 I will present in this webinar some of the newest results from me with a particular focus on the energetic universe and the Oscar X-ray service as seen by Zeta. Indeed. So my first disclaimer is that I will present all the selected results from this very successful mission so far, but you will have a lot of to learn also in the near future with the coming releases. So let's start from the, let's see if it is working. Let's start from the very beginning, some very, I mean, broad introduction on the topic of the X-ray sky. So why we are interested in serving the sky and X-rays? Well, X-rays provide the unique view of the hot and energetic universe. So this is in fact also the tagline of one of the next generation X-ray satellites, Athena that many of you for sure will know that it's supposed to be launched in the late 30s. Coming back to these two topics, the X-ray webrent is the best to investigate the energetic universe because X-rays are some of the most exotic and energetic events in the new universe itself, like for example, accretion onto compact cellar objects and shock traced by supernova rendments and supernova explosions. And among these exotic and energetic events, there are also the ubiquitous phenomena of active galactic nuclei in the galactic nuclei of host galaxies that has been recognized as agents of feedback in the past year. So we'll come back later on this. And as far as the outer universe concerned, we know that most of the biomes are in a warm and dot X-ray emitting phase that can be revealed only thanks to sensitive observation and we also know that the knots of the large scale structure clusters of galaxies dominate and have such a bright X-ray mission that become severely observable and that these can provide a powerful tracer of structure growth with important cosmological implications. So here I want just to stress that this is particularly true if for X-ray band we consider the bandwidth between 0.1 to 10 kV because at these energies, both of these phenomena can be traced at best. So, but what do we do? We learn by observing this kind of sources of the class of sources in, in this particular way. Well, in terms of energetic universe, we can learn a lot in terms of particle acceleration, the mechanism of particle acceleration, the matter under extreme condition and also we can be able to test general relativity there. And as we focus a bit more, because it's the field that I'm more familiar with, also we can learn a lot on the formation and evolution of galaxies. And, instead, from the study of clusters and groups and the evolution with the redshift, we can, of course, provide the better sensors of the matter budget in the universe. And more directly than with other probes, we can also probe dark matter and dark energy. So, putting as I mentioned before, best or high quality cosmological constraints to understand the evolution of the universe. So, all I said, as of now, it's particular to when the entire sky is considered or when the sky is considered in its entirety. Here is some artistic representation of our, let's say, universe, projected in the galactic plane where we can spot the, the largest matter assembly, like the Virgo and the Perseus clusters and a couple of other big clusters there. And the main message is that the value source population that I mentioned before and that they can be easily traced with the X-ray service may reside both in the galactic plane and in this aspect, the population of supernova remnants, compact binaries, and of course also coronally active stars that also them are expected to be bright X-ray emitters are mainly expected to populate the galactic region of the sky. While the other two big classes of sources that again I mentioned before, like the galactic nuclei and clusters are populating mostly the extra galactic sky. And in terms of, and if we just consider AGN, when looked at in the X-ray band, really the AGN dominated all the other extra galactic population in terms of contrast of emission in that particular band. And, sorry, and instead, as mentioned before, it's only when you map a larger fraction of the large area of the sky that you can really understand and single out the not and the largest case structure of the universe, including the one tested by filaments and the most massive ALOS that are tested by clusters. So this is basically a motivation of having an X-ray sky over the entire, an X-ray survey over the entire sky. We indeed live in the year of all sky surveys. The picture on the left is, I think, the best example of one of the best and the newest, I think, or sky survey available to us that is the Gaia survey. And in this image taken from that release three, there are about 1.5 billion of sources and less numbers, one or two order of minus or less number of sources are present in other extra galactic surveys that map our universe in other way from the UV to the infrared over the entire sky or over a significantly larger of the sky. Here are some examples listed just to give you an idea. And, of course, the UK and LST in the near future will revolutionize this field. As far as we go to the energy of the EV level, so we approach the X-ray band, instead, the number of sources and our knowledge of the entire sky distribution of these X-ray meters is instead still pretty much limited. The only X-ray survey that we had so far is Rosat, that is unfortunately too shallow to compete to the detail and let's say in the picture that is emerging at the other web band. And it's a sample only fluxes of the order of 10 to the minus 13 CGS and it has in the catalog about 1,100,000 sources. While the most powerful X-ray tests that are able to go deeper or two or three order of magnitude with respect to Rosat have instead two smaller field of view to provide efficient and sensitive coverage of the entire sky. This is a map of all the observation performed by XMM Newton and as you can see all the observational market by the red spots but there is still large gap and more than three quarter of the sky still left unexplored. This is, this was the situation until now, well actually until a couple of years ago when finally Erosita came into the game and so this talk is devoted to Rosita. Erosita stands for Extended Rontken Sari with an imaging telescope array. It's a telescope built by consortium led by MP, the PI was Peter Peddel, but recently the PI ship has been passed to Andre Merlois. Erosita as the name said is not a single telescope in fact is an array of seven telescope with associated detectors that uses the technology of XMM Newton but in terms of mirrors and the detector the PN CCDs. So, we basically base everything on the XMM architecture but with all the improvement needed and let's say developed in these 20 years. The sand is the combination of the field of view that is of the order of one degree. I hope you can see my point here and the effective area that combined is compared to the one of XMM. The combination of the two gives basically a survey speed of 1000 and this figure of merit is a factor of five larger than any current X-ray telescope. That means that to map the same earth, the sky to the same depth, Erosita is five times faster than any other instrument. And this is coupled with a relatively good, I would say more than decent, positional accuracy of the order of 18 arcs second, 20 arcs second average of the field of view with source location of course of the order of 385 arcs second. So, Erosita was launched in July 2019 on a spectrum around 10 gamma that is an observatory led by our Russian colleague and Erosita is the primary instrument on this observatory. The second one is Arctic Sea that is a telescope that is performing a survey in the even harder part of the XK sky but at a much lower sensitivity and being such a proprietary mission of course and split in the German and Russian collaboration. This basically brings to the fact that each consortium has access or will have access when the survey will be finished to half sky each. All the data obtained by Erosita in the eastern galactic hemisphere, this is the galactic sky in galactic coordinate, belong to our Russian colleagues and to a consortium led by Ikki and all the data obtained in the western part of the galactic hemisphere are analyzed and belong to a consortium led by MP and the German consort. So, the other important point is that Erosita, again, as the name says, will perform a survey over the entire sky. So it will scan the sky from L2 competing a full sky map in six months. This is an animation that should give an idea of how this scanning is. In fact, the shift of the telescope is exaggerated, it's much smaller and in fact every point of the sky is seen six times before going out of the field of view. This basically translates to the fact that after six months, there are a region of the sky that are sampled just one time, well, actually, six times within one day, and the region of the sky like the one at the galactic poles that are instead observed and exported for much, much longer time. So in this translate, basically, to an exposure map of the entire sky that the one shown here. In fact, the key feature of Erosita, in addition to the to be an extra galactic or sky survey, is that it adds the time axis, so the time domain to the imaging and spectroscopy domain that the typical X-ray telescope already has over the entire sky. And it will provide eight independent all-sky surveys with a range of exposure depending on the position on the sky for each survey, and these surveys are called ERAS-1, ERAS-8, and of course it will also produce eight cumulative all-sky surveys by stacking all together the photons at the position in the sky in the four years at the end of the four years dedicated to the surveys, and these cumulative all-sky surveys are called ERAS-1, column 8 that indicate the stacking of all the previous exposure. So the combination of area coverage and sensitivity will return another key feature of Erosita that is the number of statistics, and so the number of sources or cluster sources that will be detected at the end of the survey. In fact, this can be seen here in terms of X-ray fluxes and area coverage, and the line here denotes the limiting fluxes versus area curve for the final four-year surveys. As you can appreciate, for point-like source, the Erosita will be about 30 times more sensitive than the current all-sky survey rosette, and this will be able to deliver these numbers of cluster of galaxies, more than 100,000 clusters, and more than 3 million HGN over the entire sky. These numbers have been tuned and at the same time also the observational strategy to address the two driving science case of the Erosita that is cluster cosmology. And therefore, how you will be able to constrain cosmological parameters with X-ray observation and the HGN evolution and for HGN science, all the parts of HGN and galaxy evolution, including the detection of the most luminous in the ray population that are still missing as you will see in a moment also from current X-ray service. This is one of many other clusters of sources that will be detected. I won't focus on this. In fact, I won't focus even on the main driver of the cluster cosmology for Erosita. This is probably the most relevant person to speak about this topic, but I will concentrate. I will just give you an example of the kind of revolution that the Erosita will bring in the field of HGN evolution. Just as a background in the past two decades, there have been several breakthroughs in HGN studies and demographics, thanks to what we learned from Serendipu to send dedicated X-ray service. This is a compilation for sure, incomplete just to give you an idea of how many topics has been addressed with this. And if we just want to focus on one or two of these, this topic, one of the main breakthrough in my view, my personal view of these HGN studies from X-ray service has been the discovery force and then the characterization with more and more details of the downsizing in HGN evolution. This has been shown, this can be shown in these two figures. The first figure basically show the, let's say, detection of this effect from the very forces Serendipu to X-ray service with Chandra and XMM. And what you see here is the space density as a function of a rash shift for different HGN populations fitted in luminosity classes and what we could probe there at the beginning only on the basis of a few hundreds of sources is that the less luminous X-ray population at the peak of their activity in a later cosmic time, so at lower rash shift than the most luminous X-ray population that seems to have peaked at higher and higher rash shift. This has been confirmed with the subsequent and dedicated large area X-ray service that returned the samples of the size of 1000, 2000 HGN and it's important because basically it's the same behavior that is seen also in the evolution of the star formation properties and mass properties of the galaxy population and this similar behavior has been used or it's now considered one of the key observation that we have to probe the existence of a galaxy and HGN co-evolution. And EOSETA will revolutionize this field because at the end of the service, these are predictions that have been done in 2019, it will basically redo the same experiments with this time to order of magnitude more HGN. And basically it will be able to bring the statistics we have that is still limited for this kind of studies to statistics and allow SDSS like samples that basically will mean that we will be able for example to sample the most luminous properties where EOSETA is more sensitive from the seven beams that we have up to now in rash shift to more than 20 beams with associated errors shrink from 10-30% to less than 10%. This means that with such a large statistics, we can also split the study of the evolution of the genus in terms of the creation properties of the genus themselves, like the integration and the many others. Okay. This is what we expected at the end. I will focus here on a few selected results from what we have in hand so far. Again, I will focus on the x-galactic engine population and I refer to a webinar of about one year a role by Manami Sasaki on the galactic emission, the galactic sources. So this is the fourth x-ray map that has been delivered by EOSETA. So the results of the first six months of observation performed between December 2019 and June 2020. This is basically the best and the deepest image of the x-ray sky we have in hand right now and it's really beautiful in my view. It's color code in terms of the x-ray band. The best regions are the hardest, mark the hardest x-ray emission, while the red ones are the softest x-ray emission. What you cannot appreciate in this image is that the exposure is pretty uniform over all the sky at the order of 100 seconds and the pulse reach 35-kilosecond exposure. What you cannot also appreciate in this image by itself, but you can appreciate with a nice detection algorithm is that this image contains more than one million sources, x-ray sources by itself. This is one of all the classes many of those I also already mentioned before. But probably the most striking and the most notable feature that can be appreciated in this image is this symmetric extended emission that is perpendicular to the galactic plane that is extended both in the north and the south direction. So this is an extended emission, food trace, extended emission, and shock gas in the ISM, and it's even more evident and more clear when we consider only when we remove all the points like sources in the image, and we consider only the 0.621 kV energy band. The two bubbles are now very clear visible. So this bubble basically enclose the more famous Fermi bubble that were discovered about 10 years before in the Fermi map at energy larger than one JV. And the coincidence, the special coincidence of the Fermi bubble with these other components in the x-rays that are called as being dubbed the erosita bubble basically was the first highlight results of erosita that was published back in 2020. And it's so far I think the only results that put together the two collaboration, the German and the Russian collaboration. The special coincidence and also the properties of the bubbles have been, let's say, have been interpreted as a past evidence for past activity in our galactic center. The theory is relatively simple. There is an injection of energy from the galactic center that accelerates relativistic electrons that emit by inverse Compton on the radiation field at the encounter. The same shock basically factor shock in the ISM that encounters in the galaxy, and this produced the observant x-ray emission with the strong shock fronts that we can see in the sharp edges of the bubbles. With relatively simple calculation in terms of, in some relatively simple assumptions in terms of geometry, size, time space and so forth, one can figure out that the thermal energy needed to inflate these bubbles is the order including the x-rays ones that are times larger in volume than the Fermi bubble should be of the order of three times 10 to the 56 eras. And this can be this injection of energy are most likely, is most likely due to past activity and phenomenon of feedback in terms of winds or jets, there is still some controversial on this, on from our galactic centers, up and at about a few up to a few 10,000 million years ago and of the order 10 to the 41 per second. So all of these as of course profound implication on structure and chemical enrichment of galaxy yellow and more in general on how the all these components evolve in our own galaxy but also in other galaxy because the same phenomenon in fact can be one of the main part of the agent feedback needed to explain the properties of the galaxies we have in our website in our local universe. In fact, now I do dynamic assimilation suggested this thermal agent feedback in the microwave like galaxies may results in these erosital like bubbles in the CGM. The erosital bubbles them up. I've shown before, and this is using the same color scheme in order to help also the high the prediction of some. In this case the last cng assimilation in a paper by Pichetal 2021 for which you can see in all the systems that are mostly milky way like system ratio zero you expect the same the same broad thermal emission that can be sampled only with extra observation and probably we will see that can access to some of them in other system either individually in the very close. In the very close universe or via stocking. But coming back to today, here's one map of this is the the the full sky. With some of the key sources lab lead and as I said before, we have access as the German consults only to the western part of the galactic sky where you recognize some of the most important famous artists sources like the Magellanic cloud the crab and the bigger cluster just to make a few examples. So as I said, each consultant is exploiting the data independently and also each consults human tested in their own alpha of the of the sky, the performance of the instrument in the mass and verification phase that took place the first three months of of the year was it a mission when it arrived in L2 right before the start of the salary. So what we did as the German consultant we dedicated we perform a dedicated point of observation on different fields and targets in our hemisphere this is after the sky, the one to which we have access. Here are the law, some of what they saw the fields or the fields that we targeted them for this PV phase. What I want to highlight here is that all the data from these PV phase are public and are being distributed in the early data release of a Rosetta that happened in July 2021. There is a lot of information if you are curious curious and if you are, if you have your favorite target here. Please go and go check in the catalogs and in the Associated Science papers. There is a lot of work done by the entire German consultant consults human members. So what I want to stress here I present here are a few results from the main problem what we think it's the main program of the PV phase of the German consultant that is a mini survey that is called the Rosetta final equatorial depth survey efforts. And as the name says, basically this survey has been performed and has been told to be a pathfinder for a gen stars and cluster studies in the old sky sorry, basically what what we did was to observe a large fraction of the sky of the order of 140 square degrees at the same depth more or less and with the same scanning strategy that Eros data is doing for the four sky four year old sky survey. And so far, if it's the largest deepest and contiguous x-ray survey existing and can really be considered an appetizer for those guys are especially in terms of our unique disease already and this will be to unveil a rare source population. The, again, also in this case, all the data and the catalogs including multi-webrent and the ratio for all the possible classes that you may be interested in are available for to the entire community, and here are the six key papers that detail independently the different classes of sources galaxy, galaxy clusters, stars, a gen point like sources as a whole, which include both stars and a gen. But again, if you are interested to this field to these topics, please exploit this data because they are really amazing. The other thing is that we use the effects also to tune and to understand what we will release for the data for the old sky survey data, and so basically the column in the catalogs that are present in these effects catalog are the same that you will find in the Eros data sky catalogs. I just want to acknowledge also the tremendous job that we have done, especially in the follow-up group of the German consultant and this work has been led by Mara Salvatto for the identification of these 28,000 sources that we are dealing with. That is relatively challenging given the combination of the special resolution that it's, as I said, it's of the order of few to 10 or second and the depth of the catalogs available. And then using the combination of all the information we had, the spectroscopic ratio in particular from Sloan, both from Sloan, including the Sloan 5 release and all the information we can have from the available exa-galactic survey or sky survey that I mentioned before, we were able to divide or to associate classification as exa-galactic, galactic and cluster for all the source classes that we have. And again, these highlighted strong synergies that we need in order to build reliable catalogs for the source and scientific exploitation. This is a sample of the exploitation of these catalogs. Well, as two examples, I like here two papers. The one is the one I led in the early data release and again, the topic is the selection of quasi in the feedback phase and how Erosita may be critical in selecting this very rare population. And basically, we exploited the effects multi-weatherling catalog, not all the full effects catalog. In fact, we exploited a much smaller catalog that is the sources that are detected all in the Rdix red band. And we adopted a method to isolate obscured and the resources that we already tested in our previous exa-galactic survey campaigns and we isolate a source that we put forward as a prototypical obscured quasars in the key phase of gene feedback that is affecting the evolution. And in fact, all our subsequent observations, including deep imaging that revealed that this source is clearly an emergent state, the Erosita spectrum itself that clearly revealed a significant absorption of the X-ray type 2 nature of this quasar and optical spectroscopy that revealed very broad or three lines. Probably you cannot appreciate in this figure, but the line is so broad that cannot be ascribed to set the gas motions in the galaxy that is tracer of powerful ionized flows that has been launched in this galaxy. So this source was not a new source by Perce, it was already known from previous works, but it was only when it was serviced with the Rosita for the first time and almost by chance because the sky was chosen almost randomly that it has been recognized as such important as such a prototypical object. Again, this highlight the need for these X-ray or sky surveys of these large area surveys that are still lacking to put in a better context, a gene in the galaxy formation and evolution context. And speaking again of rare sources and rare population, another rare population are the X-ray selected quasar, a ratio larger than 5.5. Before Erosita, there were no yet blindly selected quasars in this range. There were a lot of sources for which X-ray observation and therefore the X-ray properties has been investigated by dedicated follow-up. These are reported in this plot where there is the X-ray luminosity versus the redshift, it's a zoom at the redshift. And these four sources listed here were discovered by Erosita blindly from the X-ray observation. Here you can appreciate that of course Erosita sample the IS luminosity part as we have seen also before. And again, there have been a lot of studies on these sources because they have been most associated with radio loud objects and so the connection and the coexistence of relatively strong radio sources and the strong X-ray emitters at the redshift, it had a boost in the past few years. But most important being given that at least the two effects sources were selected blindly in a homogeneous covered survey, it was possible for the first time to put in the black color ratio rate versus redshift. Basically it's a complication of the figure I've shown before on the space density of DGN, it was possible to put for the first time a data point at a redshift larger than 5.5. And again, populating these plots and these diagrams with more and more sources will help us in this entangled galaxy formation models, first seed black cores and the sense of all this work has been led by Julian Wolff who just finished his PhD at NTE. So this is what we have in hand right now coming back to Eros one. These are some key features, the force or sky survey by itself will be a factor of four or five deeper than RAS and as I already said before, it contains about 1.1 million sources and just if we just consider half of the sky, the one that we have in hand right now is the German consortium, simply half of the sky, double the number of non-extra sources that has been detected in the past six years. So the good news is that data release of these catalogs of the German sky only is expected this spring and again this will be a huge resource for the SOFIS community at large. And I'm here is that everything is going as expected, probably even better in terms of data quality and results. What is said was not expected at all is the twist that the mission had about one year ago, in fact 11 months actually today ago as a consequence of the Russian invasion of Ukraine. In fact, immediately after just two days after the beginning of the war, Erosita was put in place into safe mode, as I said, as a response to this attack. This means that this is the official statement that was put forward back one year ago from the DLR and MP joint statement, the instrument is paused and we hope that the circumstances will permit a return to normal operation as soon as possible. As you will be aware of, this is not yet happening. The only thing positive thing that I can report is that in November 2022, the German consortium test for health of the instruments by switching on again opening it and everything is still all under control and Erosita is idle and ready to start as soon as possible. This is, of course, a bit depressing, but there is some bright side. There is, at least for the overall community, there is the, this is the usual programmatic slide that we show in terms of the development of the mission. We already delivered on the bottom line is what we deliver to the community on the upper part, it's what we have in the consortium. We already delivered the early data release, early data release, the data release one of years one is still in place and it's not affected by the situation of the Russian war. The process, since Erosita is in safe mode, all that is happening after in the next years, so the data release of the subsequent part of the survey will be needed to be revisited and negotiated again also in collaboration with EK. As I said, the Erosita, as of today, completed for our SkyService and a fraction of the Eros five, and this is the full map of our hemisphere of the cumulative two years survey that is show even more details than the one of Eros one that I shown before. And of course, even with these limited data sets, even if Erosita is basically one year that is not taken data, the exploration, the exploitation of what we have in hand in terms of the Eros service is still amazing. And just a comparison of the second third and fourth survey with the first one and with each other and with the archival data already helped a lot and brought significant discoveries, especially in terms of nuclear transients, including TD candidates, quasi-periodic eruptions that led to a nature paper led by Ricardo Agodia and a plethora of galactic sources, including the first Avernova-Farbol, again, which went into a nature paper in this case led by Conig et al. So there is really a treasure, there is a treasure hunt in these catalogs and the entire consortium, a German consortium is looking, I mean, endlessly on exploiting these data sets. So again, stay tuned and with many other nice results that are coming in the few months. So in the last two minutes, three minutes, I just want to give a few words of possible synergies with CT AO. I'm not involved in the project, so I just put a few considerations I may add in mind from material that I have found in the public websites. I don't have to explain what is CT AO, the first message I want to make is given the Russian-German split of Erosita, probably CT AO south, so the southern part, the southern array is the best-matched with the Erosita-German sky. This is the split in equatorial coordinates, so the western part in galactic coordinate basically it's the southern sky. And the other bottom line I want to say is that the start of CT AO, if it is still at the full operation, if it is at around 2025, I don't know, you may correct me. All the ERAS catalogs will be already public, so they can be exploited immediately by the CT AO community. There is also the possibility for memorandum of understanding with Erosita. Erosita just signed such a memorandum of understanding with LASO for example. And this may be very, very helpful or important if one wanted to exploit also some other key products of the Erosita-German collaborator. And you are invited to contact André Merloni if you are interested in this kind of synergies and collaboration. Again, searching a bit in the literature here and there. A still few minutes, Marcello. In two minutes I think I'm done, thank you. And again, looking a bit in the literature here and there, I came out with this, I learned that it's called Qifune plot by Frank et al 2012. Basically it shows you the number of sources detected as a function of here for different high energy band. Here there was Chandra and XMM at the time, Erosita already in 2021 surpassed in one million and it will be three or four million in 2025 or so. That means that Erosita can provide position at five, ten or second level, identification, special properties of few million of sources and I bet that among these few million sources basically there will be all the sources that will be detected at a few minute level on from the CTA experiments. Again, that would be of the order of one thousand sources. Again, if this number of sources in this plot is correct. And similarly, this is an old figure of the sensitivity versus energy for different energy band. Here Chandra was reported, I put Erosita and as a comparison and there is the sensitivity of CTA and the strength of Erosita with her to Chandra is that this is to the entire sky and as I said before the catalogue will be already and released when the CTA of full operation will start. And of course, it's quite obvious, but identification is also understanding of the sources. This is an example of one of the higher ashift blazara detected by very high energy. I don't know if it is still the highest ashift one. I liked it because the flux was reported and as you can see here in the X-ray band, the flux was of the order 10 to the minus 12 and the Erosita will be down 10 to the minus 14. So it's clearly be able to provide those excellent spectra in case. I live here with the final slide and maybe the point is a bit obvious but the synergy for CTA and Erosita is that Erosita may be crucial for identification and characterization of the TV sources. The X-ray sample by Erosita is the closest band with minimum contamination from background sources and good position sensitivity for the reliable identification. As I said, the identification is understanding and also the processes map pretty well each other. Yes, I live here with my conclusion. And the bottom line is that really if it's that thanks to its large grasp of stable background and observe with cadence, Erosita really opens up a new parameter space for X-ray astronomy across different source classes. We demonstrated that the survey design can be met. There will be a huge data release in spring 2023, so stay tuned about that. And we are happy to provide this unique legacy dataset that would be very important and crucial for the identification and characterization of very energy sources. Okay. Thanks a lot.