Leiden Observatory

Results from the Juno investigation of Jupiter have challenged our understanding of Jupiter origin and evolution. As the archetype of giant planets, the study of Jupiter provides knowledge needed to understand the origin of our own solar system and the planetary systems being discovered around other stars. Jupiter uniquely informs us about the origin of our own planetary system. The mass of Jupiter’s heavy element core and the abundance of heavy elements in the atmosphere discriminate among models for giant planet formation. Measurements by Juno of Jupiter’s gravity field suggest Jupiter’s core is diffuse, extended and contains compositional gradients. These new results require new models of Jupiter’s formation and evolution. The gravity science results on the measurement of J4 coupled to current estimates on the hydrogen and helium equation of state suggests Jupiter’s interior composition has low metallicity, potentially solar or even sub-solar. This is inconsistent with measurements of the atmosphere by both Juno and the Galileo probe which indicate the atmospheric composition is of higher metallicity (2-4x solar).The combined results from Juno provide new constraints on theories of Jupiter’s formation and evolution and giant planets in general. A summary of Juno’s results relevant to Jupiter’s formation and evolution will be presented along with a discussion of theoretical implications on Jupiter, and giant planets both within our solar system and beyond.

Abstract The X-ray source around supermassive black holes in active galactic nuclei (AGN) has been dubbed the corona by analogy to the solar (and stellar) corona. Both stellar and AGN coronae are orders of magnitude hotter than their counterpart optical source; the stellar photosphere and accretion disk respectively. Both coronae vary on short time scales down to seconds. The coronal activity in the Sun is well imaged and its activity has been shown to be driven by magnetic energy converted into heat through the process of magnetic reconnection. While it has been theorized that AGN corona are also magnetically driven, the driving mechanism of AGN coronal activity has not been directly observed. A smoking gun of magnetic reconnection is when a coronal flare’s temporal evolution in hard and soft X-rays follows the Neupert Effect. These flares result in both a solar coronal mass ejection, and energetic particles streaming down along magnetic field lines to the photosphere. Here, we report the detection of the Neupert Effect in an AGN corona, providing the first direct evidence for magnetic reconnection in AGN. Our measurements indicate a magnetic field loop height of up to 30 gravitational radii, and a distance of about 400 gravitational radii between the corona and the UV emitting accretion disk. The present findings thus enable the application of solar coronal physics to the less accessible AGN corona.

Glycolamide, a precursor to amino acids, is synthesized efficiently at cryogenic temperatures on interstellar nanoparticles through radical coupling mechanisms.

Abstract Black hole-created radio jets frequently interact violently with their host galaxies at z > 2, creating stars. Coma A (3C277.3) is one of few luminous low-redshift radio sources where jet-galaxy interactions deflect the jet and induce star formation - a nearby laboratory of massive galaxy formation. We present the first LOFAR VLBI radio image of Coma A and compare it with VLT/MUSE optical images and Chandra X-ray maps. Remarkable features of the radio emission are clumpiness, multiple filaments and the relation of the radio to the optical and X-ray morphologies. The optical continuum image shows a swarm of galaxies apparently merging with Coma A, similar to high-redshift radio protoclusters. Three optical clumps are probable remnants of a merging galaxy, fragmented by collision with the jet. We suggest that magnetic turbulence in Coma A-type radio-emitting clumps, could trigger radio jets in quiescent black holes and that positive feedback from radio jets could contribute to the structure of the high-redshift cosmic web. A prediction of such a scenario is that the morphologies of high-redshift extended radio sources are oriented preferentially along cosmic web filaments, with important implications for how the first supermassive black holes formed.

High-energy irradiation in X-rays and UV (XUV) can transform the planetary atmospheres through photoevaporation and photochemistry. This is more crucial for M stars, whose habitable zones for Earth-like planets are located within a few percent of an AU. Transiting exoplanets around M dwarfs offer the opportunity to study their characteristics and habitability conditions. L 98-59 is an M3 dwarf hosting six Earth-like planets, with two of them in the habitable zone of the star. X-ray observations made in 2020 and 2021 detected significant flares above a quiescent luminosity of 4-10 x 10^26 erg/s. We present the results from two short XMM-Newton observations of L 98-59, which are part of a monitoring survey to detect long-term X-ray variability and activity cycles. In October 2024 the X-ray quiescent luminosity of the star was about 5.9 x 10^25 erg/s, and it was about 6.3 x 10^26 erg/s in February 2025. We speculate that in late 2024 the star had a minimum of activity; in 2021 the star was near a maximum of an activity cycle, and in 2025 it was at the middle of the cycle. We suggest a coarse estimate of the period of about 2 years and a peak-to-peak amplitude of about 10, which is the highest among the stars with a known X-ray cycle other than the Sun. We also infer that even the outer planet in the habitable zone, L 98-59f, is exposed to an X-ray dose between 100 and 1600 times the X-ray irradiation of the Earth in the XMM band.

Context. The large-scale environments of active galactic nuclei (AGNs) reveal important information on the growth and evolution of supermassive black holes (SMBHs). Previous AGN clustering measurements using two-point correlation functions have hinted that AGNs with massive black holes preferentially reside in denser cosmic regions than AGNs with less massive SMBHs. At the same time, little to no dependence on the accretion rate has been found; however, the significance of such trends has been limited. Aims. Here, we present k th-nearest-neighbor ( k NN) statistics of 2MASS galaxies around AGNs from the Swift/BAT AGN Spectroscopic survey. These statistics have been shown to contribute additional higher order clustering information on the cosmic density field. Methods. By calculating the distances to the nearest seven galaxy neighbors in angular separation to each AGN within two redshift ranges (0.01 < z < 0.03 and 0.03 < z < 0.06), we compared their cumulative distribution functions to that of a randomly distributed sample to demonstrate the sensitivity of this method to the clustering of AGNs. We also split the AGNs into bins of bolometric luminosity, black hole mass, and Eddington ratio (while controlling for redshift) to search for trends between k NN statistics and fundamental AGN properties. Results. We find that AGNs with massive SMBHs have significantly closer neighbors than AGNs with less massive SMBHs (at the 99.98% confidence level), especially in our lower redshift range. We find less significant trends with luminosity or Eddington ratio. By comparing our results to empirical SMBH-galaxy-halo models implemented in N-body simulations, we show that small-scale k NN trends with black hole mass may go beyond stellar mass dependencies. Conclusions. This suggests that massive SMBHs in the local universe reside in more massive dark matter halos and denser regions of the cosmic web, which may indicate that environment is important for the growth of SMBHs, bolstering prior conclusions based on correlation functions.

Abstract The hottest, most ionized, and fastest winds driven by accretion onto massive black holes have the potential to reshape their host galaxies. Calorimeter-resolution X-ray spectroscopy is the ideal tool to understand this feedback mode, as it enables accurate estimates of the physical characteristics needed to determine the wind’s kinetic power. We report on a photoionization analysis of five observations of the Seyfert 1.5 galaxy NGC 4151, obtained with XRISM/Resolve in 2023 and 2024. In the Fe K band, individual spectra require as many as six wind absorption components. Slow “warm absorbers” (WAs; v out ∼ 100–1000 km s−1), “very fast outflows” (VFOs; v out ∼ 103–104 km s−1), and “ultrafast outflows” (UFOs; v out ∼ 104–105 km s−1 or 0.033–0.33c) are detected simultaneously and indicate a stratified, multiphase wind. Fast and variable emission components suggest that the wind is axially asymmetric. All of the wind components have mass flow rates comparable to or in excess of the mass accretion rate, though the slowest zones may be “failed” winds that do not escape. Two UFO components have kinetic luminosities that exceed the theoretical threshold of L kin ≥ 0.5% L Edd necessary to strip the host bulge of gas and halt star formation, even after corrections for plausible filling factors. The bulk properties of the observed winds are consistent with magnetocentrifugal driving, where the density depends on the radius as n ∝ r −1.5, but radiative driving and other mechanisms may also be important. Numerous complexities and variability require further analysis.

Carbonyl sulfide (OCS) is currently the only securelydetectedsulfur-bearing species in interstellar ices, making it an ideal windowinto solid-state sulfur chemistry in dense star-forming regions. Previousastronomical observations of the OCS asymmetric stretching mode (ν3) at ∼2040 cm–1 (∼4.9 μm)demonstrate that interstellar OCS may be embedded in CH3OH-rich ices, indicating that OCS likely forms in the coldest, densestparts of star-forming regions where catastrophic CO freezeout occurs.However, a significant portion of the OCS ice observations cannotbe fit with binary OCS:CH3OH laboratory ice mixtures alone,suggesting a greater degree of chemical complexity in the local iceenvironment. With this work, we aim to aid future studies of the abundance,physicochemical environment, and evolutionary history of interstellarOCS ice, now enabled for many more interstellar environments by the James Webb Space Telescope. We provide a library of newlaboratory IR transmission spectra of the tetrahedron of the OCS inCH3OH- and CO-rich ice mixtures, some of which also includeH2S and H2O. Of these new spectra, the tertiaryOCS:CO:CH3OH ice mixtures provide the best fits to observationsof high-mass protostars, providing further support for the hypothesisthat the atom of the OCS forms with CH3OH, possibly viachemical pathways involving frozen-out CO. We calculate apparent bandstrengths of the ν3 mode in the OCS:CH3OH and the OCS:CO:CH3OH ice mixtures. The derived valuesare consistent (within uncertainties) with the apparent band strengthof the feature in pure OCS ice, 1.2 × 10–16 cm molec–1. We therefore recommend using thisvalue when quantifying interstellar OCS ice column densities.

The evolution ofinterstellar ices can be studied withthermaltracers such as the vibrational modes of CO2 ice that showgreat diversity depending on their local chemical and thermal environment.Now with the wide spectral coverage and sensitivity of the James WebbSpace Telescope we can obtain observations of the weak and strongCO2 absorption features inhabiting the near- and mid-infraredspectral region. In this work we present observations of the 15.2μm bending mode, the 4.39 μm stretching mode and the 2.70μm combination mode of 12CO2 and 13CO2 ice in the high-mass protostar IRAS 20126and the low-mass protostar Per-emb 35, two sources that show clearsigns of ice heating. The 15.2 μm bending mode of both protostarsshows the characteristic double peak profile that is associated withpure CO2 ice and a sharp short-wavelength peak is observedat 4.38 μm in the 13CO2 bands of the twosources. Furthermore, a narrow short-wavelength feature is detectedat 2.69 μm in the 12CO2 combination modeof Per-emb 35. We perform a consistent profile decomposition on allthree vibrational modes and show that the profiles of all three bandscan be reproduced with the same linear combination of CO2 ice in mixtures with mostly CH3OH and H2Oices when the ices undergo segregation due to heating. The findingsshow that upon heating, CO2 ice is likely segregating frommostly the water-rich ice layer and the CO2–CH3OH component becomes dominant in all three vibrational modes.Additionally, we find that the contribution of the different CO2 components with respect to the total absorption band is similarfor both 12CO2 and 13CO2. This indicates that fractionation processes must not play a significantrole during the different formation epochs, H2O-dominatedand CO-dominated, of the CO2 ices and that the ratio persiststhrough the heating stage. We quantify the 12CO2 and 13CO2 ice column densities and derive 12C/13Cice = 90 ±9 in IRAS 20126, a value that is lower compared to what was previouslyreported for warm gaseous CO in this source. Finally, we report thedetection of the 13CO2 bending mode of pureCO2 ice at 15.64 μm in both IRAS 20126 and Per-emb35.

The Sun was born in a clustered environment with 10,000 other stars. Being an isolated star today, the Sun must have left the nest. We do not directly know when that happened, how violent the ejection was, or how far the Solar siblings have drifted apart. The mass of the fragile outer Opic-Oort cloud, (between $r_{\rm inner} \sim 30,000$\,au and $200\,000$au from the Sun) and the orbital distribution of planetesimals in the inner Hills-Oort cloud (between $\sim 1000$\,au and $\sim 30\,000$ au) are sensitive to the dynamical processes involving the Sun in the parent cluster. We aim at understanding the extend to which observing the Oort cloud constrains the Sun's birth environment. This is achieved by a combination of theoretical arguments and N-body simulations. We show that the current mass of the Opic-Oort cloud (between 0.2 and $2.0$ Earth masses) is best explained if the Sun left the nest within $\sim 20$\,Myr after the giant planets formed and migrated. As a consequence, the possible dynamical encounter with another star carving the Kuiper belt, the Sun's abduction of Sedna, and other perturbations induced by nearby stars then must have happened shortly after the giant planets in the Solar system formed, but before the Sun left the parent cluster. Signatures of the time spend in the parent cluster must still be visible in the outer parts of the Solar system today. The strongest constraints will be the discovery of a population of relatively low-eccentricity ($e < 0.9$) inner Oort-cloud (but $500 < a < 10^4$\,au) objects.