131 research outputs found
Large Population of ALMA Galaxies at z>6 with Very High [OIII]88um to [CII]158um Flux Ratios: Evidence of Extremely High Ionization Parameter or PDR Deficit?
We present our new ALMA observations targeting [OIII]88um, [CII]158um,
[NII]122um, and dust continuum emission for three Lyman break galaxies at
z=6.0293-6.2037 identified in the Subaru/Hyper Suprime-Cam survey. We clearly
detect [OIII] and [CII] lines from all of the galaxies at 4.3-11.8sigma levels,
and identify multi-band dust continuum emission in two of the three galaxies,
allowing us to estimate infrared luminosities and dust temperatures
simultaneously. In conjunction with previous ALMA observations for six galaxies
at z>6, we confirm that all the nine z=6-9 galaxies have high [OIII]/[CII]
ratios of L[OIII]/L[CII]~3-20, ~10 times higher than z~0 galaxies. We also find
a positive correlation between the [OIII]/[CII] ratio and the Lya equivalent
width (EW) at the ~90% confidence level. We carefully investigate physical
origins of the high [OIII]/[CII] ratios at z=6-9 using Cloudy, and find that
high density of the interstellar medium, low C/O abundance ratio, and the
cosmic microwave background attenuation are responsible to only a part of the
z=6-9 galaxies. Instead, the observed high [OIII]/[CII] ratios are explained by
10-100 times higher ionization parameters or low photodissociation region (PDR)
covering fractions of 0-10%, both of which are consistent with our [NII]
observations. The latter scenario can be reproduced with a density bounded
nebula with PDR deficit, which would enhance the Lya, Lyman continuum, and C+
ionizing photons escape from galaxies, consistent with the [OIII]/[CII]-Lya EW
correlation we find.Comment: 20 pages, 18 figures, Accepted for publication in Ap
Molecular outflow in the reionization-epoch quasar J2054-0005 revealed by OH 119 m observations
Molecular outflows are expected to play a key role in galaxy evolution at
high redshift. To study the impact of outflows on star formation at the epoch
of reionization, we performed sensitive ALMA observations of OH 119 m
toward J2054-0005, a luminous quasar at . The OH line is detected and
exhibits a P-Cygni profile that can be fitted with a broad blue-shifted
absorption component, providing unambiguous evidence of an outflow, and an
emission component at near-systemic velocity. The mean and terminal outflow
velocities are estimated to be
and , respectively, making the molecular outflow in
this quasar one of the fastest at the epoch of reionization. The OH line is
marginally spatially resolved for the first time in a quasar at ,
revealing that the outflow extends over the central 2 kpc region. The mass
outflow rate is comparable to the star formation rate
(), indicating rapid
() quenching of star formation. The mass outflow rate in
a sample star-forming galaxies and quasars at exhibits a positive
correlation with the total infrared luminosity, although the scatter is large.
Owing to the high outflow velocity, a large fraction (up to ) of the
outflowing molecular gas may be able to escape from the host galaxy into the
intergalactic medium.Comment: Accepted to Ap
Identification of Large Equivalent Width Dusty Galaxies at 4 z 6 from Sub-mm Colours
Infrared (IR), sub-millimetre (sub-mm) and millimetre (mm) databases contain
a huge quantity of high quality data. However, a large part of these data are
photometric, and are thought not to be useful to derive a quantitative
information on the nebular emission of galaxies. The aim of this project is
first to identify galaxies at z > 4-6, and in the epoch of reionization from
their sub-mm colours. We also aim at showing that the colours can be used to
try and derive physical constraints from photometric bands, when accounting for
the contribution from the IR fine structure lines to these photometric bands.
We model the flux of IR fine structure lines with CLOUDY, and add them to the
dust continuum emission with CIGALE. Including or not emission lines in the
simulated spectral energy distribution (SED) modifies the broad band emission
and colours. The introduction of the lines allows to identify strong star
forming galaxies at z > 4 - 6 from the log10 (PSW_250um/PMW_350um) versus log10
(LABOCA_870um/PLW_500um) colour-colour diagramme. By comparing the relevant
models to each observed galaxy colour, we are able to roughly estimate the
fluxes of the lines, and the associated nebular parameters. This method allows
to identify a double sequence in a plot built from the ionization parameter and
the gas metallicity. The HII and photodissociation region (PDR) fine structure
lines are an essential part of the SEDs. It is important to add them when
modelling the spectra, especially at z > 4 - 6 where their equivalent widths
can be large. Conversely, we show that we can extract some information on
strong IR fine structure lines and on the physical parameters related to the
nebular emission from IR colour-colour diagrams.Comment: Paper accepted in Astronomy and Astrophysics on 10 November 202
Influence of Calendar Period on the Association Between BMI and Coronary Heart Disease: A Meta-Analysis of 31 Cohorts
Objective: The association between obesity and coronary heart disease (CHD) may have changed over
time, for example due to improved pharmacological treatment of CHD risk factors. This meta-analysis of
31 prospective cohort studies explores the influence of calendar period on CHD risk associated with
body mass index (BMI).
Design and Methods: The relative risks (RRs) of CHD for a five-BMI-unit increment and BMI categories
were pooled by means of random effects models. Meta-regression analysis was used to examine the
influence of calendar period (>1985 v 1985) in univariate and multivariate analyses (including mean
population age as a covariate). Results: The age, sex, and smoking adjusted RR (95% confidence intervals) of CHD for a five-BMI-unit
increment was 1.28(1.22:1.34). For underweight, overweight and obesity, the RRs (compared to normal
weight) were 1.11(0.91:1.36), 1.31(1.22:1.41), and 1.78(1.55:2.04), respectively. The univariate analysis
indicated 31% (95%CI: 56:0) lower RR of CHD associated with a five-BMI-unit increment and a 51%
(95%CI: 78: 14)) lower RR associated with obesity in studies starting after 1985 (n ¼ 15 and 10,
respectively) compared to studies starting in or before 1985 (n ¼ 16 and 10). However, in the multivariate
analysis, only mean population age was independently associated with the RRs for a five-BMI-unit
increment and obesity ( 29(95%CI: 55: 5)) and 31(95%CI: 66:3), respectively) per 10-year
increment in mean age).
Conclusion: This study provides no consistent evidence for a difference in the association between BMI
and CHD by calendar period. The mean population age seems to be the most important factor that
modifies the association between the risk of CHD and BMI, in which the RR decreases with increasing
age
Bright Extragalactic ALMA Redshift Survey (BEARS) III: Detailed study of emission lines from 71 Herschel targets
We analyse the molecular and atomic emission lines of 71 bright
Herschel-selected galaxies between redshifts 1.4 to 4.6 detected by the Atacama
Large Millimetre/submillimetre Array. These lines include a total of 156 CO, [C
I], and H2O emission lines. For 46 galaxies, we detect two transitions of CO
lines, and for these galaxies we find gas properties similar to those of other
dusty star-forming galaxy (DSFG) samples. A comparison to photo-dissociation
models suggests that most of Herschel-selected galaxies have similar
interstellar medium conditions as local infrared-luminous galaxies and
high-redshift DSFGs, although with denser gas and more intense far-ultraviolet
radiation fields than normal star-forming galaxies. The line luminosities agree
with the luminosity scaling relations across five orders of magnitude, although
the star-formation and gas surface density distributions (i.e.,
Schmidt-Kennicutt relation) suggest a different star-formation phase in our
galaxies (and other DSFGs) compared to local and low-redshift gas-rich, normal
star-forming systems. The gas-to-dust ratios of these galaxies are similar to
Milky Way values, with no apparent redshift evolution. Four of 46 sources
appear to have CO line ratios in excess of the expected maximum (thermalized)
profile, suggesting a rare phase in the evolution of DSFGs. Finally, we create
a deep stacked spectrum over a wide rest-frame frequency (220-890 GHz) that
reveals faint transitions from HCN and CH, in line with previous stacking
experiments.Comment: 30 pages, 17 figures, accepted for publication in Monthly Notices of
the Royal Astronomical Society Main Journal. Comments are warmly welcome
Fingertip digital thermal monitoring: a fingerprint for cardiovascular disease?
Cardiac Dysfunction and Arrhythmia
Medicine is patriarchal, but alternative medicine is not the answer
Women are over-represented within alternative medicine, both as consumers and as service providers. In this paper, I show that the appeal of alternative medicine to women relates to the neglect of women’s health needs within scientific medicine. This is concerning because alternative medicine is severely limited in its therapeutic effects; therefore, those who choose alternative therapies are liable to experience inadequate healthcare. I argue that while many patients seek greater autonomy in alternative medicine, the absence of an evidence base and plausible mechanisms of action leaves patients unable to realize meaningful autonomy. This seems morally troubling, especially given that the neglect of women’s needs within scientific medicine seems to contribute to preferences for alternative medicine. I conclude that the liberatory credentials of alternative medicine should be questioned and make recommendations to render scientific medicine better able to meet the needs of typical alternative medicine consumers
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