Abstract
We make use of JWST medium-band and broadband NIRCam imaging, along with ultradeep MIRI 5.6
μ
m imaging, in the Hubble eXtreme Deep Field to identify prominent line emitters at
z
≃ 7–8. Out ...of a total of 58 galaxies at
z
≃ 7–8, we find 18 robust candidates (≃31%) for (H
β
+ O
iii
) emitters, based on their enhanced fluxes in the F430M and F444W filters, with EW
0
(H
β
+O
iii
) ≃87–2100 Å. Among these emitters, 16 lie in the MIRI coverage area and 12 exhibit a clear flux excess at 5.6
μ
m, indicating the simultaneous presence of a prominent H
α
emission line with EW
0
(H
α
) ≃200–3000 Å. This is the first time that H
α
emission can be detected in individual galaxies at
z
> 7. The H
α
line, when present, allows us to separate the contributions of H
β
and O
iii
to the (H
β
+O
iii
) complex and derive H
α
-based star formation rates (SFRs). We find that in most cases O
iii
/H
β
> 1. Instead, two galaxies have O
iii
/H
β
< 1, indicating that the NIRCam flux excess is mainly driven by H
β
. Most prominent line emitters are very young starbursts or galaxies on their way to/from the starburst cloud. They make for a cosmic SFR density
log
10
(
ρ
SFR
H
α
/
(
M
⊙
yr
−
1
Mpc
−
3
)
)
≃
−
2.35
, which is about a quarter of the total value (
log
10
(
ρ
SFR
tot
/
(
M
⊙
yr
−
1
Mpc
−
3
)
)
≃
−
1.76
) at
z
≃ 7–8. Therefore, the strong H
α
emitters likely had a significant role in reionization.
Prolonged PR interval, or first degree AV block, has been traditionally regarded as a benign electrocardiographic finding in healthy individuals, until recent studies have suggested that it may be ...associated with increased mortality and morbidity. The aim of this study was to further elucidate clinical and prognostic importance of prolonged PR interval in a large middle-aged population with a long follow-up.
We evaluated 12-lead electrocardiograms of 10 785 individuals aged 30-59 years (mean age 44 years, 52% males) recorded between 1966 and 1972, and followed the subjects for 30 ± 11 years. Prolonged PR interval was defined as PR >200 ms, with further analysis performed using PR ≥220 ms. Main endpoints were all-cause mortality, cardiovascular mortality, and sudden cardiac death, and other endpoints included hospitalizations due to cardiovascular causes. During the baseline examination, prolonged PR interval >200 ms was present in 2.1% of the subjects, but PR interval normalized to ≤200 ms in 30% of these individuals during the follow-up. No increase in mortality or in hospitalizations due to coronary artery disease, heart failure, atrial fibrillation, or stroke was associated with prolonged PR interval (P = non-significant for all endpoints). These results were not changed after multivariate adjustment or in several subanalyses.
In the middle-aged general population, prolonged PR interval normalizes in a substantial proportion of subjects during the time course, and it is not associated with an increased risk of all-cause or cardiovascular mortality.
We present an estimate of the performance that will be achieved during on-orbit operations of the JWST mid-infrared instrument, MIRI. The efficiency of the main imager and spectrometer systems in ...detecting photons from an astronomical target are presented, based on measurements at subsystem and instrument-level testing, with the end-to-end transmission budget discussed in some detail. The brightest target fluxes that can be measured without saturating the detectors are provided. The sensitivity for long-duration observations of faint sources is presented in terms of the target flux required to achieve a signal-to-noise ratio of 10 after a 10,000 s observation. The algorithms used in the sensitivity model are presented, including the understanding gained during testing of the MIRI flight model and flight-like detectors.
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, UL, UM, UPUK
Abstract By using an ultradeep JWST/MIRI image at 5.6 μ m in the Hubble eXtreme Deep Field, we constrain the role of strong H α emitters (HAEs) during “cosmic reionization” at z ≃ 7–8. Our sample of ...HAEs is comprised of young (<35 Myr) galaxies, except for one single galaxy (≈300 Myr), with low stellar masses (≲10 9 M ⊙ ). These HAEs show a wide range of rest-frame UV continuum slopes ( β ), with a median value of β = −2.15 ± 0.21, which broadly correlates with stellar mass. We estimate the ionizing photon production efficiency ( ξ ion,0 ) of these sources (assuming f esc,LyC = 0%), which yields a median value log 10 ( ξ ion , 0 / ( Hz erg − 1 ) ) = 25.50 − 0.12 + 0.10 . We show that ξ ion,0 positively correlates with H α equivalent width and specific star formation rate. Instead ξ ion,0 weakly anticorrelates with stellar mass and β . Based on the β values, we predict f esc , LyC = 4 % − 2 + 3 , which results in log 10 ( ξ ion / ( Hz erg − 1 ) ) = 25.55 − 0.13 + 0.11 . Considering this and related findings from the literature, we find a mild evolution of ξ ion with redshift. Additionally, our results suggest that these HAEs require only modest escape fractions ( f esc,rel ) of 6%–15% to reionize their surrounding intergalactic medium. By only considering the contribution of these HAEs, we estimated their total ionizing emissivity ( N ̇ ion ) as N ̇ ion = 10 50.53 ± 0.45 s − 1 Mpc − 3 . When comparing their N ̇ ion with non-HAE galaxies across the same redshift range, we find that that strong, young, and low-mass emitters may have played an important role during cosmic reionization.
Abstract
Supernova (SN) 1987A is the nearest supernova in ∼400 yr. Using the JWST MIRI Medium Resolution Spectrograph, we spatially resolved the ejecta, equatorial ring (ER), and outer rings in the ...mid-infrared 12,927 days (35.4 yr) after the explosion. The spectra are rich in line and dust continuum emission, both in the ejecta and the ring. The broad emission lines (280–380 km s
−1
FWHM) that are seen from all singly-ionized species originate from the expanding ER, with properties consistent with dense post-shock cooling gas. Narrower emission lines (100–170 km s
−1
FWHM) are seen from species originating from a more extended lower-density component whose high ionization may have been produced by shocks progressing through the ER or by the UV radiation pulse associated with the original supernova event. The asymmetric east–west dust emission in the ER has continued to fade, with constant temperature, signifying a reduction in dust mass. Small grains in the ER are preferentially destroyed, with larger grains from the progenitor surviving the transition from SN into SNR. The ER dust is fit with a single set of optical constants, eliminating the need for a secondary featureless hot dust component. We find several broad ejecta emission lines from Ne
ii
, Ar
ii
, Fe
ii
, and Ni
ii
. With the exception of Fe
ii
25.99
μ
m, these all originate from the ejecta close to the ring and are likely to be excited by X-rays from the interaction. The Fe
ii
5.34 to 25.99
μ
m line ratio indicates a temperature of only a few hundred K in the inner core, which is consistent with being powered by
44
Ti decay.
Abstract
We present initial results from JWST NIRSpec integral field unit observations of the nearby supernova SN 1987A. The observations provide the first spatially resolved spectroscopy of the ...ejecta and equatorial ring (ER) over the 1–5
μ
m range. We construct 3D emissivity maps of the Fe
i
1.443
μ
m line from the inner ejecta and the He
i
1.083
μ
m line from the reverse shock (RS), where the former probes the explosion geometry and the latter traces the structure of the circumstellar medium. We also present a model for the integrated spectrum of the ejecta. The Fe
i
3D map reveals a highly asymmetric morphology resembling a broken dipole, dominated by two large clumps with velocities of ∼2300 km s
−1
. We also find evidence that the Fe-rich inner ejecta have started to interact with the RS. The RS surface traced by the He
i
line extends from just inside the ER to higher latitudes on both sides of the ER with a half-opening angle ∼45°, forming a bubble-like structure. The spectral model for the ejecta allows us to identify the many emission lines, including numerous H
2
lines. We find that the H
2
is most likely excited by far-UV emission, while the metal-line ratios are consistent with a combination of collisional excitation and recombination in the low-temperature ejecta. We also find several high-ionization coronal lines from the ER, requiring a temperature ≳2 × 10
6
K.
Abstract There exist very few mid-infrared (IR) observations of supernovae (SNe) in general. Therefore, SN 1987A, the closest visible SN in 400 yr, gives us the opportunity to explore the mid-IR ...properties of SNe, the dust in their ejecta, and the surrounding medium and to witness the birth of an SN remnant (SNR). The James Webb Space Telescope, with its high spatial resolution and extreme sensitivity, gives a new view on these issues. We report on the first imaging observations obtained with the Mid-InfraRed Instrument (MIRI). We build temperature maps and discuss the morphology of the nascent SNR. Our results show that the temperatures in the equatorial ring (ER) are quite nonuniform. This could be due to dust destruction in some parts of the ring, as had been assumed in some previous works. We show that the IR emission extends beyond the ER, illustrating the fact that the shock wave has now passed through this ring to affect the circumstellar medium on a larger scale. Finally, while submillimeter Atacama Large Millimeter Array observations have hinted at the location of the compact remnant of SN 1987A, we note that our MIRI data have found no such evidence.
The variations in the electrocardiographic patterns of J-point elevations, and the complex of J-points and J-waves in early repolarization (ER), in conjunction with disparities in associated sudden ...cardiac death (SCD) risk, have lead to a recognition of the need to carefully classify the spectrum of these observations. Many questions about the pathogenesis of J-wave patterns, and the associated magnitudes of risk, remain unanswered, especially in regard to the risk implications in certain high-prevalence subpopulations such as athletes, children, and adolescents. Interest in these electrocardiography (ECG) patterns has grown dramatically in recent years, in large part because of the frequency with which these patterns are observed on routine ECGs. In this review, we discuss the current knowledge on the prevalence of different J-point/J-wave patterns and estimates of the magnitude of mortality and SCD risk associated with J-point elevations and J-waves, in what has become known as ER patterns.
OBJECTIVE:To define the prevalence and prognosis of ECG abnormalities in hypertensive individuals.
METHODS:ECG, blood pressure and other cardiovascular risk factors were recorded in a nationwide ...population sample of 5800 Finns. The presence of 15 ECG abnormalities was evaluated. Participants were divided into categories by blood pressure and followed for coronary heart (CHD) and cardiovascular disease (CVD) events.
RESULTS:Mean follow-up was 10.4 ± 2.2 years. The age- and sex-adjusted prevalence rates of ECG abnormalities were generally higher in the hypertensive participants than in normotensive individuals. In multivariable-adjusted Cox models, the following ECG abnormalities predicted CHD in hypertensive participantsleft ventricular hypertrophy (LVH) by Sokolow-Lyon criteria hazard ratio, 1.47; 95% confidence interval (CI), 1.07–2.01; P = 0.02, LVH with ST-depression and negative T wave (ST/T changes) (hazard ratio, 2.31; 95% CI, 1.20–4.43, P = 0.01), ST/T changes (hazard ratio, 2.12; 95% CI, 1.34–3.36; P = 0.001), positive T wave in lead aVR (AVRT+) (hazard ratio, 1.74; 95% CI, 1.15–2.64; P = 0.009) and poor R-wave progression (hazard ratio, 2.02; 95% CI, 1.27–3.22; P = 0.003). These ECG abnormalities were also significant predictors of CVD in hypertensive participants (P ≤ 0.03 for all). Nonspecific intraventricular conduction delay predicted CVD in the whole population (hazard ratio, 1.50; 95% CI, 1.06–2.13; P = 0.02). Prolonged QT interval, abnormal P-wave indices, left axis deviation and early repolarization pattern were not associated with CHD or CVD.
CONCLUSION:ECG abnormalities are highly prevalent in hypertensive individuals. LVH is still the cornerstone of cardiovascular risk assessment in hypertensive patients. The additional assessment of ST/T changes, AVRT+ and poor R-wave progression in ECGs could improve risk prediction in hypertensive patients.
![MIDIS: Strong (Hβ+[O iii]) ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0004-637X_1538-4357/small "MIDIS: Strong (Hβ+[O iii]) and Hα Emitters at Redshift z ≃ 7–8 Unveiled with JWST NIRCam and MIRI Imaging in the Hubble eXtreme Deep Field")
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