Abstract
New CCD photometric light curves of the short-period (P = 0.285 d) eclipsing binary RW Dor are presented. The observations were performed with the PROMPT-8 robotic telescope at CTIO in Chile ...between 2015 March and 2017 March. Other eclipse timings were obtained from the 2.15 m JS telescope at CASLEO, San Juan, Argentina in 2011 December. Based on a light curve analysis, it is found that RW Dor is a W-type shallow contact binary with a fill-out factor f ∼ 11% and a high mass ratio q ∼ 1.587 (1/q = 0.63), where the hotter component is the less massive one (M1 ∼ 0.52 M⊙ and M2 ∼ 0.82 M⊙). For orbital-period investigation, 15 new eclipse times and those previously published were compiled. O − C analysis with very weak evidence suggests that a long-term decrease in period with a rate of dP/dt = −9.61 × 10−9 d yr−1 is superimposed on a cyclic variation (A3 = 0.0054 d and P3 = 49.9 yr). The long-term decrease can be interpreted as mass transfer from the more massive component to the less massive one, or combined with angular momentum loss via magnetic braking. In addition, the marginal contact phase, high mass ratio (1/q > 0.4), and long-term decrease in period all suggest that RW Dor is a newly formed contact binary via Case A mass transfer, and it will evolve into a deeper normal contact binary. If the cyclic change is correct, the light travel-time effect via the presence of a cool third body will be a more plausible explanation for this.
We present the C4 Cluster Catalog, a new sample of 748 clusters of galaxies identified in the spectroscopic sample of the Second Data Release (DR2) of the Sloan Digital Sky Survey (SDSS). The C4 ...cluster-finding algorithm identifies clusters as overdensities in a seven-dimensional position and color space, thus minimizing projection effects that have plagued previous optical cluster selection. The present C4 catalog covers ~2600 deg2 of sky and ranges in redshift from z = 0.02 to 0.17. The mean cluster membership is 36 galaxies (with measured redshifts) brighter than r = 17.7, but the catalog includes a range of systems, from groups containing 10 members to massive clusters with over 200 cluster members with measured redshifts. The catalog provides a large number of measured cluster properties including sky location, mean redshift, galaxy membership, summed r-band optical luminosity (Lr), and velocity dispersion, as well as quantitative measures of substructure and the surrounding large-scale environment. We use new, multicolor mock SDSS galaxy catalogs, empirically constructed from the CDM Hubble Volume (HV) Sky Survey output, to investigate the sensitivity of the C4 catalog to the various algorithm parameters (detection threshold, choice of passbands, and search aperture), as well as to quantify the purity and completeness of the C4 cluster catalog. These mock catalogs indicate that the C4 catalog is 90% complete and 95% pure above M200 = 1 X 1014 h-1 M and within 0.03 <= z <= 0.12. Using the SDSS DR2 data, we show that the C4 algorithm finds 98% of X-ray-identified clusters and 90% of Abell clusters within 0.03 <= z <= 0.12. Using the mock galaxy catalogs and the full HV dark matter simulations, we show that the Lr of a cluster is a more robust estimator of the halo mass (M200) than the galaxy line-of-sight velocity dispersion or the richness of the cluster. However, if we exclude clusters embedded in complex large-scale environments, we find that the velocity dispersion of the remaining clusters is as good an estimator of M200 as Lr. The final C4 catalog will contain 2500 clusters using the full SDSS data set and will represent one of the largest and most homogeneous samples of local clusters.
Abstract
We present high-cadence optical and ultraviolet light curves of the normal Type Ia supernova (SN) 2021aefx, which shows an early bump during the first two days of observation. This bump may ...be a signature of interaction between the exploding white dwarf and a nondegenerate binary companion, or it may be intrinsic to the white dwarf explosion mechanism. In the case of the former, the short duration of the bump implies a relatively compact main-sequence companion star, although this conclusion is viewing-angle dependent. Our best-fit companion-shocking and double-detonation models both overpredict the UV luminosity during the bump, and existing nickel-shell models do not match the strength and timescale of the bump. We also present nebular spectra of SN 2021aefx, which do not show the hydrogen or helium emission expected from a nondegenerate companion, as well as a radio nondetection that rules out all symbiotic progenitor systems and most accretion disk winds. Our analysis places strong but conflicting constraints on the progenitor of SN 2021aefx; no current model can explain all of our observations.
We present a summary of the results of the OJ 287 observational campaign, which was carried out during the 2021/2022 observational season. This season is special in the binary model because the major ...axis of the precessing binary happens to lie almost exactly in the plane of the accretion disc of the primary. This leads to pairs of almost identical impacts between the secondary black hole and the accretion disk in 2005 and 2022. In 2005, a special flare called “blue flash” was observed 35 days after the disk impact, which should have also been verifiable in 2022. We did observe a similar flash and were able to obtain more details of its properties. We describe this in the framework of expanding cloud models. In addition, we were able to identify the flare arising exactly at the time of the disc crossing from its photo-polarimetric and gamma-ray properties. This is an important identification, as it directly confirms the orbit model. Moreover, we saw a huge flare that lasted only one day. We may understand this as the lighting up of the jet of the secondary black hole when its Roche lobe is suddenly flooded by the gas from the primary disk. Therefore, this may be the first time we directly observed the secondary black hole in the OJ 287 binary system.
SN 2009bb: A Peculiar Broad-lined Type Ic Supernova Pignata, Giuliano; Stritzinger, Maximilian; Soderberg, Alicia ...
Astrophysical journal/The Astrophysical journal,
02/2011, Volume:
728, Issue:
1
Journal Article
Peer reviewed
Open access
Ultraviolet, optical, and near-infrared photometry and optical spectroscopy of the broad-lined Type Ic supernova (SN) 2009bb are presented, following the flux evolution from --10 to +285 days past ...B-band maximum. Thanks to the very early discovery, it is possible to place tight constraints on the SN explosion epoch. The expansion velocities measured from near maximum spectra are found to be only slightly smaller than those measured from spectra of the prototype broad-lined SN 1998bw associated with GRB 980425. Fitting an analytical model to the pseudobolometric light curve of SN 2009bb suggests that 4.1 ? 1.9 M of material was ejected with 0.22 ? 0.06 M of it being 56Ni. The resulting kinetic energy is 1.8 ? 0.7 X 1052 erg. This, together with an absolute peak magnitude of M B = --18.36 ? 0.44, places SN 2009bb on the energetic and luminous end of the broad-lined Type Ic (SN Ic) sequence. Detection of helium in the early time optical spectra accompanied with strong radio emission and high metallicity of its environment makes SN 2009bb a peculiar object. Similar to the case for gamma-ray bursts (GRBs), we find that the bulk explosion parameters of SN 2009bb cannot account for the copious energy coupled to relativistic ejecta, and conclude that another energy reservoir (a central engine) is required to power the radio emission. Nevertheless, the analysis of the SN 2009bb nebular spectrum suggests that the failed GRB detection is not imputable to a large angle between the line-of-sight and the GRB beamed radiation. Therefore, if a GRB was produced during the SN 2009bb explosion, it was below the threshold of the current generation of Delta *g-ray instruments.
Transcatheter mitral valve-in-valve/valve-in-ring procedures (TM-VIVoR) are increasing. The authors aimed to identify independent predictors for hospital mortality in redo mitral valve surgery as ...possible future selection criteria for TM-VIVoR.
Retrospective multicenter registry.
Tertiary university and community hospitals.
Two-hundred and sixty patients (out of 920 enrolled) who are potentially candidates for TM-VIVoR undergoing redo-surgery.
Redo mitral surgery.
Regression analyzes and receiver operating characteristic (ROC) curves identified independent predictors of death. Patients potentially candidates for TM-VIVoR reported significant hospital mortality (9.2%; EuroSCORE II: 13.2 ± 13.1, Society of Thoracic Surgeons STS score: 6.2 ± 3.1) and major morbidity (3.8% acute myocardial infarction, 5% stroke, 16.9% perioperative respiratory failure, 16.5% acute renal insufficiency, 25% massive transfusions). EuroSCORE II (odds ration OR 1.06; confidence interval CI 1.01-1.10; p = 0.005), STS score (OR 1.58; CI 1.27-1.97; p = 0.001), age at surgery (OR 1.05; CI 1.00-1.15; p = 0.05), preoperative dialysis (OR 2.5; CI 1.8-12.6; p = 0.042), left ventricular ejection fraction (LVEF) <30% (OR 4.8; CI 1.12-37.1; p = 0.021), severe pulmonary hypertension (OR 7.5; CI 1.9-29.4; p = 0.003), and previous coronary artery bypass grafting (CABG) (OR 11.8; CI 1.7-36.9; p = 0.002) were independent predictors of hospital mortality. ROC analyses reported good prediction for EuroSCORE II (AUC: 0.76; cut-off value: >13.1; 70.8% sensitivity and 68.2% specificity) and better prediction for STS score (AUC: 0.81; cut-off value: 7.4; 75.0% sensitivity and 66.2% specificity). Quintiles stratification identified EuroSCORE II ≥18.7 (5th quintile, observed mortality: 19.3%) and STS score >9.1 as strong predictors of death within each risk-categorization (OR 5.9 and 12.1, respectively).
High EuroSCORE II and STS scores, advanced age at surgery, LVEF <30%, previous CABG, severe pulmonary hypertension or preoperative dialysis might represent in the future preferred indications for TM-VIVoR in the redo-mitral surgery scenario.
Full text
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Abstract
We present optical, infrared, ultraviolet, and radio observations of SN 2022xkq, an underluminous fast-declining Type Ia supernova (SN Ia) in NGC 1784 (
D
≈ 31 Mpc), from <1 to 180 days ...after explosion. The high-cadence observations of SN 2022xkq, a photometrically transitional and spectroscopically 91bg-like SN Ia, cover the first days and weeks following explosion, which are critical to distinguishing between explosion scenarios. The early light curve of SN 2022xkq has a red early color and exhibits a flux excess that is more prominent in redder bands; this is the first time such a feature has been seen in a transitional/91bg-like SN Ia. We also present 92 optical and 19 near-infrared (NIR) spectra, beginning 0.4 days after explosion in the optical and 2.6 days after explosion in the NIR. SN 2022xkq exhibits a long-lived C
i
1.0693
μ
m feature that persists until 5 days post-maximum. We also detect C
ii
λ
6580 in the pre-maximum optical spectra. These lines are evidence for unburnt carbon that is difficult to reconcile with the double detonation of a sub-Chandrasekhar mass white dwarf. No existing explosion model can fully explain the photometric and spectroscopic data set of SN 2022xkq, but the considerable breadth of the observations is ideal for furthering our understanding of the processes that produce faint SNe Ia.
Background:Glycated hemoglobin (HbA1c) is a suspected risk factor for sternal wound infection (SWI) after CABG.Methods and Results:Data on preoperative HbA1c and SWI were available in 2,130 patients ...undergoing isolated CABG from the prospective E-CABG registry. SWI occurred in 114 (5.4%). Baseline HbA1c was significantly higher in patients with SWI (mean, 54±17 vs. 45±13 mmol/mol, P<0.0001). This difference was also observed in patients without a diagnosis of diabetes (P=0.027), in insulin-dependent diabetic (P=0.023) and non-insulin-dependent diabetic patients (P=0.034). In the overall series, HbA1c >70 mmol/mol (NGSP units, 8.6%) was associated with the highest risk of SWI (20.6% vs. 4.6%; adjusted OR, 5.01; 95% CI: 2.47–10.15). When dichotomized according to the cut-off 53 mmol/mol (NGSP units, 7.0%) as suggested both for diagnosis and optimal glycemic control of diabetes, HbA1c was associated with increased risk of SWI in the overall series (10.6% vs. 3.9%; adjusted OR, 2.09; 95% CI: 1.24–3.52), in diabetic patients (11.7% vs. 5.1%; adjusted OR, 2.69; 95% CI: 1.38–5.25), in patients undergoing elective surgery (9.9% vs. 2.7%; adjusted OR, 2.09; 95% CI: 1.24–3.52) and in patients with bilateral mammary artery grafts (13.7% vs. 4.8%; adjusted OR, 2.35; 95% CI: 1.17–4.69).Conclusions:Screening for HbA1c before CABG may identify untreated diabetic patients, as well as diabetic patients with suboptimal glycemic control, at high risk of SWI.
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