Astrophysics of Galaxies
BASS. LI. Cool gas supply of HI-massive local Seyfert galaxies
Jeein Kim, Aeree Chung, O. Ivy Wong et al. (+19 more)
We present neutral atomic hydrogen (HI) imaging observations of 22 HI-rich ($M_{\rm HI} \gtrsim 10^{9.7} M_\odot$), hard X-ray-selected local Seyferts to explore how cool gas is supplied to active
galactic nuclei (AGN) hosts. The sample predominantly resides in group-like, gas-rich environments. About 80% (18/22) of the
galaxies have HI-detected neighbors, 61% (11/18) of which clearly exhibit strong lopsidedness, one-sided gas tails, and/or gas structures connecting to nearby companion
galaxies, suggesting gas exchange histories. We examine the HI size-mass relation and
star formation properties of these HI-rich AGN hosts, finding no systematic deviations from known scaling relations. In most cases, our samples are the most massive systems within their respective groups, implying that our sample is more likely to acquire gas rather than lose it. Interestingly,
galaxies with more extended HI disks show stronger AGN activity. Considering that extended HI is often associated with external processes, this finding suggests that environmentally accreted gas - through
galaxy interactions and gas exchange with neighboring systems - may have played a role in supplying additional fuel to the AGNs in our sample. Notably, the HI extent-AGN activity correlation becomes even tighter for those AGN hosts whose neighboring
galaxies are gas poor or lack HI, further supporting externally supplied gas as a fuel source.
Read the full abstract ▾
All authors Jeein Kim, Aeree Chung, O. Ivy Wong, Junhyun Baek, Chandrashekar Murugeshan, Michael J. Koss, Kyuseok Oh, Franz Erik Bauer, Chin-Shin Chang, Yaherlyn Diaz, Kohei Ichikawa, Darshan Kakkad, Minjin Kim, Macon Magno, Ignacio del Moral-Castro, Richard Mushotzky, Alessandro Peca, Claudio Ricci, Matilde Signorini, Miguel Parra Tello, Benny Trakhtenbrot, Jong-Hak Woo
Solar and Stellar Astrophysics
Magnetar counterparts, kinematics and birth sites with HST and JWST
A. A. Chrimes, J. D. Lyman, A. J. Levan et al. (+7 more)
Magnetars are highly magnetised, isolated
neutron stars with uncertain formation channels. They comprise a potentially significant fraction of the young
neutron star population in the Milky Way, and are implicated in the explosion mechanisms of some of the most powerful explosions in nature. We aim to identify magnetars in the near-infrared with Hubble Space
Telescope (HST) and James Webb Space
Telescope (JWST) imaging, in order to measure their proper motions and search for their birth sites. Candidate infrared counterparts are selected based on variability, colours and proper motions which are outliers with respect to sources in the field. Proper motions are obtained by tying HST and JWST images to the
Gaia absolute astrometric reference frame. We newly identify infrared counterparts for PSRJ1622-4950, 1RXSJ170849.0-400910 and CXOUJ164710.2-455216, representing a substantial increase in the population. The past trajectory of the 1RXSJ170849.0-400910-associated source coincides with the
supernova remnant G346.6-0.2. The transverse velocity distribution is found to be marginally inconsistent with young
pulsars, due primarily to a dearth of high velocity magnetars. A candidate birth site is identified in nearly every case. We show, based on the inferred kinematic ages, that magnetar characteristic ages may frequently be lower than the true age, but caution that this depends on the reliability of the birth site associations. We conclude that magnetars are broadly similar in terms of their kinematics and birth sites to the wider
Galactic neutron star population, consistent with magnetar formation being a common outcome of core-collapse. However, tentative evidence for a dearth of high-velocity magnetars is emerging. If real, this may arise from physical differences in the progenitor population giving rise to magnetars, or from differences in their post-formation velocity
evolution.
Read the full abstract ▾
All authors A. A. Chrimes, J. D. Lyman, A. J. Levan, A. Borghese, J. H. J. de Bruijne, A. S. Fruchter, M. G. Guarcello, C. Kouveliotou, N. R. Tanvir, K. Wiersema
High Energy Astrophysical Phenomena
BL Lac host galaxies: how to systematically characterise them in optical-NIR spectroscopy
Gaia Delucchi, Tullia Sbarrato, Giorgio Calderone et al. (+3 more)
Host
galaxies of Active
Galactic Nuclei give crucial information on the interaction between accreting Supermassive Black Holes and their surroundings, and on their common
evolution. Their study in the case of aligned jetted AGN - BL Lacertae objects in particular - is complicated by the non-thermal jet component, whose bright and multi-frequency emission easily dominates over the whole electromagnetic spectrum. BL Lac host
galaxies have thus been sparsely studied, and their elliptical nature is currently a hypothesis supported by few observations. With the broad aim of a systematic analysis of these sources, and in light of the many optical and NIR spectroscopic facilities that are now available, we implement an easily applicable method to determine whether a BL Lac is hosted in an elliptical or spiral
galaxy. Building on the only systematic study currently available on BL Lac hosts, we worked on a sample of realistic BL Lac synthetic spectra. We analysed them and characterized their statistics using QSFit, a publicly available spectroscopy software. If BL Lac host
galaxies were both elliptical and spiral, our method would be able to discriminate between them, provided that BL Lac jets are fainter than $L_\gamma\sim10^{46}$erg/s. Just two runs of QSFit for each BL Lac spectrum would return a single parameter, that would allow for a first broad distinction between the two classes. We finally discuss the two
galaxy types that introduce some uncertainty in their classification, that might lead to possible classification biases.
Read the full abstract ▾
All authors Gaia Delucchi, Tullia Sbarrato, Giorgio Calderone, Chiara Righi, Silvano Tosi, Boris Sbarufatti
Instrumentation and Methods for Astrophysics
A 5kHz modulator for pyramid wavefront sensors
Maximilian Häberle, Vianak Naranjo, Yared Reinarz et al. (+5 more)
Despite the emergence of new types of wavefront sensors, the modulated pyramid wavefront sensor remains the workhorse for ELT instrumentation, and is among the options even for advanced high-contrast, high-Strehl instrumentation like PCS and SAXO+. To achieve the required degree of wavefront control, an operation at frequencies of 3kHz, ideally up to 5kHz, is necessary, requiring an optomechanical device capable of delivering accurate circular modulation patterns with these frequencies. Here, we present tests of a novel type of high-frequency modulator based on shearing piezo actuators. The modulator prototype moves a flat circular mirror (15mm diameter) with a tip-tilt range of plus/minus 50 arcsec. At a typical 10mm pupil diameter on the modulator mirror, and operating at 2.2$\mu$m, this will create a modulation circle with a radius of slightly greater than 2 $\lambda$/D. While this is less than conventionally specified for most instruments, it should already be sufficient for any practical application except for very bad conditions or extended targets. We performed modulation tests at frequencies between 250 Hz to 5 kHz using a test setup including a modulated
laser beam probed with a high-speed camera. The prototype showed stable behaviour during a one-hour-long operation at a maximum frequency of 5 kHz and with negligible heat generation. The maximum modulation amplitude was 60 arcsec. We observed very accurate reproduction of the input modulation pattern with typical ellipticities less than 1% and random deviations below 0.2% for frequencies below 4.5kHz. These tests demonstrate the prototype's capabilities and could be followed by on-sky tests or the integration of the modulator into XAO testbeds.
Read the full abstract ▾
All authors Maximilian Häberle, Vianak Naranjo, Yared Reinarz, Markus Feldt, Silvia Scheithauer, Thomas Bertram, Arne Bramigk, Harry Marth
Cosmology and Nongalactic Astrophysics
Shocks from Exploding Primordial Black Holes in the Early Universe
Miguel Vanvlasselaer, Sokratis Trifinopoulos, Alexandra P. Klipfel et al. (+1 more)
We investigate how Hawking radiation from low-mass
primordial black holes deposits energy into the early-universe
plasma and show that the resulting phenomena are hydrodynamic rather than purely diffusive. Combining analytic arguments with relativistic hydrodynamic simulations, we find that the
plasma first develops a quasi-steady
outflow during the slow evaporation stage, while the final runaway phase of evaporation produces an expanding fireball that launches a shock wave into the surrounding medium. We characterize the thermalization scale of the Hawking products, the conditions under which shocks form, and the
evolution and propagation of shocks. Additionally, we show that these shocks can locally restore electroweak
symmetry, identifying exploding PBHs as a potentially important source of out-of-
equilibrium dynamics in the early universe with profound phenomenological implications.
Read the full abstract ▾
All authors Miguel Vanvlasselaer, Sokratis Trifinopoulos, Alexandra P. Klipfel, David I. Kaiser
High Energy Astrophysical Phenomena
Hankel low-rank matrix approximation for gravitational-wave data analysis
Nicholas Geissler, Vladimir Strokov, Christian Kümmerle et al. (+2 more)
Next-generation gravitational-wave (GW) detectors, such as the
Laser Interferometer Space
Antenna (LISA), will observe vast numbers of overlapping signals. Disentangling these signals from instrumental noise and from one another constitutes a significant data analysis challenge. We explore a denoising technique based on
embedding time series into Hankel
matrices: a superposition of $n$ (damped) sinusoids corresponds to a
matrix of rank $2n$. Thus, the problem of signal extraction is reduced to a structured low-rank approximation problem. Using synthetic data tailored to GW applications, we
benchmark three Hankel-based
algorithms: ESPRIT, Cadzow iterations, and iteratively reweighted least squares (IRLS). Our test scenarios include isolated and multi-component monochromatic signals, the resolution of sources with closely spaced frequencies, and the recovery of black hole quasinormal modes (QNM). All three
algorithms achieve near-optimal performance consistent with Fisher
matrix bounds, evidenced by an inverse-square scaling of the mismatch with the signal-to-noise ratio. Furthermore, a proof-of-concept application to numerical relativity waveforms validates the ability of these
algorithms to extract QNM frequencies from ringdown signals. Hankel low-rank approximation therefore offers a transparent, computationally efficient avenue for preprocessing GW time series.
Read the full abstract ▾
All authors Nicholas Geissler, Vladimir Strokov, Christian Kümmerle, Sergey Kushnarev, Emanuele Berti
Astrophysics of Galaxies
Multi-phase AGN-driven outflow in the NLSy1 IRAS 17020+4544. Unveiling dual-feedback and an energy-conserving ionized outflow with MEGARA/GTC integral field spectroscopy
E. Bellocchi, A. L. Longinotti, Q. Salomé et al. (+9 more)
The narrow-line Seyfert 1 (NLSy1)
galaxy IRAS~17020+4544 is one of the few known sources exhibiting a multi-phase
outflow detected in both highly ionized and molecular gas, consistent with AGN feedback operating in an `energy-conserving' regime. We investigate the properties and kinematics of the warm ionized gas using new optical seeing-limited integral-field spectroscopic observations obtained with MEGARA at the Gran Telescopio Canarias in both low- (R$\sim$6000) and medium-resolution (R$\sim$12000) modes. The H$\alpha$ and [OIII]$\lambda$5007 emission lines are modeled with multi-Gaussian fitting to characterize the ionized gas kinematics and derive the energetics of the
outflow, which we compare with those of the X-ray and molecular phases. Ionization diagnostic diagrams (WHAN, WHaD, and BPT) are used to investigate the dominant ionization mechanism. We detect a fast ionized
outflow traced by both H$\alpha$ and [OIII] emission lines, with similar spatial extensions (R$_\mathrm{out}\sim$1 kpc and $\sim$0.5 kpc) and velocities (v$_\mathrm{out}\sim$1460 and 1240 km s$^{-1}$, respectively), as well as a slower ionized
outflow (v$_\mathrm{out}\sim$450 km s$^{-1}$) detected in the secondary component of the [OIII] line. The fast
outflow follows an `energy-conserving' regime, while the slower component is consistent with a `momentum-driven' regime. The ionized
outflows are enclosed within the molecular
outflow detected with NOEMA (R$_\mathrm{CO}$=2.8$\pm$0.3 kpc), and the large momentum boosts derived in both phases suggest efficient AGN feedback, likely dominated by radiatively driven winds (
quasar-mode) rather than kinetic (jet-driven) processes. Ionization diagnostics suggest that the
outflow is mainly AGN-driven, with potential contributions from
star formation and shocks. The molecular
outflow dominates, with the ionized phase contributing less to the mass and feedback efficiency.
Read the full abstract ▾
All authors E. Bellocchi, A. L. Longinotti, Q. Salomé, A. Gil de Paz, J. P. Torres-Papaqui, Divakara Mayya, Y. Krongold, A. Castillo-Morales, A. Robleto-Orús, C. Catalán-Torrecilla, O. Vega, D. Rosa González
Cosmology and Nongalactic Astrophysics
Halo assembly bias in the early Universe: a clustering probe of the origin of the Little Red Dots
Zihao Wang, Fangzhou Jiang, Haonan Zheng et al. (+5 more)
The clustering of
galaxies encodes key information about the structure and assembly history of their host dark matter (DM)
haloes, providing a powerful probe of the origin of extreme high-
redshift systems. While
halo assembly bias has been extensively studied at low
redshift, its behavior in the early Universe remains poorly explored. Using the large-volume, high-resolution Shin-Uchuu cosmological $N$-body simulation, we characterize
halo assembly bias associated with formation time, concentration, and angular momentum across a wide range of
halo masses and
redshifts. We find that the sign and amplitude of assembly bias depend on
halo mass for both concentration and
spin. High-concentration and low-
spin haloes are more strongly clustered below characteristic peak heights of $\nu \sim 1.5$ and $\sim 0.75$, respectively, while the trends weaken or reverse at higher masses.
Halo age bias persists at all
redshifts but decreases toward higher masses and earlier
cosmic times. We apply these results to assess whether clustering can distinguish competing formation scenarios for the Little Red Dots (LRDs). We find that the direct-collapse-black-hole (DCBH) scenario predicts the strongest large-scale bias and enhanced pair fractions, the self-interacting-dark-matter (SIDM) core-collapse scenario and low-
spin compact-
galaxy scenarios yield weaker clustering due to lower characteristic
halo masses and
spin-related secondary bias, and a
primordial-black-hole (PBH) scenario predicts unbiased clustering. Our results demonstrate that
halo assembly bias and characteristic host masses provide powerful diagnostics for constraining the physical origin of LRDs, offering testable predictions for upcoming clustering measurements with JWST and future deep surveys.
Read the full abstract ▾
All authors Zihao Wang, Fangzhou Jiang, Haonan Zheng, Xuejian Shen, Zixiang Jia, Luis C. Ho, Kohei Inayoshi, Linhua Jiang
Earth and Planetary Astrophysics
Inferring the mass and size of 3I/ATLAS from its non-gravitational acceleration
Valentin Thoss, Abraham Loeb and Andreas Burkert
Observations of the interstellar object 3I/ATLAS have revealed a strong production of gas and
dust near perihelion, together with rapid brightening. The outgassing from the
nucleus has led to a detectable non-gravitational acceleration. In this work, we combine models of the mass loss rate of water and carbon dioxide to derive the non-gravitational parameters and estimate the mass and size of 3I/ATLAS. In addition, we take into account a conservative constraint on the
nucleus size from the active surface area required for sublimation. If the mass loss is dominated by the sublimation of CO$_2$, then the
nucleus radius and mass are $R_{\rm 3I}=0.42\,\rm{km}$ and $M_{\rm 3I}=1.6\times10^{11}\,\rm{kg}$, assuming a density of $\rho=0.5\,\rm{g\,cm}^{-3}$ and an asymmetry factor of $\zeta=0.5$. This estimate is consistent with the lower bound from the active surface and independently supported by the slight preference of the orbital fit for a $a_{\rm ng}(r)\sim 1/r^2$ scaling of the non-gravitational acceleration. Models that cover the range of reported water production near perihelion give $R_{3I}=0.74-1.15\,\rm{km}$ and $M_{\rm 3I}=8.5-32\times10^{11}\,\rm{kg}$ but require a cometary surface that is in tension with the estimate from the rocket effect. Therefore, our results indicate that a large fraction of water sublimation is occurring in the coma and that CO$_2$ dominates sublimation on the surface. The
nucleus radius that we obtain is much smaller than a recent photometric estimate of $R_{\rm 3I}\sim 1.3\,\rm{km}$, which could be resolved if CO$_2$ production is larger than observed or if the density of 3I/ATLAS is significantly lower than assumed. An overall lighter
nucleus of 3I/ATLAS might be favored based on its recently claimed origin from a metal-poor environment and the corresponding mass budget of interstellar objects.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics · Cross-listed from hep-ph
Crowdsourcing Gravitational Waves from Superradiant Axions
Sebastian A. R. Ellis, Orion Ning, Nicholas L. Rodd et al. (+1 more)
Black hole superradiance is a powerful probe of ultralight
axions. If nature contains a
boson with a mass of order $10^{-12}\,$eV, $\textit{mere vacuum fluctuations}$ will lead to its efficient production around spinning
stellar mass black holes, forming a gravitational atom that both drains the black hole
spin and decays to produce near-monochromatic gravitational waves. Existing superradiance constraints derive primarily from
spin measurements of a handful of identified black holes. Here we instead present a detailed study of the population level effect: gravitational waves arising from both the 100 million black holes in the Milky Way and the
stochastic signal from
axion clouds throughout the universe. We study the impact of a broad range of systematic uncertainties on the black hole properties and compute the projected
axion sensitivity for LIGO, as well as the future instruments Einstein
Telescope,
Cosmic Explorer, and a high-frequency
Magnetic Weber Bar. We demonstrate that LIGO can robustly probe
axion masses from roughly $10^{-13}\,$eV to $4 \times 10^{-12}\,$eV. If the black hole population extends to masses slightly below $5\,M_{\odot}$ - as hinted for by LIGO inspiral observations - LIGO would approach $10^{-11}\,$eV. Under that same assumption we show that a future high-frequency detector could push considerably higher, potentially beyond $10^{-10}\,$eV in the most optimistic scenarios, reaching towards the lowest masses within the projected sensitivity of
axion dark matter searches.
Read the full abstract ▾
All authors Sebastian A. R. Ellis, Orion Ning, Nicholas L. Rodd, Jan Schütte-Engel
Cosmology and Nongalactic Astrophysics
Field-Level Inference from Galaxies: BAO Reconstruction
Adrian E. Bayer, Liam Parker, David Valcin et al. (+3 more)
Baryon acoustic oscillations (BAO) underpin the key cosmological results from modern spectroscopic
galaxy surveys, but nonlinear gravitational
evolution limits the precision achievable with traditional analysis methods. To overcome this, we develop field-level inference for BAO, first reconstructing the initial linear density field and then fitting the BAO signal therein. We
benchmark three reconstruction methods: (i) traditional reconstruction based on the Zel'dovich approximation, (ii) explicit field-level inference using differentiable forward modeling with hybrid effective field theory, and (iii) implicit field-level inference using a convolutional neural network to augment traditional reconstruction. Using DESI-like Luminous Red
Galaxy (LRG) and Bright
Galaxy Survey (BGS) catalogs, we find that field-level approaches significantly sharpen the BAO feature relative to traditional reconstruction. For LRGs, explicit field-level inference improves constraints on the BAO scale parameters ($\alpha_{\rm iso}, \alpha_{\rm ap}$) by 26%, while implicit inference improves constraints by 35%, corresponding to a 2.4$\times$ improvement in figure of merit. For the higher-density, lower-
redshift BGS sample, field-level inference enables information extraction from smaller scales, yielding an improvement in constraints of up to 46%, corresponding to a 3.2$\times$ improvement in figure of merit. Crucially, we address longstanding concerns regarding the robustness of field-level reconstruction by leveraging 1,000 mock realizations to perform extensive coverage tests. Our results are both unbiased and statistically well-calibrated, maintaining nominal coverage even when using tight simulation-informed priors and under model misspecification.
Read the full abstract ▾
All authors Adrian E. Bayer, Liam Parker, David Valcin, Shi-Fan Chen, Chirag Modi, Uros Seljak
Astrophysics of Galaxies
AGILE: an end-to-end Rubin-LSST simulation of AGNs, galaxies, and stars I. Software description and first data release
A. Viitanen, A. Bongiorno, I. Saccheo et al. (+37 more)
Contemporary large-scale surveys such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) and Euclid present an unprecedented discovery potential for studying AGNs at the population level in the big data era. However, one major challenge is the accurate identification and classification of AGNs from optical/NIR photometry, or variability data alone. In order to optimize AGN selection, classification, and systematics, as well as to test different data analysis tools, we present AGILE (AGNs In the LSST Era), an LSST end-to-end simulation software. AGILE – developed as part of the INAF LSST in-kind contribution – is capable of simulating the anticipated AGN population in LSST and Euclid. We based AGILE on existing simulations of
galaxies and
stars, while we developed an AGN recipe based on empirical relations. AGILE populates complete
galaxy samples with AGNs according to the observed AGN
accretion rate distribution, and each AGN is assigned an optical/UV spectral energy distribution. Optical AGN variability is added using a damped random walk model connected to the AGN physical parameters. Finally, AGILE creates both LSST-like images and related data products. Using AGILE, we build a $24$ deg$^2$ complete mock truth catalog of AGNs,
galaxies, and
stars with $0.2 < z < 5.5$, $\log M/M_\odot > 8.5$ (AGNs and
galaxies), and $r < 27.5$ mag (
stars). We perform a pilot simulation (AGILE DR1) consisting of $1$ deg$^2$ of LSST operations in the COSMOS field observed up to three years according to the survey strategy. We use AGILE DR1 to quantify the accuracy of the LSST Science Pipelines in recovering true fluxes of AGNs,
galaxies, and
stars. We quantify the LSST completeness and purity in recovering Type 1 AGNs using typical color-color and variability selections. We share the AGILE DR1
dataset, an ideal test-bench for further scientific exploitation.
Read the full abstract ▾
All authors A. Viitanen, A. Bongiorno, I. Saccheo, A. Grazian, M. Paolillo, V. Petrecca, D. De Cicco, D. Roberts, F. Shankar, V. Allevato, E. Merlin, D. Ilić, A. B. Kovačević G. De Somma, M. Di Criscienzo, L. Girardi, M. Marconi, A. Mazzi, G. Pastorelli, M. Trabucchi, T. Ananna, R. J. Assef, W. N. Brandt, M. Brescia, A. W. Graham, G. Li, D. Marsango, A. Peca, M. Polioudakis, C. M. Raiteri, B. Rani, C. Ricci, G. Richards, M. Salvato, S. Satheesh-Sheeba, R. Shirley, S. Tang, M. J. Temple, F. Tombesi, I. Yoon, F. Zou
Cosmology and Nongalactic Astrophysics · Cross-listed from hep-ph
Cosmological Collider Searches beyond the Hubble Scale with Planck Data
Soubhik Kumar, Qianshu Lu, Zhong-Zhi Xianyu et al. (+1 more)
Searches for
primordial non-Gaussianity (NG) has the potential to not only reveal the physics of
cosmic inflation, but also the structure of fundamental interactions at the highest energies. The cosmological
collider (CC) physics program exemplifies this possibility and demonstrates how searches for oscillatory NG can lead to mass-
spin spectroscopy of extremely heavy states. Adopting an effective field theory approach, we find the class of Feynman diagrams that can give the largest NG mediated by a heavy scalar particle with mass $M\sim H$, the inflationary Hubble scale. We compute the full shape of the NG and perform the first search for this shape using Planck data, finding no evidence for NG. This search loses its sensitivity as $M\gg H$ since
quantum vacuum fluctuations cannot efficiently produce such heavier particles. We then focus on a mechanism where a chemical potential excites on-shell scalar particles with mass $M\gg H$. Computing the full shapes, we perform the first CC search for particles parametrically heavier than $H$ using Planck data. For a range of chemical potential $\omega$ and $M$ satisfying $\omega-M \simeq 3H$, we find a global $1.7\sigma$ evidence for non-zero NG, after taking into account the look-elsewhere effect.
Read the full abstract ▾
All authors Soubhik Kumar, Qianshu Lu, Zhong-Zhi Xianyu, Yisong Zhang
Cosmology and Nongalactic Astrophysics
Formation and relaxation of halos in the context of wave DM particles evolving on a background of neutrino condensate
A. Capolupo, I. De Martino, S. Monda et al. (+2 more)
We investigate the formation and relaxation of dark matter
halos in the context of wave dark matter particles evolving on a background of
neutrino condensate. To this aim, we solved numerically the Schrodinger-Poisson system to model the dynamical
evolution of ultralight bosonic dark matter particles in the presence of
neutrino condensate. The latter appears as an additional source of the gravitational field in the Poisson equation, while its dynamical
evolution and interaction with the environment are neglected. We found that, depending by the value of the cutoff parameter, the presence of the background
neutrino condensate can affect the formation and relaxation of wave dark matter
halos. Nevertheless, for value of the cutoff of the order of a few eV, the two species can coexist showing only marginal differences with the only-wave dark matter case. These results open to the possibility of investigate about more complex cosmological scenarios involving the formation of dark matter
halos.
Read the full abstract ▾
All authors A. Capolupo, I. De Martino, S. Monda, R. Della Monica, A. Quaranta
Instrumentation and Methods for Astrophysics
py5vec: a modular Python package for the 5-vector method to search for continuous gravitational waves
Luca D'Onofrio, Federico Muciaccia, Lorenzo Mirasola et al. (+7 more)
We present py5vec, a Python package for implementing and extending the 5-vector method, used to search for continuous gravitational wave (CW) signals. We also provide a comprehensive theoretical review of the 5-vector method and extend the relative likelihood formalism by marginalizing over the noise variance, resulting in a more robust Student's t-likelihood, and over the initial phase to account for
pulsar glitches. py5vec provides a modular architecture that separates data representation, signal demodulation, and statistical inference into independent abstract stages. It supports multiple input data formats and interoperates with existing Python software, providing a bridge between different approaches. For example, using a bilby-based interface, py5vec implements
Bayesian parameter estimation within the 5-vector formalism for the first time. The modular design also allows for making exact multi-level and direct comparisons between other software, such as cwinpy and SNAG in MATLAB. In py5vec, we implement a multidetector targeted search for known
pulsars, validated using LIGO data from the O4a run and hardware injections, demonstrating consistent reconstruction of signal parameters. This package therefore provides a flexible platform for current targeted searches and for future extensions to other CW search strategies.
Read the full abstract ▾
All authors Luca D'Onofrio, Federico Muciaccia, Lorenzo Mirasola, Matthew Pitkin, Cristiano Palomba, Paola Leaci, Francesco Safai Tehrani, Francesco Amicucci, Lorenzo Silvestri, Lorenzo Pierini
Cosmology and Nongalactic Astrophysics · Cross-listed from gr-qc
Optical Magnus effect on gravitational lensing
Yusuke Nishida
The optical Magnus effect refers to transverse shift of a trajectory of light caused by its polarization and appears as a correction to geometrical optics at the linear order in wavelength. Here, we start from Maxwell's equations in a curved spacetime to derive the equation of motion for a wave packet of circularly polarized light, which confirms the known result involving the helicity-dependent anomalous velocity with some generalization and clarification. We then study possible consequences of the optical Magnus effect on gravitational
lensing in the Schwarzschild spacetime as well as under a weak gravitational potential in an expanding spacetime. Among others, by formulating the lens equation modified to incorporate the optical Magnus effect, the Einstein ring is found impossible to emerge from a point source for any axially symmetric thin lens. Analytic solutions to the modified lens equation are also obtained for simple lens models, illuminating how image formation is affected by the optical Magnus effect.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics · Cross-listed from hep-ph
QCD-driven dark matter: AQNs formation and observational tests
Ludovic Van Waerbeke
The nature of dark matter remains a central problem in cosmology. A compelling possibility is that dark matter is macroscopic, consisting of composite objects formed in the early Universe. We introduce the QCD-AQN framework, a well-motivated scenario in which dark matter is composed of dense aggregates of
quark and antiquark matter stabilised by
axion domain walls. The framework proposes a unified explanation for both dark matter and the observed matter-antimatter asymmetry. Particular emphasis is placed on existing observational constraints and on observational tests. Finally, we explore a possible QCD-based scenario for dark energy.
Read the full abstract ▾
High Energy Astrophysical Phenomena
Probing the potential high-energy messengers of the anticipated T Coronae Borealis outburst
O. Petruk, T. Kuzyo, S. Orlando et al. (+4 more)
T Coronae Borealis (T CrB) is a nearby recurrent nova expected to erupt in the near future, offering a unique opportunity to study particle acceleration and high-energy emission from novae in real time. We investigate the production of gamma-rays and
neutrinos following the T CrB outburst by combining three-dimensional hydrodynamical simulations with a detailed diffusive shock acceleration model. Our simulations account for the complex circumbinary medium, including the red
giant wind, equatorial density enhancement, and
accretion disk. We compute spatially resolved spectra of accelerated
protons and electrons at the forward shock, accounting for downstream velocity gradients and variations in shock properties. Using a multi-zone approach, we synthesize hadronic gamma- ray emission from
proton-
proton interactions, leptonic gamma-rays from inverse-Compton scattering, and the associated
neutrino emission. We present predicted gamma-ray spectra, light curves, and images from our numerical models of T CrB, and assess their detectability with current gamma-ray and
neutrino observatories. We find that the early high-energy emission is dominated by the ejecta, with the
accretion disk significantly boosting the gamma-ray flux and particle normalization during the first hours after the outburst. By incorporating velocity gradients in the post-shock flow, we demonstrate that maximum particle energies can reach the PeV scale in high-energy explosion scenarios. We show that while GeV gamma-rays are prominent messengers,
neutrino detection is feasible primarily in models with high explosion energy and high ambient density.
Read the full abstract ▾
All authors O. Petruk, T. Kuzyo, S. Orlando, L. Chomiuk, F. Bocchino, M. Miceli, S. Ustamujic
High Energy Astrophysical Phenomena
An extreme particle accelerator powered by pulsar PSR J1849-0001
The LHAASO Collaboration
Pulsar wind nebulae (PWNe) are bubbles of relativistic particles, powered by the rotational energy loss of the central
pulsars. The Crab Nebula, powered by the Milky Way's most energetic
pulsar, was discovered by the Large High Altitude Air Shower Observatory (LHAASO) as a PeV gamma-ray emitter, thereby establishing it as an extreme particle accelerator along with multiwavelength observations. Here we report LHAASO's detection of a point-like ultrahigh-energy (UHE,
photon energy $E>100\,$TeV) gamma-ray source associated with the PWN powered by PSR J1849-0001, a
pulsar of spindown power 50 times lower than the Crab
pulsar. The measured gamma-ray spectrum extends to PeV energies following a power-law distribution, with the PeV luminosity a few times higher than that of the Crab Nebula. Combined X-ray observations constrain the average
magnetic field within the source to about $3\mu\,$G, and reveal an extreme particle acceleration efficiency approaching or even exceeding unity in the PWN, which we refer to as the "Aquila Booster". The result challenges the particle acceleration theory in PWN and implies non-ideal magnetohydrodynamics (MHD) conditions within the accelerator, potentially involving
magnetic reconnection upstream of the termination shock.
Read the full abstract ▾
High Energy Astrophysical Phenomena
The hidden population of long gamma-ray bursts from compact object mergers
R. Maccary, C. Guidorzi, L. Amati et al. (+6 more)
Context. The
prompt-emission time profiles of GRB 230307A and other long-duration compact object merger (COM) candidates exhibit a unique set of temporal properties, characterised by a deterministic
evolution of waiting times and pulse widths. Aims. We searched the
Fermi/GBM catalogue for other unidentified long COM candidates exhibiting temporal properties similar to those observed in GRB 230307A. Methods. We examined the temporal and spectral
prompt-emission properties of GRBs featuring at least eight light-curve peaks. For candidates, all with unknown
redshifts, that exhibited properties similar to GRB 230307A, we analysed their trajectories in the Ep,i-Eiso plane as a function of
redshift. We then evaluated the joint likelihood of their compatibility with the Ep,i-Eiso relation satisfied by the bulk of long GRBs. Furthermore, we calculated their minimum variability timescales (MVTs) for comparison against known COM and collapsar populations. Results. We identified 9 COM candidates with unknown
redshifts and demonstrated that there are at least two outliers of the Ep,i-Eiso relation with 3.1 sigma (Gaussian) confidence level. Furthermore, their MVTs are more consistent with those of COM than with collapsar GRBs. Conclusions. These results indicate that this specific set of temporal properties can serve as a diagnostic tool to distinguish long-duration COMs from the broader collapsar population. Furthermore, our findings suggest that the fraction of unidentified COMs among long GRBs may be larger than previously assumed.
Read the full abstract ▾
All authors R. Maccary, C. Guidorzi, L. Amati, M. Bulla, S. Kobayashi, M. Maistrello, A. Rossi, G. Stratta, A.Tsvetkova
Cosmology and Nongalactic Astrophysics
Probing Gravitational-Wave Four-Point Correlators
Martina Ciprini, Maria Lucia Marcelli and Gianmassimo Tasinato
Stochastic gravitational-wave backgrounds (SGWBs) of
primordial origin offer a powerful probe of early-Universe physics and possible dark-sector dynamics. While most searches focus on the GW power spectrum, additional information is encoded in higher-order correlators that characterize the statistical properties of the signal. In this work we study non-Gaussian features of a cosmological SGWB generated at second order by vector fluctuations, a class of sources well motivated in early-Universe scenarios. Within this framework we develop tools to characterize higher-order GW correlators and compute representative four-point functions that generate a connected contribution to the GW trispectrum. We show that the trispectrum amplitude scales as the square of the GW power spectrum and peaks in characteristic folded momentum configurations, reflecting the structure of the nonlinear source. We then explore the observational implications. First, we demonstrate that the connected trispectrum contributes to the variance of two-point overlap reduction functions, including the Hellings-Downs curve relevant for
pulsar timing arrays. We then construct the optimal
estimator to measure the connected trispectrum with ground-based interferometers. Our results highlight how non-Gaussian SGWB statistics provide a complementary observable to probe the origin of GW backgrounds and to distinguish cosmological from astrophysical sources.
Read the full abstract ▾
Instrumentation and Methods for Astrophysics
SIMTERFERE: An optical interferometry simulator for quantifying the coherent flux stability of VLTI/GRAVITY+. Reaching per mill stability: Application to exoplanet spectroscopy
J. R. Sauter, A. von Stauffenberg, G. Bourdarot et al. (+7 more)
The implementation of the
GRAVITY+ Adaptive Optics (GPAO) system at VLTI enables unprecedented sensitivity and stability in optical interferometry. This allows high-precision characterization of directly imaged
exoplanets at medium spectral resolution, providing a new pathway for studying planetary atmospheres. We aim to quantify and characterize the short- and long-term stability of
GRAVITY+ through a consecutive seven-hour observation of the bright and stable
star beta Pictoris, providing a
benchmark for future
exoplanet observations. We developed SIMTERFERE, a data-driven simulation tool that reproduces
GRAVITY+ on-
star observations using ancillary instrument and telemetry data. By comparing the simulations with the measured coherent fluxes, we traced the origins of systematic flux variations and assessed their impact on
exoplanet contrast measurements. We find that the approximately 10% variations are dominated by throughput changes driven by variable fiber coupling, which depends on wavefront stability, atmospheric dispersion, and residual fiber offsets. These variations appear as smooth continuum changes across wavelength and can be effectively mitigated using second-order
polynomial corrections. After removing these instrumental effects, the remaining approximately 1% variations are almost purely of telluric origin, which we can reliably correct down to the
photon-noise limit (0.1% precision) using a contrast spectrum approach with linear airmass interpolation. The
GRAVITY+ inferometric instrument is highly stable: low-order continuum and telluric variations can be corrected with high precision, making it uniquely capable of high-fidelity characterization of directly imaged
exoplanets.
Read the full abstract ▾
All authors J. R. Sauter, A. von Stauffenberg, G. Bourdarot, W. Brandner, F. Eisenhauer, L. Kreidberg, L. Labadie, S. Scheithauer, D. Trevascus, R. van Boekel
Instrumentation and Methods for Astrophysics
iDaVIE v1.0: A virtual reality tool for interactive analysis of astronomical data cubes
Alexander Sivitilli, Lucia Marchetti, Angus Comrie et al. (+9 more)
As modern astronomy confronts unprecedented data volumes, automated pipelines and machine-learning techniques have become essential for processing and analysis. As these workflows grow more complex, astronomers also require input and inspection tools that can keep pace. To address challenges in navigating multidimensional
datasets for quality control and scientific interpretation, we present the immersive Data Visualisation Interactive Explorer (iDaVIE), a virtual reality (VR) software suite developed in collaboration with the astronomy community. iDaVIE enables users to import and render large 3D data cubes within a VR environment, offering real-time tools for selection, cropping, catalogue overlays, and exporting results back into existing pipelines. Built on the Unity engine and SteamVR, the system uses custom plug-ins for efficient data parsing, downsampling, and statistical calculations. The software has already been integrated into workflows such as verifying HI data cubes from MeerKAT, ASKAP, and APERTIF, refining detection masks, and identifying new sources. Its intuitive interface aims to reduce the cognitive load associated with higher-dimensional data, allowing researchers to focus more directly on scientific goals. As an open-source, scalable, and adaptable platform, iDaVIE supports continued development and integration with other tools. Version 1.0 marks a significant milestone, with planned enhancements including subcube loading, advanced rendering modes,
video-generation scripts, and collaborative capabilities. By pairing immersive visualisation with robust interaction tools, iDaVIE seeks to transform how researchers engage with complex
datasets and enhance productivity in the era of big data.
Read the full abstract ▾
All authors Alexander Sivitilli, Lucia Marchetti, Angus Comrie, P. Cilliers Pretorius, Thijs van der Hulst, Fabio Vitello, D. J. Pisano, Ugo Becciani, A. Russell Taylor, Paolo Serra, Mayhew Steyn, Michaela van Zyl
High Energy Astrophysical Phenomena
Shocks in the Symbiotic Recurrent Nova V3890 Sgr: VLBI Radio Imaging and Fermi GeV Gamma-Rays
Isabella Molina, Peter Craig, Rebecca Diesing et al. (+14 more)
We present very long baseline interferometric (VLBI)
radio imaging and
Fermi/LAT GeV $\gamma$-ray observations of the 2019 eruption of the symbiotic recurrent nova V3890 Sgr.The VLBI imaging spans 8 – 51 days after eruption, synchronous with the detected $\gamma$-rays. VLBI imaging shows the eruption starts out asymmetric on day 8 with an eastern component brighter than a western component. By day 32 the blast is rather circularly symmetric, and on day 49, the nova shell is brighter along the north–south axis. This morphological
evolution is explained by interaction with circumstellar material (CSM) comprised of a spherical wind plus an over-density in the orbital plane. Comparing
radio images to optical line widths gives an expansion parallax distance of 6.8 kpc. In the first 32 days or eruption, VLBI images capture $>$80 per cent of the integrated flux (as measured by the VLA), implying that synchrotron emission dominates. A second peak in the VLA light curve is explained by an image on day 48 that reveals the nova shell surrounded by a diffuse
halo, powered by synchrotron emission from particles that have diffused upstream of the shock. The $\gamma$-rays appear around optical maximum and remain detectable for 23 days; marginally significant $\gamma$-rays reappear around day 60, concurrent with the second
radio peak. Modelling indicates
radio and $\gamma$-ray emission arise in distinct shock regions: $\gamma$-rays from dense CSM in the orbital plane,
radio from the more spherical CSM component. X-ray observations constrain the spherical CSM density, which is higher than in other symbiotic recurrent novae. Assuming equipartition, we estimate the fraction of the post-shock pressure in
magnetic fields, $\epsilon_B = 3 \times 10^{-4} - 2 \times 10^{-3}$.
Read the full abstract ▾
All authors Isabella Molina, Peter Craig, Rebecca Diesing, Laura Chomiuk, Justin D. Linford, Brian D. Metzger, Jun Yang, Brandon Benavente, Kim L. Page, Kirill V. Sokolovsky, Elias Aydi, Amy J. Mioduszewski, Koji Mukai, Miriam M. Nyamai, Michael P. Rupen, J. L. Sokoloski, Montana N. Williams
Astrophysics of Galaxies
Spatial analysis of PAH molecules in the Pillars of Creation using JWST
Pranav R. Iyengar
I present a spatially resolved analysis of the polycyclic aromatic hydrocarbon (PAH) population in the Pillars of Creation within the Eagle Nebula (M16) using the James Webb Space
Telescope's (JWST) Mid Infrared Instrument (MIRI) and Near Infrared Camera (NIRCam) imaging. By using mid infrared PAH sensitive bands, I derive resolved maps of PAH size and ionization state across the pillars and connect these directly to variations in the radiation field and gas structure. I present the first spatial maps of PAH ionization and size in the Pillars of Creation. The analysis reveals clear internal gradients that show the PAH population is strongly shaped by local conditions within the cloud, such as the local radiation intensity and orientation of the nebular structure. The intensely radiated regions show a neutral and large PAH population, possibly due to electron recombination in these regions. I measure a mean PAH size of 198 carbon atoms with an error bar of 1.22 for M16 and use the resolved emission structure to obtain a first-order estimate of the electron density in the molecular cloud. These results provide direct evidence that PAH properties in M16 are governed by the interplay between radiation and density on sub-cloud scales, demonstrating the power of JWST imaging to probe
dust processing in
star-forming regions.
Read the full abstract ▾
Instrumentation and Methods for Astrophysics
The Effect of "Roll-Drift" in ACS/WFC Images
Yotam Cohen
In 2024, due to some operational changes, the Hubble Space
Telescope began exhibiting undeclared loss of lock events. This loss of lock can result in the smearing out of light from the target field during an exposure, which leads to data degradation, which in turn may require data to be retaken. In this work, we investigate this `roll-drift' effect in ACS/WFC images. We quantify the impact of roll-drift on measurable parameters in data by using simulations and existing data reduction techniques. We identify a threshold of one such measurable parameter beyond which data may likely be affected by roll-drift, so that users can quickly and easily assess whether their data needs further
attention.
Read the full abstract ▾
Astrophysics of Galaxies
Kinematical and dynamical properties of recently discovered bulge and disc star clusters with WINERED
Ilaria Petralia, Dante Minniti, José G. Fernández-Trincado et al. (+8 more)
Context.
Galactic globular clusters are a very important tool in explaining the characteristics of the Milky Way. Therefore it is essential to determine the kinematical and dynamical properties of the new
star cluster candidates, especially at the low-latitude regions that suffer from heavy extinction and crowding. Aims. In this work, we report the first spectroscopic analysis for seven recently identified
star cluster candidates: CWNU 4193, FSR 1700, Garro 02, Patchick 98, FSR 1767, Mercer 08, and BH 140. Our aim is to determine the kinematical properties, such as the mean cluster radial velocity, and the dynamical properties, such as the orbital parameters and the global dynamical mass, of these clusters in order to spectroscopically confirm the nature of these seven
stellar systems. Methods. We collected the high-resolution infrared spectra of 33 candidate members of these clusters using the WINERED spectrograph mounted on the Magellan Clay 6.5 m
telescope. Using the WINERED spectra, we measured the radial velocity of each individual
star to confirm its membership in the clusters. From the confirmed members, we derived the mean cluster radial velocity of each cluster. In addition, for these clusters, we computed the orbital elements using the GravPot16 model and estimated their global dynamical masses based on the virial
theorem. Results. As a result, we confirmed enough member
stars (from three to seven
stars per cluster) to reliably derive the mean cluster radial velocity and compute the orbital parameters of the clusters CWNU 4193, FSR 1700, Garro 02, and BH 140. For clusters CWNU 4193, FSR 1700, and BH 140, the number of confirmed members also allowed us to estimate their global dynamical masses. Therefore, we successfully derived key kinematical and dynamical properties for four of the most obscured
star clusters in the Milky Way.
Read the full abstract ▾
All authors Ilaria Petralia, Dante Minniti, José G. Fernández-Trincado, Noriyuki Matsunaga, Daisuke Taniguchi, Sasi Saroon, Elisa R. Garro, Hiroaki Sameshima, Shogo Otsubo, Yuki Sarugaku, Tomomi Takeuchi
Astrophysics of Galaxies
The Steep-spectrum Radio-loud AGN Luminosity Function and Its Implications for Black Hole Growth and Star Formation
Wenjie Wang, Zunli Yuan, B. Šlaus et al. (+2 more)
We study the
cosmic evolution of
radio-loud active
galactic nuclei (AGNs) using a beaming-minimized sample of 4{,}555 steep-spectrum sources over $0<z\lesssim4$, compiled from the XXL survey, VLA-COSMOS, and other wide-field data sets. We model the rest-frame 1.4 GHz
radio luminosity function (RLF) with a luminosity-and-density
evolution (LADE; DE+LE) framework coupled to a flexible local LF family. Among the tested parameterizations, Model~C is statistically preferred and provides a globally consistent description of the binned RLFs while remaining compatible with local RLF measurements and Euclidean-normalized source counts. In the fiducial solution, the LE term rises toward
cosmic noon ($z\sim2$–3) and then flattens or mildly declines, whereas the DE term decreases monotonically with
redshift. This combined
evolution naturally reproduces the observed luminosity-dependent turnover
redshift $z_{\rm peak}(L)$ (often termed “
cosmic downsizing”) without imposing a priori distinct evolutionary laws for low- and high-power sources. We further show that the same LADE functional family calibrated for
star-forming
galaxies also describes
radio-loud AGNs when fitted independently, enabling a unified two-component (SFG+AGN) model consistent with both the local RLF and source-count statistics. Finally, converting the AGN RLF to a kinetic luminosity function yields a
radio-mode black hole
accretion rate density (BHAD) whose
redshift dependence closely tracks the
radio-based
cosmic star formation rate density (after a conventional rescaling), with both histories peaking near $z\sim2$.
Read the full abstract ▾
All authors Wenjie Wang, Zunli Yuan, B. Šlaus, Hongwei Yu, Yu Luo
Instrumentation and Methods for Astrophysics
A flexible method for estimating luminosity functions via Kernel Density Estimation – III. Extending to Multiple Flux-Limited Samples
Zunli Yuan, Chuanqi Li, Wenjie Wang et al. (+2 more)
As the third paper in a series regarding the estimation of luminosity functions (LFs) via kernel density estimation (KDE), we present a further generalization of our framework by extending its applicability to multiple flux-limited samples. While our previous works addressed single flux-limited
datasets, many practical applications involve surveys that cover disjoint fields of view with different flux limits. We introduce a piecewise estimation framework that partitions the luminosity-
redshift plane into disjoint regions according to the staggered flux limits of the sub-samples. Within each region, we integrate data from all surveys capable of detecting sources into a combined sample and apply the transformation-reflection KDE method using the corresponding local flux threshold as the truncation boundary. This strategy allows for the full utilization of all available sources while maintaining rigorous statistical consistency. The robustness of this approach is validated through Monte Carlo simulations. Furthermore, application to SDSS DR7 and 2SLAQ
quasar data shows overall agreement with parametric models, while a small residual discontinuity near a survey-transition boundary is discussed as a diagnostic of independent piecewise estimation and possible inter-survey systematics. The KDE calculations in each piecewise region are performed using our previously developed public Python package kdeLF.
Read the full abstract ▾
All authors Zunli Yuan, Chuanqi Li, Wenjie Wang, Luozhenhan Liu, Longhua Qin
Astrophysics of Galaxies
The Stellar Initial Mass Function down to 0.16M$_{\odot}$ Towards the Small Magellanic Cloud
Roger E. Cohen, Mario Gennaro, Matteo Correnti et al. (+2 more)
The presence (and nature) of variations in the
stellar initial mass function (IMF) at substantially sub-
solar masses and
metallicities ($m$$<$0.5M$_{\odot}$, [M/H]$\lesssim$$-$1) remains poorly constrained. Predictions from simulations vary widely, while observationally, resolved
star studies of ultra-faint
dwarf galaxies (UFDs) suffer from small sample sizes and background
galaxy contamination due to low projected
stellar densities. As an alternative metal-poor target, we measure the IMF from resolved
stars towards a carefully selected field in the Small Magellanic Cloud (SMC), leveraging a plethora of independent constraints on the target field
stellar population including distributions of distance, %extinction, age and
metallicity. We resolve $>$15,000
stars down to 0.16M$_{\odot}$ within a single pointing of NIRCam onboard JWST, using an observing strategy that minimizes contamination from point-source-like background
galaxies. We explore three different functional forms of the IMF, forward modeling observed color-magnitude diagrams (CMDs) and luminosity functions. We find a best-fit single power law IMF slope of $\alpha$=$-$1.61$^{+0.03}_{-0.03}$, consistent with UFDs probed down to similar limiting masses. Fitting a broken power law IMF, we find low- and high-mass slopes of $\alpha_{1}$=$-$1.44$^{+0.04}_{-0.04}$, $\alpha_{2}$=$-$2.17$^{+0.11}_{-0.11}$ respectively, consistent with
solar neighborhood values. Assuming a lognormal IMF, we find a characteristic mass and lognormal width of $m_{c}$=0.12$^{+0.03}_{-0.03}$M$_{\odot}$, $\sigma$=0.61$^{+0.07}_{-0.06}$M$_{\odot}$, allowing for characteristic masses lower than local values as seen in some simulations as well as low-
metallicity Galactic clusters. Lastly, we quantify the impact of assumptions required in our analysis and discuss potential future improvements.
Read the full abstract ▾
All authors Roger E. Cohen, Mario Gennaro, Matteo Correnti, Kristen B. W. McQuinn, Vedant Chandra