Archival Data Research Articles

Climate change impacts on a sedimentary coast—a regional synthesis from genes to ecosystems

Climate change effects on coastal ecosystems vary on large spatial scales, but can also be highly site dependent at the regional level. The Wadden Sea in the south-eastern North Sea is warming faster than many other temperate coastal areas, with surface seawater temperature increasing by almost 2 °C over the last 60 years, nearly double the global ocean mean increase. Climate warming is accompanied by rising sea levels, which have increased by approximately 2 mm yr−1 over the last 120 years. For this sedimentary coast, the predicted acceleration of sea-level rise will have profound effects on tidal dynamics and bathymetry in the area. This paper synthesises studies of the effects of ocean warming and sea level rise in the northern Wadden Sea, largely based on research conducted at the Wadden Sea Station Sylt of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research. An increasing rate of sea level rise above a critical threshold will lead to coastal erosion and changes in sediment composition, and may cause the transition from a tidal to lagoon-like environment as tidal flats submerge. This involves changes to coastal morphology, and the decline of important habitats such as muddy tidal flats, salt marshes and seagrass meadows, as well as their ecological services (e.g. carbon sequestration). Ocean warming affects plankton dynamics and phenology, as well as benthic community structure by hampering cold-adapted but facilitating warm-adapted species. The latter consist mostly of introduced non-native species originating from warmer coasts, with some epibenthic species acting as ecosystem engineers that create novel habitats on the tidal flats. Warming also changes interactions between species by decoupling existing predator–prey dynamics, as well as forming new interactions in which mass mortalities caused by parasites and pathogens can play an understudied but essential role. However, Wadden Sea organisms can adapt to changing abiotic and biotic parameters via genetic adaptation and phenotypic plasticity, which can also be inherited across generations (transgenerational plasticity), enabling faster plastic responses to future conditions. Important research advances have been made using next-generation molecular tools (-omics), mesocosm experiments simulating future climate scenarios, modelling approaches (ecological network analysis), and internet-based technologies for data collection and archiving. By synthesising these climate change impacts on multiple levels of physical and biological organisation in the northern Wadden Sea, we reveal knowledge gaps that need to be addressed by future investigations and comparative studies in other regions in order to implement management, mitigation and restoration strategies to preserve the uniqueness of this ecosystem of global importance.

Radio Occultation Modeling Experiment (ROMEX): Determining the Impact of Radio Occultation Observations on Numerical Weather Prediction

Abstract The international radio occultation (RO) community is conducting a collaborative effort to explore the impact of a large number of RO observations on numerical weather prediction (NWP). This effort, the Radio Occultation Modeling Experiment (ROMEX), has been endorsed by the International Radio Occultation Working Group, a scientific working group under the auspices of the Coordination Group for Meteorological Satellites (CGMS). ROMEX seeks to inform strategies for future RO missions and acquisitions. ROMEX is planned to consist of at least one 3-month period during which all available RO data are collected, processed, archived, and made available to the global community free of charge for research and testing. Although the primary purpose is to test the impact of varying numbers of RO observations on NWP, the 3 months of RO observations during the first ROMEX period (ROMEX-1, September–November 2022) will be a rich dataset for research on many atmospheric phenomena. The RO data providers have sent their data to EUMETSAT for processing. The total number of RO profiles averages between 30 000 and 40 000 per day for ROMEX-1. The processed data (phase, bending angle, refractivity, temperature, and water vapor) will be distributed to ROMEX participants by the Radio Occultation Meteorology Satellite Application Facility (ROM SAF). The data will also be processed independently by the UCAR COSMIC Data Analysis and Archive Center (CDAAC) and available via ROM SAF. The data are freely available to all participants who agree to the conditions that the providers be acknowledged, and the data are not used for commercial or operational purposes.

Munging the Ghosts in the Machine: Coded Bias and the Craft of Wrangling Archival Data

Munging the Ghosts in the Machine: Coded Bias and the Craft of Wrangling Archival Data

Digital Transformation of Archives in the Context of the Introduction of an Electronic Document Management System in Kazakhstan

Abstract The relevance of this study is conditioned by the significant importance of the organisation of electronic document management in the Republic of Kazakhstan and the broad prospects that open up during the digitalisation of state archives. The purpose of the study is to investigate the key aspects of the digitalisation of archives in Kazakhstan at the current stage of the country’s economic development. The basis of its methodological approach was a theoretical investigation of the processes of digitalisation of archival information under the conditions of practical application of the electronic document management system in the Republic of Kazakhstan, with the results obtained indicating the major significance of the digital transformation of archives in the context of the programmes Resolution of the Government of the Republic of Kazakhstan No. 827 “About Approval of the State Program “Digital Kazakhstan” (2017) and “Information Kazakhstan-2020”: State Program (2021) adopted at the state level. The sequential transfer of archival information to digital media for storage offers numerous advantages over traditional paper media, with the state level in Kazakhstan regulating the digital transformation of archives and the adoption and use of a unified electronic document management system by enacting a number of laws that regulate a wide range of related issues. The introduction of an electronic document management system has also established numerous advantages, largely determining the significant prospects for the development of this system of interaction between organisations (state, public, legal entities, and individuals). The practical significance of the results obtained lies in the possibility of their application in the organisation of the activities of enterprises and organisations of the Republic of Kazakhstan that implement measures to digitalise archival data within the unified electronic document management system.

Design framework to renewal abandoned areas in historic districts

ABSTRACT Urbanization and population growth have profoundly impacted the environment of historic and cultural blocks, resulting in a lack of public buildings and spaces for internal adjustment, fostering pronounced homogeneity. This study focuses on completely abandoned areas within historical streets, integrating space syntax analysis with semantic analysis to explore reshaping regional public buildings. Unlike previous studies centered around restoring old objects, the abandoned disconnected areas require a novel regional public architecture design framework through the semantic transformation of archival photographs, historical plans, and local culture. Taking Huishan Ancient Town in Wuxi as a case study, this research comprehends the abandoned disconnection area through a literature review and examination of archival data. By using spatial syntax analysis to combine the overall pedestrian flow space with the depth of ancient historical plans, entrances are set according to the pedestrian flow, preserving unique spatial characteristics and transforming the abandoned land into new public building spaces with distinct regional and contiguous features. Through semantic translation rooted in local culture, classical elements were extracted from intangible cultural heritage and applied to the ancient town’s architectural facades, navigation systems, and structures, thereby mitigating homogenization tendencies in both spatial and cultural elements.

Study of hydrated asteroids via their polarimetric properties at low phase angles

Context. Ch-type asteroids are distinctive among other dark asteroids in that they exhibit deep negative polarization branches (NPBs). Nevertheless, the physical and compositional properties that cause their polarimetric distinctiveness are less investigated. Aims. We aim to investigate the polarimetric uniqueness of Ch-type asteroids by making databases of various observational quantities (i.e., spectroscopic and photometric properties as well as polarimetric ones) of dark asteroids. Methods. We conducted an intensive polarimetric survey of 52 dark asteroids (including 31 Ch-type asteroids) in the RC band to increase the size of polarimetric samples. The observed data were compiled with previous polarimetric, spectroscopic, and photometric archival data to find their correlations. Results. We find remarkable correlations between these observed quantities, particularly the depth of NPBs and their spectroscopic features associated with the hydrated minerals. The amplitude of the opposition effect in photometric properties also shows correlations with polarimetric and spectral properties. However, these observed quantities do not show noticeable correlations with the geometric albedo, thermal inertia, and diameter of asteroids. Conclusions. Based on the observational evidence, we arrive at our conclusion that the submicrometer-sized structures (fibrous or flaky puff pastry-like structures in phyllosilicates) in the regolith particles could contribute to the distinctive NPBs of hydrated asteroids.

Family Environment, Social Support, and Health-Related Quality of Life in Adolescents Following Kidney Transplant.

Kidney transplantation is the treatment of choice for pediatric end-stage renal disease. Transplant recipients often have better neurocognitive, academic, and health-related outcomes. While there is some evidence that health-related quality of life (HRQOL) improves following kidney transplant, other studies have found adolescent transplant recipients report lower overall HRQOL than healthy peers. Current research has focused on individual-level factors affecting adjustment to organ transplant, warranting examination of HRQOL from a systems perspective. Family environment and social support contribute to a system of proximal relationships that are crucial in adolescents' development, making them important factors to study in relation to HRQOL post-transplant. The current study utilized archival data of adolescent renal transplant patients who completed surveys about their family environment, social support, and HRQOL during routine transplant clinic visits. Family cohesion, as well as social support from parents, classmates, and people in school, were positively correlated with HRQOL. Social support from people in school uniquely predicted variance in HRQOL, beyond the contribution of overall family environment after controlling for demographic factors. Relative to comparable adolescent samples, transplant recipients reported more optimal overall family environment, greater social support from teachers, and lower social support from close friends. Psychosocial interventions for adolescent kidney transplant recipients may be enhanced by collaborating with school professionals and further bolstering strengths in the family environment. Kidney transplant recipients may benefit from long-term intervention, as decreased HRQOL appears to persist years post-transplant.

Learning by Necessity: Government Demand, Capacity Constraints, and Productivity Growth

This paper studies how firms adapt to demand shocks when facing capacity constraints. I show that increases in government purchases raise total factor productivity in quantity units at the production line level. Productivity gains are concentrated in plants facing tighter capacity constraints, a phenomenon I call “learning by necessity.” Evidence is based on newly digitized archival data on US World War II aircraft production. Shifts in demand across aircraft with different strategic roles provide an instrument for aircraft demand. I show that plants adapted to surging demand by improving production methods, outsourcing, and combating absenteeism, primarily when facing tighter capacity constraints. (JEL D22, D24, E62, L93, N12, N42, N62)

Neighborhood racial income inequality and cognitive health.

Neighborhood socioeconomic status (SES) has been linked to dementia, but the distribution of SES within a neighborhood may also matter. Data from 460 (47% Black, 46% White) older adults from the Michigan Cognitive Aging Project were linked to census tract-level data from the National Neighborhood Data Archive (NaNDA). Neighborhood SES included two composites reflecting disadvantage and affluence. Neighborhood racial income inequality was the ratio of median incomes for White versus Black residents. Generalized estimating equations examined associations between neighborhood factors and cognitive domains. Neighborhood racial income inequality was uniquely associated with worse cognitive health, and these associations did not differ by participant race. Neighborhood disadvantage was only associated with worse cognitive health among Black participants. Both the level and racial distribution of SES within a neighborhood may be relevant for dementia risk. Racial differences in the level and impact of neighborhood SES contribute to dementia inequalities. Black participants lived in neighborhoods with lower socioeconomic status (SES) than White participants, on average. Neighborhood SES and racial income inequality were associated with worse cognition. Effects of neighborhood racial income inequality did not differ across racial groups. Effects of neighborhood SES were only evident among Black participants.

Patterns of Physical Therapy Referral and Subsequent Attendance Among Childhood Cancer Survivors with Chemotherapy-Induced Peripheral Neuropathy at a Regional Childhood Cancer Survivorship Clinic

ObjectivesChildhood cancer survivors are at risk for chemotherapy-induced peripheral neuropathy (CIPN). Physical therapy (PT) improves CIPN symptoms, but little is known about survivors’ PT utilization. We described characteristics of survivors with ≥ grade 2 CIPN, investigated PT referral and attendance, and described characteristics of survivors who attended and did not attend PT. MethodsChildhood cancer survivors <21 years old at cancer diagnosis and ≥2 years posttherapy, living in the United States, evaluated at a regional survivorship clinic were included in this retrospective analysis if they had motor CIPN. Symptomatic CIPN (≥grade 2 by Common Terminology Criteria for Adverse Events) and PT referral/attendance were tabulated. Patient characteristics from the medical record, and neighborhood characteristics (retrieved using survivors’ zip code from the National Neighborhood Data Archive) were described by group. ResultsAmong 91 survivors with CIPN (median 17.5 years old, 8.1 years postcancer diagnosis, 45.1% female), 35 (38.5%) had ≥ grade 2 CIPN. Survivors with ≥ grade 2 CIPN were 28.6% female, and 45.7% were <13 years old. Twenty-four (68.6%) survivors with ≥ grade 2 CIPN agreed to PT referral, and 15 (42.9%) attended PT. Among survivors who attended PT, 73.3% were <13 years old. Neighborhood characteristics of survivors included median percentage of adults without a high school diploma (6.7% PT attendees, 12.5% nonattendees), median percentage of adults who are foreign-born (11.5% PT attendees, 16.4% nonattendees), and median percentage of households with an annual income of <$15,000 (3.2% PT attendees, 6.5% nonattendees). ConclusionsWhile 68.6% of survivors with ≥ grade 2 CIPN were referred to PT, only 42.9% attended. Studies to better understand barriers to PT attendance and interventions to improve attendance are needed, especially in older survivors. Implications for Nursing PracticeNurses can play a key role in survivor education and care coordination to help optimize PT attendance.

UOCS XIV: Study of the Open Cluster NGC 2627 Using UVIT/AstroSat

We study the intermediate-age open cluster NGC 2627, located at a distance of ∼2 kpc, using UVIT/AstroSat and other archival data. Using a machine learning-based algorithm, ML-MOC, on the Gaia DR3 data, we identify 422 cluster members, including four blue straggler stars (BSSs), one yellow straggler star (YSS), one blue lurker (BL), one red clump (RC) star, and two binary candidates with detection in both UVIT/F148W and UVIT/F169M filters. We characterise them using multiwavelength spectral energy distributions (SEDs). Out of the above nine sources, one BSS, the BL, and one binary candidate have a source nearby; hence, we did not fit their SEDs. Of the remaining six sources, we successfully fit two with single-component SEDs and four with binary-component SEDs. The binary-component SED-based parameters indicate that the hot companions of BSSs, the YSS, the RC star, and the binary candidate are extremely low-mass white dwarfs, confirming that at least four out of nine stars (44%) are formed via the mass transfer channel. We fit King’s profile function to the high-probability (p > 0.8) cluster members and estimate the cluster core radius (r C ) to be 3.84′ and the tidal radius (r t ) to be 36.85′. We find that the equal-mass binaries are most concentrated towards the cluster center, followed by the single massive stars, and single low-mass stars. The BSS population of the cluster is also found to be located within a radius r ∼ 10 × r C from the cluster center, suggesting the dynamical evolution of the cluster.

A Retrospective Analysis of The Causes of Industrial Fires in Istanbul Occurring Between 2015 and 2020

This study was conducted to analyze the causes of industrial fires that occurred in Istanbul from 2015 to the first half of 2020. An official application was made to the Istanbul Metropolitan Municipality Fire Brigade Department, which has archive data on this subject, to conduct the research and a sample set was created by filtering industrial fires from the data pool obtained after the approval of the application. In the analysis phase of the 4600 industrial fire data reached, the distributions of the fires according to years, the intended use of the property where the fire took place, the cause of the fire and the district where the fire took place were examined using the Chi-square analysis method. SPSS 22 software package was used in the analysis and the level of significance was determined as 0.05. The examination of the results of the analysis indicated that the leading cause of industrial fires in Istanbul between 2015 and 2020 was electrical equipment with a rate of 44.8%. Electrical equipment was followed by hot work equipment, heating equipment, cigarettes, flammable and explosive chemicals, cooking equipment and arson, respectively. In the study, the reasons of the fires obtained as a result of the analysis of the data were examined, a comparison with the US industrial fire statistics was made and recommendations for improving data and preventing the recurrence of industrial fires were made. In addition, it was emphasized that robust statistics on the causes of fires played an important role in the development of fire prevention strategies and legislation.

Численное моделирование миграции фильтрационных вод от объектов размещения твердых коммунальных отходов через грунтовые защитные сооружения

The paper studies numerically he processes of pollutant migration from the municipal solid waste (MSW) landfill and discusses the obtained results. Pollution of the natural environment with residues of substances and products resulting from the human household and industrial activities is one of the most urgent problems both in Russia and all over the world. In economically developed countries, in which waste management strategies are implemented to minimize garbage accumulation, priority is given to neutralization and recycling technologies, The beneficial effect of such strategy is a significant reduction of the waste volume. In Russia, despite the positive dynamics in the use of new waste management technologies, the main method of their treatment is disposal at MSW landfills. On the territory of Russia, along with the MSW landfills operated and built in accordance with environmental requirements, there are a large number of unauthorized landfills, which are of serious hazard to the environment. This raises the question of assessing the impact of such facilities on the environment. To study the characteristics of the pollutant distribution and determine the waste migration parameters, the archival data from a set of field and laboratory studies in the area of the existing MSW disposal site were used. A numerical model was constructed to describe the hydrodynamics of the migration of substances in the soil and soil layer forming the base of a solid waste disposal facility. The process of pollutant spreading is described in terms of dry residue. The model takes into account such factors as convective transport, diffusion and geological composition of the base of the waste disposal site, which have a significant impact on the pollutant migration.

OMEGACat. II. Photometry and Proper Motions for 1.4 Million Stars in Omega Centauri and Its Rotation in the Plane of the Sky

Omega Centauri (ω Cen) is the most massive globular cluster of the Milky Way. It is thought to be the nucleus of an accreted dwarf galaxy because of its high mass and its complex stellar populations. To decipher its formation history and study its dynamics, we created the most comprehensive kinematic catalog for its inner region, by analyzing both archival and new Hubble Space Telescope (HST) data. Our catalog contains 1,395,781 proper-motion measurements out to the half-light radius of the cluster ( ∼5.0′ ) and down to m F625W ≈ 25 mag. The typical baseline for our proper-motion measurements is 20 yr, leading to a median 1D proper motion precision of ∼11 μas yr−1 for stars with m F625W ≈ 18 mag, with even better precision (∼6.6 μas yr−1) achieved in the extensively observed centermost ( r<1.5′ ) region. In addition to our astrometric measurements, we also obtained precise HST photometry in seven filters spanning from the ultraviolet to the near-infrared. This allows detailed color–magnitude diagram studies and separation of the multiple stellar populations of the cluster. In this work, we describe the data reduction used to obtain both the photometric and the proper-motion measurements. We also illustrate the creation and the content of our catalog, which is made publicly available. Finally, we present measurements of the plane-of-sky rotation of ω Cen in the previously unprobed inner few arcminutes and a precise measurement of the inclination, i = 43.°9 ± 1.°3.

EXPRESS: Untangling the Duality of Emerging Market Firms’ Response to OFDI Policies on Their Innovation Performance: A Resource Dependence Perspective

Firms’ international expansion, affected by outward foreign direct investment (OFDI) policies of home countries, can greatly shape their innovation performance. Yet, existing literature lacks sufficient investigation toward the nexus between corporate response to policies in OFDI activities and subsequent innovation performance. Thus, the authors designed this study to examine how a firm’s response to OFDI policies affects its innovation performance. Drawing upon the resource dependence theory, the authors theorize corporate response to OFDI policies as firm dependence on home government. By arguing that such dependence differentially affects firm innovation through support and control mechanisms, they elucidate the inverted U-shaped relationship between corporate response to OFDI policies (measured by the percentage of a firm’s OFDI projects in policy-favored markets) and innovation performance (measured as patent counts). Furthermore, this curvilinear relationship, they posit, is moderated and strengthened by home-government subsidies the firm receives (calculated as the ratio of annual subsidies received to yearly sales). With archival data of 2,050 Chinese listed manufacturing firms responding to specific OFDI policies during 2013–2021, their predictions are corroborated. Overall, by illuminating the innovation implications of OFDI as corporate response to policies, this study contributes to the international marketing literature in the context of emerging markets.

ЖАЛАЛ-АБАДДАГЫ КЫСКА МӨӨНӨТТҮҮ ПАДАГОГИКАЛЫК ОКУУ КУРСУНУН ТАРЫХЫ

This scientific article provides a scientific analysis of the history of a short-term pedagogical training course in the Jalal-Abad region, opened in 1923, and issues of education, public enlightenment in a historical context. The geographical scope of the article presented to the scientific community is the Jalal-Abad region, the time frame of which covers the period from 1923 to 1926, and examines historical events that contributed to the elimination of illiteracy and the development of education in the Jalal-Abad region. Historical facts are archival data of the National State Archive of the Republic of Uzbekistan, the State Archive in the capital, archival data in the Osh region and Jalal-Abad region, V.F. Trunov's data for 1887-1997 and other historical and source materials are presented. As a result of archival research, it was found that in 1923 there was a short-term pedagogical course in the Jalal-Abad region, opinions were added about a number of obstacles, shortcomings and prerequisites for the development of the historical process of education. In conclusion, the article emphasized the need for scientific study of the history of the educational direction in this area.

The accretion burst of the massive young stellar object G323.46−0.08

Context. Accretion bursts from low-mass young stellar objects (YSOs) have been known for many decades. In recent years, the first accretion bursts of massive YSOs (MYSOs) have been observed. These phases of intense protostellar growth are of particular importance for studying massive star formation. Bursts of MYSOs are accompanied by flares of Class II methanol masers (hereafter masers), which are caused by an increase in exciting mid-infrared (MIR) emission. They can lead to long-lasting thermal afterglows of the dust continuum radiation visible at infrared (IR) and (sub)millimeter (hereafter (sub)mm) wavelengths. Furthermore, they might cause a scattered light echo. The G323.46−0.08 (hereafter G323) event, which shows all these features, extends the small sample of known MYSO bursts. Aims. Maser observations of the MYSO G323 show evidence of a flare, which was presumed to be caused by an accretion burst. This should be verified with IR data. We used time-dependent radiative transfer (TDRT) to characterize the heating and cooling timescales for eruptive MYSOs and to infer the main burst parameters. Methods. Burst light curves, as well as the pre-burst spectral energy distribution (SED) were established from archival IR data. The properties of the MYSO, including its circumstellar disk and envelope, were derived by using static radiative transfer modeling of pre-burst data. For the first time, TDRT was used to predict the temporal evolution of the SED. Observations with SOFIA/HAWC+ were performed to constrain the burst energy from the strength of the thermal afterglow. Image subtraction and ratioing were applied to reveal the light echo. Results. The G323 accretion burst is confirmed. It reached its peak in late 2013/early 2014 with a Ks-band increase of ∼2.5 mag. Both Ks-band and integrated maser flux densities follow an exponential decay. TDRT indicates that the duration of the thermal afterglow in the far-infrared (FIR) can exceed the burst duration by years. The latter was proved by SOFIA observations, which indicate a flux increase of (14.2 ± 4.6)% at 70 μm and (8.5 ± 6.1)% at 160 μm in 2022 (2 yr after the burst ended). A one-sided light echo emerged that was propagating into the interstellar medium. Conclusions. The burst origin of the G323 maser flare has been verified. TDRT simulations revealed the strong influence of the burst energetics and the local dust distribution on the strength and duration of the afterglow. The G323 burst is probably the most energetic MYSO burst that has been observed so far. Within 8.4 yr, an energy of (0.9−0.8+2.5) × 1047 erg was released. The short timescale points to the accretion of a compact body, while the burst energy corresponds to an accumulated mass of at least (7−6+20) MJup and possibly even more if the protostar is bloated. In this case, the accretion event might have triggered protostellar pulsations, which give rise to the observed maser periodicity. The associated IR light echo is the second observed from a MYSO burst.

Indigenizing Christianity: Indigenous instruments in the Zimbabwean United Methodist Church

This study examines indigenization in the Zimbabwean United Methodist Church. It utilizes historical analysis of archival data to investigate the role of indigenous instrumentations, songs, and music in the indigenization process. The premise is that traditional instruments are operative in the continual indigenization process and play a fundamental role in the 21st-century Zimbabwean United Methodist Church. It further underscores indigenous instruments as a method of theologizing, identity expression and self-imagination. The study concludes that indigenous instruments represent and express United Methodist Church congregants’ spiritual and political liberation in post-missionary Zimbabwe.

Establishing Baselines for Six Short-period δ Scuti Variables

As part of our variable star follow-up program, we have examined a number of stars from the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey. Using a combination of our own data, ATLAS data, and other archival data, we confirmed the published periods and established a baseline ephemeris for each star. This initial sample of six stars are from the PUL or mono-periodic set from the ATLAS survey. Our determined periods agreed well with the published values. Five targets were found to be high amplitude δ Scuti variables (HADS), and one a low-amplitude δ Scuti (LADS). Beyond the primary period we examined the frequency content, Q value, position in the PL relation, and position within the instability strip of each object. We found ATO J070.9950+37.4038 to be the most complex target. The frequency content is likely a set of nonradial pulsations. ATO J328.8034+58.0406 is a multiperiodic HADS variable that is pulsating in the first and second overtones. ATO 345.4240+42.0479 was found to be a simple HADS monoperiodic fundamental pulsator. In the case of ATO J086.0780+30.3287, we found a strong fundamental pulsation with many harmonics and a weaker first overtone pulsation. We classify ATO J086.0780+30.3287 as a HADS. ATO J077.6090+36.5619 was found to be an interesting case of a monoperiodic star that appears to be pulsating in the third overtone. The lower amplitude for this target would put it in the LADS group. ATO J045.8159+46.0090 was found to be a multiperiodic HADS pulsating in the first and second overtones.

Blind and robust estimation of adaptive optics point spread function and diffuse halo with sharp-edged objects

Context. Initially designed to detect and characterise exoplanets, extreme adaptive optics (AO) systems open a new window onto the Solar System by resolving its small bodies. Nonetheless, their study remains limited by the accuracy of the knowledge of the AO-corrected point spread function (AO-PSF) that degrades their image and produces a bright halo, potentially hiding faint moons in their close vicinity. Aims. To overcome the random nature of AO-PSFs, I aim to develop a method that blindly recovers the PSF and its faint structured extensions directly into the data of interest, without any prior on the instrument or the object’s shape. The objectives are both to deconvolve the object and to properly estimate and remove its surrounding halo to highlight potential faint companions. Methods. My method first estimated the PSF core via a parametric model fit, under the assumption of a sharp-edged flat object. Then, the resolved object and the PSF extensions were alternatively deconvolved with a robust method, insensitive to model outliers, such as cosmic rays or unresolved moons. Finally, the complex halo produced by the AO system was modelled and removed from the data. Results. The method is validated on realistic simulations with an on-sky AO-PSF from the SPHERE/ZIMPOL instrument. On real data, the proposed blind deconvolution algorithm strongly improves the image sharpness and retrieves details on the surface of asteroids. In addition, their moons are visible in all tested epochs despite important variability in turbulence conditions. Conclusions. My method shows the feasibility of retrieving the complex features of AO-PSFs directly from the data of interest. It paves the way towards more precise studies of asteroid surfaces and the discovery and characterisation of Solar System moons in archival data or with future instruments on extremely large telescopes with ever more complex AO-PSFs.