PoS(ICRC2021)971 International th 12–23 July 2021 July 12–23 37 SICS CONFERENCE SICS CONFERENCE Berlin | Germany Berlin Berlin | Germany Cosmic Ray Conference Ray Cosmic ICRC 2021 THE ASTROPARTICLE PHY ICRC 2021 THEASTROPARTICLE PHY https://pos.sissa.it/ ONLINE 1 , Erin O. Sullivan ∗ 1 Ankur Sharma [email protected], [email protected] International Cosmic Ray Conference (ICRC 2021) th Dept. of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden Presenter Copyright owned by the author(s) under the terms of the Creative Commons 37 July 12th – 23rd, 2021 Online – Berlin, Germany © Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). 1 ∗ Corresponding authors: Blazars are among the mostfor powerful steady blazars sources have in the traditionallysimultaneously Universe. with focused neutrinos Multi-messenger in on searches photohadronic their interactions.vital However, gamma-ray X-ray to data emission, can constrain be which equally thecould can SED get be of absorbed produced by theseescaping. the sources, ambient In since photon this theneutrino work, fields hadronically flares we and from co-produced present cascade the gamma-rays thebinomial direction down outline of test to for X-ray will X-ray selected an energies be blazarsstatistically untriggered, before significant using performed time-dependent emission. 10 on analysis years of the The ofand best-fit sources IceCube population flare are data. parameters to are selected obtained reveal A frommaximisation. for each if RomaBZCat, source and using a the the subcategory method p-values of of unbinned likelihood sources has The IceCube Collaboration (a complete list of authors canE-mail: be found at the end of the proceedings) A model-independent analysis of neutrino flaresin detected IceCube from X-ray selected blazars PoS(ICRC2021)971 shift the (b) synchrotron-pair cascades pairs generated by pion decay produce ± 2 (photohadronic) interactions between the accelerated cosmic W − ? (a) interactions, X-ray data can provide useful constraints on the neutrino flux ?c . X-ray data is incompatible with the assumption that gamma-rays in the second hump originate (b) Leptohadronic modelling of the Spectral Energy Distribution (SED) of TXS 0506+056 from [1] IceCube is a cubic-kilometer neutrino detector installed in ice at the geographic South Pole Blazars are widely favored to be the progenitors of EeV cosmic rays and PeV neutrinos along Leptohadronic emission models for blazars accommodate the possibility of high-energy neu- and [2] [7] between depths ofof 1450 neutrinos m relies and on 2450 theparticles m. optical produced detection in the Reconstruction of interactions Cherenkov of of radiation the neutrinos emitted with direction, by the energy secondary surrounding charged and ice or flavor the nearby bedrock. Figure 1: (a) from pion decays, given the neutrino event association is physical. high energy photons via Synchrotronnew and pairs Compton which processes, radiate which a inextreme new photon turn generation energies combine of down to to photons. produce thetons These X-ray and band they until can the escape. sourcetraced becomes back transparent Since to to the the the origin pho- from of the the cascade source. emission [1] andthe and 2017 the [2] gamma-ray neutrino flare utlilize flux of the can TXSIC-170922A NuSTAR be [5], 0506+056 [ 3] to which suggest are and that almost SWIFT-XRT one-zone simultaneousevent [4] models with from cannot observations the reconcile this during detection the source of X-ray data assumingRecently, and [6] that the have the neutrino explored association the of possibilityduring a the for period PKS event of 1502+106 with enhanced and neutrino thesibly a production, blazar due the couple holds to gamma-ray of emission absorption1). (Fig. might other within bewith blazars, the subdued the that (pos- source) radio and while neutrino the emission. X-ray data might have a stronger association rays and the ambient or external photon fields. Secondary e with TeV gamma-rays, due toThey the have strong prime magnetic fields conditions that can injets trap their particles, for ambient the jets radiation particles within for to or accelerationhighest proximal interact to energies of with, the observable. and cosmic large rays. scale structure to accommodate acceleration totrino the production in the jets via Neutrino flares from X-ray selected blazars 1. Motivation PoS(ICRC2021)971 and flare duration is fit for each W 3 ) fits flares of the box profile, based on an unbinned csky Temporally clustered neutrino emission has been previously reported by IceCube from the This work will use 10 years of IceCube data to look for untriggered time-dependent neutrino The dataset being used for this study spans a period of 10 years from 6th April 2008 to 10th The software used for the analysis ( The cumulative significance of all signal-like flares from a direction will provide a p-value A neutrino flare can be characterized by an excess of neutrinos or a hardening of the neu- likelihood maximization (see Section3). The spectral index direction of TXS 0506+056 [8].from the These source location studies over identified thesources the duration like most analyzed. blazars significant However, it to period is have more not ofthe than unlikely emission continuously for one increasing highly period length variable of of time slightinformation for to which moderately from IceCube increased has activity multiple been within collecting flaressensitivity data. to from Combining time-dependent searches. a location also provides the benefit2. of improvement Analysis overview in emission correlated with Northern sky blazarsbe selected obtained based on for their each X-ray fluxes.performing blazar an A by unbinned p-value combining likelihood will maximization the onperform significance the a data. of statistical These all study, called local the the p-valuesin will neutrino binomial the be test, flares catalog used to show to detected determine a by and statisticallyassociated significant identify with emission. if each any source, The of and final the a outcome sources binomial will p-value be for a each list of of theJuly p-values catalogs 2018, including we data test. collected with detector configurationsoptimized of for 40, all-sky 59, high-energy 79 muon and 86 neutrino stringsatmospheric candidate [9]. neutrinos events, It and with is down-going a very-high background energy of atmospheric up-going muons. for the source, and these p-valuesstatistic. will The be test used assumes that as p-values inputs areaffect for randomly the the distributed background between population 0 expectation test and of using 1.simulating the binomial Correlations test test. background can trials The with decorrelation a strategythe similar actual for search, this configuration in analysis and order involves using thatcan the the correlations be same are accounted source present for in locations while the as is background comparing more scrambles with as sensitive the well to and background a distribution.Lacs smaller and catalog Since FSRQs. of the neutrino-emitting statistical sources, test we will test separately for BL 3. A multi-flare search trino spectral index observed overastrophysical a object, length that of exceeds the time background fromwith expectation a enhanced for neutrino particular that production direction period. within associated theobserved It source. with electromagnetic can an Blazars (EM) be are flares associated highly lasting variable typically sources, for with several the months. Assuming that neutrino Neutrino flares from X-ray selected blazars The instrumented volume consists ofhousing a an 3-D 8-inch array photomultiplier of tube 5160 (PMT) Digital sensitive to Optical Cherenkov Modules photons. (DOMs), each individual flare, while the maximum flare duration to be tested has to be supplied externally. PoS(ICRC2021)971 (1) (2) ] ) )) B 0 ˆ = = = B = = L( L( source directions: × k 9 ) 30C0 Δ ) refers to the total livetime of B 9 Δ = [ ) 0 Δ events) presents a possible flare > 9 events and 0 ;>6 (sum of the number of signal events Õ 2 # B )( N − = = = B 2000 is chosen. ˜ 9 = ) > Δ | 9 0=3 9 4 is to adjust for the fact that many more small test (Fig. 2b). This way individual events don’t end up )( 9 0 ) 9 ,)( 30C0 Δ > ) ) 9 8 Δ 12 year period that IceCube has been taking data. Thus, )( Õ  ’ for each source can also be obtained in the same way by ) )( ∼ B = # = ). There can be several overlapping flare windows (see Fig. 2a) ˜ − 2 )( 1 )/ 1 are considered, and all the overlapping flares are removed by keeping + ( − 9 8 0 ( multi-flare TS B # )( # ( = 0 ( and duration of flare. The multi-flare TS for each source can be converted to # 1 .A’ = # 9 8 ∗ W Ö , : = refers to the duration of the test window, while )( B 9 ) ∼ 9 = B , ) = 9 Δ L( )( , number of flare hypotheses tested, as well as the fit parameters for the individual flares, W Here, the sample. The correction factor summing all the individual flares from the source direction. contributing to more thanremaining one flare. A global TS can be obtained by summing all the only the interval with the largest windows can be formed than large ones, therefore the small windows are downweighted. signal and background PDFs (S/B). This alsohypotheses. cuts down For on this the analysis, possible a test threshold intervals of for flare S/B flare in the selected flare window.S/B All events threshold) within contribute the to window the (and likelihood. not just those above the window ( The above method returns some global parameters: TS, In contrast to single-flare searches, which report the single most significant flare for each 4. Only non-negative 1. The more signal-like events are filtered based on a threshold defined through the ratio of the 2. Each pair of events in the remaining sub-sample (of 3. A test statistic (TS) is calculated for each flare hypothesis, evaluating the likelihood of a real a corresponding (one sided) pre-trial p-value by comparing with the TS distribution from several above the average background expectation,index detected during each flare duration),including average spectral direction searched, a multi-flare search addssource. up the It significance becomes of moreweak all useful and the under that signal-like the a flares source from hypothesis flaresdeveloped a that within more most than IceCube individual two for flares times stacking are onsources searches moderate average. [10]. where to A The individual method multi-flare flares is fitting can described algorithm be below was stacked for a instead sample of of Neutrino flares from X-ray selected blazars flares show a similarmore behavior than as once EM on average flares,performing within a it search the for is multiple flares reasonable over timesearch from to direction. each source assume boosts the that significance from a each source can flare PoS(ICRC2021)971 (3) (b) < corresponding to the best binomial multi-flare significance required to − : # f ) 4 : ? , and a demonstrative figure underlining the − and (a) 1 ( f 3 : < , or more sources with p-values equal to or lower ? p-values is given by: 5  f : 2 # # <  : = # Õ < from the analysis. ) for each source and a = ) f : ) of finding 5 ( : ) ( % : % ( % identifies the number of sources in the catalog with a statistically . The orange flare candidates end up getting removed in favor of the blue : (b) , in an ordered list of : ? (a) Flare window construction using seed events An example of the output of a single binomial test, performed on simulated p-values is shown in It returns a binomial p-value ( A catalog search has the possibility of revealing a few signal sources spread among a background The binomial probability 3.Fig. The final significance is deriveddata, by performing to the trial binomial test correct many for timespost over looking trial scrambled p-value at by multiple comparing locations with the inshows results the the from number multiple sky. trials of with Fig. individual simulated4a data sourcesshows and with the Fig. 4b calculation of p-value. The binomialemission p-value from is the an source. indicatorsignificant of emission. the individual significance of time-dependent obtain a final discovery potential of than the local p-value of sources. While theunderstand sources if the may whole not catalog be istest individually compatible is a significant, with statistical the it method background-only to is determine hypothesis.from if nonetheless The a a important subset binomial random of to values distribution in of aif given the sample a sample exceed subset the size. expectation of these Given values an are ordered statistically set significant of or p-values, not. it can determine Neutrino flares from X-ray selected blazars Figure 2: 4. Binomial Test background trials using simulated data. Therandomizing simulated the data right (called scrambled ascension data) (RA) isthe generated of data by the are preserved. events in real data so that the physical properties of flare candidates that are of higher significance. removal of overlapping flares PoS(ICRC2021)971 overlap 60% > (b) multiflare significance required to obtain . f (b) 4 of 190. and : f 3 , 6 f 2 300 sources and comprises solely of BL Lac type blazars. ∼ is achieved for a 017 . 0 in 50% of pseudo-experiments = f 5 14BC (a)  edition of RomaBZCAT [13]. It contains information on 3561 blazar AGNs (BL Cℎ 5 Post-trial p-value calculation by comparing with 10000 binomial tests performed on simulated Binomial probability distribution for a single binomial test with 1000 simulated p-values. The , and the number of individual sources with For the purpose of this analysis, we order the the sources in the catalog by their X-ray fluxes While gamma-ray catalogs of Active Galactic Nuclei (AGN) have existed for a while now and (a) Figure 4: data with RomaBZCat. Lacs, FSRQs and blazars of uncertain type).the data Apart from is positions available and for redshifts radio whereverfrom fluxes available, the in Planck the survey, the 1.4 R-band GHz magnitude,gamma-ray band soft flux from X-ray in flux NVSS, (1-100 in microwave band GeV) (0.1 from (143 -with Fermi-LAT. GHz) 2.4 sources The keV) covering catalog from the has ROSAT, and entire a Northern comprehensive and sky Southern coverage, sky. XRAYSELBLL has a Multi-frequency catalogs, however, do exist for blazars. Amongof the these most is recent the and comprehensive are among the most detailed catalogs forcompile this X-ray catalogs class of of blazars. sources Although [11], anthe few exclusive XRAYSELBLL [12], attempts catalog it have for contains been X-ray only selected made BL to Lacs exists, a final discovery potential of 5. X-ray selected blazar catalog Figure 3: best binomial probability Neutrino flares from X-ray selected blazars PoS(ICRC2021)971 ) from ◦ 85 + , ◦ 5 /s respectively. − 2 ). The flare strength ◦ (b) ). The distribution of erg/cm ◦ 10 85 − + , 10 ◦ 5 × − 8 . 1 and 13 − 44%. 10 ∼ × 1 7 . 3 , and the distribution of the X-ray fluxes for these 1000 sources (a) ) and the flare duration (dT = 30 days) were kept constant for all the 2 = discovery potential (D.P.) with an S/B threshold of 2000 are shown in W (a) f Skymap of the 1000 sources with the highest X-ray fluxes in the declination ( The down-selected catalog contains 586 BL Lacs, 361 FSRQs and 53 uncertain type blazars. We have presented here an outline for our intended search for time-clustered neutrino emission Sensitivity studies for a single source were performed by injecting signal flares of varying . The dotted lines indicate the median X-ray flux for each category. (b) The minimum and maximum X-ray fluxes are RomaBZCat shown in Galactic coordinates in IceCube data from blazars selectedto on test the the basis hypothesis of that their X-ray bright softneutrinos. blazars X-ray fluxes can (0.1 The be - importance potential 2.4 sources of keV). of X-ray We high-energy datais aim astrophysical when explained through trying the to recent constrain attempts theAdditionally, at neutrino leptohadronic this emission modelling of analysis of blazars the has SEDover the of 10 TXS advantage 0506+056. years of of accumulating IceCubepopulation information test neutrino through from the data. binomial flares test statistic observed A is also brief provided. description The catalog of of the sources is multi-flare derived fit method and a Neutrino flares from X-ray selected blazars and keep only the topthese 1000 1000 blazars sources in in the the sky Northern and hemisphere their X-ray ( fluxes can be seen in5. Fig. Figure 5: Overlap between our catalog and aNorthern previous sky study blazars that of looked Fermi at 3LAC the catalog neutrino [11] flares is from top 1000 was varied by changing the numberflare. of The flares spectral injected index ( asinjections. well as These the were number compared of witha events background injected single trials per source. to obtain The the number sensitivityC.L. of of sensitivity events the and per analysis flare to a vs. 3 Fig. 6b. the number of flares required to obtain a 90% 7. Summary and Outlook strength at arbitrary times at the location of TXS 0506+056 (declination = 5.69 6. Per source sensitivity PoS(ICRC2021)971 ) ◦ (Jul, 2010). (2019) 950. no. 1, (Nov, 2018) 88–92. (b) ICRC2019 3 (Jan., 2021). PoS no. 1, (May, 2015) 75. (2018) eaat1378. (2018) 147–151. no. 1, (Aug, 2015) 14. no. 03, (2017) P03012. 357 361 361 no. 1, (Aug, 2018) 84. 810 . The 5-sigma D.P. is not shown here due to no. 2, (Apr, 2021) L18. 12 (b) no. 3-4, (Oct, 2005) 165–195. no. 2, (Feb., 2013) 31. 864 911 Nature Astronomy 120 145 8 et al. Science et al. JINST et al. Science et al. arXiv:2101.09836v2 The Astrophysical Journal Astrophysics and Space Science The Astrophysical Journal (a) The Astronomical Journal et al. Space Science Reviews et al. Space Telescopes and Instrumentation: UV to Gamma Ray Collaboration, W. Luszczak, J. Braun, and A. Karle Collaboration, M. G. Aartsen Collaboration, M. G. Aartsen Collaboration, R. Abbasi Collaboration, M. G. Aartsen et al. The Astrophysical Journal Letters Background multi-flare TS distribution for a source at the declination of TXS 0506+056 (5.69 IceCube IceCube IceCube IceCube IceCube , and the strength of individual flares from a single source (at the declination of TXS 0506+056) required [2] S. Gao, A. Fedynitch, W. Winter, and M.[3] Pohl S. D. Hunter [6] E. Kun [9] [1] A. Keivani and et al. [5] [7] [4] D. N. Burrows [8] Figure 6: (a) to obtain a final D.P. of 3-sigma and a 90% C.L. sensitivity [10] [11] M. Ackermann and et al. [12] B. Z. Kapanadze limited statistics but will be available in future tests. from RomaBZCat by selecting 1000dataset blazars and with other the parameters to highest be X-ray used fluxcurrently for under in the progress. analysis the have Northern been Sensitivity defined sky. of andfull the background The catalog analysis trials sensitivity to are and a a single finalemission source p-value potential is for will presented each be source here, published signifying while soon. their the time-dependent neutrino References [13] E. Massaro and et al. Neutrino flares from X-ray selected blazars PoS(ICRC2021)971 , , , , , , , , , , , , , , , 1 2 59 38 38 38 45 58 38 38 11 31 50 27 56 , J. , J. , J. , F. , S. , P. , S. , Y. , P. , S. , S. , S. , L. , B. , U. , K. , C. , K. , C. , K. , A. , K. 26 61 42 26 59 39 38 40 15 31 16 53 , J. 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Unland Elorrieta Institut für Physik, Humboldt-Universität zu Berlin,Fakultät D-12489 für Berlin, Physik Germany & Astronomie, Ruhr-Universität Bochum,Université Libre D-44780 de Bochum, Bruxelles, Germany Science FacultyVrije CP230, Universiteit B-1050 Brussel Brussels, (VUB), Belgium Dienst ELEM,Department B-1050 of Brussels, Physics Belgium and Laboratory forDept. Particle of Physics and Physics, Massachusetts Cosmology, Harvard Institute University, of Cambridge, Technology, Cambridge, MA MA 02138, 02139, USA USA 38 III. Physikalisches Institut, RWTH Aachen University, D-52056Department Aachen, of Germany Physics, University of Adelaide,Dept. Adelaide, 5005, of Australia Physics and Astronomy, UniversityDept. of Alaska of Anchorage, Physics, 3211 University of Providence Texas Dr.,CTSPS, at Anchorage, Clark-Atlanta Arlington, AK University, Atlanta, 502 99508, GA Yates USA St., 30314, Science USA School Hall of Rm Physics 108, and Box Center 19059, forDept. Arlington, Relativistic TX Astrophysics, of Georgia 76019, Physics, Institute USA Southern of University, Technology, Baton Atlanta,Dept. Rouge, GA LA of 30332, 70813, Physics, USA University USA of California,Lawrence Berkeley, Berkeley CA National 94720, Laboratory, USA Berkeley, CA 94720, USA Naumann Meighen-Berger I. C. Mariş F. Lucarelli Leonard N. Kurahashi Köpke Kelley W. Kang M. Hünnefeld Hoffman Hauser A. Hallgren Goldschmidt Gallagher K. Filimonov Eller Deoskar A. Diaz Coppin C. Chen Bron Bellenghi M. Boddenberg A. Barbano Neutrino flares from X-ray selected blazars Full Author List: IceCube Collaboration R. Abbasi Amin 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Wulff 1 J. Werthebach Verpoest Ty Toscano Sullivan Stachurska B. Skrzypek G. Schröder Satalecka Cantu B. Riedel Rawlins M. Oehler Pérez de los Heros Popovych PoS(ICRC2021)971 10 Institute of Physics, University of Mainz,Department Staudinger Weg of 7, Physics, D-55099 Marquette Mainz, University, Milwaukee, Germany WI,Institut 53201, für USA Kernphysik, Westfälische Wilhelms-Universität Münster, D-48149Bartol Münster, Research Germany Institute and Dept.Dept. of Physics of and Physics, Astronomy, Yale University University, of New Haven, Delaware,Dept. CT Newark, of DE 06520, Physics, 19716, USA University USA of Oxford,Dept. Parks of Road, Oxford Physics, OX1 Drexel University, 3PU, 3141 UK Physics Chestnut Department, Street, South Philadelphia, Dakota PA 19104, School of USA Dept. Mines of and Physics, Technology, Rapid University City, of SD Wisconsin,Dept. 57701, River USA of Falls, WI Physics and 54022, Astronomy, USA UniversityDepartment of of Rochester, Rochester, Physics NY and 14627, Astronomy, University USA ofOskar Utah, Klein Salt Centre Lake and City, Dept. UTDept. of 84112, Physics, USA of Stockholm Physics University, and SE-10691 Astronomy, Stockholm, Stony Sweden Dept. Brook University, of Stony Physics, Brook, Sungkyunkwan NY University, Suwon 11794-3800,Institute 16419, USA of Korea Basic Science, Sungkyunkwan University,Dept. Suwon 16419, of Korea Physics and Astronomy, UniversityDept. of Alabama, of Tuscaloosa, Astronomy AL and 35487, Astrophysics, USA PennsylvaniaDept. State University, of University Physics, Park, Pennsylvania PA State 16802, University, USA UniversityDept. Park, of PA 16802, Physics and USA Astronomy, UppsalaDept. University, Box of 516, Physics, S-75120 University Uppsala, of Sweden Wuppertal,DESY, D-15738 D-42119 Zeuthen, Wuppertal, Germany Germany Università di Padova, I-35131 Padova, Italy National Research Nuclear University, Moscow Engineering PhysicsEarthquake Institute Research (MEPhI), Institute, Moscow University 115409, of Russia Tokyo, Bunkyo, Tokyo 113-0032, Japan Dept. of Physics and Institute forDepartment Global of Prominent Physics, Research, Loyola University Chiba Chicago, University, ChibaDept. Chicago, 263-8522, IL of Japan 60660, Physics USA and Astronomy, UniversityDept. of Canterbury, of Private Physics, Bag University of 4800, Maryland, Christchurch,Dept. College New of Zealand Park, Astronomy, MD Ohio 20742, State USA University,Dept. Columbus, OH of 43210, Physics USA and Center forNiels Cosmology Bohr and Institute, Astro-Particle University of Physics, Ohio Copenhagen,Dept. State DK-2100 Copenhagen, University, of Columbus, Denmark Physics, OH TU 43210, Dortmund USA Dept. University, D-44221 of Dortmund, Physics Germany and Astronomy, MichiganDept. State University, of East Physics, Lansing, University MI of 48824, Alberta,Erlangen USA Centre Edmonton, for Alberta, Astroparticle Canada Physics, T6G Friedrich-Alexander-Universität Erlangen-Nürnberg, 2E1 Physik-department, D-91058 Technische Universität Erlangen, München, Germany D-85748 Garching, Germany Département de physique nucléaire et corpusculaire,Dept. Université of de Physics Genève, and CH-1211 Astronomy, Genève, University Switzerland Dept. of Gent, of B-9000 Physics and Gent, Astronomy, Belgium UniversityKarlsruhe of Institute California, of Irvine, Technology, Institute CA 92697, for Astroparticle USA Karlsruhe Physics, Institute D-76021 of Karlsruhe, Technology, Institute Germany of ExperimentalDept. Particle of Physics, Physics, D-76021 Engineering Karlsruhe, Physics, Germany andDept. Astronomy, Queen’s of University, Physics Kingston, and ON Astronomy, K7L UniversityDepartment 3N6, of of Canada Kansas, Physics Lawrence, and KS Astronomy, 66045, UCLA, USA Department Los of Angeles, Physics, CA Mercer 90095, University, USA Macon,Dept. GA 31207-0001, of USA Astronomy, University of Wisconsin–Madison, Madison, WI 53706, USA Dept. of Physics and Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin–Madison, Madison, WI 53706, USA 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 Acknowledgements USA – U.S. Nationaltional Science Science Foundation-Office Foundation-EPSCoR, Wisconsin of Alumni Polar ResearchUniversity Foundation, Programs, of Center Wisconsin–Madison, U.S. for Open High National Science ThroughputFrontera Science Grid Computing computing Foundation-Physics (CHTC) project (OSG), Division, at at Extreme the the U.S. Science Texas AdvancedComputing and Na- Computing Center, Center, Particle Engineering U.S. astrophysics Discovery research Department computing Environment of center Energy-Nationalat (XSEDE), at Energy Michigan the Research State University Scientific of University, and Maryland, Astroparticle InstituteResearch for physics (FRS-FNRS Cyber-Enabled computational Research and facility FWO), at FWO Marquette OdysseusGermany University; and – Belgium Bundesministerium Big – für Science Funds Bildung programmes, for und Scientific ForschungAstroparticle and (BMBF), Physics Belgian Deutsche (HAP), Initiative Forschungsgemeinschaft Federal (DFG), and Science Networking Helmholtz Fund Alliance Policy of for and Office the Helmholtz High (Belspo); Association, Performance Deutsches Elektronen Computing Synchrotron cluster (DESY), retariat, of Swedish the National RWTH Aachen; Infrastructure Sweden for – Computing Swedish (SNIC), Research and Council, Knut Swedish Polar and Research Alice Sec- Wallenberg Foundation; Australia – Australian 39 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Neutrino flares from X-ray selected blazars 16 PoS(ICRC2021)971 11 Neutrino flares from X-ray selected blazars Research Council; Canada – Natural Sciences andFoundation Engineering for Research Innovation, Council of WestGrid, Canada, and CalculMarsden Compute Québec, Fund; Compute Canada; Japan Ontario, – Denmark Canada Japan –University; Society Korea Villum – for Fonden Promotion National Research and of Foundation Science CarlsbergKingdom of (JSPS) Foundation; – Korea and (NRF); Department New Institute Switzerland of Zealand – for Physics, – University Swiss Global of National Prominent Oxford. Science Research Foundation (IGPR) (SNSF); of United Chiba