then continuously could add together and.
Alec Habig: kind of do some threshold work as an ensemble if that experiments want to contribute that kind of data.
Alec Habig: Even andromeda will still be too far away a pre supernova neutrinos this will definitely help, and if there is some sub luminous something we don't know about this will be a way to pick it up, which we would not notice in any one experiment.
Alec Habig: A that I stole the networking for the original snooze so it's still running from metric the very first esports game which I spent too much time on as a graduate student.
Alec Habig: But we're asking questions, how can we combine it with better modern technology, both on the code side statistics kind.
Alec Habig: And there is a project, an SS supported called semi that has made a network layer called hopscotch which we are using its Kafka based pub sub system that is much more robust and just raw sockets that I wrote once as a postdoc.
Alec Habig: And right now, it goes out there is, you know if you go to snooze that biennale.gov you can sign up for the signup or put your name on mailing list now and get an email in case of a supernova.
Alec Habig: And these other things as we discussed can do it as well, and we send that out as well, if you have an experiment, you want to plug in and do that.
Alec Habig: uh, we know that this works there is these etfs wiki transplant facility rapidly shooting frames over the frames over the error box of a gravitational wave alert covering it and.
Alec Habig: There are several networks of telescopes which do this so if we can send them a gravitational wave likes box on the sky they'll they'll shoot it.
Alec Habig: they've got pictures and they can keep doing it until the i'd actually comes.
Alec Habig: And we will be able to get those pictures of before and after of a star going to boom somewhere in our galaxy that we would not have been able to do.
Alec Habig: Without paper early alert so we're working on less news to is also spending a lot of effort talking to astronomers amateur astronomers the Web so.
Alec Habig: So that the output side of this is also prepared to combine with our luck to get some opportunity to make our luck right so.
Alec Habig: Now, at a time, we will get a CT lab supernova in our galaxy sooner or later, and you know odds are once per career so we're preparing it'll produce a neutrino signal that arrives hopefully hours in advance that the light and early warning.
Alec Habig: Pointing won't necessarily be great until someone sees it with photons even with know pointing people can be getting revved up to take the pictures and if we get any pointing today's transit hunting community can quickly cover the sky and be ready for it.
Alec Habig: snooze has been ready for a couple decades to do this with a quick alarm that eliminates sources of noise, by coincidence trigger between experiments and will continue in the future, and we will be better at it.
Alec Habig: Once the reef right into a snooze 2.0 and adding new stuff which we're we're working on from this very moment comes online, in addition to new experiments coming on like unum hyper K, which are you know very keen on finding supernova.
Alec Habig: So when one of those 200 wave fronts hits us hopefully we'll be ready at the neutrino the astronomy and the network side to get the most information out.
Alec Habig: We have a White Paper was published earlier this year for snooze 2.0 that describes all our capabilities and what we're doing in much more detail if you would like that, as well, so yeah questions, mostly just talked I can't see anybody, and if you have questions so shut up.
Hristova, Ivana (STFC,RAL,PPD): Oh yes, thank you, thank you very much Alex for this interesting overview of this news network.
Hristova, Ivana (STFC,RAL,PPD): So yeah, we must stop the recording and then we have to.