bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the frequencies of circumbinary discs in protostellar systems
Authors: Elsender Daniel , Bate Matthew R , Lakeland Ben S , Jensen Eric L N , Lubow Stephen H 
Published: June 2023

ABSTRACT
We report the analysis of circumbinary (CB) discs formed in a radiation hydrodynamical simulation of star cluster formation. We consider both pure binary stars and pairs within triple and quadruple systems. The protostellar systems are all young (ages &lt; 105 yrs). We find that the systems that host a CB disc have a median separation of ≈11 au, and the median characteristic radius of the discs is ≈64 au. We find that 89 per cent of pure binaries with semimajor axes a &lt; 1 au have a CB disc, and the occurrence rate of CB discs is bimodal with log-separation in pure binaries with a second peak at a ≈ 50 au. Systems with a &gt; 100 au almost never have a CB disc. The median size of a CB disc is between ≈5 and 6 a depending on the order of the system, with higher order systems having larger discs relative to binary separation. We find the underlying distributions of mutual inclination between CB discs and binary orbits from the simulation are in good agreement with those of observed CB discs.
Uncovering the geometry of the hot X-ray corona in the Seyfert galaxy NGC 4151 with IXPE
Authors: Gianolli V E , Kim D E , Bianchi S , Agís-González B , Madejski G , Marin F , Marinucci A , Matt G , Middei R , Petrucci P-O , Soffitta P , Tagliacozzo D , Tombesi F , Ursini F , Barnouin T , De Rosa A , Di Gesu L , Ingram A , Loktev V , Panagiotou C , Podgorny J , Poutanen J , Puccetti S , Ratheesh A , Veledina A , Zhang W , Agudo I , Antonelli L A , Bachetti M , Baldini L , Baumgartner W H , Bellazzini R , Bongiorno S D , Bonino R , Brez A , Bucciantini N , Capitanio F , Castellano S , Cavazzuti E , Chen C-T , Ciprini S , Costa E , Del Monte E , Di Lalla N , Di Marco A , Donnarumma I , Doroshenko V , Dovčiak M , Ehlert S R , Enoto T , Evangelista Y , Fabiani S , Ferrazzoli R , García J A , Gunji S , Heyl J , Iwakiri W , Jorstad S G , Kaaret P , Karas V , Kislat F , Kitaguchi T , Kolodziejczak J J , Krawczynski H , La Monaca F , Latronico L , Liodakis I , Maldera S , Manfreda A , Marscher A P , Marshall H L , Massaro F , Mitsuishi I , Mizuno T , Muleri F , Negro M , Ng C-Y , O’Dell S L , Omodei N , Oppedisano C , Papitto A , Pavlov G G , Peirson A L , Perri M , Pesce-Rollins M , Pilia M , Possenti A , Ramsey B D , Rankin J , Roberts O J , Romani R W , Sgrò C , Slane P , Spandre G , Swartz D A , Tamagawa T , Tavecchio F , Taverna R , Tawara Y , Tennant A F , Thomas N E , Trois A , Tsygankov S S , Turolla R , Vink J , Weisskopf M C , Wu K , Xie F , Zane S 
Published: June 2023

ABSTRACT
We present an X-ray spectropolarimetric analysis of the bright Seyfert galaxy NGC 4151. The source has been observed with the Imaging X-ray Polarimetry Explorer (IXPE) for 700 ks, complemented with simultaneous XMM–Newton (50 ks) and NuSTAR (100 ks) pointings. A polarization degree Π = 4.9 ± 1.1 per cent and angle Ψ = 86° ± 7° east of north (68 per cent confidence level) are measured in the 2–8 keV energy range. The spectropolarimetric analysis shows that the polarization could be entirely due to reflection. Given the low reflection flux in the IXPE band, this requires, however, a reflection with a very large (&gt;38 per cent) polarization degree. Assuming more reasonable values, a polarization degree of the hot corona ranging from ∼4 to ∼8 per cent is found. The observed polarization degree excludes a ‘spherical’ lamppost geometry for the corona, suggesting instead a slab-like geometry, possibly a wedge, as determined via Monte Carlo simulations. This is further confirmed by the X-ray polarization angle, which coincides with the direction of the extended radio emission in this source, supposed to match the disc axis. NGC 4151 is the first active galactic nucleus with an X-ray polarization measure for the corona, illustrating the capabilities of X-ray polarimetry and IXPE in unveiling its geometry.
Prominence detection and chromosphere feature on the prototype RS CVn of active binary systems
Authors: Cao Dongtao , Gu Shenghong , Wolter U , Mittag M , Schmitt J H M M , Gao Dongyang , Hu Shaoming 
Published: June 2023

ABSTRACT
We present a study of high-resolution spectra of RS Canum Venaticorum (RS CVn), a prototype of active binary systems. Our data were obtained from 1998 to 2017 using different telescopes. We analyse the chromospheric activity indicators $\rm{Ca~{\small II}}$ IRT, Hα, $\rm{Na~{\small I}}$ D1, D2 doublet, $\rm{He~{\small I}}$ D3, and Hβ using a spectral subtraction technique. The chromospheric emission stems mainly from the K2 IV primary star, while the F5 V secondary star only shows weak emission features in a few of our spectra. We find excess absorption features in the subtracted Hα lines and other activity indicators from spectra taken near primary eclipse, which we ascribe to prominence-like material associated with the primary star. We estimate size limits of these tentative prominences based on the geometry of the binary system, and investigate the physical properties of the strongest prominence. An optical flare, characterized by $\rm{He~{\small I}}$ D3 line emission, together with stronger emission in other activity lines, was detected. The flare energy is roughly comparable to strong flares observed on other RS CVn-type stars. The chromospherically active longitudes of RS CVn most frequently appear near the two quadratures of the system and display changes between observing runs, which indicates an ongoing evolution of its active regions.
High-z galaxies with JWST and local analogues – it is not only star formation
Authors: Brinchmann Jarle 
Published: June 2023

ABSTRACT
I present an analysis of the JWST NIRSpec data of SMACS 0723 released as Early Release Observations. As part of this three new redshifts are provided, bringing the total of reliable redshifts to 14. I propose a modification to the direct abundance determination method that reduces sensitivity to flux calibration uncertainties by a factor of ∼3 and show that the resulting abundances are in good agreement with Bayesian photoionization models of the rest-frame optical spectrum. I also show that 6355 is most likely a narrow-line active galactic nucleus (AGN) with $M_*\lt 10^9\, \mathrm{M}_\odot$ at z = 7.66 and argue that 10 612 might also have an AGN contribution to its flux through comparison to photoionization models and low-redshift analogues. Under the assumption that the lines come from star formation, I find that the galaxies have gas depletion times of ∼107 yr, comparable to similar galaxies locally. I also identify a population of possibly shock-dominated galaxies at z &lt; 3, whose near-IR emission lines plausibly come nearly all from shocks and discuss their implications. I close with a discussion of the potential for biases in the determination of the mass–metallicity relation using samples defined by detected [O iii]4363 and show using low-z galaxies that this can lead to biases of up to 0.5 dex with a systematic trend with mass.
LOFAR observations of gravitational wave merger events: O3 results and O4 strategy
Authors: Gourdji K , Rowlinson A , Wijers R A M J , Broderick J W , Shulevski A 
Published: June 2023

ABSTRACT
The electromagnetic counterparts to gravitational wave (GW) merger events hold immense scientific value, but are difficult to detect due to the typically large localization errors associated with GW events. The Low-Frequency Array (LOFAR) is an attractive GW follow-up instrument owing to its high sensitivity, large instantaneous field of view, and ability to automatically trigger on events to probe potential prompt emission within minutes. Here, we report on 144-MHz LOFAR radio observations of three GW merger events containing at least one neutron star that were detected during the third GW observing run. Specifically, we probe 9 and 16 per cent of the location probability density maps of S190426c and S200213t, respectively, and place limits at the location of an interesting optical transient (PS19hgw/AT2019wxt) found within the localization map of S191213g. While these GW events are not particularly significant, we use multi-epoch LOFAR data to devise a sensitive wide-field GW follow-up strategy to be used in future GW observing runs. In particular, we improve on our previously published strategy by implementing direction-dependent calibration and mosaicing, resulting in nearly an order of magnitude increase in sensitivity and more uniform coverage. We achieve a uniform 5σ sensitivity of 870 μJy beam−1 across a single instantaneous LOFAR pointing’s 21 deg2 core, and a median sensitivity of 1.1 mJy beam−1 when including the full 89 deg2 hexagonal beam pattern. We also place the deepest transient surface density limits yet on time-scales of the order of month for surveys between 60 and 340 MHz (0.017 deg−2 above 2.0 mJy beam−1 and 0.073 deg−2 above 1.5 mJy beam−1).
Variability and evolution of the optical polarization of a sample of gamma-ray blazars
Authors: Otero-Santos J , Acosta-Pulido J A , González J Becerra , Raiteri C M , Carnerero M I , Segura N Castro , González-Martín O , Luashvili A 
Published: June 2023

ABSTRACT
We present a polarization variability analysis of a sample of 26 γ-ray blazars monitored by the Steward Observatory between 2008 and 2018 in the optical band. We investigate the properties and long-term variability of their optical polarization, searching for differences between blazar types. We observe that BL Lac objects are typically less polarized and less variable than flat spectrum radio quasars (FSRQs). Moreover, BL Lacs display a distribution of their polarization angle typically oriented in a preferential direction, contrary to the rather random distribution of FSRQs. For the latter blazar type, as well as those sources showing a bright stellar emission, we take into account the depolarizing effect introduced by the broad line region and the host galaxy on the measured polarization degree. In this sample, we also observe that BL Lacs present an uncorrelated evolution of the flux and the polarization. Contrary, FSRQs show a correlation before the depolarization correction, that is lost however after considering this effect. In addition, we study the behaviour of the polarization angle, searching for angle rotations in its long-term evolution. We derive that the FSRQs studied here show rotations more frequently than BL Lac objects by a factor ∼1.5. During these periods, we also observe a systematic decrease of the polarization fraction, as well as a marginal flux increase, not significant however to connect rotations with optical flares. We interpret these results within the extended shock-in-jet scenario, able to explain the overall features observed here for the polarization of the blazar sample.
The relationship between the incidence of X-ray selected AGN in nearby galaxies & star-formation rate
Authors: Birchall Keir L , Watson M G , Aird J , Starling R L C 
Published: June 2023

ABSTRACT
We present the identification and analysis of an X-ray selected AGN sample that lie within the local (z &lt; 0.35) galaxy population. From a parent sample of 22 079 MPA-JHU (based on SDSS DR8) galaxies, we identified 917 galaxies with central, excess X-ray emission (from 3XMM-DR7) likely originating from an AGN. We measured the host galaxies’ star formation rates and classified them as either star-forming or quiescent based on their position relative to main sequence of star formation. Only 72 per cent of the X-ray selected sample were identified as AGN using BPT selection; this technique is much less effective in quiescent hosts, only identifying 50 per cent of the X-ray AGN. We also calculated the growth rates of the black holes powering these AGN in terms of their specific accretion rate (∝ LX/M*) and found quiescent galaxies, on average, accrete at a lower rate than star-forming galaxies. Finally, we measured the sensitivity function of 3XMM so we could correct for observational bias and construct probability distributions as a function of accretion rate. AGN were found in galaxies across the full range of star formation rates ($\log _{10} \, \mathrm{SFR/M_\odot \ yr^{-1}} = -3\ \mathrm{to}\ 2$) in both star-forming and quiescent galaxies. The incidence of AGN was enhanced by a factor 2 (at a 3.5σ significance) in star-forming galaxies compared to quiescent galaxies of equivalent stellar mass and redshift, but we also found a significant population of AGN hosted by quiescent galaxies.
Lopsided galaxies in a cosmological context: a new galaxy–halo connection
Authors: Varela-Lavin Silvio , Gómez Facundo A , Tissera Patricia B , Besla Gurtina , Garavito-Camargo Nicolás , Marinacci Federico , Laporte Chervin F P 
Published: June 2023

ABSTRACT
Disc galaxies commonly show asymmetric features in their morphology, such as warps and lopsidedness. These features can provide key information regarding the recent evolution of a given disc galaxy. In the nearby Universe, up to ∼30 per cent of late-type galaxies display a global non-axisymmetric lopsided mass distribution. However, the origin of this perturbation is not well understood. In this work, we study the origin of lopsided perturbations in simulated disc galaxies extracted from the TNG50 simulation of the IllustrisTNG project. We statistically explore different excitation mechanisms for this perturbation, such as direct satellite tidal interactions and distortions of the underlying dark matter distributions. We also characterize the main physical conditions that lead to lopsided perturbations. 50 per cent of our sample galaxy have lopsided modes m = 1 greater than ∼0.12. We find a strong correlation between internal galaxy properties, such as central stellar surface density and disc radial extension with the strength of lopsided modes. The majority of lopsided galaxies have lower central surface densities and more extended discs than symmetric galaxies. As a result, such lopsided galaxies are less self-gravitationally cohesive, and their outer disc region is more susceptible to different types of external perturbations. However, we do not find strong evidence that tidal interactions with satellite galaxies are the main driving agent of lopsided modes. Lopsided galaxies tend to live in asymmetric dark matter haloes with high spin, indicating strong galaxy–halo connections in late-type lopsided galaxies.
Classifying IGR J15038−6021 as a magnetic CV with a massive white dwarf
Authors: Tomsick John A , Kumar Snehaa Ganesh , Coughenour Benjamin M , Shaw Aarran W , Mukai Koji , Hare Jeremy , Clavel Maïca , Krivonos Roman , Fornasini Francesca M , Gerber Julian , Joens Alyson 
Published: June 2023

ABSTRACT
Cataclysmic variables (CVs) are binary systems consisting of a white dwarf (WD) accreting matter from a companion star. Observations of CVs provide an opportunity to learn about accretion discs, the physics of compact objects, classical novae, and the evolution of the binary and the WD that may ultimately end in a Type Ia supernova (SN). As Type Ia SNe involve a WD reaching the Chandrasekhar limit or merging WDs, WD mass measurements are particularly important for elucidating the path from CV to Type Ia SN. For intermediate polar (IP) type CVs, the WD mass is related to the bremsstrahlung temperature of material in the accretion column, which typically peaks at X-ray energies. Thus, the IPs with the strongest hard X-ray emission, such as those discovered by the INTEGRAL satellite, are expected to have the highest masses. Here, we report on XMM–Newton, Nuclear Spectroscopic Telescope Array (NuSTAR), and optical observations of IGR J15038−6021. We find an X-ray periodicity of 1678 ± 2 s, which we interpret as the WD spin period. From fitting the 0.3–79 keV spectrum with a model that uses the relationship between the WD mass and the post-shock temperature, we measure a WD mass of $1.36^{+0.04}_{-0.11}$ M⊙. This follows an earlier study of IGR J14091−6108, which also has a WD with a mass approaching the Chandrasekhar limit. We demonstrate that these are both outliers among IPs in having massive WDs and discuss the results in the context of WD mass studies as well as the implications for WD mass evolution.
SIRT1 regulates DNA damage signaling through the PP4 phosphatase complex
Authors: Rasti George , Becker Maximilian , Vazquez Berta N , Espinosa-Alcantud Maria , Fernández-Duran Irene , Gámez-García Andrés , Ianni Alessandro , Gonzalez Jessica , Bosch-Presegué Laia , Marazuela-Duque Anna , Guitart-Solanes Anna , Segura-Bayona Sandra , Bech-Serra Joan-Josep , Scher Michael , Serrano Lourdes , Shankavaram Uma , Erdjument-Bromage Hediye , Tempst Paul , Reinberg Danny , Olivella Mireia , Stracker Travis H , de la Torre Carolina , Vaquero Alejandro 
Published: June 2023

Abstract
The Sirtuin family of NAD+-dependent enzymes plays an important role in maintaining genome stability upon stress. Several mammalian Sirtuins have been linked directly or indirectly to the regulation of DNA damage during replication through Homologous recombination (HR). The role of one of them, SIRT1, is intriguing as it seems to have a general regulatory role in the DNA damage response (DDR) that has not yet been addressed. SIRT1-deficient cells show impaired DDR reflected in a decrease in repair capacity, increased genome instability and decreased levels of γH2AX. Here we unveil a close functional antagonism between SIRT1 and the PP4 phosphatase multiprotein complex in the regulation of the DDR. Upon DNA damage, SIRT1 interacts specifically with the catalytical subunit PP4c and promotes its inhibition by deacetylating the WH1 domain of the regulatory subunits PP4R3α/β. This in turn regulates γH2AX and RPA2 phosphorylation, two key events in the signaling of DNA damage and repair by HR. We propose a mechanism whereby during stress, SIRT1 signaling ensures a global control of DNA damage signaling through PP4.
The 3D chromatin landscape of rhabdomyosarcoma
Authors: Wang Meng , Sreenivas Prethish , Sunkel Benjamin D , Wang Long , Ignatius Myron , Stanton Benjamin Z 
Published: June 2023

Abstract
Rhabdomyosarcoma (RMS) is a pediatric soft tissue cancer with a lack of precision therapy options for patients. We hypothesized that with a general paucity of known mutations in RMS, chromatin structural driving mechanisms are essential for tumor proliferation. Thus, we carried out high-depth in situ Hi-C in representative cell lines and patient-derived xenografts (PDXs) to define chromatin architecture in each major RMS subtype. We report a comprehensive 3D chromatin structural analysis and characterization of fusion-positive (FP-RMS) and fusion-negative RMS (FN-RMS). We have generated spike-in in situ Hi-C chromatin interaction maps for the most common FP-RMS and FN-RMS cell lines and compared our data with PDX models. In our studies, we uncover common and distinct structural elements in large Mb-scale chromatin compartments, tumor-essential genes within variable topologically associating domains and unique patterns of structural variation. Our high-depth chromatin interactivity maps and comprehensive analyses provide context for gene regulatory events and reveal functional chromatin domains in RMS.
Unbundling Property in Welfare
Authors: Cohen-Rimer Yael , Stern Shai 
Published: June 2023

Abstract
In most Western jurisdictions, welfare law utilises means testing to determine whether individuals are eligible for welfare allowances, often using property ownership as one of the eligibility criteria. Crucially, the prevailing conception of property ownership is premised on the notion that property rights are applied equally to all owners in matters relating to the control and management of that property. When this assumption proves not to reflect reality, it can have devastating consequences for those most in need of the support ostensibly provided by welfare law. The present qualitative empirical study examines two cases in which such adverse consequences are felt: in the two largest minority communities in Israel—the Palestinians and the Ultraorthodox Jews (Charedi). The findings show that property ownership in these communities is realised hierarchically, along patriarchal lines, and that family members occupy and manage property in accordance with community customs and traditional norms, often far removed from state laws. Beyond theoretical debates or ethnographic observations, the discrepancies between the state’s ideas of ownership and those recognised by members of the Palestinian and Charedi communities in Israel often result in the denial of financial aid to those who need it most. This article will identify such differences in conception and will describe how they provide an additional explanation for the high levels of poverty in minority communities. Finally, it will examine two private law doctrines that can be used as inspiration to better interpret welfare law and make it more nuanced and culturally sensitive, especially when it encounters people in poverty and marginalised groups.
Sport-related concussion and bodychecking in children and youth: Evaluation, management, and policy implications
Authors: Goulet Kristian , Beno Suzanne 
Published: June 2023

AbstractConcussions are a common injury both within and outside sport and recreational settings, and they remain a serious concern for children and youth. Any young person suspected of sustaining a concussion should be medically evaluated as soon as possible, and when the injury occurs during sport, the individual must be removed from play immediately to avoid secondary injury. A brief initial period of physical and cognitive rest is followed by supervised, stepwise return-to-learn and return-to-play protocols. All individuals involved in child and youth sports and recreation must be able to recognize risk for, and signs and symptoms of, concussion. They must also ensure that any participant suspected of sustaining a concussion is properly evaluated and managed by qualified medical personnel. Evolving data and literature have strengthened both our pathophysiological understanding of concussion and guidance for clinical management, especially related to acute care, persistent symptoms, and prevention. This statement also re-examines the relationship between bodychecking in hockey and injury rates, and advocates for a change in policy in youth hockey.