Search

We present new model results for H2O, O2, H2, O, and H in the atmosphere of Ganymede. The results are obtained from a collision-less 3D Monte-Carlo model that includes sublimation, ion and electron sputtering, and ion and electron radiolysis. Because Ganymede has its own magnetic field, its immediate plasma environment is particularly complex. The interaction between Ganymede's and Jupiter's magnetospheres makes it highly variable in both space and time. The recent Juno Ganymede flyby provided us with new data on the electron local environment. Based on the electron measurements recorded by the Jovian Auroral Distributions Experiment (JADE), we implement two electron populations, one for the moon's polar regions and one for the moon's auroral regions. Comparing the atmospheric contribution of these newly defined electron populations to the overall source and loss processes is one of the main goals of this work. Our analysis shows that for H2O, sublimation remains the most important source process even after accounting for the new electron populations, delivering more than three orders of magnitude more H2O molecules to the atmosphere than all other source processes combined. The source fluxes for O2 and H2, on the other hand, are dominated by radiolysis induced by the auroral electrons, assuming that the electron fluxes JADE measured during Juno's transit of Ganymede's magnetopause current layer are representative of auroral electrons. Atomic O and H are mainly added to the atmosphere through the dissociation of O2 and H2, which is primarily induced by auroral electrons. Our understanding of Ganymede's atmosphere today is mainly based on spectroscopic observations. The interpretation of spectroscopic data strongly depends on assumptions taken, though. Our analysis shows that for a holistic understanding of Ganymede's atmosphere, simultaneous observations of the moon's surface, atmosphere, and full plasma environment (thermal and energetic ions and electrons) at diff

Through stars, the formation and evolution of the Galaxy goes hand-in-hand with the cosmic origin of the elements. As stars form, they carry chemical fingerprints of their birthclouds, providing us with chemical timestamps of the Galaxy.The detailed history of the Galactic disk and bulge is still to be untagled. The same goes for the origin of elements – where some still have elusive origins. Disentagling the origin of the Galaxy and the elements can only be acchived by continued efforts by combining the most accurate and precise data with the latest state-of-the art theoretical models.In this thesis, I present high-precision chemical abundances of red giant stars in the Galactic disk and bulge, obtained by careful analysis of high-resolution optical and infrared spectra. Using red giant stars in the bulge and disk populations allows for an unique differential comparison of the two Galactic components. I focus the analysis to obtain abundances of neutron-capture elements, which can shed new light on the origin of the Galactic components.The abundance trends of the Galactic bulge show great similarities with the Galactic (thick) disk, pointing at a similar history. However, there are possible enrichments in both lanthanum and molybdenum, which require further follow-up studies to confirm. I identify a chemically-peculiar star in the bulge, standing out by its high abundances of europium and molybenum.Finally, I demonstrate the need for high-resolution and spectra in order to access abundances of neutron-capture elements in the infrared. Including heavy elements is essential in getting the full chemical view of the Galaxy, which is shown in this thesis.

We examine the origin of electrons in a weakly outgassing comet, using Rosetta mission data and a 3D collisional model of electrons at a comet. We have calculated a new data set of electron-impact ionization (EII) frequency throughout the Rosetta escort phase, with measurements of the Rosetta Plasma Consortium's Ion and Electron Sensor (RPC/IES). The EII frequency is evaluated in 15-min intervals and compared to other Rosetta data sets. EII is the dominant source of electrons at 67P away from perihelion and is highly variable (by up to three orders of magnitude). Around perihelion, EII is much less variable and less efficient than photoionization at Rosetta. Several drivers of the EII frequency are identified, including magnetic field strength and the outgassing rate. Energetic electrons are correlated to the Rosetta-upstream solar wind potential difference, confirming that the ionizing electrons are solar wind electrons accelerated by an ambipolar field. The collisional test particle model incorporates a spherically symmetric, pure water coma and all the relevant electron-neutral collision processes. Electric and magnetic fields are stationary model inputs, and are computed using a fully kinetic, collision-less Particle-in-Cell simulation. Collisional electrons are modelled at outgassing rates of Q = 1026 s-1 and Q = 1.5 × 1027 s-1. Secondary electrons are the dominant population within a weakly outgassing comet. These are produced by collisions of solar wind electrons with the neutral coma. The implications of large ion flow speed estimates at Rosetta, away from perihelion, are discussed in relation to multi-instrument studies and the new results of the EII frequency obtained in this study.

We apply a recently proposed method to estimate heavy ion escape from Mars. The method combines in situ observations with a hybrid plasma model, which treats ions as particles and electrons as a fluid. With this method, we investigate how solar upstream conditions, including solar extreme ultraviolet (EUV) radiation, solar wind dynamic pressure, and interplanetary magnetic field (IMF) strength and cone angle, affect the heavy ion loss. The results indicate that the heavy ion escape rate is greater in high EUV conditions. The escape rate increases with increasing solar wind dynamic pressure, and decreases as the IMF strength increases. The ion escape rate is highest when the solar wind is parallel to the IMF and lowest when they are perpendicular. The plume escape rate decreases when the solar wind convective electric field increases.

No spacecraft visiting a comet has been equipped with instruments to directly measure the static electric field. However, the electric field can occasionally be estimated indirectly by observing its effects on the ion velocity distribution. We present such observations made by the Rosetta spacecraft on 19 April 2016, 35 km from the nucleus. At this time comet 67P was at a low outgassing rate and the plasma environment was relatively stable. The ion velocity distributions show the cometary ions on the first half of their gyration. We estimate the bulk drift velocity and the gyration speed from the distributions. By using the local measured magnetic field and assuming an E × B drift of the gyrocentre, we get an estimate for the average electric field driving this ion motion. We analyze a period of 13 hr, during which the plasma environment does not change drastically. We find that the average strength of the perpendicular electric field component is 0.21 mV/m. The direction of the electric field is mostly anti-sunward. This is in agreement with previous results based on different methods.

The astrophysical origin of rapid neutron capture (r-process) elements has long remained a puzzle and been the object of scientific debate. Neutron star (NS) mergers have historically been suggested as an ideal site for the creation of these elements, and were propelled into focus following the detection of the first binary neutron star (BNS) merger in 2017. The gravitational wave (GW) signal GW170817 was accompanied by a short gamma-ray burst (sGRB) GRB170817A, and a radioactively powered electromagnetic (EM) transient AT2017gfo, known as a kilonova (KN). Since this detection, the study of NS mergers has greatly expanded across the diverse fields that model the various stages of the merger, from GW signal modelling, to radiative transfer studies predicting the emergent KN lightcurves (LCs) and spectra. One main goal of studying NS mergers and the associated KNe is to establish the importance of compact object mergers as key sites of r-process nucleosynthesis in the Universe. As such, identification of elements and their abundances within the merger ejecta represents a critical objective. LC and spectral analyses of KNe provide promising channels to do so, and require detailed models in order to interpret observational data. With complete GW and multi-band EM data only available for a single object thus far, the importance of detailed models regarding every aspect of KN physics is paramount. KN simulations typically make use of radiative transfer (RT) codes that propagate photons through the expanding ejecta, in order to provide LC and spectral outputs. These often model the early, photospheric times of the KN, when the ejecta are still dense enough such that the gas state is well described by Local Thermodynamic Equilibrium (LTE) conditions, which requires thermal collisional processes to dominate within the ejecta. Since the ejecta are expanding rapidly however, these conditions cease to apply after several days, and the KN transitions to the Non-Local Thermodynam

This thesis is a contribution to the search for new fundamental physics in the form of axionlike particles (ALPs). ALPs are relatively light and feebly interacting particles that are part of many theories extending the Standard Model of particle physics, e.g., to solve the strong-CP problem, the dark matter problem, or quantum gravity in the form of string theory. We use astrophysical observations mainly related to core-collapse supernovae to search for signatures of the existence of ALPs. In the first part of this thesis, we study in some detail the effective field theory of ALPs with a focus on quantum loop effects. These loops necessarily induce correlations between the effective couplings of the theory such that, e.g., the interaction between ALPs and photons sourced by quantum loops due to their coupling to leptons cannot be neglected. In the second part of the thesis, as well as in three of the publications that it is comprised of, we demonstrate the importance of the effective ALP-photon coupling defined here for dark matter ALPs, whose loop induced decay to photons excludes a large region of their parameter space that was believed to be accessible to direct detection experiments, as well as ALPs produced in supernova explosions. Through the loop-induced interaction with photons more ALPs can be produced in supernovae than was calculated previously. Additionally, the photon-decay channel implies ways in which ALPs could have been observed that would not be possible if they only interacted with leptons. For instance, if a nearby supernova such as SN 1987A or the recently observed SN 2023ixf, emitted a large number of ALPs that afterwards decayed into gamma-ray photons, such a signal could have been detected by telescopes. The precise prediction of this signal is a further focus of this thesis and three of the included publications. Additionally, we improve many technical aspects of the determination of the number and energy of ALPs produced in supernovae, as w

This thesis is a contribution to the search for new fundamental physics in the form of axionlike particles (ALPs). ALPs are relatively light and feebly interacting particles that are part of many theories extending the Standard Model of particle physics, e.g., to solve the strong-CP problem, the dark matter problem, or quantum gravity in the form of string theory. We use astrophysical observations mainly related to core-collapse supernovae to search for signatures of the existence of ALPs. In the first part of this thesis, we study in some detail the effective field theory of ALPs with a focus on quantum loop effects. These loops necessarily induce correlations between the effective couplings of the theory such that, e.g., the interaction between ALPs and photons sourced by quantum loops due to their coupling to leptons cannot be neglected. In the second part of the thesis, as well as in three of the publications that it is comprised of, we demonstrate the importance of the effective ALP-photon coupling defined here for dark matter ALPs, whose loop induced decay to photons excludes a large region of their parameter space that was believed to be accessible to direct detection experiments, as well as ALPs produced in supernova explosions. Through the loop-induced interaction with photons more ALPs can be produced in supernovae than was calculated previously. Additionally, the photon-decay channel implies ways in which ALPs could have been observed that would not be possible if they only interacted with leptons. For instance, if a nearby supernova such as SN 1987A or the recently observed SN 2023ixf, emitted a large number of ALPs that afterwards decayed into gamma-ray photons, such a signal could have been detected by telescopes. The precise prediction of this signal is a further focus of this thesis and three of the included publications. Additionally, we improve many technical aspects of the determination of the number and energy of ALPs produced in supernovae, as w

The astrophysical origin of rapid neutron capture (r-process) elements has long remained a puzzle and been the object of scientific debate. Neutron star (NS) mergers have historically been suggested as an ideal site for the creation of these elements, and were propelled into focus following the detection of the first binary neutron star (BNS) merger in 2017. The gravitational wave (GW) signal GW170817 was accompanied by a short gamma-ray burst (sGRB) GRB170817A, and a radioactively powered electromagnetic (EM) transient AT2017gfo, known as a kilonova (KN). Since this detection, the study of NS mergers has greatly expanded across the diverse fields that model the various stages of the merger, from GW signal modelling, to radiative transfer studies predicting the emergent KN lightcurves (LCs) and spectra. One main goal of studying NS mergers and the associated KNe is to establish the importance of compact object mergers as key sites of r-process nucleosynthesis in the Universe. As such, identification of elements and their abundances within the merger ejecta represents a critical objective. LC and spectral analyses of KNe provide promising channels to do so, and require detailed models in order to interpret observational data. With complete GW and multi-band EM data only available for a single object thus far, the importance of detailed models regarding every aspect of KN physics is paramount. KN simulations typically make use of radiative transfer (RT) codes that propagate photons through the expanding ejecta, in order to provide LC and spectral outputs. These often model the early, photospheric times of the KN, when the ejecta are still dense enough such that the gas state is well described by Local Thermodynamic Equilibrium (LTE) conditions, which requires thermal collisional processes to dominate within the ejecta. Since the ejecta are expanding rapidly however, these conditions cease to apply after several days, and the KN transitions to the Non-Local Thermodynam

In 2021 July, PKS 1510-089 exhibited a significant flux drop in the high-energy & gamma;-ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state throughout 2022. Similarly, the optical polarization in the source vanished, resulting in the optical spectrum being fully explained through the steady flux of the accretion disk and the broad-line region. Unlike the aforementioned bands, the very-high-energy & gamma;-ray and X-ray fluxes did not exhibit a significant flux drop from year to year. This suggests that the steady-state very-high-energy & gamma;-ray and X-ray fluxes originate from a different emission region than the vanished parts of the high-energy & gamma;-ray and optical jet fluxes. The latter component has disappeared through either a swing of the jet away from the line of sight or a significant drop in the photon production efficiency of the jet close to the black hole. Either change could become visible in high-resolution radio images.

The origin of supermassive black holes (SMBHs,∼ 10^9M⊙) in the first billion years of cosmic history remains a mystery. Direct Collapse Black Holes (DCBHs,∼ 10^4M⊙) are considered one of the most promising hypotheses for the progenitor of SMBHs, as they are believed to provide a favorable starting point as massive seeds for SMBH formation. Based on the models of Pacucci et al. (2016), the DCBHs at birth are expected to exhibit an unusual steep (red) spectral energy distribution (SED) in the 1-5 micrometer range. In this study,we investigate degeneracies between DCBHs and dusty galaxies using synthetic data from the Pacucci model. Furthermore, we employ James Webb Space Telescope (JWST) photometric data obtainedfrom the Cosmic Evolution Early Release Science (CEERS) survey,which has been processed and reduced by Gabriel Brammer using the Grizli pipeline. By analyzing this JWST photometric data, we aim to identify potential DCBH candidates for further spectroscopic observations. We find that the dusty galaxies over a wide range ofredshift could mimic the SED shape of DCBHs, and that obscured active galactic nuclei (AGN) could potentially act as interlopers as well. The similarities in certain observational characteristics between DCBHs and dusty galaxies/AGN can obscure their distinct identities. In a localized region of the Extended Groth Strip field, we identify 12, 17, and 77 objects in three catalogues with increasing aperture sizesthat show relatively good fits with the DCBH models. However, upon further examination of their images, we do not find any candidatesthat are particularly compelling or convincing.

At higher redshift galaxies exhibit increasingly irregular and clumpy morphologies, withstar-forming clumps dominating the FUV output of their host galaxies thus being inti-mately related to star formation and the formation and evolution of galaxies. This workexamines star-forming clumps in a remarkable, young spiral galaxy at Cosmic Noon witha redshift ofz= 2.584, lensed by the galaxy cluster Abell 2744. To this aim, NIRCamobservations in 7 filter bands are utilized to determine photometry of clumps and performbroadband SED fitting to determine characteristic sizes, ages and masses and infer theirdynamical ages and mass surface densities. The clump within this galaxy spans a widerange of properties with sizes between 20 to 200 pc and masses between 105M⊙and109M⊙. While clumps are not resolved down to scales of individual star clusters, small,dense clumps may host star clusters. A number of clumps exhibits agestage>100 Myr,thus being able to survive feedback up to these timescales. This population of clumpsalso appears to be dynamically evolved and gravitationally bound as well as the denseststructures within the investigated sample, with roughly∼20% of clumps exhibiting masssurface densities comparable to bound stellar clusters in the local Universe.

We report the discovery of Mothra, an extremely magnified monster star, likely a binary system of two supergiant stars, in one of the strongly lensed galaxies behind the galaxy cluster MACS J0416.1-2403. Mothra is in a galaxy with spectroscopic redshift z = 2.091 in a portion of the galaxy that is parsecs away from the cluster caustic. The binary star is observed only on the side of the critical curve with negative parity but has been detectable for at least eight years, implying the presence of a small lensing perturber. Microlenses alone cannot explain the earlier observations of this object made with the Hubble Space Telescope. A larger perturber with a mass of at least 10(4 )M(circle dot) offers a more satisfactory explanation. Based on the lack of perturbation on other nearby sources in the same arc, the maximum mass of the perturber is 2.5 x 10(6) M-circle dot, making this the smallest substructure constrained by lensing at z > 0.3. The existence of this millilens is fully consistent with expectations from standard cold dark matter cosmology. On the other hand, the existence of such a small substructure in a cluster environment has implications for other dark matter models. In particular, warm dark matter models with particle masses below 8.7 keV are excluded by our observations. Similarly, axion dark matter models are consistent with the observations only if the axion mass is in the range 0.5 x 10(-22) eV < m(a )< 5 x 10(-22) eV.

Accurately estimating the C/O ratio of hot Jupiter atmospheres is a promising pathway towards understanding planet formation and migration, as well as the formation of clouds and the overall atmospheric composition. The atmosphere of the hot Jupiter WASP-43b has been extensively analysed using low-resolution observations with HST and Spitzer, but these previous observations did not cover the K band, which hosts prominent spectral features of major carbon-bearing species such as CO and CH4. As a result, the ability to establish precise constraints on the C/O ratio was limited. Moreover, the planet has not been studied at high spectral resolution, which can provide insights into the atmospheric dynamics. In this study, we present the first high-resolution dayside spectra of WASP-43b with the new CRIRES+ spectrograph. By observing the planet in the K band, we successfully detected the presence of CO and provide evidence for the existence of H2O using the cross-correlation method. This discovery represents the first direct detection of CO in the atmosphere of WASP-43b. Furthermore, we retrieved the temperature-pressure profile, abundances of CO and H2O, and a super-solar C/O ratio of 0.78 by applying a Bayesian retrieval framework to the data. Our findings also shed light on the atmospheric characteristics of WASP-43b. We found no evidence for a cloud deck on the dayside, and recovered a line broadening indicative of an equatorial super-rotation corresponding to a jet with a wind speed of similar to 5kms(-1), matching the results of previous forward models and low-resolution atmospheric retrievals for this planet.

In this work we discuss various selected mission concepts addressing Venus evolution through time. More specifically, we address investigations and payload instrument concepts supporting scientific goals and open questions presented in the companion articles of this volume. Also included are their related investigations (observations & modeling) and discussion of which measurements and future data products are needed to better constrain Venus' atmosphere, climate, surface, interior and habitability evolution through time. A new fleet of Venus missions has been selected, and new mission concepts will continue to be considered for future selections. Missions under development include radar-equipped ESA-led EnVision M5 orbiter mission (European Space Agency 2021), NASA-JPL's VERITAS orbiter mission (Smrekar et al. 2022a), NASA-GSFC's DAVINCI entry probe/flyby mission (Garvin et al. 2022a). The data acquired with the VERITAS, DAVINCI, and EnVision from the end of this decade will fundamentally improve our understanding of the planet's long term history, current activity and evolutionary path. We further describe future mission concepts and measurements beyond the current framework of selected missions, as well as the synergies between these mission concepts, ground-based and space-based observatories and facilities, laboratory measurements, and future algorithmic or modeling activities that pave the way for the development of a Venus program that extends into the 2040s (Wilson et al. 2022)., Correction in: Space Sci Rev 219, 72 (2023)DOI: 10.1007/s11214-023-01022-5

We utilize theoretical models of Population III stellar + nebular spectra to investigate the prospects of observing and accurately identifying Population III galaxies with JWST using both deep imaging and spectroscopy. We investigate a series of different colour cuts, finding that a combination of NIRCam and MIRI photometry through the F444W-F560W, F560W-F770W colours offers the most robust identifier of potential z = 8 Pop III candidates. We calculate that NIRCam will have to reach similar to 28.5-30.0 AB mag depths (1-20 h), and MIRI F560W must reach similar to 27.5-29.0 AB mag depths (10-100 h) to achieve 5 sigma continuum detections of M-* = 10(6) M-circle dot Pop III galaxies at z = 8. We also discuss the prospects of identifying Pop III candidates through slitless and NIRSpec spectroscopic surveys that target Ly alpha, H beta, and/or He II lambda 1640. We find small differences in the H beta rest-frame equivalent width (EW) between Pop III and non-Pop III galaxies, rendering this diagnostic likely impractical. Instead, we find that the detection of high EW He II lambda 1640 emission will serve as the definitive Pop III identifier, requiring (ultra-)deep integrations (5-150 h) with NIRSpec/G140M for M-* = 10(6) M-circle dot Pop III galaxies at z = 8. However, MIRI F770W detections of Pop III galaxies will require substantial gravitational lensing (mu = 10) and/or fortuitous imaging of exceptionally massive (M-* = 10(7) M-circle dot) Pop III galaxies. Thus, NIRCam medium-band imaging surveys that can search for high EW He II lambda 1640 emitters in photometry may perhaps be a viable alternative for finding Pop III candidates.

The Galactic plane, harboring a diffuse neutrino flux, is a particularly interesting target in which to study potential cosmic-ray acceleration sites. Recent gamma-ray observations by HAWC and LHAASO have presented evidence for multiple Galactic sources that exhibit a spatially extended morphology and have energy spectra continuing beyond 100 TeV. A fraction of such emission could be produced by interactions of accelerated hadronic cosmic rays, resulting in an excess of high-energy neutrinos clustered near these regions. Using 10 years of IceCube data comprising track-like events that originate from charged-current muon neutrino interactions, we perform a dedicated search for extended neutrino sources in the Galaxy. We find no evidence for time-integrated neutrino emission from the potential extended sources studied in the Galactic plane. The most significant location, at 2.6 sigma post-trials, is a 1.degrees 7 sized region coincident with the unidentified TeV gamma-ray source 3HWC J1951+266. We provide strong constraints on hadronic emission from several regions in the galaxy., For complete list of authors see http://dx.doi.org/10.3847/1538-4357/acf713

The bright star lambda Ser hosts a hot Neptune with a minimum mass of 13.6 M & OPLUS; and a 15.5 day orbit. It also appears to be a solar analog, with a mean rotation period of 25.8 days and surface differential rotation very similar to the Sun. We aim to characterize the fundamental properties of this system and constrain the evolutionary pathway that led to its present configuration. We detect solar-like oscillations in time series photometry from the Transiting Exoplanet Survey Satellite, and we derive precise asteroseismic properties from detailed modeling. We obtain new spectropolarimetric data, and we use them to reconstruct the large-scale magnetic field morphology. We reanalyze the complete time series of chromospheric activity measurements from the Mount Wilson Observatory, and we present new X-ray and ultraviolet observations from the Chandra and Hubble space telescopes. Finally, we use the updated observational constraints to assess the rotational history of the star and estimate the wind braking torque. We conclude that the remaining uncertainty on the stellar age currently prevents an unambiguous interpretation of the properties of lambda Ser, and that the rate of angular momentum loss appears to be higher than for other stars with a similar Rossby number. Future asteroseismic observations may help to improve the precision of the stellar age.

Exploring planetary systems similar to our solar system can provide a means to explore a large range of possibly temperate climates on Earth-like worlds. Rather than run hundreds of simulations with different eccentricities at fixed obliquities, our variable-eccentricity approach provides a means to cover an incredibly large parameter space. Herein Jupiter's orbital radius is moved substantially inward in two different scenarios, causing a forcing on Earth's eccentricity. In one case, the eccentricity of Earth varies from 0 to 0.27 over similar to 7000 yr for three different fixed obliquities (0 degrees, 23 degrees, and 45 degrees). In another case, the eccentricity varies from 0 to 0.53 over similar to 9400 yr in a single case with zero obliquity. In all cases, we find that the climate remains stable, but regional habitability changes through time in unique ways. At the same time, the moist greenhouse state is approached but only when at the highest eccentricities.

The current state and surface conditions of the Earth and its twin planet Venus are drastically different. Whether these differences are directly inherited from the earliest stages of planetary evolution, when the interior was molten, or arose later during the long-term evolution is still unclear. Yet, it is clear that water, its abundance, state, and distribution between the different planetary reservoirs, which are intimately related to the solidification and outgassing of the early magma ocean, are key components regarding past and present-day habitability, planetary evolution, and the different pathways leading to various surface conditions. In this chapter we start by reviewing the outcomes of the accretion sequence, with particular emphasis on the sources and timing of water delivery in light of available constraints, and the initial thermal state of Venus at the end of the main accretion. Then, we detail the processes at play during the early thermo-chemical evolution of molten terrestrial planets, and how they can affect the abundance and distribution of water within the different planetary reservoirs. Namely, we focus on the magma ocean cooling, solidification, and concurrent formation of the outgassed atmosphere. Accounting for the possible range of parameters for early Venus and based on the mechanisms and feedbacks described, we provide an overview of the likely evolutionary pathways leading to diverse surface conditions, from a temperate to a hellish early Venus. The implications of the resulting surface conditions and habitability are discussed in the context of the subsequent long-term interior and atmospheric evolution. Future research directions and observations are proposed to constrain the different scenarios in order to reconcile Venus' early evolution with its current state, while deciphering which path it followed.

This paper presents a simultaneous observation of the inner and outer electron diffusion region (EDR) at the dayside magnetopause by the magnetospheric multiscale (MMS) spacecraft. The EDR was observed in magnetic reconnection with a large guide field. The inner EDR was characterized by positive J center dot E ' while the outer EDR is manifested by negative J center dot E ' and opposite out-of-plane electric field to that in the inner EDR. One pair of the spacecraft detected the inner EDR while the other pair encountered the outer EDR. Moreover, the two pairs were on the opposite side of the X-line as they observed the bidirectional accelerated electron jets. The fortuitous formation of MMS allows us to estimate the maximum length of the inner EDR as similar to 36 d e and the lower bound of the reconnection rate as 0.142 +/- 0.041. These observations have far-reaching implications for understanding the electron physics in reconnection.

Using a data sample collected with the BESIII detector operating at the BEPCII storage ring, the Born cross section of the process e+e- -> eta J=psi at a center-of-mass energy pffisffi = 3.773 GeV is measured to be (8.88 +/- 0.87 +/- 0.42) pb. We fit the cross section line shape before correcting for the initial state radiation ffiffifromps = 3.773 to 4.600 GeV to obtain the branching fraction B(psi(3770) -> eta J=psi). We obtain B(psi(3770) -> eta J=psi) = (11.3 +/- 5.9 +/- 1.1) x 10-4 when the psi(3770) decay amplitude is added coher-ently to the other contributions, and (8.7 +/- 1.0 +/- 0.8) x 10-4 when it is added incoherently. Here the quoted uncertainties are statistical and systematic, respectively. In both cases, the statistical significance of psi(3770) resonance is above 7 sigma. This is the first time the decay psi(3770) -> eta J=psi is observed with a statistical significance greater than 5 sigma., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.107.L091101

The Atacama Large Millimeter/submillimeter Array (ALMA) was used in 2021 to image the carbon-rich evolved star R Lep in Bands 8-10 (397-908 GHz) with baselines up to 16 km. The goal was to validate the calibration, using band-to-band (B2B) phase referencing with a close phase calibrator J0504-1512, 1.degrees 2 from R Lep in this case, and the imaging procedures required to obtain the maximum angular resolution achievable with ALMA. Images of the continuum emission and the hydrogen cyanide (HCN) maser line at 890.8 GHz, from the J = 10-9 transition between the (1110) and (0400) vibrationally excited states, achieved angular resolutions of 13, 6, and 5 mas in Bands 8-10, respectively. Self-calibration (self-cal) was used to produce ideal images to compare with the B2B phase referencing technique. The continuum emission was resolved in Bands 9 and 10, leaving too little flux for the self-cal of the longest baselines, so these comparisons are made at coarser resolution. Comparisons showed that B2B phase referencing provided phase corrections sufficient to recover 92%, 83%, and 77% of the ideal image continuum flux densities. The HCN maser was sufficiently compact to obtain self-cal solutions in Band 10 for all baselines (up to 16 km). In Band 10, B2B phase referencing as compared to the ideal images recovered 61% and 70% of the flux density for the HCN maser and continuum, respectively.

We report a measurement of the cross section for the process e(+)e(-) -> pi(+)pi(-)J/psi around the X(3872) mass in search for the direct formation of e(+)e(-) -> X(3872) through the two-photon fusion process. No enhancement of the cross section is observed at the X(3872) peak and an upper limit on the product of electronic width and branching fraction of X(3872) -> pi(+)pi(-) J/psi is determined to be Gamma(ee) x B(X(3872) -> pi(+)pi(-) J/psi) <7.5 x 10(-3) eV at 90% confidence level under an assumption of total width of 1.19 +/- 0.21 MeV. This is an improvement of a factor of about 17 compared to the previous limit. Furthermore, using the latest result of B(X(3872) -> pi(+)pi(-) J/psi), an upper limit on the electronic width Fee of X(3872) is obtained to be <0.32 eV at the 90% confidence level., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.107.032007

Using o1.0087 similar to 0.0044THORN x 1010 J=. events collected by the BESIII detector at the BEPCII collider, we report the first search for the baryon and lepton number violating decays.0. K-ethorn with.oB - LTHORN 1/4 0 and.0. Kthorne- with j.oB - LTHORNj 1/4 2, where B (L) is the baryon (lepton) number. While no signal is observed, the upper limits on the branching fractions of these two decays are set to Bo.0. K-ethornTHORN < 3.6 x 10- 6 and Bo.0. Kthorne- THORN < 1.9 x 10- 6 at the 90% confidence level, respectively. These results offer a direct probe of baryon number violating interactions involving a strange quark., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.108.012006

The upcoming Comet Interceptor mission involves a parking phase around the Sun-Earth L2 point before transferring to intercept the orbit of a long period comet, interstellar object or a back-up target in the form of a short-period comet. The target is not certain to be known before the launch in 2029. During the parking phase there may thus arise a scenario wherein a decision needs to be taken of whether to go for a particular comet or whether to discard that option in the hope that a better target will appear within a reasonable time frame later on. We present an expectation value-based formalism that could aid in the associated decision making provided that outlined requirements for its implementation exist.

The Gaia-ESO Survey is a public spectroscopic survey that targeted greater than or similar to 10(5) stars covering all major components of the Milky Way from the end of 2011 to 2018, delivering its final public release in May 2022. Unlike other spectroscopic surveys, Gaia-ESO is the only survey that observed stars across all spectral types with dedicated, specialised analyses: from O (T-eff similar to 30 000-52 000 K) all the way to K-M (greater than or similar to 3500 K). The physics throughout these stellar regimes varies significantly, which has previously prohibited any detailed comparisons between stars of significantly different types. In the final data release (internal data release 6) of the Gaia-ESO Survey, we provide the final database containing a large number of products, such as radial velocities, stellar parameters and elemental abundances, rotational velocity, and also, for example, activity and accretion indicators in young stars and membership probability in star clusters for more than 114 000 stars. The spectral analysis is coordinated by a number of working groups (WGs) within the survey, each specialised in one or more of the various stellar samples. Common targets are analysed across WGs to allow for comparisons (and calibrations) amongst instrumental setups and spectral types. Here we describe the procedures employed to ensure all survey results are placed on a common scale in order to arrive at a single set of recommended results for use by all survey collaborators. We also present some general quality and consistency checks performed on the entirety of the survey results.

Based on e+e- collision data corresponding to an integrated luminosity of 4.5 fb-1 collected at the center-of-mass energies between 4.600 and 4.699 GeV with the BESIII detector at BEPCII, the absolute branching fraction of the inclusive decay over bar ? - c & RARR; n over bar + X, where X refers to any possible final state particles, is measured. The absolute branching fraction is determined to be B( over bar ?-c & RARR; n over bar + X) = (32.4 + 0.7 + 1.5)%, where the first uncertainty is statistical and the second systematic. Assuming CP symmetry, the measurement indicates that about one fourth of ?+ c ( over bar ?-c) decay modes with a neutron (an antineutron) in the final state have not been observed., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.108.L031101

Using data corresponding to an integrated luminosity of 651 pb-1 accumulated at 22 center-of-mass energies from 2.00 to 3.08 GeV by the BESIII experiment, the process e+e- & RARR; 0ic+ic- is studied. The cross sections for e+e- & RARR; 0ic+ic- are consistent with previous results, but with improved precision. To measure the mass and width of the structure observed in the cross section line shape, a combine fit is performed after enhancing the contribution from 0f0(980). The fit reveals a structure with the mass of M = 2178 +20 +5 MeV=c2 and the width of & UGamma; = 140 +36 +16 MeV, where the first uncertainties are statistical and the second ones are systematic., For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.108.032011

Context. The motion of stars has been used to reveal details of the complex history of the Milky Way, in constant interaction with its environment. Nevertheless, to reconstruct the Galactic history puzzle in its entirety, the chemo-physical characterisation of stars is essential. Previous Gaia data releases were supported by a smaller, heterogeneous, and spatially biased mixture of chemical data from ground-based observations. Aims. Gaia Data Release 3 opens a new era of all-sky spectral analysis of stellar populations thanks to the nearly 5.6 million stars observed by the Radial Velocity Spectrometer (RVS) and parametrised by the GSP-Spec module. In this work, we aim to demonstrate the scientific quality of Gaia's Milky Way chemical cartography through a chemo-dynamical analysis of disc and halo populations. Methods. Stellar atmospheric parameters and chemical abundances provided by Gaia DR3 spectroscopy are combined with DR3 radial velocities and EDR3 astrometry to analyse the relationships between chemistry and Milky Way structure, stellar kinematics, and orbital parameters. Results. The all-sky Gaia chemical cartography allows a powerful and precise chemo-dynamical view of the Milky Way with unprecedented spatial coverage and statistical robustness. First, it reveals the strong vertical symmetry of the Galaxy and the flared structure of the disc. Second, the observed kinematic disturbances of the disc - seen as phase space correlations - and kinematic or orbital substructures are associated with chemical patterns that favour stars with enhanced metallicities and lower [alpha/Fe] abundance ratios compared to the median values in the radial distributions. This is detected both for young objects that trace the spiral arms and older populations. Several alpha, iron-peak elements and at least one heavy element trace the thin and thick disc properties in the solar cylinder. Third, young disc stars show a recent chemical impoverishment in several elements. Fourth, the, For complete list of authors see http://dx.doi.org/10.1051/0004-6361/202243511

The IceCube Neutrino Observatory sends realtime neutrino alerts with a high probability of being astrophysical in origin. We present a new method to correlate these events and possible candidate sources using 2089 blazars from the Fermi-LAT 4LAC-DR2 catalog and with 3413 active galactic nuclei (AGNs) from the Radio Fundamental Catalog. No statistically significant neutrino emission was found in any of the catalog searches. The result suggests that a small fraction, <1%, of the studied AGNs emit neutrinos that pass the alert criteria, and is compatible with prior evidence for neutrino emission presented by IceCube and other authors from sources such as TXS 0506 + 056 and PKS 1502 + 106. We also present cross-checks to other analyses that claim a significant correlation using similar data samples., For complete list of authors see http://dx.doi.org/10.3847/1538-4357/acdfcb

We present Magnetospheric Multiscale (MMS) observations of a K-H wave event under southward IMF conditions, accompanied by ongoing magnetic reconnection. The nonlinear K-H waves are characterized by quasi-periodic fluctuations, the presence of low-density and high-speed ions, and variations in the boundary normal vectors at both the leading and trailing edges. Our observations reveal clear evidence of on-going magnetic reconnection through the identification of Alfvenic ion jets and the escape of energetic magnetospheric electrons. Among the 36 magnetopause current-sheet crossings in this event, 19 exhibit unambiguous signatures of reconnection at both the leading (7) and trailing (12) edges. Notably, the estimated current-sheet thicknesses at both edges are comparable to the ion-inertial scale, confirming the compression effect resulting from the large-scale evolution of the K-H waves. The reconnection jets potentially contribute to the suppression of K-H growth through boundary-layer broadening and the development of complex flow and magnetic field patterns.

ESA's Jupiter Icy Moons Explorer (JUICE) will provide a detailed investigation of the Jovian system in the 2030s, combining a suite of state-of-the-art instruments with an orbital tour tailored to maximise observing opportunities. We review the Jupiter science enabled by the JUICE mission, building on the legacy of discoveries from the Galileo, Cassini, and Juno missions, alongside ground- and space-based observatories. We focus on remote sensing of the climate, meteorology, and chemistry of the atmosphere and auroras from the cloud-forming weather layer, through the upper troposphere, into the stratosphere and ionosphere. The Jupiter orbital tour provides a wealth of opportunities for atmospheric and auroral science: global perspectives with its near-equatorial and inclined phases, sampling all phase angles from dayside to nightside, and investigating phenomena evolving on timescales from minutes to months. The remote sensing payload spans far-UV spectroscopy (50-210 nm), visible imaging (340-1080 nm), visible/near-infrared spectroscopy (0.49-5.56 & mu;m), and sub-millimetre sounding (near 530-625 GHz and 1067-1275 GHz). This is coupled to radio, stellar, and solar occultation opportunities to explore the atmosphere at high vertical resolution; and radio and plasma wave measurements of electric discharges in the Jovian atmosphere and auroras. Cross-disciplinary scientific investigations enable JUICE to explore coupling processes in giant planet atmospheres, to show how the atmosphere is connected to (i) the deep circulation and composition of the hydrogen-dominated interior; and (ii) to the currents and charged particle environments of the external magnetosphere. JUICE will provide a comprehensive characterisation of the atmosphere and auroras of this archetypal giant planet.

Context. We present the third data release of the European Space Agency's Gaia mission, Gaia DR3. This release includes a large variety of new data products, notably a much expanded radial velocity survey and a very extensive astrophysical characterisation of Gaia sources. Aims. We outline the content and the properties of Gaia DR3, providing an overview of the main improvements in the data processing in comparison with previous data releases (where applicable) and a brief discussion of the limitations of the data in this release. Methods. The Gaia DR3 catalogue is the outcome of the processing of raw data collected with the Gaia instruments during the first 34 months of the mission by the Gaia Data Processing and Analysis Consortium. Results. The Gaia DR3 catalogue contains the same source list, celestial positions, proper motions, parallaxes, and broad band photometry in the G, GBP, and G(RP) pass-bands already present in the Early Third Data Release, Gaia EDR3. Gaia DR3 introduces an impressive wealth of new data products. More than 33 million objects in the ranges G(RVS) < 14 and 3100 < T-eff < 14 500, have new determinations of their mean radial velocities based on data collected by Gaia. We provide GRVS magnitudes for most sources with radial velocities, and a line broadening parameter is listed for a subset of these. Mean Gaia spectra are made available to the community. The Gaia DR3 catalogue includes about 1 million mean spectra from the radial velocity spectrometer, and about 220 million low-resolution blue and red prism photometer BP /RP mean spectra. The results of the analysis of epoch photometry are provided for some 10 million sources across 24 variability types. Gaia DR3 includes astrophysical parameters and source class probabilities for about 470 million and 1500 million sources, respectively, including stars, galaxies, and quasars. Orbital elements and trend parameters are provided for some 800 000 astrometric, spectroscopic and eclipsing, For complete list of authors see http://dx.doi.org/10.1051/0004-6361/202243940

GJ 367 is a bright (V approximate to 10.2) M1 V star that has been recently found to host a transiting ultra-short period subEarth on a 7.7 hr orbit. With the aim of improving the planetary mass and radius and unveiling the inner architecture of the system, we performed an intensive radial velocity follow-up campaign with the HARPS spectrograph-collecting 371 high-precision measurements over a baseline of nearly 3 yr-and combined our Doppler measurements with new TESS observations from sectors 35 and 36. We found that GJ 367 b has a mass of M-b = 0.633 +/- 0.050M. and a radius of R-b = 0.699 +/- 0.024 R-circle plus, corresponding to precisions of 8% and 3.4%, respectively. This implies a planetary bulk density of rho(b) = 10.2 +/- 1.3 g cm(-3), i.e., 85% higher than Earth's density. We revealed the presence of two additional non-transiting low-mass companions with orbital periods of similar to 11.5 and 34 days and minimum masses of M-c sin i(c) = 4.13 +/- 0.36 M-circle plus and M-d sin i(d) = 6.03 +/- 0.49M(circle plus), respectively, which lie close to the 3:1 mean motion commensurability. GJ 367 b joins the small class of highdensity planets, namely the class of super-Mercuries, being the densest ultra-short period small planet known to date. Thanks to our precise mass and radius estimates, we explored the potential internal composition and structure of GJ 367 b, and found that it is expected to have an iron core with a mass fraction of 0.91(-0.23)(+0.07). How this iron core is formed and how such a high density is reached is still not clear, and we discuss the possible pathways of formation of such a small ultra-dense planet.

This paper presents a search for a new Z' vector gauge boson with the ATLAS experiment at the Large Hadron Collider using pp collision data collected at root s = 13TeV, corresponding to an integrated luminosity of 139 fb(-1). The new gauge boson Z' is predicted by L-mu - L-tau models to address observed phenomena that can not be explained by the Standard Model. The search examines the four-muon (4 mu) final state, using a deep learning neural network classifier to separate the Z' signal from the Standard Model background events. The di-muon invariant masses in the 4 mu events are used to extract the Z' resonance signature. No significant excess of events is observed over the predicted background. Upper limits at a 95% confidence level on the Z' production cross-section times the decay branching fraction of pp -> Z' mu mu -> 4 mu are set from 0.31 to 4.3 fb for the Z' mass ranging from 5 to 81 GeV. The corresponding common coupling strengths, g(Z'), of the Z' boson to the second and third generation leptons above 0.003 - 0.2 have been excluded., For complete list of authors see http://dx.doi.org/10.1007/JHEP07(2023)090

We report a search for a dark photon using 14.9 fb(-1) of e(+)e(-) annihilation data taken at center-of-mass energies from 4.13 to 4.60 GeV with the BESIII detector operated at the BEPCII storage ring. The dark photon is assumed to be produced in the radiative annihilation process of e(+)e(-) and to predominantly decay into light dark matter particles, which escape from the detector undetected. The mass range from 1.5 to 2.9 GeV is scanned for the dark photon candidate, and no significant signal is observed. The mass dependent upper limits at the 90% confidence level on the coupling strength parameter epsilon for a dark photon coupling with an ordinary photon vary between 1.6 x 10(-3) and 5.7 x 10(-3)., For complete list of authors see http://dx.doi.org/10.1016/j.physletb.2023.137785

Gamma-ray bursts (GRBs) have long been considered a possible source of high-energy neutrinos. While no correlations have yet been detected between high-energy neutrinos and GRBs, the recent observation of GRB 221009A-the brightest GRB observed by Fermi-GBM to date and the first one to be observed above an energy of 10 TeV-provides a unique opportunity to test for hadronic emission. In this paper, we leverage the wide energy range of the IceCube Neutrino Observatory to search for neutrinos from GRB 221009A. We find no significant deviation from background expectation across event samples ranging from MeV to PeV energies, placing stringent upper limits on the neutrino emission from this source., For complete list of authors see http://dx.doi.org/10.3847/2041-8213/acc077

Context. The third Gaia data release (Gaia DR3) contains, beyond the astrometry and photometry, dispersed light for hundreds of millions of sources from the Gaia prism spectra (BP and RP) and the spectrograph (RVS). This data release opens a new window on the chemo-dynamical properties of stars in our Galaxy, essential knowledge for understanding the structure, formation, and evolution of the Milky Way. Aims. To provide insight into the physical properties of Milky Way stars, we used these data to produce a uniformly derived all-sky catalogue of stellar astrophysical parameters: atmospheric properties (T-e ff, log g, [M /H], [alpha/Fe], activity index, emission lines, and rotation), 13 chemical abundance estimates, evolution characteristics (radius, age, mass, and bolometric luminosity), distance, and dust extinction. Methods. We developed the astrophysical parameter inference system (Apsis) pipeline to infer astrophysical parameters of Gaia objects by analysing their astrometry, photometry, BP /RP, and RVS spectra. We validate our results against those from other works in the literature, including benchmark stars, interferometry, and asteroseismology. Here we assess the stellar analysis performance from Apsis statistically. Results. We describe the quantities we obtained, including the underlying assumptions and the limitations of our results. We provide guidance and identify regimes in which our parameters should and should not be used. Conclusions. Despite some limitations, this is the most extensive catalogue of uniformly inferred stellar parameters to date. They comprise T-eff, log g, and [M/H] (470 million using BP/RP, 6 million using RVS), radius (470 million), mass (140 million), age (120 million), chemical abundances (5 million), di ffuse interstellar band analysis (half a million), activity indices (2 million), H ff equivalent widths (200 million), and further classifications of spectral types (220 million) and emission-line stars (50 thousand). More preci

In 2021 July, PKS 1510-089 exhibited a significant flux drop in the high-energy & gamma;-ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state throughout 2022. Similarly, the optical polarization in the source vanished, resulting in the optical spectrum being fully explained through the steady flux of the accretion disk and the broad-line region. Unlike the aforementioned bands, the very-high-energy & gamma;-ray and X-ray fluxes did not exhibit a significant flux drop from year to year. This suggests that the steady-state very-high-energy & gamma;-ray and X-ray fluxes originate from a different emission region than the vanished parts of the high-energy & gamma;-ray and optical jet fluxes. The latter component has disappeared through either a swing of the jet away from the line of sight or a significant drop in the photon production efficiency of the jet close to the black hole. Either change could become visible in high-resolution radio images.

Magnetic fields in galaxies and galaxy clusters are believed to be the result of the amplification of intergalactic seed fields during the formation of large-scale structures in the universe. However, the origin, strength, and morphology of this intergalactic magnetic field (IGMF) remain unknown. Lower limits on (or indirect detection of) the IGMF can be obtained from observations of high-energy gamma rays from distant blazars. Gamma rays interact with the extragalactic background light to produce electron-positron pairs, which can subsequently initiate electromagnetic cascades. The gamma-ray signature of the cascade depends on the IGMF since it deflects the pairs. Here we report on a new search for this cascade emission using a combined data set from the Fermi Large Area Telescope and the High Energy Stereoscopic System. Using state-of-the-art Monte Carlo predictions for the cascade signal, our results place a lower limit on the IGMF of B > 7.1 x 10(-16) G for a coherence length of 1 Mpc even when blazar duty cycles as short as 10 yr are assumed. This improves on previous lower limits by a factor of 2. For longer duty cycles of 10(4) (10(7)) yr, IGMF strengths below 1.8 x 10(-14) G (3.9 x 10(-14) G) are excluded, which rules out specific models for IGMF generation in the early universe.

The generation of kinetic-scale flux ropes (KSFRs) is closely related to magnetic reconnection. Both flux ropes and reconnection sites are detected in the magnetosheath and can impact the dynamics upstream of the magnetopause. In this study, using the Magnetospheric Multiscale satellite, 12,623 KSFRs with a scale <20 RCi are statistically studied in the Earth's dayside magnetosheath. It is found that they are mostly generated near the bow shock (BS), and propagate downstream in the magnetosheath. Their quantity significantly increases as the scale decreases, consistent with a flux rope coalescence model. Moreover, the solar wind parameters can control the occurrence rate of KSFRs. They are more easily generated at high Mach number, large proton density, and weak magnetic field strength of the solar wind, similar to the conditions that favor BS reconnection. Our study shows a close connection between KSFR generation and BS reconnection.

We examine the origin of electrons in a weakly outgassing comet, using Rosetta mission data and a 3D collisional model of electrons at a comet. We have calculated a new data set of electron-impact ionization (EII) frequency throughout the Rosetta escort phase, with measurements of the Rosetta Plasma Consortium's Ion and Electron Sensor (RPC/IES). The EII frequency is evaluated in 15-min intervals and compared to other Rosetta data sets. EII is the dominant source of electrons at 67P away from perihelion and is highly variable (by up to three orders of magnitude). Around perihelion, EII is much less variable and less efficient than photoionization at Rosetta. Several drivers of the EII frequency are identified, including magnetic field strength and the outgassing rate. Energetic electrons are correlated to the Rosetta-upstream solar wind potential difference, confirming that the ionizing electrons are solar wind electrons accelerated by an ambipolar field. The collisional test particle model incorporates a spherically symmetric, pure water coma and all the relevant electron-neutral collision processes. Electric and magnetic fields are stationary model inputs, and are computed using a fully kinetic, collision-less Particle-in-Cell simulation. Collisional electrons are modelled at outgassing rates of Q = 1026 s-1 and Q = 1.5 × 1027 s-1. Secondary electrons are the dominant population within a weakly outgassing comet. These are produced by collisions of solar wind electrons with the neutral coma. The implications of large ion flow speed estimates at Rosetta, away from perihelion, are discussed in relation to multi-instrument studies and the new results of the EII frequency obtained in this study.

We apply a recently proposed method to estimate heavy ion escape from Mars. The method combines in situ observations with a hybrid plasma model, which treats ions as particles and electrons as a fluid. With this method, we investigate how solar upstream conditions, including solar extreme ultraviolet (EUV) radiation, solar wind dynamic pressure, and interplanetary magnetic field (IMF) strength and cone angle, affect the heavy ion loss. The results indicate that the heavy ion escape rate is greater in high EUV conditions. The escape rate increases with increasing solar wind dynamic pressure, and decreases as the IMF strength increases. The ion escape rate is highest when the solar wind is parallel to the IMF and lowest when they are perpendicular. The plume escape rate decreases when the solar wind convective electric field increases.