33 research outputs found
Retrieval of the dayside atmosphere of WASP-43b with CRIRES+
Accurately estimating the C/O ratio of hot Jupiter atmospheres is a promising
pathway towards understanding planet formation and migration, as well as the
formation of clouds and the overall atmospheric composition. The atmosphere of
the hot Jupiter WASP-43b has been extensively analysed using low-resolution
observations with HST and Spitzer, but these previous observations did not
cover the K band, which hosts prominent spectral features of major
carbon-bearing species such as CO and CH. As a result, the ability to
establish precise constraints on the C/O ratio was limited. Moreover, the
planet has not been studied at high spectral resolution, which can provide
insights into the atmospheric dynamics.
In this study, we present the first high-resolution dayside spectra of
WASP-43b with the new CRIRES spectrograph. By observing the planet in the K
band, we successfully detected the presence of CO and provide evidence for the
existence of HO using the cross-correlation method. This discovery
represents the first direct detection of CO in the atmosphere of WASP-43b.
Furthermore, we retrieved the temperature-pressure profile, abundances of CO
and HO, and a super-solar C/O ratio of 0.78 by applying a Bayesian
retrieval framework to the data. Our findings also shed light on the
atmospheric characteristics of WASP-43b. We found no evidence for a cloud deck
on the dayside, and recovered a line broadening indicative of an equatorial
super-rotation corresponding to a jet with a wind speed of 5 km
s, matching the results of previous forward models and low-resolution
atmospheric retrievals for this planet.Comment: 15 pages, 14 figure
Atmospheric characterization of the ultra-hot Jupiter WASP-33b: Detection of Ti and V emission lines and retrieval of a broadened line profile
Ultra-hot Jupiters are highly irradiated gas giant exoplanets on close-in
orbits around their host stars. We analyzed high-resolution spectra from
CARMENES, HARPS-N, and ESPaDOnS taken over eight observation nights to study
the emission spectrum of WASP-33b and draw conclusions about its atmosphere. By
applying the cross-correlation technique, we detected the spectral signatures
of Ti I, V I, and a tentative signal of Ti II for the first time via emission
spectroscopy. These detections are an important finding because of the
fundamental role of Ti- and V-bearing species in the planetary energy balance.
Moreover, we assessed and confirm the presence of OH, Fe I, and Si I from
previous studies. The spectral lines are all detected in emission, which
unambiguously proves the presence of an inverted temperature profile in the
planetary atmosphere. By performing retrievals on the emission lines of all the
detected species, we determined a relatively weak atmospheric thermal inversion
extending from approximately 3400 K to 4000 K. We infer a supersolar
metallicity close to 1.5 dex in the planetary atmosphere, and find that its
emission signature undergoes significant line broadening with a Gaussian FWHM
of about 4.5 km/s. Also, we find that the atmospheric temperature profile
retrieved at orbital phases far from the secondary eclipse is about 300 K to
700 K cooler than that measured close to the secondary eclipse, which is
consistent with different day- and nightside temperatures. Moreover, retrievals
performed on the emission lines of the individual chemical species lead to
consistent results, which gives additional confidence to our retrieval method.
Increasing the number of species included in the retrieval and expanding the
set of retrieved atmospheric parameters will further advance our understanding
of exoplanet atmospheres.Comment: Accepted for publication in A&
CRIRES+ detection of CO emissions lines and temperature inversions on the dayside of WASP-18b and WASP-76b
The dayside atmospheres of ultra-hot Jupiters (UHJs) are predicted to possess
temperature inversion layers with extremely high temperatures at high
altitudes. We observed the dayside thermal emission spectra of WASP-18b and
WASP-76b with the new CRIRES+ high-resolution spectrograph at near-infrared
wavelengths. Using the cross-correlation technique, we detected strong CO
emission lines in both planets, which confirms the existence of temperature
inversions on their dayside hemispheres. The two planets are the first UHJs
orbiting F-type stars with CO emission lines detected; previous detections were
mostly for UHJs orbiting A-type stars. Evidence of weak H2O emission signals is
also found for both planets. We further applied forward-model retrievals on the
detected CO lines and retrieved the temperature-pressure profiles along with
the CO volume mixing ratios. The retrieved logarithmic CO mixing ratio of
WASP-18b (-2.2) is slightly higher than the value predicted by the
self-consistent model assuming solar abundance. For WASP-76b, the retrieved CO
mixing ratio (-3.6) is broadly consistent with the value of solar abundance. In
addition, we included the equatorial rotation velocity (Veq ) in the retrieval
when analyzing the line profile broadening. The obtained Veq is 7.0 km/s for
WASP-18b and 5.2 km/s for WASP-76b, which are consistent with the tidally
locked rotational velocities.Comment: 11 pages, 12 figures; accepted for publication in A&
Using a population-based approach to prevent hepatocellular cancer in New South Wales, Australia: effects on health services utilisation
<p>Abstract</p> <p>Background</p> <p>Australians born in countries where hepatitis B infection is endemic are 6-12 times more likely to develop hepatocellular cancer (HCC) than Australian-born individuals. However, a program of screening, surveillance and treatment of chronic hepatitis B (CHB) in high risk populations could significantly reduce disease progression and death related to end-stage liver disease and HCC. Consequently we are implementing the <it>B Positive </it>pilot project, aiming to optimise the management of CHB in at-risk populations in south-west Sydney. Program participants receive routine care, enhanced disease surveillance or specialist referral, according to their stage of CHB infection, level of viral load and extent of liver injury. In this paper we examine the program's potential impact on health services utilisation in the study area.</p> <p>Methods</p> <p>Estimated numbers of CHB infections were derived from Australian Bureau of Statistics data and applying estimates of HBV prevalence rates from migrants' countries of birth. These figures were entered into a Markov model of disease progression, constructing a hypothetical cohort of Asian-born adults with CHB infection. We calculated the number of participants in different CHB disease states and estimated the numbers of GP and specialist consultations and liver ultrasound examinations the cohort would require annually over the life of the program.</p> <p>Results</p> <p>Assuming a 25% participation rate among the 5,800 local residents estimated to have chronic hepatitis B infection, approximately 750 people would require routine follow up, 260 enhanced disease surveillance and 210 specialist care during the first year after recruitment is completed. This translates into 5 additional appointments per year for each local GP, 25 for each specialist and 420 additional liver ultrasound examinations.</p> <p>Conclusions</p> <p>While the program will not greatly affect the volume of local GP consultations, it will lead to a significant increase in demand for specialist services. New models of CHB care may be required to aid program implementation and up scaling the program will need to factor in additional demands on health care utilisation in areas of high hepatitis B sero-prevalence.</p
“I want to save my life”: Conceptions of cervical and breast cancer screening among urban immigrant women of South Asian and Chinese origin
Análise das relações interdisciplinares das pesquisas científicas em sistemas de informação
Increased Night Temperature Negatively Affects Grain Yield, Biomass and Grain Number in Chilean Quinoa
Screening for abdominal aortic aneurysm: does it affect men's quality of life?
A prospective study investigated the psychological wellbeing and quality of life of older rural men after a community-based screening for abdominal aortic aneurysm (AAA). Five hundred and sixteen men aged 65-74 years attended the screening program; 53 had an abnormal aorta detected. These and a subsample of men with a normal aorta were followed up 6 months post-screening. All men completed a pre-screening questionnaire including the Medical Outcomes Short Form 36v 2 (MOSF36) and Hospital Anxiety and Depression Scale (HADS). Six months after screening all 53 men with an abnormal and 130 with a normal aorta were sent a questionnaire including MOSF36 and HADS. Baseline and 6 month scores for both MOSF36 and HADS scores were compared between the two groups and within each group. Baseline scores for both MOSF36 and HADS were not significantly different between men who were subsequently diagnosed with an abnormal aorta and those with a normal aorta. After 6 months there was no difference in HADS scores but a significant increase in the MOSF36 dimension of general health. Those with a normal aorta reported better general health, social functioning andgreater freedom from bodily pain. AAA screening appears highly acceptable to men in the target age group and future research should focus on implementation, cost effectiveness and collateral benefits of AAA screening