Disc Size Research Articles

P-1341. Differential Frequency of Persister cells in Clinically Derived Pseudomonas aeruginosa Isolates after Exposure to Cefiderocol (FDC) or Ceftolozane/tazobactam (C/T)

Abstract Background Bacterial persistence is a phenomenon where a subpopulation of bacteria can survive high concentrations of an active antibiotic in the absence of genotypic alterations. Persisters are associated with chronic and recurrent infections for pathogens including Pseudomonas aeruginosa. Evaluating persister profiles of FDC and C/T against P. aeruginosa is warranted as they are needed for difficult-to-treat infections. Methods Persisters were assessed using in vitro assays against 9 clinical P. aeruginosa isolates that developed resistance to C/T during therapy. Only index isolates (FDC and C/T-susceptible) were tested. Quantitative persister assays were performed using a stationary phase bacteria challenged with 10-fold MIC drug concentrations. Persisters were quantitated as the percent persisters at 24h and the log ratio (LR) difference in area under the curve for CFU (AUCFU) for each antibiotic alone referenced to control. Tolerance disk test (TDtest) was used to qualitatively detect persisters using full, half and quarter disks. Colonies within the inhibition zone after replacement of drug disk with a glucose disk indicated the presence of persister cells. Results Percent persisters at 24h ranged from 4.1% to 64.3% and 1.9% to 81.1% for FDC and C/T, respectively. Percent persisters at 24h was lower for FDC compared with C/T groups in 6 of the 9 tested isolates. 8 of the 9 isolates had higher reduction in LR for FDC groups (range, -0.6 to -0.9), indicating an overall higher and more rapid bacterial reduction in FDC groups compared to C/T (range, -0.3 to -0.9). For FDC, 5/9 tested isolates lacked regrowth after replacement with glucose disk suggesting no persistence per the TDtest. For C/T, only 3 isolates lacked persister formation. TDtest results were consistent across disk sizes and concordant with the quantitative assay. Conclusion These data link isolates that developed resistance to C/T with persister formation. FDC resulted in less bacterial persistence relative to C/T against 9 P. aeruginosa isolates. FDC’s siderophore mechanism may be advantageous over typical β-lactams via enhanced anti-persister activity. Clinical correlation of these findings are warranted as persisters can lead to antibiotic resistance and treatment failure. Disclosures Samantha Nicolau, PhD, Sanofi Pasteur: Full time research scientist Patricia J. Simner, PhD, Affinity Biosensors: Grant/Research Support|BD Diagnostics: Grant/Research Support|bioMérieux: Grant/Research Support|Entasis: Personal fees|GeneCapture: Personal Fees|Merck: Personal fees|OpGen Inc: Grant/Research Support|Qiagen: Grant/Research Support|Shionogi: Personal fees|T2 Biosystems: Grant/Research Support David P. Nicolau, PharmD, CARB-X: Grant/Research Support|Innoviva: Grant/Research Support|Innoviva: Honoraria|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Honoraria|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Pfizer: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Grant/Research Support|Shionogi: Honoraria|Venatorx: Grant/Research Support Christian M. Gill, PharmD, Cepheid: Grant/Research Support|Entasis: Grant/Research Support|Everest Medicines: Grant/Research Support|Shionogi: Grant/Research Support

Constraining Binary Mergers in Active Galactic Nuclei Disks Using the Nonobservation of Lensed Gravitational Waves

Abstract The dense and dynamic environments within active galactic nuclei (AGN) accretion disks may serve as prolific birthplaces for binary black holes (BBHs) and one possible origin for some of the BBHs detected by gravitational-wave (GW) observatories. We show that a considerable fraction of the BBH in AGN disks will be strongly lensed by the central supermassive black hole (SMBH). Thus, the nonobservation of lensed GW signals can be used to constrain the fraction of BBH binaries residing in AGN disks. The nondetection of lensing with current O ( 100 ) detections will be sufficient to start placing constraints on the fraction of BBHs living within accretion disks near the SMBH. In the next-generation detectors era, with O ( 1 0 5 ) BBH observations and no lensed events, we will be able to rule out most migration traps as dominant birthplaces of BBH mergers; moreover, we will be able to constrain the minimum size of the accretion disk. On the other hand, should AGNs constitute a major formation channel, lensed events from AGNs will become prominent in the future.

Automated analysis of retinal vascular features, age, sex and disc size in a large cohort of primary open angle glaucoma patients

Aims/Purpose: Deriving vascular features of retinal images is a proposed noninvasive method to assess vascular health. Although several studies have linked cardiovascular risk to retinal image features, they often rely on limited datasets or have used deep learning approaches with limited explainability. This research introduces an end‐to‐end method for analyzing the retinal vasculature in large retinal image datasets, applied for primary open angle glaucoma (POAG).Methods: 115,237 retinal images of the UZ Leuven Glaucoma Clinic were extracted. 4858 unique images remain of POAG patients (n = 3010) and controls (n = 1848) after image quality assessment, optic disk detection, region of interest definition, automated segmentation of arterioles and venules (LUNet algorithm), and parametrization of the vascular biomarkers (PVBM toolbox). Analysis of covariance and linear mixed models were used to adjust for age, sex and disc size.Results: Both arteriolar and venular diameter, area, length, tortuosity, branching angle, endpoints, intersection points and both mono‐ as multifractal dimension levels are independently lower in POAG patients and older patients (all p < 0.001), after adjustment for sex, disc size and multiple testing. The multivariate linear mixed models additionally show that the vascular features are significantly influenced by sex and disc size, which necessitates correct adjustment.Conclusions: This is the first time a fully automated end‐to‐end pipeline is published for the analysis of retinal vascular geometry in a large cohort (n = 4858). Given the independent similarities in retinal vascular geometry changes between older age and POAG prevalence the theory of pronounced vascular ageing in POAG patients is proposed. This novel approach enables quantitative analysis of eye vasculature and supports the study of its correlation with specific diseases, facilitating reproducible analysis of large datasets and providing explainability to deep learning approaches.

Modeling of intervertebral discs’ parameters of the lumbar spine base on somatometric data

The relevance of the study arises from the high prevalence of spinal column pathology and the rapid advancement of diagnostic technologies, which necessitate the refinement of criteria for identifying changes in the structural components of the spine, particularly one of its most vulnerable elementsт – the intervertebral discs. The reliance on subjective criteria for assessing intervertebral discs during magnetic resonance imaging (MRI) or computed tomography (CT) highlights the need for more objective, quantitative criteria to evaluate intervertebral disc changes. The aim of the study was to develop an optimal, practical model for calculating the total size index of intervertebral discs based on external body parameters, applicable in clinical practice, and to validate its effectiveness. To achieve this goal, lumbar spine MRI was performed on young women aged 16 to 26 years who were native residents of the Vinnytsia region. The main group consisted of 80 participants, including 52 young women aged 16-20 years and 28 women aged 21-26 years; the validation group included 65 females aged 16-26 years. Anthropometric measurements, including height and body weight, were recorded for all participants. Using data from the main group, mathematical modeling was conducted to determine the total size of lumbar intervertebral discs. The modeling process employed stepwise regression analysis based on somatodisc coefficients of individual intervertebral discs and anthropometric parameters. As a result, a model was developed to calculate somatodisc coefficients using body height and weight. Further algebraic transformations of the somatodisc coefficient yielded a formula for calculating individualized total disc size indicators, integrating vertical, sagittal, and transverse dimensions. The predictive accuracy of the obtained models ranged from 85 % to 91 %. When the actual total size measurements of intervertebral discs in the main group were compared to the mathematically modeled values, deviations did not exceed ±10 %. This mathematical model for calculating the total size of lumbar intervertebral discs based on somatometric data enables the determination of individualized normative metrics and the objective identification of early degenerative disc changes. When comparing clinical visual assessments of intervertebral disc changes using Pfirrmann grading with mathematical evaluations in the validation group, agreement was observed in 91 % of cases. Discrepancies were identified in 9 %, necessitating further analysis to prevent underdiagnosis or overdiagnosis of intervertebral disc changes. Thus, mathematical modeling serves as a tool for determining individualized normative metrics. The proposed mathematical models for calculating the total size of intervertebral discs based on body height and weight represent a powerful supplement to existing criteria for intervertebral disc assessment.

Muscle System of <i>Aspidogaster limacoides</i> (Trematoda, Aspidogastridae )

The article describes the musculature of the body, the pharynx and the ventral disc of Aspidogaster limacoides. The body wall contains three muscle layers: circular, longitudinal and diagonal. Numerous chordal muscles oriented both transversely and longitudinally, along with body wall and radial musculature, precondition the oral funnel mobility. Apart from radial, the pharynx musculature includes outer longitudinal, inner circular and outer circular muscles, the latter forming the anterior sphincter. The ventral disc being alveolar in its structure, the diversity of its musculature is restricted: the septa contain no chordal muscles or sphincters. The architectonics of parenchymal musculature has three main features resulting from large disc size, i.e. the presence of two muscle septa in the parenchima, dorso-ventral musculature being located latero-ventrally from muscle septa and a considerable development of viscero-motor muscles.

Phenotypic plasticity and spatial distribution of Simulium pertinax larvae from the Tijuca National Park

Black fly larvae are filter feeding organisms that inhabit lotic systems and are considered key-organisms for their role as trophic link converting Fine Particles Organic Matter (FPOM) into Compact Particles Organic Matter (CPOM) making it available to a broader range of microorganisms. Literature suggests that black fly larvae may present phenotypic plasticity due to a wide range of physical factors such as water velocity, as well as food availability. The present study investigates the variation of morphological characteristics of Simulium pertinax larvae among different microhabitats in the Tijuca National Park, finding significant correlations among proleg length, anal disk and cephalic capsule sizes and the water velocity.

Intermediate mass T Tauri disk masses and a comparison to their Herbig disk descendants

Herbig disks are prime sites for the formation of massive exoplanets and looking into the precursors of these disks can offer clues for determining planet formation timescales. The precursors of Herbig stars, called intermediate-mass T Tauri (IMTT) stars, have spectral types later than F, but stellar masses between 1.5 and 5 $M_ These stars will eventually become Herbig stars of spectral types A and B. The aim of this work is to obtain the dust and gas masses and radii of all IMTT disks with ALMA archival data. The obtained disk masses are then compared to Herbig disks and T Tauri disks and the obtained disks sizes to those of Herbig disks. ALMA Band 6 and 7 archival data were obtained for 34 IMTT disks with continuum observations, 32 of which have at least ^12CO ^13CO or C^18O observations, but with most of them at quite shallow integrations. The disk integrated flux together with a stellar luminosity-scaled disk temperature were used to obtain a total disk dust mass by assuming optically thin emission. Using thermochemical Dust And LInes (DALI) models drawn from previous works, we also obtained gas masses of 10 out of 35 of the IMTT disks based on the CO isotopologues. From the disk masses and sizes, we obtained the cumulative distributions. The IMTT disks in this study have the same dust mass and radius distributions as Herbig disks. The dust mass of the IMTT disks is higher compared to that of the T Tauri disks, as also found for the Herbig disks. No differences in dust mass were found for group I versus group II disks, in contrast to Herbig disks. The disks for which a gas mass could be determined display a similarly high-mass as to the Herbig disks. Comparing the disk dust and gas mass distributions to the mass distribution of exoplanets shows that there also is not enough dust mass in disks around intermediate-mass stars to form massive exoplanets. On the other hand, there is more than enough gas to form the atmospheres of exoplanets. We conclude that the sampled IMTT disk population is almost indistinguishable compared to Herbig disks, as their disk masses are the same, even though the former objects are younger. Based on this study, we conclude that planet formation is already well underway in these objects and, thus, planet formation is expected to start early on in the lifetime of Herbig disks. Combined with our findings on group I and group II disks, we conclude that most disks around intermediate-mass pre-main sequence stars converge quickly to small disks, unless they are prevented from doing so by a nearby massive exoplanet.

The performance of optic disc-macula distance to disc-diameter ratio in qualitative and quantitative assessment of the optic disc size.

We aimed to evaluate the performance of the optic disc-macula distance to disc-diameter ratio (DM/DD) in qualitative and quantitative assessment of optic disc size. In 300 apparently normal eyes, we determined the correlation between DM/DD and the planimetric disc area (DA) and evaluated the performance of DM/DD in discriminating between small and large discs. The ability of DM/DD to predict the actual DA was validated in a separate cohort of 200 eyes. The disc size in eyes with glaucoma or related diseases was compared with DA- or DM/DD-based disc size. The DM/DD and its square of inverse (DD2/DM2) showed excellent non-linear and linear correlations, respectively, with DA (p < 0.001 and p < 0.001, respectively), demonstrating their performance in discriminating between small (<2.04 mm2) and large (>2.94 mm2) disc sizes with an area under the receiver operating characteristic curve of 0.901 and 0.959, respectively. The difference between the predicted DA and planimetric DA was within ±10% in more than 80% of the eyes. Eyes with suspected and normal-tension glaucoma exhibited larger discs (p < 0.01) when evaluated using both DM/DD and DA. The variation in disc-macula distance seemed to be a confounding factor for DM/DD in inferring the precise disc size. DM/DD, which can be easily calculated from various kinds of fundus photographs or images, was an excellent and interchangeable tool for qualitative and quantitative assessment of disc size, which did not require correction for ocular magnification.

Pre-operative Disc Volume Measurement as a Predictor for Sufficient Intra-operative Excision in Lumbar Open Fenestration Discectomies

Background and objectives: A study was implemented by assessing pre-operative disc volume and compare it to resected disc volume intra-operatively to minimize complications. The purpose of this study is to determine whether preoperative measurement of disc volume by magnetic resonance imaging could estimate the amount of disc need to be removed intraoperatively. Methods: This prospective cross-sectional study was conducted between 2021 and 2023, in which 44 patients were involved, the volume of the herniated disc. The height, width, and length of prolapsed disc were multiplied together and by 0.523, measured on magnetic resonance imaging machine, intraoperatively the resected disc was placed in the sterile syringe for measurement. Results: Out of 44 patients, 23 of them were males, and 21 were females. The mean age was 41.4 years. The most common level of involvement was the L4-L5 levels. The size of the herniated disc preoperatively ranged from 0.70 cc to 3.70, among them 72.7% of patients had a measurement between 1.0 cc and 2.0. Intraoperatively, the size of resected disc ranged from 1.0 cc to 4.2, 63.6% of them had volume exceeding 2.0 cc. Our data showed that neither the volume of the herniated disc nor the volume of the resected disc has any correlation to the age, gender and the level of disc involved. Conclusion: Preoperative measurement of lumbar disc herniation with a magnetic resonance image do not predict the disc volume that needs to be removed during surgery.

Multiwavelength coverage of the 2024 periastron passage of PSR B1259–63/LS 2883

ABSTRACT PSR B1259$-$63is a gamma-ray binary system with a 48 ms radio pulsar orbiting around an O9.5Ve star, LS 2883, in a highly eccentric ${\sim} 3.4$ yr long orbit. Close to the periastron the system is detected from radio up to the TeV energies due to the interaction of the stellar wind from LS 2883 and the pulsar’s relativistic outflow. Observations of the last four periastron passages, taken in 2010–2021, demonstrate periastron-to-periastron variability at all wavelengths, probably linked to the state of the Be star’s decretion disc. In this paper, we present the results of our optical, radio and X-ray observational campaigns on PSR B1259$-$63 performed in 2024 accompanied with the analysis of the publicly available GeV Fermi/LAT data. We show that this periastron passage was characterized by the early flaring of X-rays before the periastron passage and GeV emission after the periastron passage, which can be explained by a larger size of the decretion disc as supported by the optical observations. The structure of the GeV flare is also in agreement with the disruption of the large dense disc. The possible X-ray/radio correlation was observed only during the post-periastron rise of X-ray and radio emission.

Intraocular pressure and optical coherence tomography concerning visual field outcomes in "green" patients: An observational study.

This study investigates the relationship between intraocular pressure (IOP), optical coherence tomography (OCT) parameters, and visual field (VF) outcomes in 'Green' patients-those with normal OCT findings but potential VF abnormalities. Understanding this relationship is crucial for improving early detection and management strategies for glaucoma, especially in patients who show functional loss despite normal structural findings on OCT. A cross-sectional study was conducted at Taipei City Hospital, Renai Branch, Taiwan, from July 1, 2015, to July 1, 2023. Participants were referred for suspected glaucoma and included based on normal OCT parameters ('green' coding) and completed VF tests. Patients with any ocular disease that could confound results were excluded. Logistic regression models were used to assess relationships between IOP, OCT parameters (rim area, disc area, retinal nerve fiber layer thickness, cup-to-disc ratios, and cup volume), and VF outcomes. Age, sex, and IOP status (normal or ocular hypertension) were also included in the analysis. All data were analyzed using Statistical Package for the Social Sciences version 23.0. Larger disc area was a significant predictor of VF abnormalities, with an adjusted OR of 3.72 (95% confidence interval [CI], 1.14-12.15). Neither normal IOP nor ocular hypertension significantly predicted VF loss (adjusted OR = 0.89; 95% CI, 0.27-2.96). Female sex was associated with a higher likelihood of VF abnormalities (adjusted OR = 5.68; 95% CI, 1.03-31.25). Other OCT parameters, including retinal nerve fiber layer thickness and cup-to-disc ratios, were not significantly associated with VF outcomes. Disc area plays a critical role in predicting VF abnormalities in "green" patients, suggesting the importance of integrating disc size into screening and monitoring protocols. These findings challenge the reliance on IOP alone for predicting VF loss and support the need for more comprehensive assessments. Future research should explore longitudinal studies to further assess the predictive value of disc area and investigate additional factors, such as vascular and biomechanical influences, that may contribute to VF deterioration in this population.

Comparison of magnification corrected optic disc size by slit-lamp biomicroscopy, fundus photography, and optical coherence tomography

Abstract PURPOSE: Optic disc size measurement is essential for determining landmarks, lesions, and distances of the retina. Due to the size variability in nature and when measured with different instruments, newer methods to compare sizes between different instruments are needed. We aimed to determine the comparability of slit lamp, fundus photography, and optical coherence tomography (OCT) measurements of optic disc size after correcting for both ocular and instrument magnification. MATERIALS AND METHODS: In this prospective, observational study, optic disc size was measured by slit-lamp biomicroscopy, fundus photography, and OCT. Instrument and ocular magnification was calculated, and the measured size was corrected for both using the Littman formula. The corrected values were analyzed using Bland–Altman plots and intra-class correlation (ICC) for agreeability and correlation, respectively. Linear regression analysis was conducted to estimate the systematic errors and interconvertibility in cases of high correlation. RESULTS: Fifty-six eyes were included for the analysis. Uncorrected and corrected values for each method had excellent correlation and agreeability (ICC absolute agreement &gt;0.75, P &lt; 0.01). Among magnification corrected values, slit lamp and OCT had excellent correlation and agreement (ICC consistency = 0.846, confidence interval 0.75–0.91, P &lt; 0.01). This pair had R 2 = 0.73 on linear regression (P &lt; 0.01). Linear regression formulas for interconverting uncorrected and corrected values for the three methods had variable accuracy (R 2 from 0.47 to 0.66). CONCLUSION: Uncorrected values of different methods for disc size measurement cannot be compared directly; they need ocular and instrument magnification correction. Among the three methods compared, the best interconvertible pairs of measurement were magnification corrected slit lamp and OCT values.

A small disc size, a big challenge: effect of optic disc size on the correlation between peripapillary choroidal thickness, peripapillary retinal nerve fiber layer, and ganglion cell layer.

We aimed to analyze the effect of optic disc size on the correlation between the peripapillary choroid (PPC), peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell inner plexiform layer (MGCIPL) thicknesses in subjects with ocular hypertension (OHT) and primary open angle glaucoma (POAG). This study included 61 eyes with a disc area (DA) of ≤ 1.63 mm2, 92 eyes with a DA of 1.63-2.42 mm2, and 59 eyes with a DA of ≥ 2.42 mm2 in small disc, regular disc, and large disc groups, respectively. The swept-source optical coherence tomography scans of the PPC, RNFL, and MGCIPL were analyzed according to disc size. The three groups did not significantly differ in RNFL or MGCIPL measurements, but the PPC measurement was statistically significantly higher in the small disc group and statistically significantly thinner in the large disc group. Most of the correlations observed between the RNFL and MGCIPL measurements and eye characteristics in the regular disc group were not detected in the small and large disc groups. While the RNFL and MGCIPL were well correlated in all disc size groups, the PPC did not correlate with the RNFL or MGCIPL in any of the groups. Overall, the RNFL and MGCIPL measurements were consistent across all three disc sizes. While the PPC was thicker in small discs than in larger discs, it was not correlated with the RNFL or MGCIPL.

Multifractality signatures in lensed quasars

ABSTRACT Variations in scaling behaviour in the flux and emissions of gravitational lensed quasars can provide valuable information about the dynamics within the sources and their cosmological evolution with time. Here, we study the multifractal behaviour of the light curves (LCs) of 14 lensed quasars with multiple images in the r band, with redshift ranging from 0.657 to 2.730, in the search for potential differences in non-linearity between the signals of the quasar multiple images. Among these lensed systems, nine present two images, two present three images, and three present four images. To this end, we apply the wavelet transform-based multifractal analysis formalism called wavelet transform modulus maxima. We identify strong multifractal signatures in the LCs of the images of all analysed lensed quasar systems, independently of the number of images, with a significant difference between the degree of multifractality of all the images and combinations. We have also searched for a possible connection between the degree of multifractality and the characteristic parameters related to the quasar source and the lensing galaxy. These parameters include the Einstein ring radius and the accretion disc size and the characteristic time-scales related to microlensing variability. The analysis reveals some apparent trends, pointing to a decrease in the degree of multifractality with the increase of the quasar’s source size and time-scale. Using a larger sample and following a similar approach, this study confirms a previous finding for the quasar Q0957 + 561.

Dust Drift Timescales in Protoplanetary Disks at the Cusp of Gravitational Instability

Millimeter emitting dust grains have sizes that make them susceptible to drift in protoplanetary disks due to the difference between their orbital speed and that of the gas. The characteristic drift timescale depends on the surface density of the gas. By comparing disk radius measurements from Atacama Large Millimeter/submillimeter Array CO and continuum observations at millimeter wavelengths, the gas surface density profile and dust drift time can be self-consistently determined. We find that profiles which match the measured dust mass have very short drift timescales, an order of magnitude or more shorter than the stellar age, whereas profiles for disks that are on the cusp of gravitational instability, defined via the minimum value of the Toomre parameter, Qmin∼1−2 , have drift timescales comparable to the stellar lifetime. This holds for disks with masses of dust ≳5 M ⊕ across a range of absolute ages from less than 1 Myr to over 10 Myr. The inferred disk masses scale with stellar mass as Mdisk≈M*/5Qmin . This interpretation of the gas and dust disk sizes simultaneously solves two long standing issues regarding the dust lifetime and exoplanet mass budget, and suggests that we consider millimeter wavelength observations as a window into an underlying population of particles with a wide size distribution in secular evolution with a massive planetesimal disk.

Evaluation of Traditional Liposuction, VASER Liposuction, and VASER Liposuction Combined with J-plasma in Management of Gynecomastia.

Because gynecomastia is one of the most considerable aesthetic procedures for men, we are researching in our article recent management methods for high grades of gynecomastia. This prospective study included 45 individuals with gynecomastia, divided into 3 groups: group A (15 individuals) managed by traditional liposuction, group B (15 individuals) managed by vibration amplification of sound energy at resonance (VASER)-assisted lipoplasty, and group C (15 individuals) managed by VASER and J-plasma. Authors used a skin fold caliper for measurement of subareolar disk size and a Cutometer for assessment of skin pliability and firmness. The study was conducted at the Department of Plastic Surgery, Menoufia University Hospital, Egypt, and Reflect Center for Plastic Surgery in Riyadh, Saudi Arabia. Statistically significant differences were found among the groups in terms of reduction of subareolar disk size (assessed by skinfold caliper), skin redundancy (assessed by Cutometer), the need for a second stage of treatment, and patient satisfaction (by questionnaire). The combination of VASER and J-plasma is effective for managing grade 2 and 3 gynecomastia, resulting in significant reduction in subareolar disk size, minimal skin redundancy with enhanced skin firmness, reduced need for further procedures, and improved patient satisfaction compared with traditional methods.

Impact of H I cooling and study of accretion disks in asymptotic giant branch wind-companion smoothed particle hydrodynamic simulations

Context. High-resolution observations reveal that the outflows of evolved low- and intermediate-mass stars harbour complex morphological structures that are linked to the presence of one or multiple companions. Hydrodynamical simulations provide a way to study the impact of a companion on the shaping of the asymptotic giant branch (AGB) star out-flow. Aims. Using smoothed particle hydrodynamic (SPH) simulations of an AGB star undergoing mass loss, which also has a binary companion, we study the impact of including H I atomic line cooling on the flow morphology. We also study how this affects the properties of the accretion disks that form around the companion. Methods. We used the PHANTOM code to perform high-resolution 3D SPH simulations of the interaction of a solar-mass companion with the outflow of an AGB star, using different wind velocities and eccentricities. We compared the model properties, computed with and without the inclusion of H I cooling. Results. The inclusion of H I cooling produces a sizeable decrease in the temperature, up to one order of magnitude, in the region closely surrounding the companion star. As a consequence, the morphological irregularities and relatively energetic (bipolar) outflows that were obtained without H I cooling no longer appear. In the case of an eccentric orbit and a low wind velocity, these morphologies are still highly asymmetric, but the same structures recur at every orbital period, making the morphology more regular. Flared accretion disks, with a (sub-)Keplerian velocity profile, are found to form around the companion in all our models with H I cooling, provided the accretion radius is small enough. The disks have radial sizes ranging from about 0.4 to 0.9 au and masses around 10−7−10−8 M⊙. For the considered wind velocities, mass accretion onto the companion is up to a factor of 2 higher than predicted by the standard Bondi Hoyle Littleton rate, ranging between ~4 to 21% of the AGB wind mass loss rate. The lower the wind velocity at the location of the companion, the larger and the more massive the disk and the higher the mass accretion efficiency. In eccentric systems, the disk size, disk mass, and mass accretion efficiency vary, depending on the orbital phase. Conclusions. H I cooling is an essential ingredient to properly model the medium around the companion where density-enhanced wind structures form and it favours the formation of an accretion disk.

Microlensing analysis of 14.5-year light curves in SDSS J1004+4112: Quasar accretion disk size and intracluster stellar mass fraction

Context. The gravitational lens system SDSS J1004+4112 was the first known example of a quasar lensed by a galaxy cluster. The interest in this system has been renewed following the publication of r-band light curves spanning 14.5 years and the determination of the time delays between the four brightest quasar images. Aims. We constrained the quasar accretion disk size and the fraction of the lens mass in stars using the signature of microlensing in the quasar image light curves. Methods. We built the six possible histograms of microlensing magnitude differences between the four quasar images and compared them with simulated model histograms, using a χ2 test to infer the model parameters. Results. We infer a quasar disk half-light radius of R1/2 = (0.70 ± 0.04)RE = (6.4 ± 0.4) √M/0.3M⊙ light-days at 2407 Å in the rest frame and stellar mass fractions at the quasar image positions of αA &gt; 0.059, αB = 0.056+0.021-0.027, αC = 0.030+0.031-0.021, and αD = 0.072+0.034-0.016. Conclusions. The inferred disk size is broadly compatible with most previous estimates, and the stellar mass fractions are within the expected ranges for galaxy clusters. In the region where image C lies, the stellar mass fraction is compatible with a stellar contribution from the brightest cluster galaxy, galaxy cluster members, and intracluster light, but the values at images B, D, and especially A are slightly larger, possibly suggesting the presence of extra stellar components.

The Arizona Molecular ISM Survey with the SMT: Survey Overview and Public Data Release

The CO(1–0) line has been carefully calibrated as a tracer of molecular gas mass. However, recent studies often favor higher J transitions of the CO molecule, which are brighter and accessible for redshift ranges where CO(1–0) is not. These lines are not perfect analogs for CO(1–0), owing to their more stringent excitation conditions, and must be calibrated for use as molecular gas tracers. Here, we introduce the Arizona Molecular ISM Survey with the SMT, a multi-CO line survey of z ∼ 0 galaxies conducted to calibrate the CO(2–1) and CO(3–2) lines. The final survey includes CO(2–1) spectra of 176 galaxies and CO(3–2) spectra for a subset of 45. We supplement these with archival CO(1–0) spectra from xCOLD GASS for all sources and additional CO(1–0) observations with the Kitt Peak 12 m Telescope. Targets were selected to be representative of the 109 M ⊙ ≤ M * ≤ 1011.5 M ⊙ galaxy population. Our project emphasized careful characterization of statistical and systematic uncertainties to enable studies of trends in CO line ratios. We show that optical and CO disk sizes are on average equal, for both the CO(1–0) and CO(2–1) line. We measure the distribution of CO line luminosity ratios, finding medians (16th–84th percentile) of 0.71 (0.51–0.96) for the CO(2–1)-to-CO(1–0) ratio, 0.39 (0.24–0.53) for the CO(3–2)-to-CO(1–0) ratio, and 0.53 (0.41–0.74) for the CO(3–2)-to-CO(2–1) ratio. A companion paper presents our study of CO(2–1)'s applicability as a molecular gas mass tracer and search for trends in the CO(2–1)-to-CO(1–0) ratio. Our catalog of CO line luminosities is publicly available.

Hydrodynamic 3D Simulation of Roche Lobe Overflow in High-mass X-Ray Binaries

Abstract While binary merger events have been an active area of study in both simulations and observational work, the formation channels by which a high-mass star extends from Roche lobe overflow (RLO) in a decaying orbit of a black-hole (BH) companion to a binary black-hole (BBH) system merits further investigation. Variable length-scales must be employed to accurately represent the dynamical fluid transfer and morphological development of the primary star as it conforms to a diminishing Roche lobe under the runaway influence of the proximal BH. We have simulated and evolved binary mass flow under these conditions to better identify the key transitional processes from RLO to BBHs. We demonstrate a new methodology to model RLO systems to unprecedented resolution simultaneously across the envelope, donor wind, tidal stream, and accretion disk regimes without reliance upon previously universal symmetry, mass flux, and angular momentum flux assumptions. We have applied this method to the semidetached high-mass X-ray binary M33 X-7 in order to provide a direct comparison to recent observations of an RLO candidate system at two overflow states of overfilling factors f = 1.01 and f = 1.1. We found extreme overflow (f = 1.1) to be entirely conservative in both mass and angular momentum transport, forming a conical L1 tidal stream of density and deflected angle comparable to existing predictions. This case lies within the unstable mass transfer (MT) regime as recently proposed of M33 X-7. The f = 1.01 case differed in stream geometry, accretion disk size, and efficiency, demonstrating nonconservative stable MT through a ballistic uniform-width stream. The nonconservative and stable nature of the f = 1.01 case MT also suggests that existing assumptions of semidetached binaries undergoing RLO may mischaracterize their role and distribution as progenitors of BBHs and common envelopes.