 Thank you very much for the kind invitation. It's really a pleasure to present the mission and the first results from one year of observation almost one year of observations to the CTA consortium. Let me start with some general consideration, of course, useless to say that information on celestial extrasolar sources are even if now we have in the so called multi messenger era are still mostly provided by electromagnetic radiation, and they can be obtained by studying the special spectral timing but also polarization properties. In particular, polarization properties give us information on geometry geometry of course of the meeting matter, in case in which the region is too small to be resolved especially by our telescopes, but geometry in a broad sense I mean also geometry of the magnetic gravitational fields of the space time and so on and so forth. And the position degree depends on the level and type of symmetry of the system so in a sense measure the asphherical level of the source, the position angle indicates its orientation so the preferred orientation of the system. Therefore, our knowledge of the mission from a celestial source in any energy band is therefore incomplete without polarity. But polarity metric information before expert, we're basically missing in the experiment, this is, this was particularly sad because in x rays we in general in high energies we expect sources to be more asphherical and nontermal mission to be more common with longer woven and so we expect that the sources are more polarized and that polarization may convey a large degree of information with respect to other bands, especially the optical and the infrared bands in which emission in the universe is dominated by stellar processes. So any story we before XP we have only one positive measurements was the crab Nebula measured back in the 70s by the also a satellite was really pioneering observation. The problem with this kind of the kind of detector on also a it was the very very narrow band was a black reflector which worked in a very extremely narrow band. So the sensitivity of such a detector was very limited. And indeed, the only positive measurement to show sure positive measurement we obtained was that of the crab Nebula 90% we both they sorry I was I wasn't there at the time. So measure the very tight upper limit of score to six one the brightest six resource in the sky, and a bunch of upper limits. And I have to say that in a few cases our results seems to be, you know, confirming in a sense, the upper limits are the two to three sigma results that were obtained at the time. Anyway, for many years we assume that only one measurement was obtained. But no extra polarimeters were put on board of any three satellites simply due to the fact that we didn't have the sensitive enough detectives. Fortunately now such detectors do exist, because thanks to the development of the photo electric polarimeters I will very briefly sketch the out is polarimeters working in a few slides. And so, for these reasons polarimetry become again an interesting technique in x rays and indeed the x ray the imaging x ray polarimetry explorer was selected by NASA in 2017 in the framework of the of a smacks book a small mission explorer. In actual XP is a NASA plus Italian space agency mission is a co bilateral collaboration by the two agencies within the NASA small explorer program as I said it was launched almost a year ago in on December nine 2021 on a Falcon nine from the Kansas Center. He was put on a 600 kilometers circular orbit, then a zero degree inclination which is very good because at this inclination the background is low and especially very stable over the orbit. The baseline mission is two year but with optical optional extension and in this case we will have a geo program I can anticipate that already because the decision for any extension will be taken by NASA every two years or something like that. The two year baseline we will end before this decision is supposed to be NASA already granted us at least nine something like nine months of let's call bridge between the two year baseline phase and the possibly extended phase and in this nine months we will have a guest observer program so stay tuned because in the some sometimes in the next year there will be a call for for for proposals. And that point is there. Meet all the preselected targets with deterring which is very useful to reduce systematics. And okay we are using Malini ground station as a primary ground station in Singapore at the at the second mission operation center is at University of Colorado. And the science operations centers is at the much much a space by center where also the PI is located. Regarding data data are archived at the NASA's as arc as typical for for NASA's mission. And what is is important to say that data are public after a week. And at the end of the observation so they are basically immediately public. So everyone can can take the days and analyze them and using standard expect software of course, you know, most of the community is not very much used to polarimetric techniques so it's not so easy but not so straightforward but still I mean it's the same thing that everybody can do and the software is available within the expect package, the tools package in general for reduction and expect for for data analysis. This is the sketch of the the institutions involved as I say the PI with with currently Brian Ramsey but was Martin biscope retired at the end of May now is Brian Ramsey the former deputy who again is going to to retire very shortly and a new PI soon anyway, at the much a space by center there is also the sock as I said, plus many other activities. As the Italian special agency is funding the detector system, which has been developed by mainly by the INFN in PISA and the enough a throne in Rome. Plus there are other contribution also from from Japan is more contribution from Japan and then we have a science advisory team which is a really international team, mostly comprised by Italian Americans but also many Europeans. Okay, just a nice photo of the launch everything went well. The satellite was put in the nominal orbit. This is a sketch of the satellite it is composed by three identical pairs of mirrors and detector units with the four meter meter focal length. This focal length has been achieved by an extendable bench. We had to do that because at the very beginning we were supposed to be launched with the Pegasus which has a very small fairing so it was wasn't possible to accommodate so long. But then in the end for financial reason NASA decided to launch with the SpaceX with the Falcon nine, which has a much, much, much larger failing so in the end, there was a lot of room and we could have spared. If not in advance, we could have spared the, you know, the cost and the complication of having an extendable bench but okay, that's a lie. This is the quality of the mirrors, the basically the angular resolution is of the order of 30 are seconds of power diameter. So, you know, all climates errors. Things like that are taking into account, which is basically what we expected the from the beginning is the nominal level of resolution, and it's not fantastic as standard of course but I mean it's still good enough for for the majority of science we want to do. It's not particularly because for point sources we are looking inevitably at very bright sources so the background is in any way a very small with respect to the source. Basically always source dominated. This is the energy dependence of the effective area of the mirrors and you can see that the energy band is basically between two and eight KB, which match very well the energy band of the detector as we will see. And the, okay, another interesting characteristic is the field of view, which is of the order of 13 minutes. The detector which is the real novel part of the mission. This is, as I say this is based on the photoelectric effect on the fact that the, when, when a photon is absolutely absolutely absorbed the photo electron remembers is preferentially directed along the direction of the electric vector of the incoming photo so from the direction of the electron you can derive the direction, the polarization vector of the incoming photo. So if you track the image, the, the direction of the electrons around the your your detector, then you can derive the average value of the polarization of the of the radiation you are you are you are. This is a typical track of the of the event. This is basically a sort of proportional counter is more sophisticated but the basic principle is that of the proportional counter. The real important here is to determine the initial direction of the pack in order to to derive the polarization vector the electric vector of the absorbed photo. The numbers for the detector, the energy resolution is typical of the of a proportional counter again is not terribly good that compare with CCD like detector. On the other end, again, for many of our cases is good enough and and then wait this is what we can get. The useful energy range basically due to the mixture of gas we are using is between two ways. An important quantity for any polarimeter is the so called the minimum detectable polarization and the P, which is the minimum polarization, you can, you can detect the certain confidence level this means that for instance 99 confidence level. If you detect a polarization larger than this value, then you are confident that your results are more significant than 99. And this depends on the observed source counting rate on the observed background counting rate on the integration time. And also on the so called modulation factor which is the amplitude of the variation of the ensemble opposition angle for 100% polarized source. In these two plots, you can see the the the distribution of the of the tracks of the direction of the tracks as a function of the azimuthal angle around the detector for on the right on the left for a 100% polarized radiation on the right for a uncolarized radiation is this are relatively old measurement means meeting the laboratory just to give you an idea of what we are really measuring for from the amplitude of the modulation, you can derive the polarization degree of your radiation from the phase of the modulation, you can derive the polarization angle. Of course, it's also they have a flat distribution for an unpolarized radiation, because this means that your systematics are very well under control, and indeed this is the case in practice we have a systematic level of polarization of the order of 1.5% so any measurement which is statistically significant above, let's say 0.5% is is should be real should be real detection and not not due to systematics. Okay, the modulation factor increases with more traditional as I say this the amplitude of the modulation for 100% polarized radiation. So, in a sense measure the ability of your detector to detect and polarization is an easy it increases with the energy simply because with increasing energy we have a increasing the length of the track so it's easier to measure the initial direction of the and if you and on the right you can see the response of the detector as a function of the energy, including the modulation factor, and again you can see that the detector is basically working between two and eight. Okay, so after the launch for about one month we expect was in operation commissioning where when solar planar solar panels were deployed the boom the standable bench where was also deployed all spacecraft function were activated and verified successfully. Also the detectors so everything went well so after a month of this checks and tests we could start observing celestial sources, our very first source. What we observed was the supernova remnant casee, and this is the very very very first track we observed was very kind because as you can see this track is very nice, there is no bending is very polite I mean you see that you in this case you can really see, really very accurately and very easily the, the initial direction of the truck so was very kind from this photo to be so nice. And this this was the very very first track with that, just for curious. Now, what are our targets well basically every class of extra sources. This is very much an exploratory mission. As I said, we didn't know much about polarization of sources in x rays before express so we want to observe basically any class of of extra sources the only class of extra sources we are not going to observe the major class I would say our classes of galaxies because they are expected to be completely unpolarized because radiation is dominated by. And also stars, even if they can be polarized when there is coronal emission flaring emission but they are to fail for us so unfortunately we are not able to upset them. So we want to observe basically any major class of of extra sources starting from article of nuclei of course we want to observe blazers which are obvious candidates for an X-ray polarimeter, but also radio quiet a GN to constrain the geometry of the the same for microquasars in which if in the art state we can constrain the geometry of the emitting region of the corona, but also we aim to put some constrain of the spin of the black hole if catching in the soft state. The radio pulsar and pulsar with nebulae the crab of causes was one of our first target but also other pulsar with nebulae are also very interesting to be observed because they are expected to be very highly polarized. The supernova nemnans too, even if they are mostly dominated by thermal emission in X-rays still in some of them at least there is a significant non-termal component, non-termal tail, which can be studied in it with an X-ray polarimeter. Magnetars is of course another very important class of sources and as well as a critical new stars especially when they very high magnetic field. This is the plot, this is a plot of our first year target in galactic coordinates, not surprisingly most of the sources are on the galactic plane because most of the sources are galactic sources. The reason is also because polarimetry is a very photon angry technique, so in the end, because in the end, I mean your unpolarized fraction of the flux acts basically as a background, so you really need a lot of photons to get a significant measurement. And so we need to have bright sources. And this is one of the reason why we are observing many, many galactic sources. On the other hand, we are also observing a number of extra galactic sources, most of them blazers, but not only blazers. Okay, I skip this one and let me start with a discussion of the results we are obtained. Because this is an exploratory mission, I prefer to go through many, many different class of sources, rather than concentrating in detail on some class of sources if you have any curiosity about a particular results, maybe we can discuss it at the end or send me an email after the seminar, I'd be happy to answer. We started naturally by observing Pulsar with Nebula in particular at the crowd. At the very beginning, of course we wanted to reproduce the old crowd results just to be sure that everything was was okay and of course we were, you know, very happy when we measure the observe the crowd measure the entire procession from the entire Nebula, which is what also it did because also it was not an imaging polarimeter. So the measurement was obtained after integrating over the entire Nebula. So we integrated of the internebula and found the results which was perfectly consistent with the other results and this was of course reassured on the other end. The internebula is a very complicated, very complex Nebula, you can see the Chandra image, you can see how structural it is. Obviously, we expect different polarization in different regions of the of the of the source, and this is indeed what we found. And for these two sources, I don't show many details for a simple reason this is the for both crab and vella papers are actually under revision on nature, almost accepted but still under embargo so I just show something or say something very general. But what is what I can say is that the these two sources are structured in indeed the polarization is different from region to region, especially in the crowd the veil is less structured than the crowd. And what is this it is interesting is that in certain regions, in particular regions. The magnetic field is very, very high, which means in some region is even very close to the synchrotron limit, which is the 70%, about 70% polarization, the maximum polarization can expect from synchrotron in case of a perfectly oriented perfectly organized magnetic field. So this means that in pulsar with nebulae, the magnetic field is very well organized is very uniform in, at least in relatively large regions, and especially is not the level of turbulence is very, very low and is much lower than expected, this is one of the first surprise we got from from from We also observed the supernova remnants in this case we expected much less polarization then in pulsar with nebulae because emissions mostly thermal in x rays. On the other end as I mentioned, in, in some supernova remnants and particularly in Cassay, we have clear evidence for a non thermal component which is not insignificant in the upper end of the energy of the x-ray energy band. So we observed also the source. At the beginning we didn't find any significant polarization, but after a more clever let's say data analysis in which we stack the signal from different regions, maybe making some assumption so assuming circular symmetry, and then the polarization vector is tangential. The radial magnetic field remember that the polarization vector in from synchrotron is perpendicular to the direction of the magnetic field. And the non thermal emission here is due to synchrotron, then a signal is detected in with this assumption with assumption that the polarization is instant, then tangential with the other possible assumption that the polarization vector is radial with it. So we don't find anything. So clearly there is clear evidence that the polarization in the outer ring and in the non thermal tail because this is a measurement which has been done especially at high energies where the non thermal tail starts to be very important. Then, as I said we could find a significant results up to almost five sigma. And the polarization in this component is less than expected from several models. In this case we have the opposite situation then impulsar with nebulae so the magnetic field seems to be more turbulent than expected. So the two kind of sources seems to behave in an opposite way as far as turbulence of the magnetic field is concerned. The stars we also observed the one magnet are at the very beginning of the mission, you know magnet are sorry, isolated Newton stars in which very, very large magnetic field up to 10 to 14 10 to 15 hours. They are relatively bright not terribly blind so we have to observe the source for a very long time to get a significant measurement. In is petrally speaking they are well fitted usually by two component a thermal component, probably from the black body from the neutral star surface and the power low component which is due to competition. We observe that I say that this particular source for you one for two. Well, there were many predictions for polarization in the sources we expected polarization to be very, very high. Indeed, actually sorry we found the polarization less than expected, still very significant. You can see the precision degree integrated over the energy and overtime is of the order of 12% plus minus one so very significant, but still lower than than expected. On the other end, at the closer inspection, we found that there is a strong energy dependence on of this polarization. The polarization starts to be relatively large not terribly large then decreases almost to zero and then increase again and at the very at the upper end of the of the energy range is pretty large. With a swing of 90 degrees of the polarization angle. So it looks because we know spectroscopically that the this emission is composed that by two components, a thermal one and the non thermal one is very, this was very natural to to assume that the what we are observing this is the sum of these two components, these two components at polarization angle 90 degrees apart at the low energy you are observing mostly the thermal emission at high energy you are observing mostly the, the polarization emission and the two components as I said are 90% 90 degrees apart in terms of polarization angle, which means that in one case you are observing very likely the ordinary mode in which polarization is parallel to the magnetic field in the other component you are observing the extraordinary mode in which the polarization is perpendicular to the. I think that this model fits the data very well, so the most likely interpretation is thermal to resonant compost happening. One important point is that the, anyway, even at high energy the polarization is lower than expected from many models, which constraints the model of the, you know, the nature of the of the, at least outer part of the the particular is suggesting that we are looking at the condensed surface on practice we have no atmosphere, because in with an atmosphere we would expect much larger polarization. And a condensed surface mode in which the atmosphere is basically condensed on the surface of the of the neutron star is provides a good fit to the data. One of the main goal of for observing the next day with polarimeters. And the next day we have to check the vagumbareficence effect, which was predicted 80 years ago by Eisenberg and Euler and is expected in QED, but never verified experimentally because even the lapses basically impossible to, to have such large magnetic effect that you need to, to, to observe this effect. Our results are, if you make all the tail calculations, our results are consistent with what with this effect being there but we cannot really say that we are finding this just a parenthesis we recently observed another magnet. I don't show the results because these work is in progress and both data analysis interpretation are still in progress so I prefer to show you are only well established results, but in this case, in 40 second magnet are we have much higher. We find much higher polarization degree so maybe in this case that can be something interesting about this aspect. Let's see. We have a critical star extra pulsars in which magnetic field are not as high as immaculate are still very high of the order of 10 to 13 to 14 hours, but 10 to 12 to 13 hours. We have a matter is a channeled on the magnetic poles from by the lines. In this case also we expected very large polarization, and we detected the clearly significant polarization at least a couple of sources but with polarization degree much lower than expected. So here I have to say that the models are very old, very simplified for many, many years, many decades I would say no one developed the most sophisticated model, I think this data really is very high for a more sophisticated theoretical model for more theoretical work. We also observe the weekly magnetize actually new stars in this case, again matter is a greeting on the neutral star, but the magnetic field is so low that matter accreted through an aggression this is not tunnel on the pole. So in this case we expect much less polarization degrees, which is indeed what we found, we found only an upper limit in what source but the positive detection in another one. And in this case, we still don't know what is the geometry of the inner region. But if the, we know that the mission is dominated by a thermal component and the componentized component, but we don't know whether the compensation is on the disc photons so like in the right in the left panel, or is on the around the neutral star like in the central panel, all the this corona emitting the contentizing corona is a sort of boundary layer so where the matter from the disc. You know spread on the neutron star. We can also say the two sources of well more than two sources so far but for two sources we finish the analysis and submit the paper. And for this source source we observe for which we have already an upper limit of the order of a little bit more than 1% so pretty constraint that the limit, we can certainly exclude from the low level of polarization, any, the geometry which is very asymptomatic so these results suggest a sort of spherical vision of the corona so the central plot here is probably the most favoured one, unless the inclination angle is because the results of course depend on the inclination angle the more inclined is the system the largest, the largest equalization expected, unless the inclination angle is much lower than expected from other consideration particular in the orbital parameter services. In six to six to we in the instead detected a significant that we have a significant detection with polarization ranging from two to four percent depending on the energy. So here we have also another information which is, we know the direction of the jet in this source. Well, we don't have any jet in the other source. So we know we assume that the jet is perpendicular to the aggression disk. So this means that the, and we found the polarization vector which is parallel to the jet, which again is very useful to constrain models in some models you expect the polarization parallel to the disk not perpendicular for this source very likely we are observing a mission from from a boundary. One of the most important results we have done so far is regarding six six one. Now we might. So we are now starting discussing microquasars microquasar polarimetry can well apart from possibly concerning the role of the jet but if the sources observed in the R state, when we expect the disk to be as to stand down only to a very large radius and then having a mission dominated by the ground, then in these sources in our state we can hope to constrain the geometry of the corona, while if the radiation comes down to the innermost stable circular orbit, which is what we expect in the soft state, we expect polarization to be so called soft state and we have a mission dominated by the disk mission by thermal disk mission. We observed the six six one for about 150 kilo seconds in our state in coordination with nicer and new star and which was very important and we found very interesting results. The six is one from the orbital parameters, the other parameter tells us that the inclination of the orbital plane is only 30 degrees. So we expected the polarization of the order of 1% or even less. At the end we found the polarization of 4% and the other important information is that the polarization angle is parallel to the, to the, to the jet. Here you can see the polarization angle with we measure with expert superimposed to the radio map of the jet. So what can we deduce from from these results. Well, first of all, the position is much larger than expected, even the 30 degrees orbital inclination, which very much suggest the misalignment between the inner accumulation flow at the orbital and the polarization angle was found to be parallel to the radio jet. And this suggests the flatfish configuration of the meeting region because any configuration of like is the famous lamp post in which you have the corona on the black hole rotating axis configuration like that inevitably produce a polarization which is perpendicular to the So we, we are, we are, even if we cannot constrain, still constrain completely the geometry of the region, we certainly can exclude any sort of spherical region on the black hole axis the so called lamp post model. And in other results if you like is that because the political polarization angle is parallel to the radio jet that we have in a sense the first observational evidence of the link between this can get. This is not surprising, everyone assumes that the jet is perpendicular to this. But as far as I, as I know this is the first observational evidence of is very well established theoretical. Now, let me, I see, I see that the time is running out so let me talk about blazers which I guess is particularly interesting for CTA people blazer of course are very promising sources for example. And indeed, I synchrotron pick blazers like mercariant 501 and mercariant 421 are indeed significantly polarized. What means I think from pick blazers you know that blazers, the spectral energy distribution of blazers is composed by two picks a the first one, the one at low energies is due to synchrotron. So the second one is possibly due to inverse Compton or to addronic synchrotron or something like that. So I think the topic blazer are two blazers in which synchrotron pick is still in the extreme so extreme mission is dominated by and these sources are expected to be more polarized because synchrotron is very much polarized. We have observed the inverse Compton pick sources, which are indeed found to be less polarized. Let me start with the mercariant 501 by the way the paper I think has been published today in nature so if you are interested in the dates please look at this issue of nature. And we observe the very significant polarization of the order of more than 10% you can see the results, we, we have a multi woven campaign in which we observe the also in radio and the optical and the two most important results are index rays depolarization is much larger than the optical in the radio depolarization angle is basically parallel to the jet. These are the two measurements, XP measurements, we observe the source twice, the two XP measurements they are not perfectly consistent one another one sigma, but three sigma they are consistent one another they are definitely consistent with being parallel to the and this is very constraining in terms of model because if you look at the most popular models for for exhibition jets for jets in general, you, you find that the energy stratified model in which you have shocks and the energy mission comes from the base of the jet. So, and the low energy mission come from farther out, when the magnetic field is probably less organized, you expect in this case strongly chromatic polarization the sense that you expect much larger than the X rays standing the optical and radio. This is what is observed, you expect a slow by the beat, which is also observed, and you expect the equalization which is along the jet axis, which is also so. So, our observation is clearly favoring the energy stratified model. Instead of other possible model for the for the jet mission so this is very, very much constraining results. And very similar conclusion for my career and for to one. We also observed the inverse quantum peak blazers, in particular, we observe the be a lack itself, which is a low syncopated blazer. In this case, the extreme issues no longer dominated by electron. The source was unfortunately pretty faint when observed by its pay, and we can also, we can only get an upper limit of about 13% less than 13% and but still good enough to put some constraints on the models, because the electronic models are clearly disfavoured in the source, because they expect larger polarization in X rays. And, and so I mean, even if we obtain only a relatively loose upper limit is still good enough to put constraints on the models. We will re-observe be a lack very soon now be a lack is in a very much brighter than when it was observed last time so we hope to put even more stringent constraints on the models by the new observation. Okay, I think I is already 45 minutes. Okay, I go quickly to the last few topics. The first one is radio quiet a GN in particular, in particular Compton tkg and you probably know the standard sketch from from from a GN, in particular, if you are observing the source from the side, you can see the reflection in X ray you cannot see the inner region but already reflection from the farther part of the tools, and you expected this reflection to be very ugly polarized. So let me go very quickly. I think that in the brightest of these kind of sources the system is called axis which is not terribly blight on absolute terms like the brightest of the class, we detected clearly a significant polarization especially between four and six KV. And we have only an upper limit for a very simple reason the simple reason is that from six to eight KV we have a lot of fluorescent emission, which is of course some polarize that we don't get any, we get only enough. Anyway, just to go very quickly the polarization of the reflection component when you perform a spectrum of arithmetic fit returns a polarization of the order of 28%. This is a very large, which can, can, can be used to put constraints on the geometry of the system and in particular to the alpha opening angle of this, of this effecting radiation, which is found to be in the range between 45 and 55 degrees which is consistent with other kind of nations. Very, very, very last result. We didn't expect to follow up on your visa because of the relatively slow reaction time of the mission due to lack of manpower. It was three days, but you know, GRB 22109 a was so exceptional, both in terms of brightness and the term operation of the afterglow operation of the prime of the prompt and also the afterglow, then we decided to observe it. We found a results, which is okay, not a game is not a terribly constraining results, but still is less than about 11% 99% confidence levels as published in the, we were very happy because in the end, we couldn't find something we didn't expect to be able to do we do. We're very happy and, and, and because we also observed the links, we hope to be able also to put some constraints on the prompt emission, studying the mission from the links. Okay, let me just conclude this space really opening a new observing window, and does expect a significant polarization is greater common next resources. Not surprisingly, most of the positive detections are related to strong magnetic fields. What are we nebulous with another 10 and six the pulsars blades as magnetars, but also scattered improvisations detected. In many cases, the results or even upper limits as I shown are discriminating between different models or challenging popular ones. We have still one more year of observation, plasticist observer time. We, as I said, I didn't, I didn't show results we are stealing with analysis or or or interpretation are still in progress but I can promise some of them are very, very interesting, which will come soon. Stay tuned and thanks very much for the attention.