Tootfinder

From a collapsing radiating star to an evaporating black hole: A smooth transition from classical to quantum entropy
Sarbari Guha, Shamima Khan, Rituparno Goswami
https://arxiv.org/abs/2507.16485

From a collapsing radiating star to an evaporating black hole: A smooth transition from classical to quantum entropy
We present a robust mechanism where the geometrical free-gravitational entropy of an isolated astrophysical radiating star undergoing continual gravitational collapse, as measured by an external observer, makes a smooth transition to the Bekenstein-Hawking entropy at the onset of the horizon formation and in the late times of black hole evaporation. It is interesting to note that both in the classical regime and the semi classical evaporating black hole regime, the matter is radiated via the Va…

Resolving Black Hole Family Issues Among the Massive Ancestors of Very High-Spin Gravitational-Wave Events Like GW231123
Jakob Stegmann, Aleksandra Olejak, Selma E. de Mink
https://arxiv.org/abs/2507.15967

Resolving Black Hole Family Issues Among the Massive Ancestors of Very High-Spin Gravitational-Wave Events Like GW231123
The latest detection of GW231123, a binary black hole (BH) merger with exceptionally large masses and high spins for the incoming components, has been suggested as a smoking gun for hierarchical formation. In this scenario, a first generation of BHs resulting from collapsing stars form in a dense environment. Here they can assemble dynamically and undergo subsequent mergers. We discuss three challenges for the formation of a GW231123-like event inside a star cluster: 1) The high masses of the i…

Predicting the Properties of the Fallback Rate from Tidal Disruption Events: Investigating the Maximum Gravity Model
Julia Fancher, Ananya Bandopadhyay, Eric R. Coughlin, C. J. Nixon
https://arxiv.org/abs/2507.16912

Predicting the Properties of the Fallback Rate from Tidal Disruption Events: Investigating the Maximum Gravity Model
A star destroyed by the tidal field of a supermassive black hole (SMBH) in a tidal disruption event (TDE) gives rise to a luminous flare. TDEs are being detected at an ever-increasing rate, motivating the need for accurate models of their lightcurves. The ``maximum gravity'' (MG) model posits that a star is completely destroyed when the tidal field of the SMBH exceeds the maximum self-gravitational field within the star, $g_{\rm max}$, and predicts the peak fallback rate $\dot{M}_{\rm peak}$ an…

Black Hole - Neutron Star and Binary Neutron Star Mergers from Population III and II stars
Benedetta Mestichelli, Michela Mapelli, Filippo Santoliquido, Manuel Arca Sedda, Marica Branchesi, Lavinia Paiella, Guglielmo Costa, Giuliano Iorio, Matthew Mould, Veronika Lipatova, Boyuan Liu, Ralf S. Klessen
https://arxiv.org/abs/2506.1…

Black Hole - Neutron Star and Binary Neutron Star Mergers from Population III and II stars
Population III (Pop.$~$III) stars are expected to be massive and to undergo minimal mass loss due to their lack of metals, making them ideal progenitors of black holes and neutron stars. Here, we investigate the formation and properties of binary neutron star (BNS) and black hole-neutron star (BHNS) mergers originating from Pop.$~$III stars, and compare them to their metal-enriched Population II (Pop.$~$II) counterparts, focusing on their merger rate densities (MRDs), primary masses and delay t…

Leveraging NRTidalv3 to develop gravitational waveform models with higher-order modes for binary neutron star systems
Adrian Abac, Felip Ramis Vidal, Marta Colleoni, Anna Puecher, Alejandra Gonzalez, Tim Dietrich
https://arxiv.org/abs/2507.15426

Leveraging NRTidalv3 to develop gravitational waveform models with higher-order modes for binary neutron star systems
Accurate and reliable gravitational waveform models are crucial in determining the properties of compact binary mergers. In particular, next-generation gravitational-wave detectors will require more accurate waveforms to avoid biases in the analysis. In this work, we extend the recent NRTidalv3 model to account for higher-mode corrections in the tidal phase contributions for binary neutron star systems. The higher-mode, multipolar NRTidalv3 model is then attached to several binary-black-hole ba…

Analogue simulation of quantum gravity black hole models in a dc-SQUID array
Marco D. Maceda, Carlos Sab\'in
https://arxiv.org/abs/2507.14150 https://

Analogue simulation of quantum gravity black hole models in a dc-SQUID array
We propose an analog quantum simulation for studying the collapse and bounce of a star from infinity. In this spacetime, which encompasses both a black hole and a white hole, we place a massless scalar field that propagates at the speed of light, which is modified by the curvature. We simulate this system using an SQUID array, in which we can alter the propagation of light using an external magnetic field. We consider both infalling and outfalling radiation, giving rise to two different scenari…

With the 5th #AAS246 presser come the paper https://arxiv.org/abs/2506.07262 (ALMA-JELLY I: High Resolution CO(2-1) Observations of Ongoing Ram Pressure Stripping in NGC 4858 Reveal Asymmetrical Gas Tail Formation and Fallback), the press release https://news.arizona.edu/news/belly-beast-massive-clumps-reveal-star-factories-bygone-era-cosmos (In the belly of the beast: massive clumps reveal star factories from a bygone era of the cosmos) and the papers https://iopscience.iop.org/article/10.3847/1538-4357/ada8a6 (UNCOVERing the Faint End of the z ∼ 7 [O iii] Luminosity Function with JWST's F410M Medium Bandpass Filter) with the press release https://science.nasa.gov/missions/webb/nasas-webb-uncovers-galaxy-population-driving-cosmic-renovation/ and https://arxiv.org/abs/2505.06198 (The "Dark-Matter Dominated" Galaxy Segue 1 Modeled with a Black Hole and no Dark Halo) with the press release https://www.utsa.edu/today/2025/06/story/researchers-offer-alternative-to-dark-matter-model.html

Double tidal disruption events in the changing-look AGN Mrk1018
Zhang XueGuang (GXU)
https://arxiv.org/abs/2507.14428 https://arxiv.o…

Double tidal disruption events in the changing-look AGN Mrk1018
Tidal disruption events (TDEs) as excellent beacons to black hole (BH) accreting systems have been studied for more than five decades with a single star tidally disrupted by a central massive BH. However, if considering two stars passing through a central BH and being tidally disrupted in a short period, so-called double TDEs could be expected and lead to unique variability features very different from features from standard TDEs. Here, we report such oversimplified double TDEs in the known cha…

Hey #StarWars #Andor fan. I think you'll enjoy these rabbit hole playlists. 😁

▶️ Star Wars Andor - Epic Themes & Moments Playlist (Edits by SWFT)

A Be star-black hole binary with a wide orbit from LAMOST time-domain survey
Qian-Yu An, Yang Huang, Wei-Min Gu, Yong Shao, Zhi-Xiang Zhang, Tuan Yi, B. D. Lailey, T. A. A. Sigut, Kyle Akira Rocha, Meng Sun, Seth Gossage, Shi-Jie Gao, Shan-Shan Weng, Song Wang, Bowen Zhang, Xinlin Zhao, Senyu Qi, Shilong Liao, Jianghui Ji, Junfeng Wang, Jianfeng Wu, Mouyuan Sun, Xiang-Dong Li, Jifeng Liu

A Be star-black hole binary with a wide orbit from LAMOST time-domain survey
Binary systems consisting of an early type star and a black hole (BH) are crucial for understanding various astrophysical phenomena, particularly the origins of detected gravitational wave sources. Be binary systems are expected to represent a key evolutionary stage in hosting BHs. However, while hundreds of Be X-ray binaries are known, the only confirmed BH candidate in a Be binary remains highly controversial. We report the discovery of ALS 8814, a Be star-BH binary with a moderately eccentri…

Probing the Schwarzschild black hole immersed in a dark matter halo through astrophysical tests
Tursunali Xamidov, Sanjar Shaymatov, Qiang Wu, Tao Zhu
https://arxiv.org/abs/2507.13147

Probing the Schwarzschild black hole immersed in a dark matter halo through astrophysical tests
We investigate a recently derived Schwarzschild-like black hole (BH) immersed in a Dehnen-type $(α,β,γ)=(1,4,5/2)$ dark matter (DM) halo. We obtain constraints on the two model parameters, i.e., the halo core radius $r_s$ and the DM density parameter $ρ_s$ in both the weak and the strong field regimes. In the weak field, we model test particle geodesics and match the predicted perihelion shift to Mercury (Solar System) and the orbit of the S2 star data, obtaining upper limits on $r_s$ and $…

Spin-orbit misalignment and residual eccentricity are evidence that neutron star-black hole mergers form through triple star evolution
Jakob Stegmann, Jakub Klencki
https://arxiv.org/abs/2506.09121

Spin-orbit misalignment and residual eccentricity are evidence that neutron star-black hole mergers form through triple star evolution
There is growing evidence that a substantial fraction of the neutron star-black holes (NSBHs) detected through gravitational waves merge with non-zero eccentricity or large BH spin-orbit misalignment. This is in tension with the leading formation scenarios to date. Residual eccentricity rules out formation through isolated binary star evolution, while NS natal kicks and the unequal masses of NSBHs inhibit efficient pairing in dense stellar environments. Here, we report that all observed propert…

So Naomi Brockwell TV blew my mind about how are smart TVs are spying on us with Automatic Content Recognition and other advertising profile scripts. Yikes!
https://youtu.be/jeq2m-OM53A?si=DPW7TQiDSopBdqiS
I don’t have the resources to switch to a more secure streaming devic…

Hyperboloidal neutron star and black hole initial data in spherical symmetry
Alex Va\~n\'o-Vi\~nuales
https://arxiv.org/abs/2506.05467 https://

Hyperboloidal neutron star and black hole initial data in spherical symmetry
The focus of this work is on the construction of initial data including a neutron star on a hyperboloidal slice. As simplest scenario for this first step, spherical symmetry is considered together with a polytropic-like equation of state for the neutron star. Constraint-satisfying hyperboloidal initial data are obtained for a single neutron star and for a combination of neutron star with a black hole in its center. To the author's best knowledge this is the first time that full hyperboloidal sl…

Multi-band Emission from Star-Disk Collision and Implications for Quasi-Periodic Eruptions
Xiaoshan Huang, Itai Linial, Yan-Fei Jiang
https://arxiv.org/abs/2506.11231

Multi-band Emission from Star-Disk Collision and Implications for Quasi-Periodic Eruptions
We perform two-dimensional, multi-group radiation hydrodynamic simulations to explore the observational properties of a solar-like star colliding with an accretion disk around a supermassive black hole at separation of $\sim 100$ gravitational radii. We find that the star-disk collision produces ejecta on both sides of the disk. As the ejecta expand and cool, transient flares arise, reaching peak bolometric luminosity of up to $L\gtrsim10^{43}\rm erg~s^{-1}$. We estimate that the typical light …

Extreme AGN feedback in the fossil galaxy group SDSSTG 4436
D. Eckert, F. Gastaldello, L. Lovisari, S. McGee, T. Pasini, M. Brienza, K. Kolokythas, E. O'Sullivan, A. Simionescu, M. Sun, M. Ayromlou, M. A. Bourne, Y. Chen, W. Cui, S. Ettori, A. Finoguenov, G. Gozaliasl, R. Kale, F. Mernier, B. D. Oppenheimer, G. Schellenberger, R. Seppi, E. Tempel

Extreme AGN feedback in the fossil galaxy group SDSSTG 4436
Supermassive black hole feedback is the currently favoured mechanism to regulate the star formation rate of galaxies and prevent the formation of ultra-massive galaxies ($M_\star>10^{12}M_\odot$). However, the mechanism through which the outflowing energy is transferred to the surrounding medium strongly varies from one galaxy evolution model to another, such that a unified model for AGN feedback does not currently exist. The hot atmospheres of galaxy groups are highly sensitive laboratories of…

Hyperboloidal neutron star and black hole initial data in spherical symmetry
Alex Va\~n\'o-Vi\~nuales
https://arxiv.org/abs/2506.05467 https://

Hyperboloidal neutron star and black hole initial data in spherical symmetry
The focus of this work is on the construction of initial data including a neutron star on a hyperboloidal slice. As simplest scenario for this first step, spherical symmetry is considered together with a polytropic-like equation of state for the neutron star. Constraint-satisfying hyperboloidal initial data are obtained for a single neutron star and for a combination of neutron star with a black hole in its center. To the author's best knowledge this is the first time that full hyperboloidal sl…

Double Compact Binary Merger Rate Density in Open Star Clusters: Black Holes, Neutron Stars, and White Dwarfs
Savannah Cary, Michiko Fujii, Long Wang, Ataru Tanikawa
https://arxiv.org/abs/2506.22673

Double Compact Binary Merger Rate Density in Open Star Clusters: Black Holes, Neutron Stars, and White Dwarfs
Studying compact-object binary mergers in star clusters is crucial for understanding stellar evolution and dynamical interactions in galaxies. Open clusters in particular are more abundant over cosmic time than globular clusters, however, previous research on low-mass clusters with $\lesssim 10^3~\textrm{M}_{\odot}$ has focused on binary black holes (BBHs) or black hole-neutron star (BH-NS) binaries. Binary mergers of other compact objects, such as white dwarfs (WDs), are also crucial as progen…

Mass Distribution of Binary Black Hole Mergers from Young and Old Dense Star Clusters
Claire S. Ye (CITA), Maya Fishbach, Kyle Kremer, Marta Reina-Campos
https://arxiv.org/abs/2507.07183

Mass Distribution of Binary Black Hole Mergers from Young and Old Dense Star Clusters
Dense star clusters are thought to contribute significantly to the merger rates of stellar-mass binary black holes (BBHs) detected by the LIGO-Virgo-KAGRA collaboration. We combine $N$-body dynamic models of realistic dense star clusters with cluster formation histories to estimate the merger rate distribution as a function of primary mass for merging BBHs formed in these environments. It has been argued that dense star clusters -- most notably old globular clusters -- predominantly produce BBH…

Enhanced Star Formation and Black Hole Accretion Rates in Galaxy Mergers in IllustrisTNG50
Aimee L. Schechter, Shy Genel, Bryan Terrazas, Julia M. Comerford, Abigail Hartley, Rachel S. Somerville, Rebecca Nevin, Joseph Simon, Erica Nelson
https://arxiv.org/abs/2507.01092

Enhanced Star Formation and Black Hole Accretion Rates in Galaxy Mergers in IllustrisTNG50
Many theoretical and observational studies have suggested that galaxy mergers may trigger enhanced star formation or active galactic nuclei (AGN) activity. We present an analysis of merging and nonmerging galaxies from $0.2 \leq z \leq 3$ in the IllustrisTNG50 simulation. These galaxies encompass a range of masses ($M_\star > 10^{8}M_\odot$), multiple merger stages, and mass ratios ($\geq1:10$). We examine the effect that galaxy mergers have on star formation and black hole accretion rates in t…

A case study of GW190425 for classifying binary neutron star versus binary black hole mergers and constraining asymmetric dark matter with gravitational wave detectors
Sanika Khadkikar, Divya Singh
https://arxiv.org/abs/2507.07895

A case study of GW190425 for classifying binary neutron star versus binary black hole mergers and constraining asymmetric dark matter with gravitational wave detectors
The LIGO Scientific, Virgo, and KAGRA collaboration has identified two binary neutron star merger candidates, GW170817 and GW190425, along with several binary black hole candidates. While GW170817 was confirmed as a BNS merger through its electromagnetic counterparts, GW190425 lacked such observations, leaving its classification uncertain. We examine the possibility that GW190425 originated from black holes that merged after dark matter accretion caused their progenitor neutron stars to implode…

Fifty Years of CAK
Jorick S. Vink (Armagh Observatory,Planetarium)
https://arxiv.org/abs/2506.06421 https://arxiv.org/pdf/2506.06421

Fifty Years of CAK
We present a new framework for massive star evolution that is no longer driven by Dutch or other mass-loss rate Recipes, but which take the physics of Gamma or L/M dependent mass loss consistently into account. We first discuss the hot-star mass-loss kink and the transition mass loss rate between optically thin and thick winds, before discussing vertical stellar evolution, mass evaporation, and the maximum black hole (BH) mass. We end with a suggestion that a recently uncovered red supergiant (…

Wind-fed Supermassive Black Hole Accretion by the Nuclear Star Cluster: the Case of M31*
Zhao Su, Zhiyuan Li, Zongnan Li
https://arxiv.org/abs/2506.04778 h…

Wind-fed Supermassive Black Hole Accretion by the Nuclear Star Cluster: the Case of M31*
The central supermassive black hole (SMBH) of the Andromeda galaxy, known as M31*, exhibits dim electromagnetic emission and is inferred to have an extremely low accretion rate for its remarkable mass ($\sim10^8~\rm~M_\odot$). In this work, we use three-dimensional hydrodynamical simulations to explore a previously untested scenario, in which M31* is fed by the collective stellar mass-loss from its surrounding nuclear star cluster, manifested as a famous eccentric disk of predominantly old stel…

Thermal electrons in the radio afterglow of relativistic tidal disruption event ZTF22aaajecp/AT2022cmc
Lauren Rhodes, Ben Margalit, Joe S. Bright, Hannah Dykaar, Rob Fender, David A. Green, Daryl Haggard, Assaf Horesh, Alexander J. van der Horst, Andrew Hughes, Kunal Mooley, Itai Sfaradi, David Titterington, David WIlliams-Baldwin
https://

Thermal electrons in the radio afterglow of relativistic tidal disruption event ZTF22aaajecp/AT2022cmc
A tidal disruption event (TDE) occurs when a star travels too close to a supermassive black hole. In some cases, accretion of the disrupted material onto the black hole launches a relativistic jet. In this paper, we present a long term observing campaign to study the radio and sub-millimeter emission associated with the fifth jetted/relativistic TDE: AT2022cmc. Our campaign reveals a long lived counterpart. We fit three different models to our data: a non-thermal jet, a spherical outflow consis…

The connection between galaxy mergers, star formation and AGN activity in the HSC-SSP
Kiyoaki Christopher Omori, Connor Bottrell, Sabine Bellstedt, Aaron Robotham, Hassen M. Yesuf, Andy D. Goulding, Marcin Sawicki, Tohru Nagao, Tsutomu T. Takeuchi
https://arxiv.org/abs/2506.08469

The connection between galaxy mergers, star formation and AGN activity in the HSC-SSP
Internal gas inflows driven by galaxy mergers are considered to enhance star formation rates (SFR), fuel supermassive black hole growth and stimulate active galactic nuclei (AGN). However, quantifying these phenomena remains a challenge, due to difficulties both in classifying mergers and in quantifying galaxy and AGN properties. We quantitatively examine the merger-SFR-AGN connection using Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) galaxies using novel methods for both galaxy classif…

MESA-QUEST: Modeling Quasi-Stars in MESA
Claire B. Campbell, Andrew D. Santarelli, Matthew E. Caplan
https://arxiv.org/abs/2507.12651 https://

MESA-QUEST: Modeling Quasi-Stars in MESA
Supermassive black hole formation remains an unsolved problem. Quasi-stars have been suggested as a viable heavy-seeding mechanism. In this work, we implement methods for modeling quasi-stars previously used with the Cambridge STARS code into the 1D stellar evolution code MESA. The computational capabilities of MESA allow for more detailed simulations of quasi-star evolution due to its modularity and the ease of implementing of new physical processes and controls. Our implementation, the MESA Q…

Early Warning From Eccentric Compact Binaries: Template Initialization And Sub-dominant Mode Effects
Priyanka Sinha, R. Prasad, Mukesh Kumar Singh, Prayush Kumar, Akash Maurya, Kaushik Paul
https://arxiv.org/abs/2507.07021

Early Warning From Eccentric Compact Binaries: Template Initialization And Sub-dominant Mode Effects
Early warning of gravitational waves (GWs) is essential for multi-messenger observations of binary neutron star and black hole-neutron star merger events. In this study, we investigate early warning prospects from eccentric compact binaries, whose mergers are expected to comprise a significant fraction of detected GW events in the future. Eccentric binaries exhibit oscillatory frequency evolution, causing GW frequencies to recur multiple times through their coalescence. Consequently, generating…

The Impact of Natal Kicks on Black Hole Binaries
Alejandro Vigna-G\'omez
https://arxiv.org/abs/2507.07573 https://arxiv.org/pdf/2…

The Impact of Natal Kicks on Black Hole Binaries
In massive binary-star systems, supernova explosions can significantly alter the orbit during the formation of compact objects. Some compact objects are predicted to form via direct collapse, a scenario with negligible mass loss and no baryonic ejecta emitted. In this scenario, most of the energy is released via neutrinos, and any resulting natal kick arises from asymmetries in their emission. Here I investigate stellar collapse leading to binary black hole (BH) formation, with a focus on how t…

Dynamical mass of the Serpens intermediate-mass young stellar system EC\,95 with DYNAMO--VLBA
Jazm\'in Ord\'o\~nez-Toro (Instituto de Radioastronom\'ia y Astrof\'isica, Universidad Nacional Aut\'onoma de M\'exico, M\'exico), Sergio A. Dzib (Max Planck Institut f\"ur Radioastronomie, Germany), Laurent Loinard (Instituto de Radioastronom\'ia y Astrof\'isica, Universidad Nacional Aut\'onoma de M\'exico, M\'exico, Black Hole Initiative a…

Dynamical mass of the Serpens intermediate-mass young stellar system EC\,95 with DYNAMO--VLBA
We present dynamical mass measurements, obtained from multi-epoch Very Long Baseline Interferometry (VLBI) observations, for the young multiple stellar system EC\,95, located in the core of the Serpens star-forming region. Our dataset includes both archival data and more recent observations obtained as part of the \textit{Dynamical Masses of Young Stellar Multiple Systems with the VLBA project} (DYNAMO--VLBA), totalling 32 epochs over 12 years of observation. The observations span more than hal…

A Black Hole is Born: 3D GRMHD Simulation of Black Hole Formation from Core-Collapse
Goni Halevi, Swapnil Shankar, Philipp M\"osta, Roland Haas, Erik Schnetter
https://arxiv.org/abs/2506.20837

A Black Hole is Born: 3D GRMHD Simulation of Black Hole Formation from Core-Collapse
We present the first three-dimensional, fully general-relativistic magnetohydrodynamic (3D GRMHD) simulation of a black hole (BH) formed from the collapsed core of a massive star. The ability to self-consistently capture the birth of a compact remnant in 3D is crucial for modeling natal BH properties (including masses, spins, and kicks), which are of particular interest in the era of gravitational wave astronomy. However, such simulations have remained elusive due to extreme computational chall…

This https://arxiv.org/abs/2411.07035 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Inferring jet physics from neutron star - black hole mergers with gravitational waves
Neutron star - black hole (NSBH) mergers that undergo tidal disruption may launch jets that could power a gamma-ray burst. We use a population of simulated NSBH systems to measure jet parameters from the gravitational waves emitted by these systems. The conditions during the tidal disruption and merger phase required to power a gamma-ray burst are uncertain. It is likely that the system must achieve some minimum remnant baryonic mass after the merger before a jet can be launched to power a gamm…

Probing the peak of star formation with the stochastic background of binary black hole mergers
Nico Bers, Sylvia Biscoveanu
https://arxiv.org/abs/2506.21868

Probing the peak of star formation with the stochastic background of binary black hole mergers
Although the LIGO-Virgo-KAGRA collaboration detects many individually resolvable gravitational-wave events from binary black hole mergers, those that are too weak to be identified individually contribute to a stochastic gravitational-wave background. Unlike the standard cross-correlation search for excess correlated power, a Bayesian search method that models the background as a superposition of an unknown number of mergers enables simultaneous inference of the properties of high-redshift binar…

The $M_{\rm BH}-M_\star$ Relation of the hyperluminous Dust-obscured Quasars up to $z \sim 4$
Yibin Luo, Lulu Fan, Weibin Sun, Haoran Yu, Yunkun Han, Guangwen Chen, Mengqiu Huang, Yihang Zhang, Zheyu Lin
https://arxiv.org/abs/2506.01218

The $M_{\rm BH}-M_\star$ Relation of the hyperluminous Dust-obscured Quasars up to $z \sim 4$
Hot dust-obscured galaxies (Hot DOGs) are a rare population of hyperluminous dust-obscured quasars discovered by the Wide-field Infrared Survey Explorer (WISE) all-sky survey. The heavy circumnuclear dust obscuration allows only a small amount of scattered light from the obscured quasar to escape, enabling the decomposition of the stellar component from the total flux. The presence of scattered light enables the redshift of the source and the properties of the black hole to be obtained from SDS…

QPEs from EMRI Debris Streams Impacting Accretion Disks in Galactic Nuclei
Itai Linial, Brian D. Metzger, Eliot Quataert
https://arxiv.org/abs/2506.10096 h…

QPEs from EMRI Debris Streams Impacting Accretion Disks in Galactic Nuclei
Quasi-periodic eruption (QPE) sources in galactic nuclei are often associated with a stellar object orbiting a supermassive black hole with hours-days period, brought in as an extreme mass-ratio inspiral (EMRI). In the presence of an accretion disk, repeated star-disk collisions lead to ablation of a small fraction of the stellar mass during each disk passage. We analytically follow the evolution of the stellar debris as it is tidally stretched outside the EMRI's Hill sphere, forming an elongat…

This https://arxiv.org/abs/2505.16380 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

On the Identification of Exotic Compact Binaries with Gravitational Waves: a Phenomenological approach
Gravitational wave (GW) astronomy has been hailed as a gateway to discovering unexpected phenomena in the universe. Over the last decade there have been close to one hundred GW observations of compact-binary mergers. While these signals are largely consistent with mergers of binary black holes, binary neutron stars, or black hole-neutron star systems, some events suggest the intriguing possibility of binaries involving exotic compact objects (ECOs). Identifying and characterising an ECO merger …

The future of gravitational wave science unlocking LIGO potential: AI-driven data analysis and exploration
Yong Xiao, Li, Zin Nandar Win, He Wang, Hla Myo Tun, Win Thu Zar
https://arxiv.org/abs/2506.04584

The future of gravitational wave science unlocking LIGO potential: AI-driven data analysis and exploration
The advent of gravitational wave astronomy (GW) has revolutionized the observation of cataclysmic cosmic events, such as black hole mergers and neutron star collisions. The Laser Interferometer Gravitational-Wave Observatory (LIGO) has been at the forefront of these discoveries. However, the immense volume and complexity of gravitational wave data present significant challenges for traditional analysis methods. This paper investigates the growing synergy between artificial intelligence (AI) and…

This https://arxiv.org/abs/2501.12905 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

The impact of hyperons on neutron star mergers: gravitational waves, mass ejection and black hole formation
We study the influence of hyperons in binary neutron star (NS) mergers considering a total of 14 temperature dependent equations of state (EoSs) models which include hyperonic degrees of freedom and partly delta resonances. Thermally produced hyperons induce a higher heat capacity and a lower thermal index, i.e. a reduced thermal pressure for a given amount of thermal energy, compared to purely nucleonic models. We run a large set of relativistic hydrodynamics simulations of NS mergers to explo…

Using gravitational waves and multi-messenger Astronomy to reverse-engineer the properties of galactic nuclei
K. E. Saavik Ford, Barry McKernan
https://arxiv.org/abs/2506.08801

Using gravitational waves and multi-messenger Astronomy to reverse-engineer the properties of galactic nuclei
Active galactic nuclei (AGN) are powered by accretion disks onto supermassive black holes in the the centers of galaxies. AGN are believed to play important roles in the evolution of both supermassive black holes and their host galaxies over cosmic time. AGN and the nuclear star clusters (NSCs) that interact with them remain unresolved with present and planned telescopes. As a result, the properties of AGN and NSCs are highly uncertain. Here we review how binary black hole (BBH) mergers can occ…

Impact of a granular mass distribution on the orbit of S2 in the Galactic center
Matteo Sadun Bordoni, Roberto Capuzzo Dolcetta, Aleksey Generozov, Guillaume Bourdarot, Antonia Drescher, Frank Eisenhauer, Reinhard Genzel, Stefan Gillessen, Simran Joharle, Felix Mang, Thomas Ott, Diogo C. Ribeiro, Sebastiano D. von Fellenberg
https://

Impact of a granular mass distribution on the orbit of S2 in the Galactic center
The orbit of the S2 star around Sagittarius A* provides a unique opportunity to test general relativity and study dynamical processes near a supermassive black hole. Observations have shown that the orbit of S2 is consistent with a Schwarzschild orbit at a 10$σ$ confidence level, constraining the amount of extended mass within its orbit to less than 1200 M$_\odot$, under the assumption of a smooth, spherically symmetric mass distribution. In this work we investigate the effects on the S2 orbit…

Radio Continuum Studies of Ultra-Compact and Short Orbital Period X-Ray Binaries
Kristen C. Dage, Teresa Panurach, Kwangmin Oh, Malu Sudha, Montserrat Armas Padilla, Arash Bahramian, Edward M. Cackett, Timothy J. Galvin, Craig O. Heinke, Renee Ludlam, Angiraben D. Mahida, Richard M. Plotkin, Thomas D. Russell, Susmita Sett, Payaswini Saikia, Aaran W. Shaw, Alexandra J. Tetarenko

Radio Continuum Studies of Ultra-Compact and Short Orbital Period X-Ray Binaries
We present the radio continuum counterparts to the enigmatic ultra-compact X-ray binaries (UCXBs); a black hole or neutron star accreting from a hydrogen-deficient white dwarf donor star, with short orbital periods ($<$ 80 minutes). For the sample of UCXBs hosted by globular clusters (GCs), we search for whether certain GC properties are more likely to enhance UCXB formation. We determine that GCs which host UCXBs are drawn from a distinct population in terms of cluster concentration, core radi…

Gas meets Kozai: the influence of a gas-rich accretion disc on hierarchical triples undergoing von Zeipel-Lidov-Kozai oscillations
Yubo Su, Connar Rowan, Mor Rozner
https://arxiv.org/abs/2505.23889

Gas meets Kozai: the influence of a gas-rich accretion disc on hierarchical triples undergoing von Zeipel-Lidov-Kozai oscillations
Active galactic nuclei (AGNs) consist of a central supermassive black hole (SMBH) embedded in a region with both high gas and stellar densities: the gas is present as a thin accretion disc that fuels the central SMBH, while the stars form a dense, roughly isotropic nuclear star cluster. The binaries present in such a cluster could be considered naturally as triples, with the SMBH as a third object, and their dynamics also depend on the interaction with the gas-rich disc. In this paper, we study…

Optical Strong Line Ratios Cannot Distinguish Between Stellar Populations and Accreting Black Holes at High Ionization Parameters and Low Metallicities
Nikko J. Cleri, Grace M. Olivier, Bren E. Backhaus, Joel Leja, Casey Papovich, Jonathan R. Trump, Pablo Arrabal Haro, Veronique Buat, Denis Burgarella, Emilie Burnham, Antonello Calabro, Jonathan H. Cohn, Justin W. Cole, Kelcey Davis, Mark Dickinson, Steven L. Finkelstein, Ray Garner III, Michaela Hirschmann, Weida Hu, Taylor A. Hutchis…

Optical Strong Line Ratios Cannot Distinguish Between Stellar Populations and Accreting Black Holes at High Ionization Parameters and Low Metallicities
High-redshift observations from JWST indicate that optical strong line ratios do not carry the same constraining power as they do at low redshifts. Critically, this prevents a separation between stellar- and black hole-driven ionizing radiation, thereby obscuring both active galactic nuclei demographics and star formation rates. To investigate this, we compute a large suite of photoionization models from Cloudy powered by stellar populations and accreting black holes over a large grid of ages, …

Evidence for enhanced mass transfer in the disc preceding the transition to the soft state in MAXI J1820 070
Pengcheng Yang, Guobao Zhang, David M. Russell, Mariano M\'endez, M. Cristina Baglio, Diego Altamirano, Yijung Yang, Payaswini Saikia, Kevin Alabarta
https://arxiv.org/abs/2507.00532

Evidence for enhanced mass transfer in the disc preceding the transition to the soft state in MAXI J1820+070
We investigate the 2018-2019 main outburst and the subsequent mini-outbursts of the black hole low-mass X-ray binary MAXI J1820+070 using optical/ultraviolet data from the Las Cumbres Observatory (LCO), the American Association of Variable Star Observers (AAVSO), and $\textit{Swift}$/UVOT, as well as X-ray data from $\textit{Insight}$-HXMT and $\textit{Swift}$/XRT. Given the high-cadence observations, we identify a broad dip-like feature in both the optical and X-ray light curves preceding the …

Elemental Abundances in X-ray Binary Outflows
Noa Keshet, Ehud Behar, Jon M. Miller
https://arxiv.org/abs/2506.19440 https://arxiv.or…

Elemental Abundances in X-ray Binary Outflows
Line resolved X-ray spectra of outflows from X-ray binaries are interesting since they provide quantifiable measures of the accreted material on to the compact object (black hole or neutron star), which can not be observed directly in the accretion disk. One such measurement that has been largely overlooked is that of the elemental abundances, which potentially provide insights into the origin of the ejected material. Using the Chandra/HETG grating spectrometer we measure and present elemental …