| 1. |
- Wallström, Sofia, 1988, et al.
(författare)
-
ATOMIUM: Molecular inventory of 17 oxygen-rich evolved stars observed with ALMA
- 2024
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 681
-
Tidskriftsartikel (refereegranskat)abstract
- Context. The dusty winds of cool evolved stars are a major contributor of the newly synthesised material enriching the Galaxy and future generations of stars. However, the details of the physics and chemistry behind dust formation and wind launching have yet to be pinpointed. Recent spatially resolved observations show the importance of gaining a more comprehensive view of the circumstellar chemistry, but a comparative study of the intricate interplay between chemistry and physics is still difficult because observational details such as frequencies and angular resolutions are rarely comparable. Aims. Aiming to overcome these deficiencies, ATOMIUM is an ALMA Large Programme to study the physics and chemistry of the circumstellar envelopes of a diverse set of oxygen-rich evolved stars under homogeneous observing conditions at three angular resolutions between ∼0.02′1.4′. Here we summarize the molecular inventory of these sources, and the correlations between stellar parameters and molecular content. Methods. Seventeen oxygen-rich or S-Type asymptotic giant branch (AGB) and red supergiant (RSG) stars have been observed in several tunings with ALMA Band 6, targeting a range of molecules to probe the circumstellar envelope and especially the chemistry of dust formation close to the star. We systematically assigned the molecular carriers of the spectral lines and measured their spectroscopic parameters and the angular extent of the emission of each line from integrated intensity maps. Results. Across the ATOMIUM sample, we detect 291 transitions of 24 different molecules and their isotopologues. This includes several first detections in oxygen-rich AGB/RSG stars: PO v = 1, SO2 v1 = 1 and v2 = 2, and several high energy H2O transitions. We also find several first detections in S-Type AGB stars: vibrationally excited HCN v2 = 2,3 and SiS v = 4,5,6, as well as first detections of the molecules SiC, AlCl, and AlF in W Aql. Overall, we find strong correlations between the following molecular pairs: CS and SiS, CS and AlF, NaCl and KCl, AlO and SO, SO2 and SO, and SO2 and H2O; meaning both molecules tend to have more detected emission lines in the same sources. The measured isotopic ratios of Si and S are found to be consistent with previous measurements, except for an anomalously high 29Si/30Si ratio of 4 ± 1 in the RSG VX Sgr. Conclusions. This paper presents the overall molecular inventory and an initial analysis of the large ATOMIUM dataset, laying the groundwork for future work deriving molecular abundances and abundance profiles using radiative transfer modeling which will provide more rigorous tests for chemical models.
|
|
| 2. |
- Jenab, M., et al.
(författare)
-
Dietary intakes of retinol, beta-carotene, vitamin D and vitamin E in the European Prospective Investigation into Cancer and Nutrition cohort
- 2009
-
Ingår i: European Journal of Clinical Nutrition. - : Springer Science and Business Media LLC. - 1476-5640 .- 0954-3007. ; 63:4s, s. 150-178
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To describe the intake of the fat-soluble nutrients retinol, beta-carotene, vitamin E and vitamin D and their food sources among 27 redefined centres in 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Methods: Between 1995 and 2000, 36 034 subjects (age range: 35-74 years) completed a single standardized 24-h dietary recall using a computerized interview software program (EPIC-SOFT). Intakes of the fat-soluble nutrients were estimated using the standardized EPIC Nutrient Database. Results: For all the nutrients, in most centres, men had a higher level of intake than did women, even after adjustments for total energy intake and anthropometric confounders. Distinct regional gradients from northern to southern European countries were observed for all nutrients. The level intake of beta-carotene and vitamin E also showed some differences by level of education, smoking status and physical activity. No meaningful differences in the nutrient intake were observed by age range. Conclusions: These results show differences by study centre, gender, age and various lifestyle variables in the intake of retinol, beta-carotene, vitamin E and vitamin D between 10 European countries. European Journal of Clinical Nutrition (2009) 63, S150-S178; doi: 10.1038/ejcn.2009.79
|
|
| 3. |
- Montargès, M., et al.
(författare)
-
The VLT/SPHERE view of the A TOMIUM cool evolved star sample: I. Overview: Sample characterization through polarization analysis
- 2023
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 671
-
Tidskriftsartikel (refereegranskat)abstract
- Context. Low- and intermediate-mass asymptotic giant stars and massive red supergiant stars are important contributors to the chemical enrichment of the Universe. They are among the most efficient dust factories of the Galaxy, harboring chemically rich circumstellar environments. Yet, the processes that lead to dust formation or the large-scale shaping of the mass loss still escape attempts at modeling. Aims. Through the ATOMIUM project, we aim to present a consistent view of a sample of 17 nearby cool evolved stars. Our goals are to unveil the dust-nucleation sites and morphologies of the circumstellar envelope of such stars and to probe ambient environments with various conditions. This will further enhance our understanding of the roles of stellar convection and pulsations, and that of companions in shaping the dusty circumstellar medium. Methods. Here we present and analyze VLT/SPHERE-ZIMPOL polarimetric maps obtained in the visible (645- 820 nm) of 14 out of the 17 ATOMIUM sources. They were obtained contemporaneously with the ALMA high spatial resolution data. To help interpret the polarized signal, we produced synthetic maps of light scattering by dust, through 3D radiative transfer simulations with the RADMC3D code. Results. The degree of linear polarization (DoLP) observed by ZIMPOL spreads across several optical filters. We infer that it primarily probes dust located just outside of the point spread function of the central source, and in or near the plane of the sky. The polarized signal is mainly produced by structures with a total optical depth close to unity in the line of sight, and it represents only a fraction of the total circumstellar dust. The maximum DoLP ranges from 0.03- 0.38 depending on the source, fractions that can be reproduced by our 3D pilot models for grains composed of olivine, melilite, corundum, enstatite, or forsterite. The spatial structure of the DoLP shows a diverse set of shapes, including clumps, arcs, and full envelopes. Only for three sources do we note a correlation between the ALMA CO ν = 0, J = 2-1 and SiO ν = 0, J = 5-4 lines, which trace the gas density, and the DoLP, which traces the dust. Conclusions. The clumpiness of the DoLP and the lack of a consistent correlation between the gas and the dust location show that, in the inner environment, dust formation occurs at very specific sites. This has potential consequences for the derived mass-loss rates and dust-to-gas ratio in the inner region of the circumstellar environment. Except for π1 Gru and perhaps GY Aql, we do not detect interactions between the circumstellar wind and the hypothesized companions that shape the wind at larger scales. This suggests that the orbits of any other companions are tilted out of the plane of the sky.
|
|
| 4. |
- Danilovich, Taissa, 1987, et al.
(författare)
-
Chemical tracers of a highly eccentric AGB–main-sequence star binary
- 2024
-
Ingår i: Nature Astronomy. - 2397-3366.
-
Tidskriftsartikel (refereegranskat)abstract
- Binary interactions have been proposed to explain a variety of circumstellar structures seen around evolved stars, including asymptotic giant branch (AGB) stars and planetary nebulae. Studies resolving the circumstellar envelopes of AGB stars have revealed spirals, disks and bipolar outflows, with shaping attributed to interactions with a companion. Here we use a combined chemical and dynamical analysis to reveal a highly eccentric and long-period orbit for W Aquilae, a binary system containing an AGB star and a main-sequence companion. Our results are based on anisotropic SiN emission, the detections of irregular NS and SiC emission towards the S-type star, and density structures observed in the CO emission. These features are all interpreted as having formed during periastron interactions. Our astrochemistry-based method can yield stringent constraints on the orbital parameters of long-period binaries containing AGB stars, and will be applicable to other systems.
|
|
| 5. |
- Skeie, G., et al.
(författare)
-
Use of dietary supplements in the European Prospective Investigation into Cancer and Nutrition calibration study
- 2009
-
Ingår i: European Journal of Clinical Nutrition. - : Springer Science and Business Media LLC. - 1476-5640 .- 0954-3007. ; 63:4s, s. 226-238
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Dietary supplement use is increasing, but there are few comparable data on supplement intakes and how they affect the nutrition and health of European consumers. The aim of this study was to describe the use of dietary supplements in subsamples of the 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). Methods: Specific questions on dietary supplement use were asked as a part of single 24-h recalls performed on 36 034 men and women aged 35-74 years from 1995 to 2000. Results: Between countries, the mean percentage of dietary supplement use varied almost 10-fold among women and even more among men. There was a clear north-south gradient in use, with a higher consumption in northern countries. The lowest crude mean percentage of use was found in Greece (2.0% among men, 6.7% among women), and the highest was in Denmark (51.0% among men, 65.8% among women). Use was higher in women than in men. Vitamins, minerals or combinations of them were the predominant types of supplements reported, but there were striking differences between countries. Conclusions: This study indicates that there are wide variations in supplement use in Europe, which may affect individual and population nutrient intakes. The results underline the need to monitor consumption of dietary supplements in Europe, as well as to evaluate the risks and benefits. European Journal of Clinical Nutrition (2009) 63, S226-S238; doi: 10.1038/ejcn.2009.83
|
|
| 6. |
- Zamora-Ros, R., et al.
(författare)
-
Tea and coffee consumption and risk of esophageal cancer: The European prospective investigation into cancer and nutrition study
- 2014
-
Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 135:6, s. 1470-1479
-
Tidskriftsartikel (refereegranskat)abstract
- Epidemiological data regarding tea and coffee consumption and risk of esophageal cancer (EC) is still inconclusive. We examined the association of tea and coffee consumption with EC risk among 442,143 men and women without cancer at baseline from 9 countries of the European Prospective Investigation into Cancer and Nutrition. Tea and coffee intakes were recorded using country-specific validated dietary questionnaires. Cox regression models were used to analyze the relationships between tea and coffee intake and EC risk. During a mean follow-up of 11.1 years, 339 participants developed EC, of which 142 were esophageal adenocarcinoma (EAC) and 174 were esophageal squamous cell carcinoma (ESCC). In the multivariable models, no significant associations between tea (mostly black tea), and coffee intake and risk of EC, EAC and ESCC were observed. In stratified analyses, among men coffee consumption was inversely related to ESCC (HR for comparison of extreme tertiles 0.42, 95% CI 0.20-0.88; p-trend = 0.022), but not among women. In current smokers, a significant and inverse association was observed between ESCC risk and tea (HR 0.46, 95% CI 0.23-0.93; p-trend = 0.053) and coffee consumption (HR 0.37, 95% CI 0.19-0.73; p-trend = 0.011). However, no statistically significant findings were observed using the continuous variable (per 100 mL/d). These data did not show a significant association between tea and coffee consumption and EC, EAC and ESCC, although a decreased risk of ESCC among men and current smokers is suggested, but need to be confirmed in further prospective studies including more cases.
|
|
| 7. |
- Decin, L., et al.
(författare)
-
(Sub)stellar companions shape the winds of evolved stars
- 2020
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 369:6509, s. 1497-1500
-
Tidskriftsartikel (refereegranskat)abstract
- Binary interactions dominate the evolution of massive stars, but their role is less clear for low- and intermediate-mass stars. The evolution of a spherical wind from an asymptotic giant branch (AGB) star into a nonspherical planetary nebula (PN) could be due to binary interactions. We observed a sample of AGB stars with the Atacama Large Millimeter/submillimeter Array (ALMA) and found that their winds exhibit distinct nonspherical geometries with morphological similarities to planetary nebulae (PNe). We infer that the same physics shapes both AGB winds and PNe; additionally, the morphology and AGB mass-loss rate are correlated. These characteristics can be explained by binary interaction. We propose an evolutionary scenario for AGB morphologies that is consistent with observed phenomena in AGB stars and PNe.
|
|
| 8. |
- Gottlieb, C. A., et al.
(författare)
-
ATOMIUM: ALMA tracing the origins of molecules in dust forming oxygen rich M-type stars: Motivation, sample, calibration, and initial results
- 2022
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 660
-
Tidskriftsartikel (refereegranskat)abstract
- This overview paper presents atomium, a Large Programme in Cycle 6 with the Atacama Large Millimeter/submillimeter Array (ALMA). The goal of atomium is to understand the dynamics and the gas phase and dust formation chemistry in the winds of evolved asymptotic giant branch (AGB) and red supergiant (RSG) stars. A more general aim is to identify chemical processes applicable to other astrophysical environments. Seventeen oxygen-rich AGB and RSG stars spanning a range in (circum)stellar parameters and evolutionary phases were observed in a homogeneous observing strategy allowing for an unambiguous comparison. Data were obtained between 213.83 and 269.71 GHz at high (0.025-0.050), medium (0.13-0.24), and low (~1) angular resolution. The sensitivity per ~1.3 km s-1 channel was 1.5-5 mJy beam-1, and the line-free channels were used to image the millimetre wave continuum. Our primary molecules for studying the gas dynamics and dust formation are CO, SiO, AlO, AlOH, TiO, TiO2, and HCN; secondary molecules include SO, SO2, SiS, CS, H2O, and NaCl. The scientific motivation, survey design, sample properties, data reduction, and an overview of the data products are described. In addition, we highlight one scientific result - the wind kinematics of the atomium sources. Our analysis suggests that the atomium sources often have a slow wind acceleration, and a fraction of the gas reaches a velocity which can be up to a factor of two times larger than previously reported terminal velocities assuming isotropic expansion. Moreover, the wind kinematic profiles establish that the radial velocity described by the momentum equation for a spherical wind structure cannot capture the complexity of the velocity field. In fifteen sources, some molecular transitions other than 12CO v = 0 J = 2 - 1 reach a higher outflow velocity, with a spatial emission zone that is often greater than 30 stellar radii, but much less than the extent of CO. We propose that a binary interaction with a (sub)stellar companion may (partly) explain the non-monotonic behaviour of the projected velocity field. The atomium data hence provide a crucial benchmark for the wind dynamics of evolved stars in single and binary star models.
|
|
| 9. |
- Sieri, S., et al.
(författare)
-
Alcohol consumption patterns, diet and body weight in 10 European countries
- 2009
-
Ingår i: European Journal of Clinical Nutrition. - : Springer Science and Business Media LLC. - 1476-5640 .- 0954-3007. ; 63:4s, s. 81-100
-
Tidskriftsartikel (refereegranskat)abstract
- Background/objectives: Europe has the highest level of alcohol consumption in the world. As drinking patterns are important determinants of the beneficial and harmful effects of alcohol consumption, we investigated alcohol consumption in relation to nutrient intake, place of consumption, education and body weight in a sample of adults from 10 European countries. Methods: A 24-h dietary recall interview was conducted on 13 025 men and 23 009 women, aged 35-74 years, from 27 centres participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Means and standard errors of alcohol consumption, adjusted for age, were calculated, stratified by gender and centre. Results: In many centres, higher level drinkers (males consuming 424 g of ethanol/day, equivalent to 42 standard drinks and females consuming 412 g of ethanol/day equivalent to 41 standard drink) obtained more energy from fat and protein and less from sugar than did abstainers. The proportion of energy from starch tended to be higher for male and lower for female higher level drinkers than for abstainers. Female higher level drinkers had a lower body mass index than did abstainers, whereas male higher level drinkers generally weighed more. Male higher level drinkers were less educated than abstainers in Mediterranean countries, but were more educated elsewhere. Female higher level drinkers were usually more educated than were abstainers. Outside the home, consumption (both genders) tended to be at friends' homes, particularly among men in Northern and Central Europe, and in bars in Spain. Conclusions: This study reveals clear geographical differences in drinking habits across Europe, and shows that the characteristics of different alcohol consumption categories also vary. European Journal of Clinical Nutrition (2009) 63, S81-S100; doi: 10.1038/ejcn.2009.76
|
|
| 10. |
- Baudry, A., et al.
(författare)
-
ATOMIUM: Probing the inner wind of evolved O-rich stars with new, highly excited H2O and OH lines
- 2023
-
Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 674
-
Tidskriftsartikel (refereegranskat)abstract
- Context. Water (H2O) and the hydroxyl radical (OH) are major constituents of the envelope of O-rich late-type stars. Transitions involving energy levels that are rotationally or vibrationally highly excited (energies & GSIM;4000 K) have been observed in both H2O and OH. These and more recently discovered transitions can now be observed at a high sensitivity and angular resolution in the inner wind close to the stellar photosphere with the Atacama Large Millimeter/submillimeter Array (ALMA). Aims. Our goals are: (1) to identify and map the emission and absorption of H2O in several vibrational states, and of OH in Lambda-doubling transitions with similar excitation energies; and (2) to determine the physical conditions and kinematics in gas layers close to the extended atmosphere in a sample of asymptotic giant branch stars (AGBs) and red supergiants (RSGs). Methods. Spectra and maps of H2O and OH lines observed in a 27 GHz aggregated bandwidth and with an angular resolution of similar to 0."02-1."0 were obtained at two epochs with the main ALMA array. Additional observations with the Atacama Compact Array (ACA) were used to check for time variability of water transitions. Radiative transfer models of H2O were revisited to characterize masing conditions. Up-to-date chemical models were used for comparison with the observed OH/H2O abundance ratio. Results. Ten rotational transitions of H2O with excitation energies similar to 4000-9000 K were observed in vibrational states up to (& upsilon;(1),& upsilon;(2),& upsilon;(3)) = (0,1,1). All but one are new detections in space, and from these we have derived accurate rest frequencies. Hyperfine split Lambda-doubling transitions in & upsilon; = 0, J = 27/2 and 29/2 levels of the (2)& pi;(3/2) state, as well as J = 33/2 and 35/2 of the (2)& pi;(1/2) state of OH with excitation energies of similar to 4780-8900 K were also observed. Four of these transitions are new detections in space. Combining our measurements with earlier observations of OH, the & upsilon; = 0 and & upsilon; = 1 Lambda-doubling frequencies have been improved. Our H2O maps show compact emission toward the central star and extensions up to twelve stellar radii or more. The 268.149 GHz emission line of water in the & upsilon;(2) = 2 state is time variable, tends to be masing with dominant radiative pumping, and is widely excited in AGBs and RSGs. The widespread but weaker 262.898 GHz water line in the & upsilon;(2) = 1 state also shows signs of maser emission. The OH emission is weak and quasithermally excited. Emission and absorption features of H2O and OH reveal an infall of matter and complex kinematics influenced by binarity. From the OH and H2O column densities derived with nonmasing transitions in a few sources, we obtain OH/H2O abundance ratios of similar to(0.7-2.8) x 10(-2).
|
|
