ABSTRACT
We present reduced images and catalogues of photometric and emission-line data (∼230 000 and ∼8000 sources, respectively) for the WFC3 (Wide Field Camera 3) Infrared Spectroscopic Parallel ...(WISP) survey. These data are made publicly available on the Mikulski Archive for Space Telescopes and include reduced images from various facilities: ground-based ugri, Hubble Space Telescope (HST) WFC3, and Spitzer IRAC (Infrared Array Camera). Coverage in at least one additional filter beyond the WFC3/IR data are available for roughly half of the fields (227 out of 483), with ∼20 per cent (86) having coverage in six or more filters from u band to IRAC 3.6 $\mu$m (0.35–3.6 $\mu$m). For the lower spatial resolution (and shallower) ground-based and IRAC data, we perform PSF (point spread function)-matched, prior-based, deconfusion photometry (i.e. forced-photometry) using the tphot software to optimally extract measurements or upper limits. We present the methodology and software used for the WISP emission-line detection and visual inspection. The former adopts a continuous wavelet transformation that significantly reduces the number of spurious sources as candidates before the visual inspection stage. We combine both WISP catalogues and perform spectral energy distribution fitting on galaxies with reliable spectroscopic redshifts and multiband photometry to measure their stellar masses. We stack WISP spectra as functions of stellar mass and redshift and measure average emission-line fluxes and ratios. We find that WISP emission-line sources are typically ‘normal’ star-forming galaxies based on the mass–excitation diagram (O iii/Hβ versus M⋆; 0.74 < zgrism < 2.31), the galaxy main sequence (SFR versus M⋆; 0.30 < zgrism < 1.45), S32 ratio versus M⋆ (0.30 < zgrism < 0.73), and O32 and R23 ratios versus M⋆ (1.27 < zgrism < 1.45).
During the Last Glacial Maximum (LGM; ~20,000 years ago), the global ocean sequestered a large amount of carbon lost from the atmosphere and terrestrial biosphere. Suppressed CO
outgassing from the ...Southern Ocean is the prevailing explanation for this carbon sequestration. By contrast, the North Atlantic Ocean-a major conduit for atmospheric CO
transport to the ocean interior via the overturning circulation-has received much less attention. Here we demonstrate that North Atlantic carbon pump efficiency during the LGM was almost doubled relative to the Holocene. This is based on a novel proxy approach to estimate air-sea CO
exchange signals using combined carbonate ion and nutrient reconstructions for multiple sediment cores from the North Atlantic. Our data indicate that in tandem with Southern Ocean processes, enhanced North Atlantic CO
absorption contributed to lowering ice-age atmospheric CO
.
ABSTRACT
We analysed 68 candidate planetary systems first identified during Campaigns 5 and 6 (C5 and C6) of the NASA K2 mission. We set out to validate these systems by using a suite of follow-up ...observations, including adaptive optics, speckle imaging, and reconnaissance spectroscopy. The overlap between C5 with C16 and C18, and C6 with C17, yields light curves with long baselines that allow us to measure the transit ephemeris very precisely, revisit single transit candidates identified in earlier campaigns, and search for additional transiting planets with longer periods not detectable in previous works. Using vespa, we compute false positive probabilities of less than 1 per cent for 37 candidates orbiting 29 unique host stars and hence statistically validate them as planets. These planets have a typical size of 2.2 R⊕ and orbital periods between 1.99 and 52.71 d. We highlight interesting systems including a sub-Neptune with the longest period detected by K2, sub-Saturns around F stars, several multiplanetary systems in a variety of architectures. These results show that a wealth of planetary systems still remains in the K2 data, some of which can be validated using minimal follow-up observations and taking advantage of analyses presented in previous catalogues.
We present the earliest X-ray observations of the 2018 outburst of XTE J1810−197, the first outburst since its 2003 discovery as the prototypical transient and radio-emitting anomalous X-ray pulsar ...(AXP). The Monitor of All-sky X-ray Image (MAXI) detected XTE J1810−197 immediately after a November 20-26 visibility gap, contemporaneous with its reactivation as a radio pulsar, first observed on December 8. On December 13 the Nuclear Spectroscopic Telescope Array (NuSTAR) detected X-ray emission up to at least 30 keV, with a spectrum well-characterized by a blackbody plus power-law model with temperature kT = 0.74 0.02 keV and photon index Γ = 4.4 0.2 or by a two-blackbody model with kT = 0.59 0.04 keV and kT = 1.0 0.1 keV, both including an additional power-law component to account for emission above 10 keV, with Γh = −0.2 1.5 and Γh = 1.5 0.5, respectively. The latter index is consistent with hard X-ray flux reported for the nontransient magnetars. In the 2-10 keV bandpass, the absorbed flux is 2 × 10−10 erg s−1 cm−2, a factor of 2 greater than the maximum flux extrapolated for the 2003 outburst. The peak of the sinusoidal X-ray pulse lags the radio pulse by 0.13 cycles, consistent with their phase relationship during the 2003 outburst. This suggests a stable geometry in which radio emission originates on magnetic field lines containing currents that heat a spot on the neutron star surface. However, a measured energy-dependent phase shift of the pulsed X-rays suggests that all X-ray emitting regions are not precisely coaligned.
ABSTRACT
We present new and archival Australia Telescope Compact Array and Atacama Large Millimeter/submillimeter Array data of the Small Magellanic Cloud supernova remnant 1E 0102.2–7219 at 2100, ...5500, 9000, and 108 000 MHz; as well as H i data provided by the Australian Square Kilometre Array Pathfinder. The remnant shows a ring-like morphology with a mean radius of 6.2 pc. The 5500 MHz image reveals a bridge-like structure, seen for the first time in a radio image. This structure is also visible in both optical and X-ray images. In the 9000 MHz image, we detect a central feature that has a flux density of 4.3 mJy but rule out a pulsar wind nebula origin, due to the lack of significant polarization towards the central feature with an upper limit of 4 per cent. The mean fractional polarization for 1E 0102.2–7219 is 7 ± 1 and 12 ± 2 per cent for 5500 and 9000 MHz, respectively. The spectral index for the entire remnant is −0.61 ± 0.01. We estimate the line-of-sight magnetic field strength in the direction of 1E 0102.2–7219 of ∼44 µG with an equipartition field of $65\pm 5\, \mu$G. This latter model uses the minimum energy of the sum of the magnetic field and cosmic ray electrons only. We detect an H i cloud towards this remnant at the velocity range of ∼160–180 km s−1 and a cavity-like structure at the velocity of 163.7–167.6 km s−1. We do not detect CO emission towards 1E 0102.2–7219.
Current estimates of gross primary productivity (GPP) of the terrestrial biosphere vary widely, from 100 to 175 Gt C year−1. Ecosystem GPP cannot be measured directly, and is commonly estimated using ...models. Among the many parameters in those models, three leaf parameters have strong influences on the modelled GPP: leaf mass per area, leaf lifespan and leaf nitrogen concentration. The first two parameters affect the modelled canopy leaf area and the last two determine the maximal leaf photosynthetic rate. Ecological studies have firmly established that these three parameters are significantly correlated at regional to global scales, but this knowledge is yet to be used in predicting global GPP. We hypothesize that incorporating multi‐trait covariance can reduce uncertainties of model predictions in a way likely to provide improved realism. Using the Australian community land surface model (CABLE), we find that correlations among these three parameters reduce the variance among GPP estimates by CABLE by over 20% for shrub, C4 grassland and tundra, and by between 5% and 20% for most other PFTs, as compared with the simulated GPP without considering the correlations. Globally the correlations do not alter the mean but reduce the variance of modeled GPP by CABLE by 28% and result in fewer extremely high or extremely low (and unlikely) global GPP predictions. Therefore correlations among the three leaf parameters, and possibly other parameters, can be used as a significant constraint on the estimates of model parameters or predictions by those models.
Key Points
Current estimates of land GPP range from 100 to 175 Gt C year‐1
Correlations among three leaf traits reduce the variance of modeled GPP by 28%
Correlations among parameters need to be considered in global land modeling
Exploring hit positions of recorded events can help to understand and suppress backgrounds in rare event searches. We propose a pulse shape analysis method to discriminate single-site events (SSEs) ...in the inner and outer layer of a small contact P-type germanium detector (HPGe). SSEs in the inner and outer layer have different pulse shape features, of which the rise time of the
(
T
Q
)
and current pulse
(
T
I
)
are selected for discrimination. A 500 Bq Thorium-228 (Th-228) source is used to determine the boundaries between the two layers. The double escape peak events from 2614.5 keV
γ
-ray are selected as typical SSEs, their numbers in the two layers are used to calculate the volumes and shapes of those layers. Considering the statistical and systematic uncertainties, the inner layer volume is evaluated to be 47.2% ± 0.26%(stat.) ± 0.18%(sys.) ± 0.22%(sys.) of the total sensitive volume. Selecting the inner layer as the analysis volume can reduce the external background in the signal region of Ge-76 neutrinoless double beta (0
ν
β
β
)
decay. We use the Th-228 data to validate the inner layer model and evaluate the background suppression power in the 0
ν
β
β
signal region
(
Q
β
β
=
2039
keV). The virtual segmentation further reduces the background from the external Th-228 source by about 10%. The virtual segmentation could be used to efficiently suppress surface background like electrons from Ar-42 decay in 0
ν
β
β
experiments using germanium detectors immersed in liquid argon.
To assess the diagnostic performance of intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) in differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs), and predicting ...the isocitrate dehydrogenase 1 (IDH1) mutational status.
IVIM imaging was performed preoperatively in 42 patients with gliomas using 10 b-values (0–1,200 s/mm2) in a 3 T MRI machine. The perfusion fraction (f), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and apparent diffusion coefficient (ADC) were calculated within the tumours and in the contralateral normal white matter, and the values were compared between the HGGs and LGGs, and between IDH1 wild-type and mutated-type gliomas. In addition, the receiver operating characteristic (ROC) was also analysed.
When compared to LGGs, HGGs had lower ADC (0.989×10−3 versus 1.243×10−3 mm2/s, p<0.001), smaller D (0.849×10−3 versus 1.062×10−3 mm2/s, p=0.001), larger D* (9.731×10−3 versus 5.442×10−3 mm2/s, p=0.006), and bigger f-values (0.204 versus 0.130, p<0.001) within the tumours. The area under the receiver operating characteristic (ROC) curve (AUC) was 0.937, 0.898, 0.770, and 0.838, respectively. Among the LGGs, tumours with the IDH1 mutation had a higher ADC (1.286×10−3 mm2/s), when compared to the wild-type IDH1 (1.122×10−3 mm2/s, p=0.003), with an AUC of 0.936. In HGGs, tumours with the IDH1 mutation had higher ADC (1.056×1010−3 versus 0.946×10−3 mm2/s, p=0.030), smaller D* (6.204×10−3 versus 11.999×10−3 mm2/s, p=0.023) and smaller f-values (0.143 versus 0.244, p<0.001), with an AUC of 0.766, 0.841 and 0.992, respectively.
Glioma grading can be differentiated and IDH1 mutational status can be predicted using IVIM.
•Glioma grading can be differentiated and IDH1 mutational status can be predicted using IVIM.•IVIM imaging can be used as a noninvasive quantitative imaging modality for differentiating HGGs from LGGs.•IVIM imaging can predicting the IDH1 mutation status by simultaneously providing diffusion and perfusion parameters.
Higher intake of fiber has been associated with lower risk of incident symptomatic osteoarthritis (OA). We examined whether levels of alkylresorcinol (AR), a marker of whole grain intake, were ...associated with OA in subjects in The Multicenter Osteoarthritis (MOST) Study.
Knee x-rays and knee pain were assessed at baseline and through 60-months. Stored baseline fasting plasma samples were analyzed for AR homologues (C17:0, C19:0, C21:0, C23:0, C25:0) and total AR levels (AR sum). Two nested case–control studies, one for incident radiographic OA and one for incident symptomatic OA were performed with participants re-assessed at 15, 30 and 60 months. Multivariable conditional logistic regression with baseline covariates including age, sex, BMI, physical activity, quadriceps strength, race, smoking, depressive symptoms, diabetes and knee injury tested the association of log transformed AR levels with OA outcomes.
Seven hundred seventy-seven subjects were, on average, in their 60's, and most were women. For 60-month cumulative incidence, there was no significant association between quartiles of AR concentration and incident radiographic (e.g., for incident radiographic OA, highest vs lowest quartile of AR sum showed RR = 0.93 (95% CI 0.59, 1.47), and for symptomatic OA RR was 1.22 (95% CI 0.76, 1.94). In secondary analyses examining 30-month incidence, high AR levels were associated with a reduced risk of X-ray OA (RR = 0.31 (95% CI 0.15, 0.64).
In primary analyses, AR levels were not associated with risk of OA, but secondary analyses left open the possibility that high AR levels may protect against OA.
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