ABSTRACT We present ALMA (Cycle 0) band 6 and band 3 observations of the transition disk Sz 91. The disk inclination and position angle are determined to be i = 49 5 3 5°and PA = 18 2 3 5 and the ...dusty and gaseous disk are detected up to ∼220 and ∼400 AU from the star, respectively. Most importantly, our continuum observations indicate that the cavity size in the millimeter-sized dust distribution must be ∼97 AU in radius, the largest cavity observed around a T Tauri star. Our data clearly confirm the presence of (2-1) well inside the dust cavity. Based on these observational constraints we developed a disk model that simultaneously accounts for the and continuum observations (i.e., gaseous and dusty disk). According to our model, most of the millimeter emission comes from a ring located between 97 and 140 AU. We also find that the dust cavity is divided into an innermost region largely depleted of dust particles ranging from the dust sublimation radius up to 85 AU, and a second, moderately dust-depleted region, extending from 85 to 97 AU. The extremely large size of the dust cavity, the presence of gas and small dust particles within the cavity, and the accretion rate of Sz 91 are consistent with the formation of multiple (giant) planets.
Abstract Objectives To date, no studies have yet assessed the characteristics of non-HCV patients with low level of cryoglobulin (≤ 0.05 g/L). The aims of the current study were thus to: 1) determine ...the prevalence of cryoglobulin ≤ 0.05 g/L in patients with non-HCV cryoglobulin; and 2) compare clinical features and long term outcome, including organ complications and mortality rate, between non-HCV patients with cryoglobulin level ≤ 0.05 g/L and those exhibiting cryoglobulin level > 0.05 g/L. Methods Among 6379 cryoglobulin testing, cryoglobulin was detected in 618 patients (9.69% of cases); of these 618 patients, 453 non-HCV patients were included in the study. The medical records of these patients were reviewed. Results Of the 453 non-HCV cryoglobulin-positive patients, 265 (58.6%) exhibited cryoglobulin level ≤ 0.05 g/L. We showed that patients with cryoglobulin level ≤ 0.05 g/L had: 1) less commonly: palpable purpura ( p < 0.001), digital ulcers ( p = 0.006), peripheral neurologic involvement ( p = 0.03) and renal impairment ( p = 0.03); and 2) lower median values of ESR ( p < 0.001) and C-reactive protein ( p = 0.001). The patients with cryoglobulin level ≤ 0.05 g/L less often experienced infections ( p = 0.04) and hematological malignancies ( p = 0.01); both groups did not differ regarding prevalence of connective tissue diseases and solid tumors. Mortality rate was as high as 13.6% in patients with cryoglobulin level ≤ 0.05 g/L; death was mainly due to: solid tumors (16.6%), cardiovascular complications (13.8%), hematological malignancies (11.1%), infections (8.3%), pulmonary/renal complications of cryoglobulin (8.3%) and connective tissue diseases (8.3%). Conclusion Our study shows a high prevalence of cryoglobulin level ≤ 0.05 g/L in clinical practice. Our findings further underscore that non-HCV cryoglobulin level ≤ 0.05 g/L may be responsible for severe renal and neurological complications, leading to high morbidity and mortality in these patients. Thus, our data suggest that both appropriate therapy and close follow-up may be required to improve such patients' outcome.
Context.
We initiated a deep-imaging survey of Scorpius-Centaurus A-F stars in 2015. These stars are predicted to host warm inner and cold outer belts of debris reminiscent of the architecture of ...emblematic systems such as HR 8799.
Aims.
We present resolved images of a ring of debris around the F5-type star HD 141011 that was observed as part of our survey. We aim to set constraints on the properties of the disk, compare them to those of other resolved debris disks in Sco-Cen, and detect companions.
Methods.
We obtained high-contrast coronagraphic observations of HD 141011 in 2015, 2016, and 2019 with VLT/SPHERE. We removed the stellar halo using angular differential imaging. We searched for scattered light emission from a disk in the residuals and applied a forward-modeling approach to retrieve its morphological and photometric properties. We combined our radial velocity and imaging data to derive detection probabilities for companions co-planar with the disk orientation.
Results.
We resolve a narrow ring of debris that extends up to ~1.1″ (~141 au) from the star in the IRDIS and IFS data obtained in 2016 and 2019. The disk is not detected in the 2015 data which are of poorer quality. The disks is best reproduced by models of a noneccentric ring centered on the star with an inclination of 69.1 ± 0.9°, a position angle of −24.6 ± 1.7°, and a semimajor axis of 127.5 ± 3.8 au. The combination of radial velocity and imaging data excludes brown-dwarf (
M
> 13.6
M
Jup
) companions coplanar with the disk from 0.1 to 0.9 au and from 20 au up to 500 au (90% probability).
Conclusions.
HD 141011 adds to the growing list of debris disks that are resolved in Sco-Cen. It is one of the faintest disks that are resolved from the ground and has a radial extent and fractional width (~12.5%) reminiscent of Fomalhaut. Its moderate inclination and large semimajor axis make it a good target for the
James Webb
Space Telescope and should allow a deeper search for putative companions shaping the dust distribution.
Context. Debris discs are thought to be formed through the collisional grinding of planetesimals, and then can be considered as the outcome of planet formation. Understanding the properties of gas ...and dust in debris discs can help us comprehend the architecture of extrasolar planetary systems. Herschel Space Observatory far-infrared (IR) photometry and spectroscopy have provided a valuable dataset for the study of debris discs gas and dust composition. This paper is part of a series of papers devoted to the study of Herschel-PACS observations of young stellar associations. Aims. This work aims at studying the properties of discs in the beta Pictoris moving group (BPMG) through far-IR PACS observations of dust and gas. Methods. We obtained Herschel-PACS far-IR photometric observations at 70, 100, and 160 μm of 19 BPMG members, together with spectroscopic observations for four of them. These observations were centred at 63.18 μm and 157 μm, aiming to detect OI and CII emission. We incorporated the new far-IR observations in the SED of BPMG members and fitted modified blackbody models to better characterise the dust content. Results. We have detected far-IR excess emission towards nine BPMG members, including the first detection of an IR excess towards HD 29391.The star HD 172555, shows OI emission, while HD 181296 shows CII emission, expanding the short list of debris discs with a gas detection. No debris disc in BPMG is detected in both OI and CII. The discs show dust temperatures in the range 55–264 K, with low dust masses (<6.6 × 10-5 M⊕ to 0.2 M⊕) and radii from blackbody models in the range 3 to ~82 AU. All the objects with a gas detection are early spectral type stars with a hot dust component.
We analysed the influence of climatic oscillations based on the Indian Oscillation Index (IOI) on monthly catch rates of two tropical tuna species in the equatorial Indian Ocean. We carried out ...wavelet analysis, an efficient method of time series analysis to study non‐stationary data. Catch per unit of effort (CPUE) of bigeye tuna was computed from Japanese longline statistics from 1955 to 2002 in the equatorial Indian Ocean and CPUE of yellowfin tuna was derived from industrial purse seine statistics from 1984 to 2003 in the Western Indian Ocean. Wavelet analyses allowed us to quantify both the pattern of variability in the time series and non‐stationary associations between tuna and climatic signals. Phase analyses were carried out to investigate dependency between the two signals. We reported strong associations between tuna and climate series for the 4‐ and 5‐yr periodic modes, i.e. the periodic band of the El Niño Southern Oscillation signal propagation in the Indian Ocean. These associations were non‐stationary, evidenced from 1970 to 1990 for bigeye, and from 1984 to 1991 and then from 1993 to 2001 for yellowfin. Warm episodes (low negative IOI values) matched increases of longline catch rates of bigeye during the 1970–1990 time frame, whereas the strong 1997–1998 warm event matched a decrease of purse seine catch rates of yellowfin. We discussed these results in terms of changes in catchability for purse seine and longline.
Context. Transition disks are considered sites of ongoing planet formation, and their dust and gas distributions could be signposts of embedded planets. The transition disk around the T Tauri star RY ...Lup has an inner dust cavity and displays a strong silicate emission feature. Aims. Using high-resolution imaging we study the disk geometry, including non-axisymmetric features, and its surface dust grain, to gain a better understanding of the disk evolutionary process. Moreover, we search for companion candidates, possibly connected to the disk. Methods. We obtained high-contrast and high angular resolution data in the near-infrared with the VLT/SPHERE extreme adaptive optics instrument whose goal is to study the planet formation by detecting and characterizing these planets and their formation environments through direct imaging. We performed polarimetric imaging of the RY Lup disk with IRDIS (at 1.6 μm), and obtained intensity images with the IRDIS dual-band imaging camera simultaneously with the IFS spectro-imager (0.9–1.3 μm). Results. We resolved for the first time the scattered light from the nearly edge-on circumstellar disk around RY Lup, at projected separations in the 100 au range. The shape of the disk and its sharp features are clearly detectable at wavelengths ranging from 0.9 to 1.6 μm. We show that the observed morphology can be interpreted as spiral arms in the disk. This interpretation is supported by in-depth numerical simulations. We also demonstrate that these features can be produced by one planet interacting with the disk. We also detect several point sources which are classified as probable background objects.
Molecular gas constitutes the dominant mass component of protoplanetary discs. To date, these sources have not been studied comprehensively at the longest far-infrared and shortest submillimetre ...wavelengths. This paper presents Herschel SPIRE FTS spectroscopic observations towards 18 protoplanetary discs, covering the entire 450–1540 GHz (666–195 μm) range at ν/Δν ≈ 400–1300. The spectra reveal clear detections of the dust continuum and, in six targets, a significant amount of spectral line emission primarily attributable to 12CO rotational lines. Other targets exhibit little to no detectable spectral lines. Low signal-to-noise detections also include signatures from 13CO, C i and HCN. For completeness, we present upper limits of non-detected lines in all targets, including low-energy transitions of H2O and CH+ molecules. The 10 12CO lines that fall within the SPIRE FTS bands trace energy levels of ∼50–500 K. Combined with lower and higher energy lines from the literature, we compare the CO rotational line energy distribution with detailed physical–chemical models, for sources where these are available and published. Our 13CO line detections in the disc around Herbig Be star HD 100546 exceed, by factors of ∼10–30, the values predicted by a model that matches a wealth of other observational constraints, including the SPIRE 12CO ladder. To explain the observed 12CO/13CO ratio, it may be necessary to consider the combined effects of optical depth and isotope selective (photo)chemical processes. Considering the full sample of 18 objects, we find that the strongest line emission is observed in discs around Herbig Ae/Be stars, although not all show line emission. In addition, two of the six T Tauri objects exhibit detectable 12CO lines in the SPIRE range.
Context. The evolution of a circumstellar disk from its gas-rich protoplanetary stage to its gas-poor debris stage is not understood well. It is apparent that disk clearing progresses from the ...inside-out on a short time scale and models of photoevaporation are frequently used to explain this. However, the photoevaporation rates predicted by recent models differ by up to two orders of magnitude, resulting in uncertain time scales for the final stages of disk clearing. Aims. Photoevaporation theories predict that the final stages of disk-clearing progress in objects that have ceased accretion but still posses considerable material at radii far from the star. Weak-line T Tauri stars (WTTS) with infrared emission in excess of what is expected from the stellar photosphere are likely in this configuration. We aim to provide observational constraints on theories of disk-clearing by measuring the dust masses and CO content of a sample of young (1.8−26.3 Myr) WTTS. Methods. We used ALMA Band 6 to obtain continuum and 12CO(2−1) line fluxes for a sample of 24 WTTS stars with known infrared excess. For these WTTS, we inferred the dust mass from the continuum observations and derived disk luminosities and ages to allow comparison with previously detected WTTS. Results. We detect continuum emission in only four of 24 WTTS, and no 12CO(2−1) emission in any of them. For those WTTS where no continuum was detected, their ages and derived upper limits suggest they are debris disks, which makes them some of the youngest debris disks known. Of those where continuum was detected, three are possible photoevaporating disks, although the lack of CO detection suggests a severely reduced gas-to-dust ratio. Conclusions. The low fraction of continuum detections implies that, once accretion onto the star stops, the clearing of the majority of dust progresses very rapidly. Most WTTS with infrared excess are likely not in transition but are instead young debris disks, whose dust is either primordial and has survived disk-clearing, or is of second-generation origin. In the latter case, the presence of giant planets within these WTTS might be the cause.
Abstract Background The aims of the present study were to determine both clinical manifestations and outcome of anti-PL7 patients with antisynthetase syndrome (ASS). Methods The medical records of 15 ...consecutive anti-PL7 patients with biopsy proven ASS were retrospectively analyzed without prior selection. Results Anti-PL7 patients exhibited polymyositis (n = 14) and dermatomyositis (n = 1); extra-pulmonary manifestations of ASS included: Raynaud's phenomenon (40%), mechanic's hands (33.3%), joint impairment (26.7%), pericardial effusion (20%) and esophageal/gastrointestinal involvement (20%). The outcome of myositis was as follows: remission/improvement (91.7%) and deterioration (8.3%). Fourteen patients (93.3%) experienced interstitial lung disease (ILD). ILD preceded ASS diagnosis (n = 5), was identified concomitantly with ASS (n = 8) and occurred after ASS diagnosis (n = 1). Patients could be divided into 3 groups according to their presenting lung manifestations: acute onset of lung disease (n = 1), progressive onset of lung signs (n = 11) and asymptomatic patients exhibiting abnormalities consistent with ILD on PFT and HRCT-scan (n = 2). No patient had resolution of ILD, whereas 64.3% and 35.7% experienced improvement and deterioration of ILD, respectively. ILD resulted in respiratory insufficiency requiring O2 therapy in 14.3% of cases. Two patients died. Predictive parameters of ILD deterioration were: DLCO < 45% at ILD diagnosis and HRCT-scan pattern of usual interstitial pneumonia (UIP). Conclusion Our series mainly underscores that ILD is frequent in anti-PL7 patients, leading to high morbidity. Our study further suggests that patients with predictive factors of ILD deterioration may require more aggressive therapy, especially the group of patients with DLCO < 45% at ILD diagnosis and UIP pattern on HRCT-scan.
There is much evidence that planet formation is occurring in the disc around the Herbig Be star HD100546. To learn more about the processes occurring in this disc, we conducted high-resolution ...imaging at 43/45 GHz with the Australia Telescope Compact Array. Multiple array configurations were used, providing a best spatial resolution of ∼0.15 arcsec, or 15 au at HD100546's distance of ∼100 pc. Significant structure is revealed, but its precise form is dependent on the u − v plane sampling used for the image reconstruction. At a resolution of ≤30 au, we detected an inner gap in the disc with a radius of ∼25 au and a position angle approximately along the known disc major axis. With different weighting, and an achieved resolution of ∼15 au, emission appears at the centre and the disc takes on the shape of an incomplete ring, much like a horseshoe, again with a gap radius of ∼25 au. The position angle of the disc major axis and its inclination from face-on are determined to be 140° ± 5° and 40° ± 5°, respectively. The ∼25 au gap radius is confirmed by a null in the real part of the binned visibilities at 320 ± 10 kλ, whilst the non-axisymmetric nature is also confirmed through significant structure in the imaginary component. The emission mechanism at the central peak is most likely to be free–free emission from a stellar or disc wind. Overall our data support the picture of at least one, but probably several, giant planets orbiting HD100546 within 25 au.
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