Search

The XMM-RM project was designed to provide X-ray coverage of the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) field. 41 XMM-Newton exposures, placed surrounding the Chandra AEGIS field, were taken, covering an area of 6.13 deg^2 and reaching a nominal exposure depth of ~15 ks. We present an X-ray catalog of 3553 sources detected in these data, using a PSF-fitting algorithm and a sample selection threshold that produces a ~5% fraction of spurious sources. In addition to the PSF-fitting likelihood, we calculate a second source reliability measure based on Poisson theory using source and background counts within an aperture. Using the Poissonian likelihood, we select a sub-sample with a high purity and find that it has similar number count profiles to previous X-ray surveys. The Bayesian method "NWAY" was employed to identify counterparts of the X-ray sources from the optical Legacy and the IR unWISE catalogs, using a 2-dimensional unWISE magnitude-color prior created from optical/IR counterparts of Chandra X-ray sources. A significant number of the optical/IR counterparts correspond to sources with low detection likelihoods, proving the value of retaining the low-likelihood detections in the catalog. 932 of the XMM-RM sources are covered by SDSS spectroscopic observations. 89% of them are classified as AGN, and 71% of these AGN are in the SDSS-RM quasar catalog. Among the SDSS-RM quasars, 80% are detectable at the depth of the XMM observations., Comment: ApJS accepted. 20 pages, 16 figures

We present a detailed characterization of the 849 broad-line quasars from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. Our quasar sample covers a redshift range of 0.1, Comment: Updated to match the accepted version (minor corrections). Catalog data and software tools are available at ftp://quasar.astro.illinois.edu/public/sdssrm/paper_data/Sample_char/

We analyze extensive spectroscopic and photometric data of the hypervariable quasar SDSS J131424+530527 (RMID 017) at z=0.456, an optical "changing look" quasar from the Sloan Digital Sky Survey Reverberation Mapping project that increased in optical luminosity by a factor of 10 between 2014 and 2017. The observed broad emission lines all respond in luminosity and width to the changing optical continuum, as expected for photoionization in a stratified, virialized broad emission line region. The luminosity changes therefore result from intrinsic changes in accretion power rather than variable obscuration. The variability is continuous and apparently stochastic, disfavoring an origin as a discrete event such as a tidal disruption flare or microlensing event. It is coordinated on day timescales with blue leading red, consistent with reprocessing powering the entire optical SED. We show that this process cannot work in a standard thin disk geometry on energetic grounds, and would instead require a large covering factor reprocessor. Disk instability models could potentially also explain the data, provided that the instability sets in near the inner radius of a geometrically thick accretion disk., Comment: 14 pages, 8 figures, submitted to AAS journals

We report on the discovery of a dramatic X-ray spectral variability event observed in a $z\sim 1$ broad line type-1 QSO. The XMM-Newton spectrum from the year 2000 is characterized by an unobscured power-law spectrum with photon index of $\Gamma\sim 2$, a column density of $N_{\mathrm{H}}\sim 5\times 10^{20}\,\mathrm{cm^{-2}}$, and no prominent reflection component. Five years later, Chandra captured the source in a heavily-obscured, reflection-dominated state. The observed X-ray spectral variability could be caused by a Compton-thick cloud with $N_{\mathrm{H}}\sim 2\times 10^{24}\,\mathrm{cm^{-2}}$ eclipsing the direct emission of the hot corona, implying an extreme $N_{\mathrm{H}}$ variation never before observed in a type-1 QSO. An alternative scenario is a corona that switched off in between the observations. In addition, both explanations require a significant change of the X-ray luminosity prior to the obscuration or fading of the corona and/or a change of the relative geometry of the source/reflector system. Dramatic X-ray spectral variability of this kind could be quite common in type-1 QSOs, considering the relatively few datasets in which such an event could have been identified. Our analysis implies that there may be a population of type-1 QSOs which are Compton-thick in the X-rays when observed at any given time., Comment: 7 pages, 4 figures, to be published in MNRAS

SPIDERS (SPectroscopic IDentification of eROSITA Sources) is an SDSS-IV survey running in parallel to the eBOSS cosmology project. SPIDERS will obtain optical spectroscopy for large numbers of X-ray-selected AGN and galaxy cluster members detected in wide area eROSITA, XMM-Newton and ROSAT surveys. We describe the methods used to choose spectroscopic targets for two sub-programmes of SPIDERS: X-ray selected AGN candidates detected in the ROSAT All Sky and the XMM-Newton Slew surveys. We have exploited a Bayesian cross-matching algorithm, guided by priors based on mid-IR colour-magnitude information from the WISE survey, to select the most probable optical counterpart to each X-ray detection. We empirically demonstrate the high fidelity of our counterpart selection method using a reference sample of bright well-localised X-ray sources collated from XMM-Newton, Chandra and Swift-XRT serendipitous catalogues, and also by examining blank-sky locations. We describe the down-selection steps which resulted in the final set of SPIDERS-AGN targets put forward for spectroscopy within the eBOSS/TDSS/SPIDERS survey, and present catalogues of these targets. We also present catalogues of ~12000 ROSAT and ~1500 XMM-Newton Slew survey sources which have existing optical spectroscopy from SDSS-DR12, including the results of our visual inspections. On completion of the SPIDERS program, we expect to have collected homogeneous spectroscopic redshift information over a footprint of ~7500 deg$^2$ for >85 percent of the ROSAT and XMM-Newton Slew survey sources having optical counterparts in the magnitude range 17, Comment: MNRAS, accepted

[Abbreviated] Upcoming large area sky surveys like EUCLID and eROSITA crucially depend on accurate photometric redshifts (photo-z). The identification of variable sources, such as AGNs, and the achievable redshift accuracy for varying objects are important in view of the science goals of the EUCLID and eROSITA missions. We probe AGN optical variability for a large sample of X-ray-selected AGNs in the XMM-COSMOS field, using the light curves provided by the Pan-STARRS1 (PS1) 3pi and MDF04 surveys. Utilizing two different variability parameters, we defined a sample of varying AGNs for every PS1 band. We investigated the influence of variability on the calculation of photo-z by applying three different input photometry sets for our fitting procedure. For each of the five PS1 bands, we chose either the epochs minimizing the interval in observing time, the median magnitude values, or randomly drawn light curve points to compute the redshift. In addition, we derived photo-z using PS1 photometry extended by GALEX/IRAC bands. We find that the photometry produced by the 3pi survey is sufficient to reliably detect variable sources provided that the fractional variability amplitude is at least 3%. Considering the photo-z of variable AGNs, we observe that minimizing the time spacing of the chosen points yields superior photo-z in terms of the percentage of outliers (33%) and accuracy (0.07), outperforming the other two approaches. Drawing random points from the light curve gives rise to typically 57% of outliers and an accuracy of 0.4. Adding GALEX/IRAC bands for the redshift determination weakens the influence of variability. Although the redshift quality generally improves when adding these bands, we still obtain not less than 26% of outliers and an accuracy of 0.05 at best, therefore variable sources should receive a flag stating that their photo-z may be low quality., Comment: Accepted by A&A, 24 pages, 13 figures

[Abbreviated] We search for scaling relations between the fundamental AGN parameters and rest-frame UV/optical variability properties for a sample of $\sim$90 X-ray selected AGNs covering a wide redshift range from the XMM-COSMOS survey, with optical light curves in four bands provided by the Pan-STARRS1 (PS1) Medium Deep Field 04 survey. To estimate the variability amplitude we utilize the normalized excess variance ($\sigma_{\mathrm{rms}}^{2}$) and probe variability on rest-frame timescales of several months and years by calculating $\sigma_{\mathrm{rms}}^{2}$ from different parts of our light curves. In addition, we derive the rest-frame optical PSD for our sources using continuous-time autoregressive moving average (CARMA) models. We observe that the excess variance and the PSD amplitude are strongly anti-correlated with wavelength, bolometric luminosity and Eddington ratio. There is no evidence for a dependency of the variability amplitude on black hole mass and redshift. These results suggest that the accretion rate is the fundamental physical quantity determining the rest-frame UV/optical variability amplitude of quasars on timescales of months and years. The optical PSD of all of our sources is consistent with a broken power law showing a characteristic bend at rest-frame timescales ranging between $\sim$100 and $\sim$300 days. The break timescale exhibits no significant correlation with any of the fundamental AGN parameters. The low frequency slope of the PSD is consistent with a value of $-1$ for most of our objects, whereas the high frequency slope is characterized by a broad distribution of values between $\sim-2$ and $\sim-4$. These findings unveil significant deviations from the simple "damped random walk" model, frequently used in previous optical variability studies. We find a weak tendency for AGNs with higher black hole mass having steeper high frequency PSD slopes., Comment: Accepted by A&A, 23 pages, 19 figures

Objective/Hypothesis: The objective of this study was to compare swing traction versus no-traction management of complex fractures of proximal interphalangeal (PIP) finger joints. We hypothesized that there is no long-term (ie, >12 month) difference between swing traction and no traction (with or without surgical fixation) in terms of motion, pain, function, patient satisfaction, or treatment cost. Materials and Methods: This cohort study recruited adults with a history of complex PIP fractures affecting ≥ 30% of articular surface injury identified from database searches at 3 public hospitals and a private clinic. The x-rays taken at the time of injury were graded by 2 blinded assessors, and participants attended a clinic for measurement of range of motion (ROM) and self-reported function, pain, and satisfaction. Participant data were then grouped by treatment provided. One group (n = 17) was treated with swing traction and the other group (n = 14) had no traction. The primary outcome was combined motion of the PIP and distal interphalangeal (DIP) joints, expressed as both total active motion and Strickland score. Secondary outcomes were physical function and symptoms as measured by the Disabilities of Arm, Shoulder and Hand (DASH), patient satisfaction, pain, complication rates, and cost of treatment, based on mean resource consumption per group. Results: Patients treated with swing traction had greater finger motion than those in the no-traction group, which was statistically and clinically significant. There were no differences in patient ratings of function, pain, or satisfaction. Complications, such as swan-neck deformity, cold sensitivity, malunion, infection, or adhesions occurred in over half of both groups of participants. During the treatment phase, the swing traction group attended hand therapy an average of 13.3 times and the no-traction group attended 11.7 times. Average costs for swing traction were less than that for surgical fixation with no traction. Conclusions: Patients treated with the swing traction protocol had greater ROM in the finger; however, this did not translate to improved patient ratings of function, pain, or satisfaction. A basic cost comparison indicated that swing traction may be less expensive than other forms of surgical repair.

Introduction Traction orthoses are thought to optimize recovery from intra-articular finger fractures by restoring joint space and allowing early motion. Evidence to date has, however, consisted only of case series. Purpose of the study To compare swing traction versus no-traction management of complex fractures of proximal inter-phalangeal (PIP) finger joints. We hypothesized that there is no long-term (i.e. >12 month) difference between swing traction and no-traction (with or without surgical fixation) in terms of motion, pain, function, patient satisfaction, or treatment cost. Methods Adults with a history of complex PIP fractures affecting ≥30% of articular surface injury were identified from database searches at three public hospitals and a private clinic and invited to participate. X-rays taken at the time of injury were graded by two blinded assessors, and participants attended a clinic for measurement of range of motion (ROM) and self-reported function, pain, and satisfaction at least one year post injury. Participant data were then were grouped by treatment provided. One group ( N = 17) was treated with swing traction and the other group ( N = 14) had no-traction. The primary outcome was combined motion of the PIP and distal inter-phalangeal (DIP) joints, expressed as both total active motion and Strickland score. Secondary outcomes were physical function and symptoms as measured by the Disabilities of Arm, Shoulder and Hand (DASH), patient satisfaction, pain, complication rates, and cost of treatment, based on mean resource consumption per group. Results Patients treated with swing traction had greater finger motion than those in the no-traction group, which was statistically and clinically significant. There were no differences in patient ratings of function, pain or satisfaction. Complications, such as swan-neck deformity, cold sensitivity, malunion, infection, or adhesions occurred in over half of both groups of participants. During the treatment phase, the swing traction group attended hand therapy an average of 13.3 times, and the no-traction group attended 11.7 times. Average costs for swing traction were less than for surgical fixation with no-traction. Discussion The significantly different range of motion found in our study did not translate to better DASH scores. The DASH is designed to measure global upper limb physical functioning and symptoms, but lacks sensitivity in populations with finger injuries. Conclusions Patients treated with the swing traction protocol had greater range of motion in the finger, however this did not translate to improved patient ratings of function, pain or satisfaction. A basic cost comparison indicated that swing traction may be less expensive than other forms of surgical repair. Level of evidence: 3.

Many previous studies have indicated that remedial teaching of reading has only a temporary effect. The present study is of large scale surveys (N = 503) of the results of remedial help in one LEA over a period of five years, and suggests that some of the improvement in reading following remedial teaching is maintained three years after discharge. When the results are compared with the results of a previous follow‐up study of backward readers the indications are that children receiving systematic remedial help in primary school stand less chance of remaining backward readers at age 15 than if they had not received such help.