Cosmology and Nongalactic Astrophysics
From the Solar System to cosmological distances: a complete formalism for gravitational wave astrometry
Gabriele Perna, Nicola Bellomo, Vincenzo Roatti et al. (+1 more)
The presence of a gravitational wave background (GWB) can be established not only via exquisitely precise
pulsar timing array (PTA) measurements, but also via astrometric observations. Indeed, the very same background responsible for the delay in the arrival time of pulse causes an apparent displacement of
galactic objects as
stars and asteroids. In this work we provide a framework that allows to derive the displacement of sources overcoming the usually adopted “infinite distance” approximation. We also present how this formalism can be used to study the displacements of objects at distances comparable to the GW wavelength, as asteroids, and of objects with a non-trivial three-dimensional distribution, as
stars in the Milky Way. Thus, it can be used to probe frequencies beyond PTA experiments, reaching the mHz GWs, also detectable by LISA. We forecast the capability of observing the astrometric deflection induced by a GWB evaluating the harmonic signal-to-noise ratio including correlations between different probes. We find an SNR greater than one for the relevant cases considered and as a consequence a promising Fisher forecast, suggesting a constraining power up to the percent level for a flat background.
Read the full abstract ▾
All authors Gabriele Perna, Nicola Bellomo, Vincenzo Roatti, Daniele Bertacca
Astrophysics of Galaxies
NGC 3521 as the Milky Way near twin: spectral energy distribution from UV to radio decameter ranges
O.V. Kompaniiets, I.B. Vavilova, Y.V. Vasylkivskyi et al. (+10 more)
Milky Way analogues (MWAs) are usually selected from structural and kinematic properties, but robust SED-based similarity criteria are limited by heterogeneous photometry and incomplete wavelength coverage. We present a homogeneous, aperture-photometry SED of the Milky Way near-twin NGC~3521 from the ultraviolet to the
radio decameter range. Fluxes are measured within a fixed elliptical isophotal aperture using GALEX, SDSS, WISE, Spitzer/MIPS, Herschel/PACS+SPIRE, and VLA data, and supplemented by meter/decameter constraints. We report new observations obtained in Jan-Feb 2022 with the Ukrainian T-shape
radio telescope and derive, for the first time, an upper limit in the 24–32~MHz band. The UV-to-decameter SED (27 points) is modelled with CIGALE, including a dedicated low-frequency
radio prescription (
radio_extra) that accounts for emission and absorption effects. Using ZTF and NEOWISE data (2014–2025), we detect genuine
nuclear variability; optical trends at $\sim2^{\prime\prime}$ primarily trace the compact
nucleus, while NEOWISE variability reflects a mix of
nuclear changes and warm-
dust emission within the larger aperture. The preferred fit yields $M_\star \simeq 6.0\times10^{10},M_\odot$, ${\rm SFR}\simeq1.65,M_\odot,{\rm yr}^{-1}$, $M_{\rm dust}\simeq1.3\times10^{8},M_\odot$, and an effective
dust temperature of $\sim23$~K. The decameter constraint gives $S_{28,{\rm MHz}}<11.22$~Jy, consistent with expectations for a Milky Way-like system placed at 10.7~Mpc. We conclude that an integrated, homogeneous SED, especially below 100~MHz, provides a complementary diagnostic for identifying and validating MWAs and for interpreting how Milky Way properties would appear to an external observer.
Read the full abstract ▾
All authors O.V. Kompaniiets, I.B. Vavilova, Y.V. Vasylkivskyi, O.O. Konovalenko, O.S.Pastoven, I.O. Izviekova, Junais, A.M. Dmytrenko, D.V. Dobrycheva, P.N. Fedorov, V.P. Khramtsov, O. Sergijenko, A.A. Vasylenko
Astrophysics of Galaxies · Cross-listed from gr-qc
Search for Gravitational Wave Memory in PPTA and EPTA Data: A Complete Signal Model
Sharon Mary Tomson, Boris Goncharov, Rutger van Haasteren et al. (+21 more)
We perform searches for gravitational wave
memory in the data of two major
Pulsar Timing Array (PTA) experiments located in Europe and Australia. Supermassive black hole binaries (SMBHBs) are the primary sources of gravitational waves in PTA experiments. We develop and carry out the first search for late inspirals and mergers of these sources based on full numerical relativity waveforms with null (nonlinear) gravitational wave
memory. Additionally, we search for generic bursts of null gravitational wave
memory, exploring possibilities of reducing the computational cost of these searches through kernel density and normalizing flow approximation of the posteriors. We rule out the mergers of SMBHBs with a chirp mass of 10^10
Solar Mass up to 700 Mpc over 18 years of observation at 95% credibility. We rule out the observation of generic displacement
memory bursts with strain amplitudes > 10^-14 in brief periods of the observation time but across the sky, or over the whole observation time but for certain preferred sky positions, at 95%$credibility.
Read the full abstract ▾
All authors Sharon Mary Tomson, Boris Goncharov, Rutger van Haasteren, Rahul Srinivasan, Enrico Barausse, Yirong Wen, Jingbo Wang, John Antoniadis, N. D. Ramesh Bhat, Zu-Cheng Chen, Ismael Cognard, Valentina Di Marco, Huanchen Hu, Gemma H. Janssen, Michael Kramer, Wenhua Ling, Kuo Liu, Saurav Mishra, Delphine Perrodin, Andrea Possenti, Christopher J. Russell, Ryan M. Shannon, Gilles Theureau, Shuangqiang Wang
Cosmology and Nongalactic Astrophysics · Cross-listed from gr-qc
Stochastic Inflation in Numerical Relativity
Yoann L. Launay, Gerasimos I. Rigopoulos and E. Paul S. Shellard
A set of 3+1 equations for
stochastic inflation incorporating all metric and scalar matter degrees of freedom, first presented in previous work, are re-derived in a gauge invariant manner. We then present numerical implementations of these
stochastic equations, cast in the BSSN formulation of Numerical Relativity, demonstrating their efficacy in both a slow-roll and an ultra slow-roll scenario. We find the
evolution is correctly reproduced for all the dynamical variables, and the energy and momentum constraints are well-satisfied. This demonstrates that the
stochastic equations are theoretically and numerically robust and ready to be applied to a wider inflationary landscape. Our simulations result in real space realizations of the fully non-linear
stochastic dynamics with \new{gradients and anisotropic expansion retained. This work generalizes standard
stochastic inflation, inflationary numerical relativity and
lattice cosmology, opening up the possibility for reliable predictions of non-perturbative phenomena and providing} precise initial conditions for subsequent cosmological eras.
Read the full abstract ▾
Astrophysics of Galaxies
Radio emission in star-forming galaxies: connection to restarted or relic AGN activity
Marco Albán, Dominika Wylezalek, Pranav Kukreti et al. (+2 more)
Increasing evidence shows that AGN with
radio detections have more perturbed ionized gas kinematics and higher
outflow detection rates, suggesting a link between
radio emission and these processes. In
galaxies with weak or ambiguous AGN signatures, some studies attribute the
radio emission to
star formation, while others propose AGN-driven winds or weak, unresolved jets as the dominant mechanism. To investigate this connection, we take a step back and analyze a sample of
star-forming (SF)
galaxies with no clear current AGN signatures. Using low-(LOFAR, 144MHz) and high-frequency (FIRST, 1.4GHz) surveys, combined with spatially resolved spectroscopy from the MaNGA survey, we compare SF
galaxies with 144 MHz detections that either do or do not have GHz detections. Despite being matched in
stellar mass,
redshift, and
radio (MHz) luminosity, GHz-detected SF
galaxies systematically differ from their non-GHz-detected counterparts. The former display enhanced ionized gas-emission line widths, higher central
outflow fractions, redder colors, increased central obscuration, and offset emission-line ratios that shift towards (or closer to) the AGN regime (in the [NII] BPT diagram). Furthermore, the non-GHz
galaxies are likely undetected due to their extended
radio morphologies, while the GHz-detected ones are significantly more
radio compact. Most of the properties from the GHz-detected (compared to non-detected) remarkably resemble the behavior found in many studies of
radio-detected AGNs. This suggests that the underlying physical mechanisms shaping GHz-detected SF
galaxies properties are fundamentally similar. This raises intriguing questions about whether some compact SF
galaxies represent a precursor phase of AGN
evolution or a form of low-power AGN. The
radio compact characteristic sizes of GHz-detected SF
galaxies also suggest a connection between AGN and old starburst
galaxies.
Read the full abstract ▾
All authors Marco Albán, Dominika Wylezalek, Pranav Kukreti, Rogemar A. Riffel, Rogerio Riffel
Instrumentation and Methods for Astrophysics
Attention-Based Preprocessing Framework for Improving Rare Transient Classification
Xinyue Sheng, Tuan Dung Pham, Zichi Zhang et al. (+2 more)
With large numbers of transients discovered by current and future imaging surveys, machine learning is increasingly applied to light curve and host
galaxy properties to select events for follow-up. However, finding rare types of transients remains difficult due to extreme class imbalances in training sets, and extracting features from host images is complicated by the presence of bright foreground sources, particularly if the true host is faint or distant. Here we present a data augmentation pipeline for images and light curves that mitigates these issues, and apply this to improve classification of Superluminous
Supernovae Type I (SLSNe-I) and
Tidal Disruption Events (TDEs) with our existing NEEDLE code. The method uses a Similarity Index to remove image artefacts, and a masking procedure that removes unrelated sources while preserving the transient and its host. This focuses classifier
attention on the relevant pixels, and enables arbitrary rotations for class upsampling. We also fit observed multi-band light curves with a two-dimensional Gaussian Process and generate data-driven synthetic samples by resampling and redshifting these models, cross-matching with
galaxy images in the same class to produce unique but realistic new examples for training. Models trained with the augmented
dataset achieve substantially higher purity: for classifications with a confidence of 0.8 or higher, we achieve 75% (43%) purity and 75% (66%) completeness for SLSNe-I (TDEs).
Read the full abstract ▾
All authors Xinyue Sheng, Tuan Dung Pham, Zichi Zhang, Matt Nicholl, Thai Son Mai
Astrophysics of Galaxies
Cluster properties as a function of dynamical state in the DESI Legacy x UNIONS surveys
Syeda Lammim Ahad, Rashaad Reid, Charlie T. Mpetha et al. (+10 more)
We investigate how the dynamical state of
galaxy clusters influences their
galaxy populations and mass distributions. Using photometrically selected clusters from the DESI Legacy Imaging Survey cross-matched with the UNIONS
galaxy shear catalogue, we classify clusters as evolved or evolving based on their rest-frame r-band magnitude gaps and
stellar mass ratios between the brightest cluster
galaxies (BCGs) and bright satellites. We measure the
stellar mass functions, weak-
lensing profiles, and radial number density and red-fraction profiles of stacked clusters in both subsamples. Evolved clusters exhibit more concentrated
lensing profiles, bimodal
stellar mass functions dominated by massive BCGs, and a deficit of intermediate-mass satellites, while evolving clusters show flatter central
lensing signals and an excess of massive satellites. Applying the same selection to IllustrisTNG clusters reproduces these trends and links the observed differences to distinct mass
accretion histories. These results demonstrate the close link between cluster
galaxy populations and the overall dynamical state of their underlying dark matter
halo.
Read the full abstract ▾
All authors Syeda Lammim Ahad, Rashaad Reid, Charlie T. Mpetha, James E. Taylor, Hendrik Hildebrandt, Michael J. Hudson, Kenneth C. Chambers, Thomas de Boer, Sacha Guerrini, Axel Guinot, Stephen Gwyn, Martin Kilbinger, Ludovic Van Waerbeke
Cosmology and Nongalactic Astrophysics
kSZ for everyone: the pseudo-Cl approach to stacking
Lea Harscouet, Kevin Wolz, Amy Wayland et al. (+2 more)
We present a harmonic-space
estimator for the cross-correlation between the kinematic Sunyaev-Zel'dovich effect and the reconstructed
galaxy momentum field that offers several practical advantages over the traditional stacking approach. The
estimator is easy to deploy using relatively modest computational resources and recovers all information available in the
galaxy-kSZ cross-correlation. In particular, by using well-understood power spectrum estimation techniques, its statistical uncertainties, including potential correlated uncertainties with other large-scale structure observables, can be easily and accurately estimated. Moreover, standard kSZ stacking measurements can be reconstructed exactly from the
estimator at a lower computational cost, employing harmonic-space, catalog-level techniques to recover all small-scale information.
Read the full abstract ▾
All authors Lea Harscouet, Kevin Wolz, Amy Wayland, David Alonso, Boryana Hadzhiyska
Instrumentation and Methods for Astrophysics
The Dynamics of the Milky Way: Unveiling the 6D Skeleton of Star Formation in the 2040s
Loredana Prisinzano, Germano G. Sacco, Francesco Damiani et al. (+5 more)
The Milky Way (MW) is our unique laboratory to test
star formation theories at the level of individual
stars, serving as the Rosetta Stone to interpret extragalactic observations. The proposed White Paper focuses on the following key questions regarding the structure and
evolution of the MW traced by young
stellar populations: Q1. How do large-scale dynamical instabilities, like warps and vertical waves, drive the
star formation of the
Galactic thin disk? Q2. Do
star-forming regions form stochastically, driven by local self-propagating feedback, or are they triggered by a common dynamical process acting on
Galactic scales? Do internal feedback loops and external interactions tend to sustain or quench
star formation in the MW? Q3. Are the clustered
star-forming regions the only environments where
stars form, or can
stars also form in more diffuse structures such as the
stellar strings?
Read the full abstract ▾
All authors Loredana Prisinzano, Germano G. Sacco, Francesco Damiani, Amelia Bayo, Salvatore Sciortino, Marco Tarantino, Rosaria Bonito, Fatemeh Zahra Majid
Astrophysics of Galaxies
The role of mergers and rejuvenation in the buildup of the quiescent population at cosmic noon
Jimi Evan Harrold, Omar Almaini, Frazer R. Pearce et al. (+6 more)
We investigate the quenching of
galaxies using a mock observational lightcone generated from the Semi-Analytic Model (SAM) L-
Galaxies, closely matched to observations from the UKIDSS Ultra Deep Survey (UDS). The sample is used to study merging, rejuvenation, and visibility times for
star-forming, quiescent, and post-starburst (PSB)
galaxies, to assess the impact on the build-up of the passive
galaxy mass functions. We find, for example, that a typical PSB ($M_\ast\sim10^{10}$\,M$_\odot$) at $z\approx1$ has a 15 per cent likelihood of merging and around a 25 per cent likelihood of rejuvenating within 1 Gyr of being identified. Applying these rates and timescales to the observational data, we estimate the fraction of quiescent
galaxies that passed through a PSB phase. We find that $18 - 28$ per cent of the build-up in the massive end ($M_\ast>10^{10}$\,M$\,_\odot$) of the passive mass function at $1<z<2$ can be explained by PSBs, with the contribution declining to $\sim5$ per cent by $z \simeq 0.5$. Accounting for mergers and rejuvenation reduces the inferred PSB contribution by approximately a factor of two. At lower
stellar masses ($M_\ast < 10^{10}$\,M$_\odot$), rapid quenching through a PSB phase explains a significantly larger fraction of the growth in the passive mass function. With a visibility time of $\sim$ 0.75 Gyr, we find that around $60-80$ per cent of low-mass passive
galaxies underwent a PSB phase. Our findings provide further evidence that low- and high-mass
galaxies follow different quenching pathways.
Read the full abstract ▾
All authors Jimi Evan Harrold, Omar Almaini, Frazer R. Pearce, Robert M. Yates, Dave Maltby, Kate Rowlands, Vivienne Wild, Maya Skarbinski, Thomas de Lisle
Solar and Stellar Astrophysics
Selection and characterisation of the M-dwarf targets in the PLATO Input Catalogue
L. Prisinzano, M. Montalto, G. Piotto et al. (+33 more)
The ESA's PLAnetary Transits and Oscillations of
Stars (PLATO) mission aims to detect
planets orbiting around
dwarfs and subgiant
stars with spectral type F5 or later, including M-
dwarfs. The PLATO Input Catalogue (PIC) contains all targets available for observation by the nominal science. The latest version, PIC2.1.0.1, focuses on the Southern PLATO field, named LOPS2, selected as the first long observation field, and includes the P4 sample, one of the four target samples outlined in the Science Requirement Document. P4 includes the M-
dwarfs with magnitudes V < 16 located within LOPS2. A characterisation of the M-
dwarfs in the PIC is essential for assessing their potentiality to host
exoplanets, and eventually estimate the hosted
planet(s) properties. The purpose of this paper is to describe how we selected the P4 M-
dwarf targets, and obtained their fundamental parameters and properties. In this work, we introduce the P4 sample and detail the methodologies adopted for the measurement of their
stellar parameters. Based on a statistical analysis of the P4 sample, we assess both the photometric and volume completeness, and classify the
stellar populations according to their
Galactic spatial-velocity components. The adopted
stellar parameters are validated by comparison with independent methods from the literature used to estimate
stellar radii. The P4 sample is compliant with the PLATO science requirements. Being magnitude limited, its volume completeness decreases going towards distances larger than 30 pc, where late-type targets are progressively less covered. The observed large spread in the colour-magnitude diagram is likely due to the combination of several effects such as
metallicity, age, binarity and activity. The strategy we adopted for deriving
stellar parameters provides results consistent with those obtained in the literature with different and independent methods.
Read the full abstract ▾
All authors L. Prisinzano, M. Montalto, G. Piotto, P. M. Marrese, S. Marinoni, V. Nascimbeni, V. Granata, J. Cabrera, K. Belkacem, M. Deleuil, L. Gizon, M. J. Goupil, I. Pagano, D. Pollacco, R. Ragazzoni, H. Rauer, S. Udry, J. Maldonado, G. Micela, F. Damiani, L. Affer, G. Altavilla, C. Argiroffi, S. Benatti, S. Cassisi, R. Claudi, S. Desidera, M. Fabrizio, E. Flaccomio, U. Heiter, A. F. Lanza, A. Maggio, L. Malavolta, D. Nardiello, S. Ortolani, A. Sozzetti
High Energy Astrophysical Phenomena
Probing hadronic interactions at the 100 TeV scale with the Pierre Auger Observatory
Eva dos Santos
Extensive air showers produced by the interaction of ultra-high-energy
cosmic rays ($E > 10^{18}$ eV) in the Earth's atmosphere provide a challenging yet unique channel to probe hadronic interactions at the 100 TeV center-of-mass energy scale. Over more than 20 years of operation, the Pierre Auger Observatory has delivered invaluable insights into the modeling of hadronic interactions at energies beyond human-made particle accelerators. Notably, predictions from current models of hadronic interactions yield a
muon deficit that becomes more pronounced with energy when compared to measurements. Presently, the interpretation of the
nuclear mass composition estimated from the
muon content is in tension with that from direct measurements of the depth of the maximum of electromagnetic profiles. Yet, the measured fluctuations of the
muon content of air showers are in agreement with model predictions. These findings hint at small deviations in hadronic models that accumulate throughout the whole shower development rather than at large errors in the calculation of the first hadronic interactions. Also, in an independent, data-driven analysis, we show that the
muon deficit can be alleviated if we allow a shift of the predicted depth of the maximum of air-shower profiles by 30 -50 g cm$^{-2}$ towards a heavier mass composition. More recently, we have also provided an updated measurement of the
proton-
proton cross-section at a center-of-mass energy of 57 TeV and the first estimates of the
neutron content of air showers by exploiting late-time signals from the surface scintillator detectors of AugerPrime, the present upgrade of the Observatory. With the advent of AugerPrime, we expect to deliver breakthrough results on the 100 TeV-scale hadronic interactions in the next decade.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics
Kinematic Reconstruction of $\Lambda(t)$CDM Models
P. A. S. Guillen, J. F. Jesus and R. Valentim
In this work, we have analysed two kinematic parametrizations for $\Lambda(t)$CDM models, namely, the linear expansions $\Lambda(z)=\Lambda_0+\Lambda_1z$ and $Q(z)=Q_0+Q_1z$, where $Q$ is the interaction term. In the case of the $Q(z)$ parametrization, we have also tested the particular case of a constant interaction term, $Q(z)=Q_0$. In order to constrain the free parameters of these models, we have used
Cosmic Chronometers (CC), SNe Ia data (Pantheon+&SH0ES) and BAO data. As a general result, we have found weak constraints over the free parameters of the analysed models. In the case of $\Lambda(z)$, we have found for the $\Lambda$ variation parameter, $\Omega_{\Lambda1}\equiv\frac{\Lambda_1}{3H_0^2}=0.02\pm0.14$. In the case of the $Q(z)$ parametrization, we have worked with the dimensionless interaction term $\gQ(z)\equiv\frac{8\pi GQ(z)}{3H_0^3}$, from which we have found $\gQ_0 = 2.2 \pm 2.7$ and $\gQ_1 = -6.2 \pm 7.6$. In the particular case of a constant interaction term, we have found $\gQ_0 = 0.18 \pm 0.7$. All these constraints are at 68% c.l. The constraints we have obtained are compatible with the standard $\Lambda$CDM model, although still providing a large margin for $\Lambda$ variation.
Read the full abstract ▾
Solar and Stellar Astrophysics
A network for solar optical observations in Bulgaria
Rositsa Miteva, Pencho Markishki, Werner Pötzi et al. (+6 more)
The report presents a new initiative for the development of a network of ground-based stations for
solar observations in the optical range. Three separate locations in Bulgaria have installed instrumentation for
solar dedicated observations. The currently used
telescopes (type, mounting, guiding systems) and designated filters (white-light, H-alpha) are described in detail. Test images are also included. Future plans for improvements are briefly discussed.
Read the full abstract ▾
All authors Rositsa Miteva, Pencho Markishki, Werner Pötzi, Momchil Dechev, Dragomir Marchev, Samuil Petrov, Georgi Latev, Hristo Kirov, Kamen Kozarev
Instrumentation and Methods for Astrophysics
Multi-messenger and time-domain astronomy in the 2040s
Samaya Nissanke, Nikhil Sarin, Chris Copperwheat et al. (+31 more)
Multi-messenger astronomy will be transformed in the 2040s by an unprecedented volume of detections from next-generation gravitational wave, high-energy, and ultra-high energy
neutrino,
cosmic ray, and time domain observatories. This white paper, prepared for the European Southern Observatory (ESO) Expanding Horizons call, outlines the key science questions enabled by this emerging multi-messenger ecosystem, ranging from nucleosynthesis and dense matter physics to cosmology, fundamental physics, and the growth of black holes across
cosmic time. We demonstrate that fully exploiting these discoveries requires a step change in optical to near infrared spectroscopic capability, including low latency response, high throughput, and flexible time domain operations across both hemispheres. We argue that without a dedicated large-aperture time domain facility, the scientific return of multi-messenger astronomy in the 2040s will be considerably limited.
Read the full abstract ▾
All authors Samaya Nissanke, Nikhil Sarin, Chris Copperwheat, Sarah Antier, David Berge, Pablo Bosch, Archisman Ghosh, Paul Groot, Gregg Hallinan, Tanja Hinderer, Kenta Hotokezaka, Theophanes Karydas, Mansi Kasliwal, Yves Kini, Rubina Kotak, Kumiko Kotera, Marek Kowalski, Luke Krauth, Kruthi Krishna, Thomas Kupfer, Paraskevas Lampropoulos, Andrew Levan, Ioannis Liodis, Lea Marcotulli, Kunal Mooley, Silvia Piranomonte, Nanda Rea, Martin Roth, Simone Scaringi, Steve Schulze, Lami Suleiman, Nial Tanvir, Angela Zegarelli, Sylvia J. Zhu
Cosmology and Nongalactic Astrophysics · Cross-listed from hep-ph
Gravitational Waves from Confinement in $SU(N)$ Yang-Mills Theory
Stephan Huber, Rory Phipps and Manuel Reichert
We provide a detailed analysis of the gravitational wave spectrum of $SU(N)$ pure Yang-Mills theory. The confinement phase transition is described with an effective Polyakov loop model, using the latest
lattice data as an input. In particular, recent
lattice studies clarified the large-$N$ scaling of the surface tension, which we incorporate through a modification of the kinetic term. We demonstrate that the thin-wall approximation agrees with the Polyakov loop model at small $N$ while it breaks down at large $N$. Furthermore, we include reliable estimates of the bubble wall velocity using a recently developed framework based on a large enthalpy jump at the phase transition. Altogether, this allows us to derive the gravitational wave signals for all $SU(N)$ confinement phase transitions and clarifies the behaviour at large $N$. The strongest signal arises for $N=20$, but overall the predicted signals remain rather weak. Our work paves the way for future studies of other gauge groups and systems with
fermions.
Read the full abstract ▾
Instrumentation and Methods for Astrophysics
Interfacing adaptive optics simulations with the optical model: a powerful tool for MORFEO
Giorgio Pariani, Guido Agapito, Demetrio Magrin et al. (+5 more)
In the framework of the MORFEO project, the Multi-Conjugated Adaptive Optics (MCAO) module for the European Extremely Large
Telescope (ELT), we developed an integrated modeling tool to interface the optical model with the adaptive optics simulations, called ASSO (Adaptive opticS Simulation interfaced with Optical model). This tool is our asso nella manica (ace in the hole) to predict the performances of the AO relay, i.e., to estimate the wavefront error within the technical and scientific fields of view after AO correction. The tool is based on the IDL based simulator PyrAmid Simulator Software for Adaptive opTics Arcetri (PASSATA), on Zemax OpticStudio for the optical modelling, and on Matlab as interface software.
Read the full abstract ▾
All authors Giorgio Pariani, Guido Agapito, Demetrio Magrin, Matteo Munari, Lorenzo Busoni, Marco Riva, Andrea Di Rocco, Paolo Ciliegi
Solar and Stellar Astrophysics
The stellar activity-rotation-age relationship under the lens of asteroseismology
C. Pezzotti, J. Bétrisey, G. Buldgen et al. (+6 more)
In low-mass
stars, the connection between
magnetic activity, rotation period, and age provides key insights into the functioning of dynamos. Fully understanding the activity-rotation-age relationship requires
stars with precise fundamental parameters, measured rotation periods, and reliable
magnetic activity indicators (e.g. X-ray luminosity). Thanks to space-based photometry, asteroseismology is now the leading method for determining
stellar parameters with unprecedented precision and accuracy. The best-characterized
solar-like
stars compose the Kepler LEGACY sample, with highest-quality asteroseismic data for 66
stars, most of which have measured rotation periods. In the X-ray band, these
stars were observed by the ROentgen Survey with an Imaging
Telescope Array (eROSITA)
telescope on the Russian Spektrum-Roentgen-Gamma (SRG) satellite in the course of its all-sky survey. We reviewed different components of the
stellar activity-rotation-age relationship using the largest sample of
solar-like
stars with highly accurate fundamental parameters from asteroseismology, along with measured rotation periods and X-ray luminosities. We cross-correlated the Kepler LEGACY sample with the SRG/eROSITA source catalogue, finding X-ray detections for 13 of them. We derived their fundamental parameters using the Forward and Inversion COmbination procedure and revisited widely studied activity-age and activity-rotation relationships by consistently incorporating our 13-
star subsample with literature samples. By implementing revised activity-rotation-age relationships in a
Star-
Planet Interaction code to compute X-ray luminosity tracks and comparing the results with observations, we found improved agreement for 7
stars of our subsample. We explored the effect of the revised relationships on the mass loss of
planets in the radius valley, finding a modest impact on
planet size distributions.
Read the full abstract ▾
All authors C. Pezzotti, J. Bétrisey, G. Buldgen, M. Gilfanov, I. Bikmaev, R. Sunyaev, E. Is{\i}k, E. Gosset, N.J. Wright
Earth and Planetary Astrophysics
Geminids are initially cracked by atmospheric thermal stress
Tomáš Henych, Jiří Borovička, David Čapek et al. (+4 more)
Geminids have the highest bulk density of all major meteor showers and their mechanical strength appears to depend on their mass. They are also the most active annual shower, enabling detailed studies of the dependence of their physical and mechanical properties on mass. We calculated the fragmentation cascades of 39 bright Geminid fireballs, as well as faint
video meteors, to derive fragmentation pressures and other physical properties characterizing the meteoroids, such as their bulk densities. Our goal is to describe the mechanical properties across a broad range of initial masses and explain the cause of the observed behavior. We used a physical fragmentation model with a semiautomatic method based on parallel genetic
algorithms to fit the radiometric and regular light curve and dynamics data. We also calculated the thermal stress of model bodies with the type of physical properties and trajectories as the observed Geminids. Then, we compared the outcomes of these simulations to our observations. We find that the Geminids are probably cracked by thermal stress in the atmosphere first and then eroded by mechanical forces. The most compact Geminids are in the 20-200 g mass range. The largest observed meteoroids have a wide range of grain sizes, from about 20 um to large, non-fragmenting parts of 1-20 mm in size. The derived bulk densities range from about 1400 to 2800 kg/m3 for smaller meteoroids and approach the assumed grain density of 3000 kg/m3 for larger Geminids.
Read the full abstract ▾
All authors Tomáš Henych, Jiří Borovička, David Čapek, Vlastimil Vojáček, Pavel Spurný, Pavel Koten, Lukáš Shrbený
Solar and Stellar Astrophysics
Orbits of Twelve Multiple Stars
Andrei Tokovinin
Inner and outer orbits in twelve hierarchical
stellar systems are determined using high-resolution speckle imaging, radial velocities, or both. Masses and fluxes of the components are estimated. The Hipparcos numbers of the main
stars are 7111, 12912, 17895, 20375, 42424, 68717, 77439, 79076, 90253, 97922, and 102855; the faint triple WDS J10367+1522 has no HIP number. Four systems are quadruple of 3+1 hierarchy, the rest are triple. Two triples with low-mass M-type components are approximately planar, with moderately eccentric orbits and near-unit mass ratios. The shortest inner period of 0.27d is found in the newly identified contact eclipsing pair belonging to the misaligned quadruple HIP 97922. The compact system HIP 102855 (periods 15.4 and 129 days) identified by
Gaia is confirmed here and has additional companion at 6 arcseconds. This work contributes new data for the study of diverse architectures of
stellar hierarchies in the field.
Read the full abstract ▾
Astrophysics of Galaxies
A first systematic study of [OIII] 88$\mu$m at $z>8$: two luminous oxygen lines and a powerful ionized outflow in the first 600 million years
Hiddo S. B. Algera, John R. Weaver, Tom J. L. C. Bakx et al. (+35 more)
We present deep ALMA Band 7 observations of the [OIII] $88\mu$m line and underlying
dust continuum emission in four UV-bright, gravitationally lensed (magnification $\mu = 1.4-3.8$), JWST-selected
galaxies at $z = 8.5 - 10.3$, with observed magnitudes $-22.5 \lesssim M_\mathrm{UV} \lesssim -20.5$. [OIII] $88\mu$m is confidently detected in UNCOVER-10646 at $z=8.5080 \pm 0.0011$ ($15\sigma$) and DHZ1 at $z=9.3113 \pm 0.0006$ ($6\sigma$), with both being intrinsically luminous systems [$L_\text{[OIII]} = (1.1 - 1.6) \times 10^9\,L_\odot$] that follow the local [OIII]-SFR relation. [OIII] $88\mu$m remains undetected in the two $z>10$ targets, including in the $z=10.07$ X-ray AGN UHZ1, where we obtain a deep limit of $L_\text{[OIII]} < 6 \times 10^7\,L_\odot$.
Dust emission is not detected in any individual source nor in a stack ($<3\sigma$). The high S/N [OIII] $88\mu$m detection in UNCOVER-10646 uniquely reveals an additional broad component ($\mathrm{FWHM} = 1366_{-329}^{+473}\,\mathrm{km/s}$; $\Delta\mathrm{BIC}\approx20$) indicative of an ionized
outflow. We infer a high
outflow rate of $\dot{M}_\mathrm{out} = 128_{-46}^{+80}\,M_\odot\,\mathrm{yr}^{-1}$, corresponding to a mass loading factor $\eta = \dot{M}_\mathrm{out}/\mathrm{SFR} = 2.9_{-1.0}^{+1.8}$ that matches or exceeds theoretical predictions and JWST-based studies of ionized
outflows at high
redshift. While high-resolution ALMA follow-up is required to confirm and spatially resolve the
outflow, this first systematic study at $z>8$ highlights the unique diagnostic power of [OIII] $88\mu$m in characterizing
galaxies in the early Universe.
Read the full abstract ▾
All authors Hiddo S. B. Algera, John R. Weaver, Tom J. L. C. Bakx, Manuel Aravena, Rychard J. Bouwens, Karin Cescon, Chian-Chou Chen, Elisabete da Cunha, Pratika Dayal, Andreas Faisst, Andrea Ferrara, Seiji Fujimoto, Takuya Hashimoto, Kasper Heintz, Rodrigo Herrera-Camus, Jacqueline Hodge, Hanae Inami, Akio K. Inoue, Jorryt Matthee, Romain Meyer, Shoichiro Mizukoshi, Chayan Mondal, Themiya Nanayakkara, Pascal A. Oesch, Andrea Pallottini, Huub Röttgering, Lucie E. Rowland, Sander Schouws, Renske Smit, Laura Sommovigo, Daniel P. Stark, Yuma Sugahara, Livia Vallini, Bovornpratch Vijarnwannaluk, Paul van der Werf, Norbert Werner, Joris Witstok, Mengyuan Xiao
Instrumentation and Methods for Astrophysics · Cross-listed from physics.optics
Construction techniques and commissioning of the Three-Backlink Experiment for the LISA mission
Lea Bischof, Melanie Ast, Jiang Ji Ho-Zhang et al. (+10 more)
Designed to detect gravitational waves in the lower-frequency band, the space mission LISA will open a new window to astronomy after its launch in the 2030s. Each LISA spacecraft houses two optical benches that require the exchange of a phase reference between them via an optical connection, called a Backlink. Here we present the construction and commissioning of an ultra-stable quasi-monolithic optical testbed to investigate different Backlink implementations: a direct fiber, a frequency-separated fiber, and a free-beam link, compared in the Three-Backlink Experiment. Dedicated
alignment techniques crucial for the construction of these optical benches are presented together with the development of a high-precision beam
alignment and measurement tool - a Calibrated Quadrant Photodiode Singleton. An upper limit for the performance of all three investigated Backlink schemes, as determined by initial experiments, can be set at a $15\text{pm}/\sqrt{\text{Hz}}$-equivalent level within the LISA band, spanning 0.1mHz to 1Hz. Our measurements were able to verify the successful construction and commissioning of this very complex interferometer as an interferometric laboratory testbed for LISA. We find no limitations due to the construction on the here reported performance levels. Our results can support the construction of high-precision metrology testbeds for space-based
laser interferometry for future gravitational wave or geodesy missions.
Read the full abstract ▾
All authors Lea Bischof, Melanie Ast, Jiang Ji Ho-Zhang, Nicole Knust, Daniel Penkert, Daniel Jestrabek, Jens Reiche, Thomas S. Schwarze, Katharina-Sophie Isleif, Oliver Gerberding, Gerhard Heinzel, Stefan Ast, Karsten Danzmann
Instrumentation and Methods for Astrophysics · Cross-listed from physics.optics
Demonstrating sub-picometer non-reciprocity levels in the Three-Backlink Experiment for LISA
Jiang Ji Ho-Zhang, Melanie Ast, Lea Bischof et al. (+9 more)
The current planned space-based gravitational-wave detectors require a bidirectional optical connection, referred to as Backlink, between two adjacent optical benches to provide a mutual phase reference for the local interferometric measurements. However, if the Backlink shows asymmetry between the two propagation directions, the effective optical pathlengths of the counter-propagating beams can introduce a differential phase noise, called non-reciprocity, into the main interferometric measurement that will limit the achievable accuracy in time-delay interferometry (TDI) post-processing. Hence, it is important to understand the properties of the Backlink to ensure that it will not compromise the interferometric detection. The Three-Backlink Experiment (3BL), which consists of an optical test facility with two rotatable benches, was designed under the
Laser Interferometer Space
Antenna (LISA) framework to study the performance of three Backlink configurations: two fiber-based and one free-beam scheme. In this paper, we report recent experimental results from the 3BL. We describe the commissioning and the subsequent noise mitigation. We achieve a setup noise floor below $1\text{ pm}\sqrt{\text{Hz}}$ across most of the LISA measurement band, and provide an understanding of the current technical limitations. With this low-noise baseline, we measured the performance of the three Backlink implementations under non-rotational conditions. We show that all three Backlinks reach sub-picometer non-reciprocity levels across most of the frequency band, with the remaining part dominated by the mentioned testbed noise. This enabled us to conduct a preliminary study of the Backlink inherent noise, where we emphasized on the backscatter noise intrinsic to a straightforward fiber-based Backlink, as this is the current baseline for LISA.
Read the full abstract ▾
All authors Jiang Ji Ho-Zhang, Melanie Ast, Lea Bischof, Michael Born, Daniel Jestrabek, Stefan Ast, Katharina-Sophie Isleif, Oliver Gerberding, Thomas S. Schwarze, Jens Reiche, Gerhard Heinzel, Karsten Danzmann
High Energy Astrophysical Phenomena
A one-parameter two-zone leptonic model for the blazar sequence
Stella Boula, Apostolos Mastichiadis and Demosthenes Kazanas
Blazars, a subclass of
radio-loud active
galactic nuclei with relativistic jets aligned close to our line of sight, emit highly variable non-thermal radiation across the electromagnetic spectrum. The physical origin of their emission and the blazar sequence remain open questions. We present a self-consistent two-zone leptonic model in which relativistic electrons accelerate in a compact region, losing energy via synchrotron and inverse Compton processes, and escape into a larger zone permeated by an external
photon field associated with magnetohydrodynamic winds from the
accretion disk. By varying only the mass
accretion rate onto the central black hole, the model naturally reproduces the blazar sequence, including Compton Dominance, $\gamma$-ray spectral indices, and the positions of synchrotron and inverse Compton peaks, while variations in secondary parameters account for the observed spread in the data. Flat Spectrum
Radio Quasars exhibit strong external Compton emission from the extended zone, whereas BL Lac objects are dominated by synchrotron and synchrotron self-Compton emission from the compact acceleration region. This framework highlights the key role of
accretion rate and spatially structured emission zones in shaping blazar spectra and provides a unified interpretation of their diverse phenomenology.
Read the full abstract ▾
Instrumentation and Methods for Astrophysics
Why the Northern Hemisphere Needs a 30-40 m Telescope and the Science at Stake: Time-domain astronomy
F. Coti Zelati, P. G. Jonker, C. P. Gutiérrez et al. (+9 more)
We outline the science case for a 30-40 m optical/infrared
telescope in the Northern Hemisphere, optimised for transformative time-domain astronomy in the 2040s. Upcoming multi-wavelength and multi-messenger facilities will reveal fast, faint, rapidly evolving Northern transients whose earliest phases carry decisive diagnostics. A Northern ELT with rapid response, broad wavelength coverage, high time resolution, polarimetric capabilities, and diffraction-limited imaging is essential to capture these phases and secure deep spectroscopy and photometry as transients fade. These capabilities will enable recovery of key physical information and detailed characterisation of transient environments, while also enabling unprecedented studies of
accretion phenomena at all scales. Among potential sites, La Palma uniquely combines atmospheric stability, complementary longitude to ESO's ELT, protected dark skies, and robust infrastructure to host this facility.
Read the full abstract ▾
All authors F. Coti Zelati, P. G. Jonker, C. P. Gutiérrez, S. Mattila, D. Pollacco, N. Rea, P. Charalampopoulos, M. A. P. Torres, T. Muñoz Darias, M. C. Baglio, L. Galbany, E. Villaver
Instrumentation and Methods for Astrophysics · Cross-listed from physics.space-ph
NASA/NOAA MOU Annex Final Report: Evaluating Model Advancements for Predicting CME Arrival Time
M. L. Mays, P. J. MacNeice, A. Taktakishvili et al. (+11 more)
The purpose of this project was to assess improvements in CME arrival time forecasts at Earth using the Air Force Data Assimilative Photospheric Flux Transport (ADAPT) model driven by data from the Global Oscillation Network Group (GONG) ground observatories. These outputs are then fed into the coupled Wang-Sheeley-Arge (WSA) - ENLIL model and compared to an operational version of WSA-ENLIL (without ADAPT). SWPC selected a set of 38 historical events over the period of five years from 2012–2014 (33 events) and 2017–2019 (5 events). The overall three-year project consisted of multiple simulation validation studies for the entire event set (1292 simulations): (a)
benchmark single map (operational version prior to May 2019) (b) time-dependent sequence of GONG maps driving WSA-ENLIL with 4 different model settings (c) single test simulation of a time-dependent sequence of GONG maps driving ADAPT-WSA-ENLIL (d) single GONG map driving ADAPT-WSA-ENLIL (e) time-dependent sequence of GONG maps driving ADAPT-WSA-ENLIL. We report that for all 38 events, within each model version/settings combination, the CME arrival time error decreased by 0.2 to 0.9 hours when using a sequence of time-dependent zero-point corrected magnetograms compared to using single magnetogram input. Overall, for all events, when using the older uncorrected magnetograms, the CME arrival time error increased for all new model versions/settings combination compared to the
benchmark. Notably for the 5 events in the period 2017–2019 when more reliable zero-point corrected magnetograms were available, the ADAPT-WSA-ENLIL (median arrival realization) CME arrival time error decreased against all
benchmarks. In this report we also discuss replicating the operational model, challenges in detecting CME arrival in simulations, and comparing zero-point corrected and uncorrected magnetogram inputs.
Read the full abstract ▾
All authors M. L. Mays, P. J. MacNeice, A. Taktakishvili, C. P. Wiegand, J. Merka, E. T. Adamson, V. J. Pizzo, D. A. Biesecker, A. R. Marble, D. Odstrcil, C. J. Henney, C. N. Arge, S. I. Jones, S. Wallace
Earth and Planetary Astrophysics
The quest for Magrathea planets. II. Orbital stability of exoplanets formed around double white dwarfs
Arianna Nigioni, Diego Turrini, Camilla Danielski et al. (+2 more)
Planetary formation might occur at different stages of the
stellar evolution of compact binaries. In recent years, the formation of second-generation
planets has been tested in circumbinary discs formed by the ejection of
stellar material from double white
dwarf (DWD) binaries. In these environments,
planets ranging from sub-Neptunian to
giant masses can form and migrate to within 1 au of the central binary. Nevertheless, studies on the orbital stability of such systems have yet to be undertaken. In this work, we use N-body simulations to study the stability of multi-
planet systems formed around compact DWDs in both resonant and non-resonant configurations over timescales of a few million years. We track the occurrence of catastrophic events and employ a variety of metrics, e.g., orbital spacing, centre-of-mass variations and Normalized Angular Momentum Deficit, to explore the outcomes of their
evolution. Furthermore, we evaluate the potential for detecting these systems in their final configurations with the
Laser Interferometer Space
Antenna (LISA) mission by measuring the overall gravitational-wave frequency shift amplitude induced by their
planets. Our results show that
planets orbiting DWDs can be stable over the studied timescales. While planetary systems starting with two-
planets are more likely to survive unaltered, planetary systems with three, four or five
planets, experience catastrophic events that cause them to lose some of their original
planets, ending up hosting only two surviving
planets in the majority of cases. This increases the number of two-
planet systems by 122% with respect to their initial abundance and creates a single-
planet population amounting to 7% of the totality of systems. The majority of these single-
planet systems are potential candidates for LISA. Concerning multi-
planet systems, a handful of systems could be detected.
Read the full abstract ▾
All authors Arianna Nigioni, Diego Turrini, Camilla Danielski, Danae Polychroni, John E. Chambers
Astrophysics of Galaxies
Bowshocks driven by the pole-on molecular jet of outbursting protostar SVS 13
G. Blázquez-Calero, G. Anglada, S. Cabrit et al. (+13 more)
Outflows play a key role in the
star and
planet formation processes. Some
outflows show discrete clumps of cold molecular gas moving at extremely high velocities (EHVs) of $\sim$100 km s$^{-1}$, known as ”molecular bullets”, that are likely closely associated with their primary driving
agent. Here we present ALMA CO(J=3-2) observations of a bright EHV molecular bullet that reveal its morphology in detail down to scales of 30 au and its kinematic structure across the entire intermediate velocity range ($\sim$30-100 km s$^{-1}$). These provide important new insights into how
outflows transfer mass and momentum to the surrounding medium. The observed channel maps display several sequences of ring-like features whose velocity increases and size decreases with projected distance from the driving source, each sequence tracing a thin, bow-shaped shell culminating on-axis in a bright EHV head. The shape, kinematics, and mass of each shell all agree remarkably well with the simplest textbook models of momentum-conserving bowshocks produced by a time-variable EHV jet. The dynamical timescale between consecutive shells is of a few decades, with the latest ejection event coinciding with the protostar optical/IR outburst observed in $\sim$1990. The very strong evidence for bowshock-driven entrainment induced by jet variability revealed by this work suggests that
accretion bursts, and therefore variations in the disk snowlines, should occur on decade timescales, which could substantially impact grain growth and
planet formation.
Read the full abstract ▾
All authors G. Blázquez-Calero, G. Anglada, S. Cabrit, M. Osorio, A.C. Raga, G.A. Fuller, J.F. Gómez, R. Estalella, A.K. Diaz-Rodriguez, J.M. Torrelles, L.F. Rodríguez, E. Macías, I. de Gregorio-Monsalvo, S.T. Megeath, L. Zapata, P.T.P. Ho
Cosmology and Nongalactic Astrophysics
Isocurvature-induced features in multi-field Higgs-$R^2$ inflation
Flavio Pineda and Luis O. Pimentel
We study
primordial perturbations in
Higgs–$R^2$ inflation in the presence of non-minimal kinetic mixing between the
Higgs field and the scalaron. By numerically solving the multifield background and linear perturbation equations, we identify distinct dynamical regimes controlled by the
Higgs non-minimal coupling $\xi_h$. For $\xi_h \sim \mathcal{O}(0.1)$, transient turning of the inflationary trajectory leads to a transfer between adiabatic and isocurvature modes, generating localized features in the
primordial curvature power spectrum. In contrast, in the weak-coupling regime $\xi_h \ll 1$, the
curvature spectrum remains nearly featureless while isocurvature perturbations do not fully decay, resulting in a residual isocurvature component at the end of inflation. We compute the associated CMB angular power spectra and discuss the observational implications of these regimes. Our results highlight the role of multifield dynamics in shaping
primordial perturbations and provide constraints on viable realizations of
Higgs–$R^2$ inflation.
Read the full abstract ▾
Earth and Planetary Astrophysics
Coexistence of coagulation and streaming instabilities in protoplanetary discs
Arnaud Pierens, Thomas Collin-Dufresne, Min-Kai Lin et al. (+1 more)
The streaming instability is considered one of the leading candidates for the formation of planetesimals, due to its ability to overcome the bouncing and fragmentation barriers. The formation of dense
dust clumps through this process, however, is possible provided it involves solids with dimensionless stopping times $\sim 0.1$ in standard discs, which typically corresponds to 1-10 cm-sized particles. This implies that
dust coagulation is required for the SI to be an efficient process. Here, we employ unstratified, shearing-box simulations combined with a moment equation for solving the coagulation equation to examine the effect of
dust growth on the SI. In
dust-rich discs with a
dust-to-gas ratio $\epsilon\gtrsim 1$, coagulation is found to have little impact on the SI; while in
dust-poor discs with $\epsilon\sim 0.01$, we observe the formation of vertically extended filaments through the action of the coagulation instability (CI), which is triggered due to the dependence of coagulation efficiency on
dust density. For moderate
dust-to-gas ratios $\epsilon\sim 0.1$ and Stokes numbers $St \lesssim 0.1$, we find onset of the SI within these filaments, with a linear growth rate significantly higher compared to standard SI. We refer to this regime as coagulation-assisted SI. The synergy between both instabilities in that case leads to isotropic
turbulence and
dust concentrations that are increased by a factor of $30-40$. As
dust continues to grow, SI tends to overcome the effect of the CI such that the nonlinear saturation phase is similar to pure SI. Our results suggest that coagulation, by simply increasing
dust size, may facilitate the formation of dense clumps through the SI; even though it has only little effect on its nonlinear
evolution.
Read the full abstract ▾
All authors Arnaud Pierens, Thomas Collin-Dufresne, Min-Kai Lin, Emmanuel DiFolco