Search

In this paper, we explore the detectability of polycyclic aromatic hydrocarbons (PAHs) under diverse planetary conditions, aiming to identify promising targets for future observations of planetary atmospheres. Our primary goal is to determine the minimum detectable mass fractions of PAHs on each studied planet. We integrate the one-dimensional self consistent model petitCODE with petitRADTRANS, a radiative transfer model, to simulate the transmission spectra of these planets. Subsequently, we employ the PandExo noise simulator using the NIRSpec PRISM instrument aboard the JWST to assess the observability. Then, we conduct a Bayesian analysis through the MULTINEST code. Our findings illustrate that variations in C/O ratios and planet temperatures significantly influence the transmission spectra and the detectability of PAHs. Our results show that planets with [Fe/H]=0 and 1, C/O=0.55, and temperatures around 1200 K are the most promising for detecting PAHs, with detectable mass fractions as low as 10$^{-7}$, or one thousandth of the ISM abundance level. For colder planets with lower metallicities and C/O ratios, as well as hotter planets with carbon-rich atmospheres, PAHs can be detected at abundances around 10$^{-6}$. These results aid our strategy for selecting targets to study PAHs in the atmospheres of exoplanets., Comment: 14 pages, 14 figures

Polycyclic Aromatic Hydrocarbons (PAHs) have been detected throughout the universe where they play essential roles in the evolution of their environments. For example, they are believed to affect atmospheric loss rates of close-in planets and might contribute to the pre-biotic chemistry and emergence of life. Despite their importance, the study of PAHs in exoplanet atmospheres has been limited. We aim to evaluate the possibility of detecting PAHs on exoplanets considering future observations using JWST's NIRSpec PRISM mode. The hot Saturn WASP-6 b shows properties that are consistent with a potential PAH presence and is thus used as a case study for this work. Here, we compare the likelihoods of various synthetic haze species and their combinations with the influence of PAHs on the transmission spectrum of WASP-6 b. This is possible by applying the atmospheric retrieval code petitRADTRANS to a collection of data from previous observations. Subsequently, by exploring synthetic, single transit JWST spectra of this planet that include PAHs, we assess if these molecules can be detected in the near future. Previous observations support the presence of cloud/haze species in the spectrum of WASP-6 b. While this may include PAHs, the current data do not confirm their existence unambiguously. Our research suggests that utilizing the JWST for future observations could lead to a notable advancement in the study of PAHs. Employing this telescope, we find that a PAH abundance of approximately 0.1 per cent of the ISM value could be robustly detectable., Comment: 15 pages,11 figures, accepted for publication in MNRAS

The most powerful stellar flares driven by magnetic energy occur during the early pre-main sequence (PMS) phase. The Orion Nebula represents the nearest region populated by young stars, showing the greatest number of flares accessible to a single pointing of Chandra. This study is part of a multi-observatory project to explore stellar surface magnetic fields (with HET-HPF), particle ejections (VLBA), and disk ionization (ALMA) immediately following the detection of PMS super-flares with Chandra. In December 2023, we successfully conducted such a multi-telescope campaign. Additionally, by analyzing Chandra data from 2003, 2012, and 2016, we examine the multi-epoch behavior of PMS X-ray emission related to PMS magnetic cyclic activity and ubiquitous versus sample-confined mega-flaring. Our findings follow. 1) We report detailed stellar quiescent and flare X-ray properties for numerous HET/ALMA/VLBA targets, facilitating ongoing multi-wavelength analyses. 2) For numerous moderately energetic flares, we report correlations (or lack thereof) between flare energies and stellar mass/size (presence/absence of disks) for the first time. The former is attributed to the correlation between convection-driven dynamo and stellar volume, while the latter suggests the operation of solar-type flare mechanisms in PMS stars. 3) We find that most PMS stars exhibit minor long-term baseline variations, indicating the absence of intrinsic magnetic dynamo cycles or observational mitigation of cycles by saturated PMS X-rays. 4) We conclude that X-ray mega-flares are ubiquitous phenomena in PMS stars, which suggests that all protoplanetary disks and nascent planets are subject to violent high-energy emission and particle irradiation events., Comment: 32 pages, 9 figures, 8 tables. Accepted for publication in The Astrophysical Journal, October 7, 2024

In recent years robots have become an important part of our day-to-day lives with various applications. Human-robot interaction creates a positive impact in the field of robotics to interact and communicate with the robots. Gesture recognition techniques combined with machine learning algorithms have shown remarkable progress in recent years, particularly in human-robot interaction (HRI). This paper comprehensively reviews the latest advancements in gesture recognition methods and their integration with machine learning approaches to enhance HRI. Furthermore, this paper represents the vision-based gesture recognition for safe and reliable human-robot-interaction with a depth-sensing system, analyses the role of machine learning algorithms such as deep learning, reinforcement learning, and transfer learning in improving the accuracy and robustness of gesture recognition systems for effective communication between humans and robots., Comment: 19 pages,1 Figure

Context: Photoevaporation is an important process for protoplanetary disc dispersal but there has so far been a lack of consensus from simulations over the mass-loss rates and the most important part of the high-energy spectrum for driving the wind. Aims: We aim to isolate the origins of these discrepancies through carefully-benchmarked hydrodynamic simulations of X-ray photoevaporation with time-dependent thermochemistry calculated on the fly. Methods: We conduct hydrodynamic simulations with pluto where the thermochemistry is calculated using prizmo. We explore the contribution of certain key microphysical processes and the impact of using different spectra used previously in literature studies. Results: We find that additional cooling results from the excitation of O by neutral H, which leads to dramatically reduced mass-loss across the disc compared to previous X-ray photoevaporation models, with an integrated rate of 10^-9 Msun/yr. Such rates would allow for longer-lived discs than previously expected from population synthesis. An alternative spectrum with less soft X-ray produces mass-loss rates around a factor of 2-3 times lower. The chemistry is significantly out of equilibrium, with the survival of H2 into the wind aided by advection. This leads to its role as the dominant coolant at 10s au - thus stabilising a larger radial temperature gradient across the wind - as well as providing a possible wind tracer., Comment: 26 pages, 16 figures, Accepted 31st July 2024 for publication in A&A

The interplay between T Tauri stars and their circumstellar disks, and how this impacts the onset of planet formation has yet to be established. We studied a seemingly old T Tauri star, PDS 111, and its disk. We analyzed optical, infrared, and sub-millimeter observations obtained with VLT/X-shooter, Mercator/HERMES, TESS, VLT/SPHERE, and ALMA, providing a new view on PDS 111 and its protoplanetary disk. The multi-epoch spectroscopy yields photospheric lines to classify the star, and emission lines to study variability in the hot inner disk and to determine the mass-accretion rate. The SPHERE and ALMA observations are used to characterize the dust distribution of the small and large grains, respectively. PDS 111 is a weak-line T Tauri star with spectral type G2, exhibits strong H$\alpha$ variability and with a low mass-accretion rate of $1-5\times10^{-10}$\,M$_{\odot}$\,yr$^{-1}$. We measured an age of the system of 15.9$^{+1.7}_{-3.7}$ Myr using pre-main sequence tracks. The SPHERE observations show a strongly flaring disk with an asymmetric substructure. The ALMA observations reveal a 30 au cavity in the dust continuum emission with a low contrast asymmetry in the South-West of the disk and a dust disk mass of 45.8\,$M_\oplus$. The $^{12}$CO radial extension is at least three times larger than that of the dust emission. Although the measured age is younger than suggested in literature, PDS 111 still seems relatively old; this provides insight into disk properties at an advanced stage of pre-main sequence evolution. The characteristics of this disk are very similar to its younger counterparts: strongly flaring, an average disk mass, a typical radial extent of the disk gas and dust, and the presence of common substructures. This suggests that disk evolution has not significantly changed the disk properties. These results show similarities with the "Peter Pan disks" around M-dwarfs., Comment: 23 pages, 23 figures, accepted by A&A (abstract shortened)

T Tauri stars are known to be magnetically active stars subject to strong flares observed in X-rays. These flares are likely due to intense magnetic reconnection events during which a part of the stored magnetic energy is converted into kinetic energy of supra-thermal particles. Since T Tauri stars are surrounded by an accretion disc, these particles may influence the disc dynamics and chemistry. This work continues on a previous stationary model, which showed that energetic particles accelerated during flares can produce a strong ionisation rate at high column densities in the inner accretion disc. The present model includes non-stationary sequences of flaring events sampled by a Chandra X-ray survey of nearby young stellar objects. We calculate the averaged ionisation rate expected in a radius range from 0.08 to 0.6 au from the central star. We confirm that energetic particles produced by the flares dominate the ionisation of the disc up to column densities of $10^{25}~\rm{cm^{-2}}$. We further study the main consequences of this additional source of ionisation on the viscosity, the accretion rate, the volumetric heating rate and the chemical complexity of inner protoplanetary discs., Comment: 20 pages, 17 figures

We present SPHERE/IRDIS H-band data for a sample of 23 stars in the Orion Star forming region observed within the DESTINYS (Disk Evolution Study Through Imaging of Nearby Young Stars) program. We use polarization differential imaging in order to detect scattered light from circumstellar dust. From the scattered light observations we characterize the disk orientation, radius and contrast. We analyse the disks in context of the stellar parameters and the environment of the Orion star-forming region. We use ancillary X-shooter spectroscopic observations to characterize the central stars in the systems. We furthermore use a combination of new and archival ALMA mm-continuum observations to characterize the dust masses present in the circumstellar disks. Within our sample we detect extended circumstellar disks in 10 of 23 systems. Of these, three are exceptionally extended (V351 Ori, V599 Ori and V1012 Ori) and show scattered light asymmetries which may indicate perturbations by embedded planets or (in the case of V599 Ori) by an outer stellar companion. Our high resolution imaging observations are also sensitive to close (sub)stellar companions and we detect 9 such objects in our sample of which 5 were previously unknown. We find in particular a possible sub-stellar companion (either a very low mass star or a high mass brown dwarf) 137 au from the star RY Ori. We find a strong anti-correlation between disk detection and multiplicity, with only 2 of our 10 disk detections located in stellar multiple systems. We also find a correlation between scattered light contrast and the millimetre flux suggesting that disks that have a high dust content are typically bright in near-infrared scattered light. Conversely we do not find significant correlations between scattered light contrast of the disks and the stellar mass or age., Comment: Accepted by A&A

We used VLT/SPHERE to observe 20 systems in the Cha I cloud in polarized scattered light in the near-infrared. We combined the scattered light observations with existing literature data on stellar properties and with archival ALMA continuum data to study trends with system age and dust mass. We also connected resolved near-infrared observations with the spectral energy distributions of the systems. In 13 of the 20 systems included in this study we detected resolved scattered light signals from circumstellar dust. For the CR Cha, CT Cha, CV Cha, SY Cha, SZ Cha, and VZ Cha systems we present the first detailed descriptions of the disks in scattered light. The observations found typically smooth or faint disks, often with little substructure, with the notable exceptions of SZ Cha, which shows an extended multiple-ringed disk, and WW Cha, which shows interaction with the cloud environment. New high S/N K- band observations of the HD 97048 system in our survey reveal a significant brightness asymmetry that may point to disk misalignment and subsequent shadowing of outer disk regions, possibly related to the suggested planet candidate in the disk. We resolve for the first time the stellar binary in the CS Cha system. Multiple wavelength observations of the disk around CS Cha have revealed that the system contains small, compact dust grains that may be strongly settled, consistent with numerical studies of circumbinary disks. We find in our sample that there is a strong anti-correlation between the presence of a (close) stellar companion and the detection of circumstellar material with five of our seven nondetections located in binary systems., Comment: Accepted by A&A

Recent measurements of carbon isotope ratios in both protoplanetary disks and exoplanet atmospheres have suggested a possible transfer of significant carbon isotope fractionation from disks to planets. For a clearer understanding of the isotopic link between disks and planets, it is important to measure the carbon isotope ratios in various species. In this paper, we present a detection of the $^{13}$CN $N=2-1$ hyperfine lines in the TW Hya disk with the Atacama Large Millimeter/submillimeter Array. This is the first spatially-resolved detection of $^{13}$CN in disks, which enables us to measure the spatially resolved $^{12}$CN/$^{13}$CN ratio for the first time. We conducted non-local thermal equilibrium modeling of the $^{13}$CN lines in conjunction with previously observed $^{12}$CN lines to derive the kinetic temperature, ${\rm H_2}$ volume density, and column densities of $^{12}$CN and $^{13}$CN. The ${\rm H_2}$ volume density is found to range between $ (4 - 10)\times10^7 \ {\rm cm^{-3}}$, suggesting that CN molecules mainly reside in the disk upper layer. The $^{12}$CN/$^{13}$CN ratio is measured to be $ 70^{+9}_{-6}$ at $30 < r < 80$ au from the central star, which is similar to the $\rm ^{12}C/^{13}C$ ratio in the interstellar medium. However, this value differs from the previously reported values found for other carbon-bearing molecules (CO and HCN) in the TW Hya disk. This could be self-consistently explained by different emission layer heights for different molecules combined with preferential sequestration of $\rm ^{12}C$ into the solid phase towards the disk midplane. This study reveals the complexity of the carbon isotope fractionation operating in disks., Comment: 16 pages, 7 figures, accepted for publication in ApJ

The effect of accretion bursts on massive young stellar objects (MYSOs) represents a new research field in the study of young stars and their environment. We aim to investigate the impact of an accretion burst on massive disks with different types of envelopes and to study the effects of an accretion burst on the temperature structure and the chemistry of the disk. We focus on water and methanol as chemical species for this paper. The thermochemical code of PRODIMO (PROtoplanetary DIsk MOdel) is used to perform simulation of high mass protoplanetary disk models with different types of envelopes under the presence of an accretion burst. The models in question represent different evolutionary stages of protostellar objects. We calculate and show the chemical abundances in three phases of the simulation (pre-burst, burst, and post-burst). More heavily embedded disks show higher temperatures. The impact of the accretion burst is mainly characterized by the desorption of chemical species present in the disk and envelope from the dust grains to the gas phase. When the post-burst phase starts, the sublimated species freeze out again. The degree of sublimation depends strongly on the type of envelope the disk is embedded in. An accretion burst in more massive envelopes produces stronger desorption of the chemical species. However, our models show that the timescale for the chemistry to reach the pre-burst state is independent of the type of envelope. The study shows that the disk's temperature increases with a more massive envelope enclosing it. Thus, the chemistry of MYSOs in earlier stages of their evolution reacts stronger to an accretion burst than at later stages where the envelope has lost most of its mass or has been dissipated. The study of the impact of accretion bursts could also provide helpful theoretical context to the observation of methanol masers in massive disks., Comment: 16 pages, 14 figures

Context. The study of protoplanetary disks is fundamental to understand their evolution and interaction with the surrounding environment, and to constrain planet formation mechanisms. Aims. We aim at characterising the young binary system HD 34700 A, which shows a wealth of structures. Methods. Taking advantage of the high-contrast imaging instruments SPHERE at the VLT, LMIRCam at the LBT, and of ALMA observations, we analyse this system at multiple wavelengths. We study the rings and spiral arms morphology and the scattering properties of the dust. We discuss the possible causes of all the observed features. Results. We detect for the first time, in the H${\alpha}$ band, a ring extending from $\sim$65 au to ${\sim}$120 au, inside the ring already known from recent studies. These two have different physical and geometrical properties. Based on the scattering properties, the outer ring may consist of grains of typical size $a_{out} > 4 {\mu}m$, while the inner ring of smaller grains ($a_{in} <= 0.4 {\mu m}$). Two extended logarithmic spiral arms stem from opposite sides of the disk. The outer ring appears as a spiral arm itself, with a variable radial distance from the centre and extended substructures. ALMA data confirm the presence of a millimetric dust substructure centred just outside the outer ring, and detect misaligned gas rotation patterns for HD 34700 A and B. Conclusions. The complexity of HD 34700 A, revealed by the variety of observed features, suggests the existence of one or more disk-shaping physical mechanisms. Possible scenarios, compatible with our findings, involve the presence inside the disk of a yet undetected planet of several Jupiter masses and the system interaction with the surroundings by means of gas cloudlet capture or flybys. Further observations with JWST/MIRI or ALMA (gas kinematics) could shed more light on these., Comment: Accepted for publication on A&A. 14 + 5 pages, 9 + 7 figures (text + appendix)

The analysis of the mid-infrared spectra helps understanding the composition of the gas in the inner, dense and warm terrestrial planet forming region of disks around young stars. ALMA has detected hydrocarbons in the outer regions of the planet forming disk and Spitzer detected \ce{C2H2} in the inner regions. JWST- MIRI provides high spectral resolution observations of \ce{C2H2} and a suite of more complex hydrocarbons are now reported. Interpreting the fluxes observed in the spectra is challenging and radiation thermo-chemical codes are needed to properly take into account the disk structure, radiative transfer, chemistry and thermal balance. Various disk physical parameters like the gas-to-dust ratio, dust evolution including radial drift, dust growth and settling can affect the fluxes observed in the mid-IR. Still, thermo-chemical disk models were not always successful in matching all observed molecular emission bands simultaneously. The goal of this project is two-fold. We analyse the warm carbon chemistry in the inner regions of the disk, i.e. within 10 au to find pathways forming \ce{C2H2} potentially missing from the existing chemical networks. Second, we analyse the effect of the new chemistry on the line fluxes of acetylene. We use radiative thermo-chemical disk code {P{\small RO}D{\small I}M{\small O}} to expand the hydrocarbon chemistry that occurs in a typical standard T Tauri disks. We used the UMIST and the KIDA rate databases for collecting reactions for the species. We include a number of three-body and thermal decomposition reactions from STAND2020 network. We included isotopomers for the species that were present in the databases. The chemistry is then analysed in the regions that produce observable features in the mid-infrared spectra. The effect of expanding the hydrocarbon chemistry on the mid-infrared spectra is studied. Acetylene is formed via two ...., Comment: accepted for publication in A&A

Theoretical models indicate that photoevaporative and magnetothermal winds play a crucial role in the evolution and dispersal of protoplanetary disks and affect the formation of planetary systems. However, it is still unclear what wind-driving mechanism is dominant or if both are at work, perhaps at different stages of disk evolution. Recent spatially resolved observations by Fang et al. (2023) of the [OI] 6300 Angstrom spectral line, a common disk wind tracer, in TW Hya revealed that about 80% of the emission is confined to the inner few au of the disk. In this work, we show that state-of-the-art X-ray driven photoevaporation models can reproduce the compact emission and the line profile of the [OI] 6300 Angstrom line. Furthermore, we show that the models also simultaneously reproduce the observed line luminosities and detailed spectral profiles of both the [OI] 6300 Angstrom and the [NeII] 12.8 micron lines. While MHD wind models can also reproduce the compact radial emission of the [OI] 6300 Angstrom line, they fail to match the observed spectral profile of the [OI] 6300 Angstrom line and underestimate the luminosity of the [NeII] 12.8 micron line by a factor of three. We conclude that, while we cannot exclude the presence of an MHD wind component, the bulk of the wind structure of TW Hya is predominantly shaped by a photoevaporative flow., Comment: 7 pages, 4 figures, accepted for publication in Astrophysical Journal Letters

Context: Polycyclic Aromatic Hydrocarbons, largely known as PAHs, are widespread in the universe and have been identified in a vast array of astronomical observations from the interstellar medium to protoplanetary discs. They are likely to be associated with the chemical history of the universe and the emergence of life on Earth. However, their abundance on exoplanets remains unknown. Aims: We aim to investigate the feasibility of PAH formation in the thermalized atmospheres of irradiated and non-irradiated hot Jupiters around Sun-like stars. Methods: To this aim, we introduced PAHs in the 1-D self-consistent forward modeling code petitCODE. We simulated a large number of planet atmospheres with different parameters (e.g. carbon to oxygen ratio, metallicity, and effective planetary temperature) to study PAH formation. By coupling the thermochemical equilibrium solution from petitCODE with the 1-D radiative transfer code, petitRADTRANS, we calculated the synthetic transmission and emission spectra for irradiated and non-irradiated planets, respectively, and explored the role of PAHs on planet spectra. Results: Our models show strong correlations between PAH abundance and the aforementioned parameters. In thermochemical equilibrium scenarios, an optimal temperature, elevated carbon to oxygen ratio, and increased metallicity values are conducive to the formation of PAHs, with the carbon to oxygen ratio having the largest effect., Comment: 10 pages, 10 figures

Embedded planets are potentially the cause of substructures like gaps and cavities observed in several protoplanetary disks. Thus, the substructures observed in the continuum and in line emission encode information about the presence of planets in the system and how they interact with the natal disk. The pre-transitional disk around the star PDS 70 is the first case of two young planets imaged within a dust depleted gap that was likely carved by themselves. We aim to determine the spatial distribution of the gas and dust components in the PDS 70 disk. The axisymmetric substructures observed in the resulting profiles are interpreted in the context of planet-disk interactions. We develop a thermo-chemical forward model for an axisymmetric disk to explain a subset of the Atacama Large Millimeter/Submillimeter Array (ALMA) band 6 observations of three CO isotopologues plus the continuum towards PDS 70. Combining the inferred gas and dust distributions, the model results in a variable gas-to-dust ratio profile throughout the disk that spans two orders of magnitude within the first $130$ au and shows a step gradient towards the outer disk, which is consistent with the presence of a pressure maxima driven by planet-disk interactions. We find a gas density drop factor of ${\sim} 19$ at the location of the planet PDS 70 c with respect to the peak gas density at $75$ au. Combining this value with literature results on the hydrodynamics of planet-disk interactions, we find this gas gap depth to be consistent with independent planet mass estimates from infrared observations. Our findings point towards gas stirring processes taking place in the common gap due to the gravitational perturbation of both planets., Comment: Accepted for publication in A&A

Photoevaporative disc winds play a key role in our understanding of circumstellar disc evolution, especially in the final stages, and they might affect the planet formation process and the final location of planets. The study of transition discs (i.e. discs with a central dust cavity) is central for our understanding of the photoevaporation process and disc dispersal. However, we need to distinguish cavities created by photoevaporation from those created by giant planets. Theoretical models are necessary to identify possible observational signatures of the two different processes, and models to find the differences between the two processes are still lacking. In this paper we study a sample of transition discs obtained from radiation-hydrodynamic simulations of internally photoevaporated discs, and focus on the dust dynamics relevant for current ALMA observations. We then compared our results with gaps opened by super Earths/giant planets, finding that the photoevaporated cavity steepness depends mildly on gap size, and it is similar to that of a 1 Jupiter mass planet. However, the dust density drops less rapidly inside the photoevaporated cavity compared to the planetary case due to the less efficient dust filtering. This effect is visible in the resulting spectral index, which shows a larger spectral index at the cavity edge and a shallower increase inside it with respect to the planetary case. The combination of cavity steepness and spectral index might reveal the true nature of transition discs., Comment: 10 pages, 7 figures, accepted for publication in MNRAS

COVID19 and asthma are respiratory diseases that can be life threatening in uncontrolled circumstances and require continuous monitoring. A poverty stricken South Asian country like Bangladesh has been bearing the brunt of the COVID19 pandemic since its beginning. The majority of the country's population resides in rural areas, where proper healthcare is difficult to access. This emphasizes the necessity of telemedicine, implementing the concept of the Internet of Things (IoT), which is still under development in Bangladesh. This paper demonstrates how the current challenges in the healthcare system are resolvable through the design of a remote health and environment monitoring system, specifically for asthma patients who are at an increased risk of COVID19. Since on-time treatment is essential, this system will allow doctors and medical staff to receive patient information in real time and deliver their services immediately to the patient regardless of their location. The proposed system consists of various sensors collecting heart rate, body temperature, ambient temperature, humidity, and air quality data and processing them through the Arduino Microcontroller. It is integrated with a mobile application. All this data is sent to the mobile application via a Bluetooth module and updated every few seconds so that the medical staff can instantly track patients' conditions and emergencies. The developed prototype is portable and easily usable by anyone. The system has been applied to five people of different ages and medical histories over a particular period. Upon analyzing all their data, it became clear which participants were particularly vulnerable to health deterioration and needed constant observation. Through this research, awareness about asthmatic symptoms will improve and help prevent their severity through effective treatment anytime, anywhere., Comment: Wireless Communications and Mobile Computing (2022)

The environment, especially water, gets polluted due to industrialization and urbanization. Pollution due to industrialization and urbanization has harmful effects on both the environment and the lives on Earth. This polluted water can cause food poisoning, diarrhea, short-term gastrointestinal problems, respiratory diseases, skin problems, and other serious health complications. In a developing country like Bangladesh, where ready-made garments sector is one of the major sources of the total Gross Domestic Product (GDP), most of the wastes released from the garment factories are dumped into the nearest rivers or canals. Hence, the quality of the water of these bodies become very incompatible for the living beings, and so, it has become one of the major threats to the environment and human health. In addition, the amount of fish in the rivers and canals in Bangladesh is decreasing day by day as a result of water pollution. Therefore, to save fish and other water animals and the environment, we need to monitor the quality of the water and find out the reasons for the pollution. Real-time monitoring of the quality of water is vital for controlling water pollution. Most of the approaches for controlling water pollution are mainly biological and lab-based, which takes a lot of time and resources. To address this issue, we developed an Internet of Things (IoT)-based real-time water quality monitoring system, integrated with a mobile application. The proposed system in this research measures some of the most important indexes of water, including the potential of hydrogen (pH), total dissolved solids (TDS), and turbidity, and temperature of water. The proposed system results will be very helpful in saving the environment, and thus, improving the health of living creatures on Earth.

Circumstellar disks do not evolve in isolation, as about half of solar-type stars were born in binary or multiple systems. Resolving disks in binary systems provides the opportunity to examine the influence of stellar companions on the outcomes of planet formation. We aim to investigate and compare disks in stellar multiple systems with near-infrared scattered-light imaging as part of the Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS) program. We used polarimetric differential imaging with SPHERE/IRDIS at the VLT to search for scattered light from the circumstellar disks in three multiple systems, CHX 22, S CrA, and HP Cha. We performed astrometric and orbit analyses for the stellar companions using archival HST, VLT/NACO, and SPHERE data. Combined with the age and orbital constraints, the observed disk structures provide insights into the evolutionary history and the impact of the stellar companions. The small grains in CHX 22 form a tail-like structure surrounding the close binary, which likely results from a close encounter and capture of a cloudlet. S CrA shows intricate structures (tentative ringed and spiral features) in the circumprimary disk as a possible consequence of perturbations by companions. The circumsecondary disk is truncated and connected to the primary disk via a streamer, suggesting tidal interactions. In HP Cha, the primary disk is less disturbed and features a tenuous streamer, through which the material flows towards the companions. The comparison of the three systems spans a wide range of binary separation (50 - 500 au) and illustrates the decreasing influence on disk structures with the distance of companions. This agrees with the statistical analysis of exoplanet population in binaries, that planet formation is likely obstructed around close binary systems, while it is not suppressed in wide binaries., Comment: 19 pages, 6 figures, accpeted for publication in A&A

EX Lup is a low-mass pre-main sequence star that occasionally shows accretion-related outbursts. Here, we present JWST/MIRI medium resolution spectroscopy obtained for EX Lup fourteen years after its powerful outburst. EX Lup is now in quiescence and displays a Class II spectrum. We detect a forest of emission lines from molecules previously identified in infrared spectra of classical T Tauri disks: H2O, OH, H2, HCN, C2H2, and CO2. The detection of organic molecules demonstrates that they are back after disappearing during the large outburst. Spectral lines from water and OH are for the first time de-blended and will provide a much improved characterization of their distribution and density in the inner disk. The spectrum also shows broad emission bands from warm, sub-micron size amorphous silicate grains at 10 and 18 um. During the outburst, in 2008, crystalline forsterite grains were annealed in the inner disk within 1 au, but their spectral signatures in the 10 um silicate band later disappeared. With JWST we re-discovered these crystals via their 19.0, 20.0, and 23.5 um emission, whose strength implies that the particles are at ~3 au from the star. This suggests that crystalline grains formed in 2008 were transported outwards and now approach the water snowline, where they may be incorporated into planetesimals. Containing several key tracers of planetesimal and planet formation, EX Lup is an ideal laboratory to study the effects of variable luminosity on the planet-forming material and may provide explanation for the observed high crystalline fraction in solar system comets., Comment: 9 pages, 4 figures, accepted for publication in ApJL. JWST/MIRI spectrum is available for download at https://tinyurl.com/spexodisksJWST

The young massive-star-forming region M17 contains optically visible massive pre-main-sequence stars that are surrounded by circumstellar disks. Such disks are expected to disappear when these stars reach the main sequence. The physical and dynamical structure of these remnant disks are poorly constrained, especially the inner regions where accretion, photo-evaporation, and companion formation and migration may be ongoing. We aim to constrain the physical properties of the inner parts of the circumstellar disks of massive young stellar objects B243 (6 Msun) and B331 (12 Msun), two systems for which the central star has been detected and characterized previously despite strong dust extinction. Two-dimensional radiation thermo-chemical modelling with ProDiMo of double-peaked hydrogen lines of the Paschen and Brackett series observed with X-shooter was used to probe the properties of the inner disks. Additionally, the dust structure was studied by fitting the optical and near-infrared spectral energy distribution. B243 features a hot gaseous inner disk with dust at the sublimation radius at 3 AU. The disk appears truncated at roughly 6.5 AU; a cool outer disk of gas and dust may be present, but it cannot be detected with our data. B331 also has a hot gaseous inner disk. A gap separates the inner disk from a colder dusty outer disk starting at up to 100 AU. In both sources the inner disk extends to almost the stellar surface. Chemistry is essential for the ionization of hydrogen in these disks. The lack of a gap between the central objects and these disks suggests that they accrete through boundary-layer accretion. This would exclude the stars having a strong magnetic field. Their structures suggest that both disks are transitional in nature, that is to say they are in the process of being cleared, either through boundary-layer accretion, photo-evaporation, or through companion activity., Comment: 18 pages, 16 figures. Accepted for publication in A&A

Context: A full understanding of the planet and moon formation process requires observations that probe the circumplanetary environment of accreting giant planets. The mid-infrared ELT imager and spectrograph (METIS) will provide a unique capability to detect warm-gas emission lines from circumplanetary disks. Aims: We aim to demonstrate the capability of the METIS instrument on the Extremely Large Telescope (ELT) to detect circumplanetary disks (CPDs) with fundamental v=1-0 transitions of $^{12}$CO from 4.5-5 $\mu$m. Methods: We consider the case of the well-studied HD 100546 pre-transitional disk to inform our disk modeling approach. We use the radiation-thermochemical disk modeling code ProDiMo to produce synthetic spectral channel maps. The observational simulator SimMETIS is employed to produce realistic data products with the integral field spectroscopic (IFU) mode. Results: The detectability of the CPD depends strongly on the level of external irradiation and the physical extent of the disk, favoring massive (~10 M$_{\rm J}$) planets and spatially extended disks with radii approaching the planetary Hill radius. The majority of $^{12}$CO line emission originates from the outer disk surface, and thus the CO line profiles are centrally peaked. The planetary luminosity does not contribute significantly to exciting disk gas line emission. If CPDs are dust-depleted, the $^{12}$CO line emission is enhanced as external radiation can penetrate deeper into the line emitting region. Conclusions: UV-bright star systems with pre-transitional disks are ideal candidates to search for CO-emitting CPDs with ELT/METIS. METIS will be able to detect a variety of circumplanetary disks via their fundamental $^{12}$CO ro-vibrational line emission in only 60 s of total detector integration time., Comment: 13 Pages, 11 Figures, accepted for publication in A&A

Winds in protoplanetary disks play an important role in their evolution and dispersal. However, what physical process is driving the winds is still unclear (i.e. magnetically vs thermally driven), and can only be understood by directly confronting theoretical models with observational data. We use hydrodynamic photoevaporative disk-wind models and post-process them with a thermo-chemical model to produce synthetic observables for the o-H$_2$ at 2.12 micron and [OI] at 0.63 micron spectral lines and directly compare the results to a sample of observations. Our photoevaporative disk-wind model is consistent with the observed signatures of the blueshifted narrow low-velocity component (NLVC), which is usually associated with slow disk winds, for both tracers. Only for one out of seven targets that show blueshifted NLVCs does the photoevaporative model fail to explain the observed line kinematics. Our results also indicate that interpreting spectral line profiles by simple methods, such as the thin-disk approximation, to determine the line emitting region can yield misleading conclusions. The photoevaporative disk-wind models are largely consistent with the studied observational data set, but it is not possible to clearly discriminate between different wind-driving mechanisms. Further improvements to the models, such as consistent modelling of the dynamics and chemistry and detailed modelling of individual targets would be beneficial. Furthermore, a direct comparison of magnetically driven disk-wind models to the observational data set is necessary in order to determine whether or not spatially unresolved observations of multiple wind tracers are sufficient to discriminate between theoretical models., Comment: 14 pages, 13 figures, accepted for publication in A&A

Magnetic reconnection is one of the major particle acceleration processes in space and astrophysical plasmas. Low-energy supra-thermal particles emitted by magnetic reconnection are a source of ionisation for circumstellar discs, influencing their chemical, thermal and dynamical evolution. The aim of this work is to propose a first investigation to evaluate how energetic particles can propagate in the circumstellar disc of a T Tauri star and how they affect the ionisation rate of the disc plasma. To that end, we have collected experimental and theoretical cross sections for the production of H$^+$, H$_2^+$ and He$^+$ by electrons and protons. Starting from theoretical injection spectra of protons and electrons emitted during magnetic reconnection events, we have calculated the propagated spectra in the circumstellar disc considering the relevant energy loss processes. We have considered fluxes of energetic particles with different spectral indices and different disc magnetic configurations, generated at different positions from the star considering the physical properties of the flares as deduced from the observations obtained by the Chandra Orion Ultra Deep point source catalogue. We have then computed the ionisation rates for a disc whose structure has been calculated with the radiation thermo-chemical code {\tt ProDiMo}. We find that energetic particles are potentially a very strong source of local ionisation with ionisation rates exceeding by several orders of magnitude the contribution due to X-rays, stellar energetic particles and radioactivity in the inner disc., Comment: 16 pages, 18 figures, accepted in MNRAS

Melanoma is regarded as the most threatening among all skin cancers. There is a pressing need to build systems which can aid in the early detection of melanoma and enable timely treatment to patients. Recent methods are geared towards machine learning based systems where the task is posed as image recognition, tag dermoscopic images of skin lesions as melanoma or non-melanoma. Even though these methods show promising results in terms of accuracy, they are computationally quite expensive to train, that questions the ability of these models to be deployable in a clinical setting or memory constraint devices. To address this issue, we focus on building simple and performant models having few layers, less than ten compared to hundreds. As well as with fewer learnable parameters, 0.26 million (M) compared to 42.5M using knowledge distillation with the goal to detect melanoma from dermoscopic images. First, we train a teacher model using a ResNet-50 to detect melanoma. Using the teacher model, we train the student model known as Distilled Student Network (DSNet) which has around 0.26M parameters using knowledge distillation achieving an accuracy of 91.7%. We compare against ImageNet pre-trained models such MobileNet, VGG-16, Inception-V3, EfficientNet-B0, ResNet-50 and ResNet-101. We find that our approach works well in terms of inference runtime compared to other pre-trained models, 2.57 seconds compared to 14.55 seconds. We find that DSNet (0.26M parameters), which is 15 times smaller, consistently performs better than EfficientNet-B0 (4M parameters) in both melanoma and non-melanoma detection across Precision, Recall and F1 scores

Disc winds and planet formation are considered to be two of the most important mechanisms that drive the evolution and dispersal of protoplanetary discs and in turn define the environment in which planets form and evolve. While both have been studied extensively in the past, we combine them into one model by performing three-dimensional radiation-hydrodynamic simulations of giant planet hosting discs that are undergoing X-ray photo-evaporation, with the goal to analyse the interactions between both mechanisms. In order to study the effect on observational diagnostics, we produce synthetic observations of commonly used wind-tracing forbidden emission lines with detailed radiative transfer and photo-ionisation calculations. We find that a sufficiently massive giant planet carves a gap in the gas disc that is deep enough to affect the structure and kinematics of the pressure-driven photo-evaporative wind significantly. This effect can be strong enough to be visible in the synthetic high-resolution observations of some of our wind diagnostic lines, such as the [OI] 6300 \r{A} or [SII] 6730 \r{A} lines. When the disc is observed at inclinations around 40{\deg} and higher, the spectral line profiles may exhibit a peak in the redshifted part of the spectrum, which cannot easily be explained by simple wind models alone. Moreover, massive planets can induce asymmetric substructures within the disc and the photo-evaporative wind, giving rise to temporal variations of the line profiles that can be strong enough to be observable on timescales of less than a quarter of the planet's orbital period., Comment: Accepted for publication in MNRAS. 13+3 pages, 8+1 figures

Disk winds are an important mechanism for accretion and disk evolution around young stars. The accreting intermediate-mass T-Tauri star RY Tau has an active jet and a previously known disk wind. Archival optical and new near-infrared observations of the RY Tau system show two horn-like components stretching out as a cone from RY Tau. Scattered light from the disk around RY Tau is visible in near-infrared but not seen at optical wavelengths. In the near-infrared, dark wedges that separates the horns from the disk, indicating we may see the scattered light from a disk wind. We use archived ALMA and SPHERE/ZIMPOL I-band observations combined with newly acquired SPEHRE/IRDIS H-band observations and available literature to build a simple geometric model of the RY Tau disk and disk wind. We use Monte Carlo radiative transfer modelling \textit{MCMax3D} to create comparable synthetic observations that test the effect of a dusty wind on the optical effect in the observations. We constrain the grain size and dust mass needed in the disk wind to reproduce the effect from the observations. A model geometrically reminiscent of a dusty disk wind with small micron to sub-micron size grains elevated above the disk can reproduce the optical effect seen in the observations. The mass in the obscuring component of the wind has been constrained to $1\times10^{-9} M_{\odot} \leq M \leq 5\times10^{-8} M_{\odot}$ which corresponds to a lower limit mass loss rate in the wind of about $\sim 1\times10^{-8}M_{\odot}\mathrm{yr}^{-1}$. While an illuminate dust cavity cannot be ruled out without measurements of the gas velocity, we argue that a magnetically launched disk wind is the most likely scenario., Comment: 11 pages, 5 figures

This COVID-19 pandemic is so dreadful that it leads to severe anxiety, phobias, and complicated feelings or emotions. Even after vaccination against Coronavirus has been initiated, people feelings have become more diverse and complex, and our goal is to understand and unravel their sentiments in this research using some Deep Learning techniques. Social media is currently the best way to express feelings and emotions, and with the help of it, specifically Twitter, one can have a better idea of what is trending and what is going on in people minds. Our motivation for this research is to understand the sentiment of people regarding the vaccination process, and their diverse thoughts regarding this. In this research, the timeline of the collected tweets was from December 21 to July 21, and contained tweets about the most common vaccines available recently from all across the world. The sentiments of people regarding vaccines of all sorts were assessed by using a Natural Language Processing (NLP) tool named Valence Aware Dictionary for sEntiment Reasoner (VADER). By initializing the sentiment polarities into 3 groups (positive, negative and neutral), the overall scenario was visualized here and our findings came out as 33.96% positive, 17.55% negative and 48.49% neutral responses. Recurrent Neural Network (RNN) oriented architecture such as Long Short-Term Memory (LSTM and Bi-LSTM) is used to assess the performance of the predictive models, with LSTM achieving an accuracy of 90.59% and Bi-LSTM achieving an accuracy of 90.83%. Other performance metrics such as Precision, Recall, F-1 score, and Confusion matrix were also shown to validate our models and findings more effectively. This study will help everyone understand public opinion on the COVID-19 vaccines and impact the aim of eradicating the Coronavirus from our beautiful world.

Sleep is an essential and vital element of a person life and health that helps to refresh and recharge the mind and body of a person. The quality of sleep is very important in every person lifestyle, removing various diseases. Bad sleep is a big problem for a lot of people for a very long time. People suffering from various diseases are dealing with various sleeping disorders, commonly known as sleep apnea. Real-time monitoring of sleep is the key to detecting sleep apnea. To solve this problem, an IoT based real-time sleep apnea monitoring system has been developed. It will allow the user to measure different indexes of sleep and will notify them through a mobile application when anything odd occurs. The system contains various sensors to measure the ECG, Heart Rate, Pulse rate, Skin response, and SpO2 of any person during the entire sleeping period. To analyze and detect sleep apnea in real time, the system monitors several people during the sleeping period. The results are displayed on the monitor of the Arduino boards and in the mobile application. The analysis of the achieved data can detect sleep apnea in some of the people that the system monitored, and it can also display the reason why sleep apnea happens. This paper will help everyone learn about sleep apnea and will help people detect it and take the necessary steps to prevent it.

In cold and shielded environments, molecules freeze out on dust grain surfaces to form ices such as H2O, CO, CO2, CH4, CH3OH, and NH3. In protoplanetary disks, the exact radial and vertical ice extension depend on disk mass, geometry, and stellar UV irradiation. The goal of this work is to present a computationally efficient method to compute ice and bare-grain opacities in protoplanetary disk models consistently with the chemistry and to investigate the effect of ice opacities on the physico-chemical state and optical appearance of the disk. A matrix of Mie efficiencies is pre-calculated for different ice species and thicknesses, from which the position dependent opacities of icy grains are then interpolated. This is implemented in the PRODIMO code by a self-consistent solution of ice opacities and the local composition of ices, which are obtained from our chemical network. Locally, the opacity can change significantly, for example, an increase by a factor of more than 200 in the midplane, especially at UV and optical wavelengths, due to ice formation. This is mainly due to changes in the size distribution of dust grains resulting from ice formation. However, since the opacity only changes in the optically thick regions of the disk, the thermal disk structure does not change significantly. For the same reason, the spectral energy distributions computed with our disk models with ice opacities generally show only faint ice emission features at far-IR wavelengths. The ice absorption features are only seen in the edgeon orientation. The assumption made on how the ice is distributed across the grain size distribution influences the far-IR and millimeter slope of the SED. The ice features and their strengths are influenced by the ice power law and the type of chemistry. Our models predict stronger ice features for observations that can spatially resolve the disk, particularly in absorption., Comment: Accepted for publication in A&A. 17 pages, 18 figures

We study the influence of different metallicities on the physical, thermal, and chemical properties of protoplanetary disks, and in particular on the formation and destruction of carbon-based molecules. With the thermo-chemical code ProoDIMO we investigate the impact of lower metallicities on the radiation field, disk temperature, and the abundance of different molecules (H$_2$O, CH$_4$, CO, CO$_2$, HCN, CN, HCO$^+$ and N$_2$H$^+$). We use a fiducial disk model as a reference model and produce two models with lower metallicity. The resulting influence on different chemical species is studied by analyzing their abundance distribution throughout the disk and their vertical column density. Furthermore, the formation and destruction reactions of the chemical species are studied. The results show a relation between the metallicity of the disk and the strength of the stellar radiation field inside the disk. As the metallicity decreases the radiation field is able to penetrate deeper regions of the disk. As a result, there is a stronger radiation field overall in the disk with lower metallicity which also heats up the disk. This triggers a series of changes in the chemical formation and destruction efficiencies for different chemical species. In most cases, the available species abundances change and have greater values compared to scaled-down abundances by constant factors. Metallicity has a clear impact on the snowline of the molecules studied here as well. As metallicity decreases the snowlines are pushed further out and existing snow rings shrink in size., Comment: 19 pages, 18 figures

While protoplanetary disks are often treated as isolated systems in planet formation models, observations increasingly suggest that vigorous interactions between Class II disks and their environments are not rare. DO Tau is a T Tauri star that has previously been hypothesized to have undergone a close encounter with the HV Tau system. As part of the DESTINYS ESO Large Programme, we present new VLT/SPHERE polarimetric observations of DO Tau and combine them with archival HST scattered light images and ALMA observations of CO isotopologues and CS to map a network of complex structures. The SPHERE and ALMA observations show that the circumstellar disk is connected to arms extending out to several hundred au. HST and ALMA also reveal stream-like structures northeast of DO Tau, some of which are at least several thousand au long. These streams appear not to be gravitationally bound to DO Tau, and comparisons with previous Herschel far-IR observations suggest that the streams are part of a bridge-like structure connecting DO Tau and HV Tau. We also detect a fainter redshifted counterpart to a previously known blueshifted CO outflow. While some of DO Tau's complex structures could be attributed to a recent disk-disk encounter, they might be explained alternatively by interactions with remnant material from the star formation process. These panchromatic observations of DO Tau highlight the need to contextualize the evolution of Class II disks by examining processes occurring over a wide range of size scales., Comment: 42 pages, 20 figures, accepted by ApJ, reduced data available at https://zenodo.org/record/6408903 (typos from v1 fixed)

Polycyclic aromatic hydrocarbons (PAHs) play a key role in the chemical and hydrodynamical evolution of the atmospheres of exoplanets and planet-forming discs. If they can survive the planet formation process, PAHs are likely to be involved in pre-biotic chemical reactions eventually leading to more complex molecules such as amino acids and nucleotides, which form the basis for life as we know it. However, the abundance and specific role of PAHs in these environments is largely unknown due to limitations in sensitivity and range of wavelength of current and previous space-borne facilities. Upcoming infrared space spectroscopy missions, such as Twinkle and Ariel, present a unique opportunity to detect PAHs in the atmospheres of exoplanets and planet-forming discs. In this work we present synthetic observations based on conservative numerical modeling of typical planet-forming discs and a transiting hot Saturnian planet around solar type star. Our models show that Twinkle and Ariel might both be able to detect the 3.3 micron PAH feature within reasonable observing time in discs and transiting planets, assuming that PAHs are present with an abundance of at least one tenth of the interstellar medium value., Comment: 11 pages, 9 figures, accepted for publication in MNRAS

X-ray- and extreme-ultraviolet- (XEUV-) driven photoevaporative winds acting on protoplanetary disks around young T-Tauri stars may strongly impact disk evolution, affecting both gas and dust distributions. We compute dust densities for the wind regions of XEUV-irradiated transition disks with gap sizes of 20 and 30 AU, and determine whether they can be observed at wavelengths $0.7 \lesssim \lambda_\mathrm{obs} [\mu\mathrm{m}] \lesssim 1.8$ in scattered and polarised light with current instrumentation. For an XEUV-driven outflow around a $M_* = 0.7 \mathrm{M}_\odot$ T-Tauri star with $L_X = 2 \cdot 10^{30} \mathrm{erg/s}$, we find dust mass-loss rates $\dot{M}_\mathrm{dust} \lesssim 2.0 \cdot 10^{-3} \dot{M}_\mathrm{gas}$, and if we invoke vertical settling, the outflow is quite collimated. The synthesised images exhibit a distinct chimney-like structure. The relative intensity of these chimneys is low, but under optimal conditions, their detection may still be feasible with current instrumentation such as JWST NIRCam and SPHERE IRDIS., Comment: Accepted for publication in A&A. 20+10 pages, 17+12 figures (References updated, minor adjustments.)

Direct observations of young stellar objects are important to test established theories of planet formation. PDS 70 is one of the few cases where robust evidence favours the presence of two planetary mass companions inside the gap of the transition disk. Those planets are believed to be going through the last stages of accretion from the protoplanetary disk, a process likely mediated by a circumplanetary disk (CPD). We aim to develop a three dimensional radiative transfer model for the dust component of the PDS 70 system which reproduces the system's global features observed at two different wavelengths: 855 $\mu\, \mathrm{m}$ with ALMA and 1.25 $\mu\, \mathrm{m}$ with VLT/SPHERE. We use this model to investigate the physical properties of the planetary companion PDS 70 c and its potential circumplanetary disk. We select initial values for the physical properties of the planet and CPD through appropriate assumptions about the nature and evolutionary stage of the object. We modify iteratively the properties of the protoplanetary disk until the predictions retrieved from the model are consistent with both data sets. We provide a model that jointly explains the global features of the PDS 70 system seen in submillimeter and polarised-scattered light. Our model suggests that spatial segregation of dust grains is present in the protoplanetary disk. The submillimeter modelling of the PDS 70 c source favours the presence of an optically thick CPD and places an upper limit to its dust mass of 0.7 $M_\oplus$. Furthermore, analysis of the thermal structure of the CPD demonstrates that the planet luminosity is the dominant heating mechanism of dust grains inside 0.6 au from the planet while heating by stellar photons dominates at larger planetocentric distances., Comment: accepted for publication in A&A

X-ray- and EUV- (XEUV-) driven photoevaporative winds acting on protoplanetary disks around young T-Tauri stars may crucially impact disk evolution, affecting both gas and dust distributions. We constrain the dust densities in a typical XEUV-driven outflow, and determine whether these winds can be observed at $\mu\mathrm{m}$-wavelengths in scattered and polarised light. For an XEUV-driven outflow around a $M_* = 0.7\,\mathrm{M}_\odot$ T-Tauri star with $L_X = 2 \cdot 10^{30}\,\mathrm{erg/s}$, we find a dust mass-loss rate $\dot{M}_\mathrm{dust} \lesssim 4.1 \cdot 10^{-11}\,\mathrm{M_\odot / yr}$ for an optimistic estimate of dust densities in the wind (compared to $\dot{M}_\mathrm{gas} \approx 3.7 \cdot 10^{-8}\,\mathrm{M_\odot / yr}$). The synthesised scattered-light images suggest a distinct chimney structure emerging at intensities $I/I_{\max} < 10^{-4.5}$ ($10^{-3.5}$) at $\lambda_\mathrm{obs} = 1.6$ ($0.4$) $\mu\mathrm{m}$, while the features in the polarised-light images are even fainter. Observations synthesised from our model do not exhibit clear features for SPHERE IRDIS, but show a faint wind signature for JWST NIRCam under optimal conditions. In conclusion, unambiguous detections of photoevaporative XEUV winds launched from primordial disks are at least challenging with current instrumentation; this provides a possible explanation as to why disk winds are not routinely detected in scattered or polarised light., Comment: Accepted for publication in A&A. 15 pages, 11 figures. (Affiliations updated, one reference corrected.)

Mid-infrared imaging traces the sub-micron and micron sized dust grains in protoplanetary disks and it offers constraints on the geometrical properties of the disks and potential companions, particularly if those companions have circumplanetary disks. We use the VISIR instrument and its upgrade NEAR on the VLT to take new mid-infrared images of five (pre-)transition disks and one circumstellar disk with proposed planets and obtain the deepest resolved mid-infrared observations to date in order to put new constraints on the sizes of the emitting regions of the disks and the presence of possible companions. We derotate and stack the data to find the disk properties. Where available we compare the data to ProDiMo (Protoplanetary Disk Model) radiation thermo-chemical models to achieve a deeper understanding of the underlying physical processes within the disks. We apply the circularised PSF subtraction method to find upper limits on the fluxes of possible companions and model companions with circumplanetary disks. We resolve three of the six disks and calculate position angles, inclinations and (upper limits to) sizes of emission regions in the disks, improving upper limits on two of the unresolved disks. In all cases the majority of the mid-IR emission comes from small inner disks or the hot inner rims of outer disks. We refine the existing ProDiMo HD 100546 model SED fit in the mid-IR by increasing the PAH abundance relative to the ISM, adopting coronene as the representative PAH, and increase the outer cavity radius to 22.3 AU. We produce flux estimates for putative planetary-mass companions and circumplanetary disks, ruling out the presence of planetary-mass companions with $L > 0.0028 L_{\odot}$ for $a > 180$ AU in the HD 100546 system. Upper limits of 0.5 mJy-30 mJy are obtained at 8 $\mu$m-12 $\mu$m for potential companions in the different disks., Comment: Accepted in A&A

Protein secondary structure is crucial to creating an information bridge between the primary and tertiary (3D) structures. Precise prediction of eight-state protein secondary structure (PSS) has significantly utilized in the structural and functional analysis of proteins in bioinformatics. Deep learning techniques have been recently applied in this research area and raised the eight-state (Q8) protein secondary structure prediction accuracy remarkably. Nevertheless, from a theoretical standpoint, there are still lots of rooms for improvement, specifically in the eight-state PSS prediction. In this study, we have presented a new deep convolutional neural network (DCNN), namely PS8-Net, to enhance the accuracy of eight-class PSS prediction. The input of this architecture is a carefully constructed feature matrix from the proteins sequence features and profile features. We introduce a new PS8 module in the network, which is applied with skip connection to extracting the long-term inter-dependencies from higher layers, obtaining local contexts in earlier layers, and achieving global information during secondary structure prediction. Our proposed PS8-Net achieves 76.89%, 71.94%, 76.86%, and 75.26% Q8 accuracy respectively on benchmark CullPdb6133, CB513, CASP10, and CASP11 datasets. This architecture enables the efficient processing of local and global interdependencies between amino acids to make an accurate prediction of each class. To the best of our knowledge, PS8-Net experiment results demonstrate that it outperforms all the state-of-the-art methods on the aforementioned benchmark datasets.

Spatially resolved continuum observations of planet-forming disks show prominent ring and gap structures in their dust distribution. However, the picture from gas observations is much less clear and constraints on the radial gas density structure (i.e. gas gaps) remain rare and uncertain. We want to investigate the importance of thermo-chemical processes for the interpretation of high-spatial-resolution gas observations of planet-forming disks and their impact on derived gas properties. We apply the radiation thermo-chemical disk code ProDiMo (PROtoplanetary DIsk MOdel) to model self-consistently the dust and gas disk of HD 163296, using the DSHARP gas and dust observations. With this model we investigate the impact of dust gaps and gas gaps, considering chemistry and heating/cooling processes, on the observables and the derived gas properties. We find distinct peaks in the radial line intensity profiles of the CO line data of HD 163296 at the location of the dust gaps. Our model indicates that those peaks are not only a consequence of a gas temperature increase within the gaps but are mainly caused by the absorption of line emission from the back side of the disk by the dust rings. For two of the three prominent dust gaps in HD 163296, we find that thermo-chemical effects are negligible for deriving density gradients via measurements of the rotation velocity. However, for the gap with the highest dust depletion, the temperature gradient can be dominant and needs to be considered to derive accurate gas density profiles. Self-consistent gas and dust thermo-chemical modelling in combination with high-quality observations of multiple molecules are necessary to accurately derive gas gap depths and shapes. This is crucial to determine the origin of gaps and rings in planet-forming disks and to improve the mass estimates of forming planets if they are the cause of the gap., Comment: 12 pages, 9 figures, accepted for publication in A&A

To understand the formation of planetary systems, one needs to understand the initial conditions of planet formation, i.e. the young gas-rich planet forming disks. Spatially resolved high-contrast observations are of particular interest, since substructures in disks, linked to planet formation, can be detected and close companions or even planets in formation embedded in the disk can be revealed. In this study we present the first result of the DESTINYS survey (Disk Evolution Study Through Imaging of Nearby Young Stars). DESTINYS is an ESO/SPHERE large program that aims at studying disk evolution in scattered light, mainly focusing on a sample of low-mass stars (<1$M_\odot$) in nearby (~200 pc) star-forming regions. In this particular study we present the observations of the ET Cha (RECX 15) system, a nearby 'old' classical T Tauri star (5-8 Myr, ~100 pc), which is still strongly accreting. We use SPHERE/IRDIS in H-band polarimetric imaging mode to obtain high contrast images of the ET Cha system to search for scattered light from the circumstellar disk as well as thermal emission from close companions. We additionally employ VLT/NACO total intensity archival data taken in 2003. We report here the discovery of a low-mass (sub)stellar companion with SPHERE/IRDIS to ET Cha. We are estimating the mass of this new companion based on photometry. Depending on the system age it is a 5 Myr, 50 $M_{Jup}$ brown dwarf or an 8 Myr, 0.10 $M_\odot$ M-type pre-main-sequence star. We explore possible orbital solutions and discuss the recent dynamic history of the system. Independent of the precise companion mass we find that the presence of the companion likely explains the small size of the disk around ET Cha. The small separation of the binary pair indicates that the disk around the primary component is likely clearing from the outside in, explaining the high accretion rate of the system., Comment: 14 pages, 9 figures, accepted for publication in A&A on 09-07-2020

RZ Psc is a young Sun-like star with a bright and warm infrared excess that is occasionally dimmed significantly by circumstellar dust structures. Optical depth arguments suggest that the dimming events do not probe a typical sight line through the circumstellar dust, and are instead caused by structures that appear above an optically thick mid-plane. This system may therefore be similar to systems where an outer disk is shadowed by material closer to the star. Here we report the discovery that RZ Psc hosts a 0.12$M_\odot$ companion at a projected separation of 23au. We conclude that the disk must orbit the primary star. While we do not detect orbital motion, comparison of the angle of linear polarization of the primary with the companion's on-sky position angle provides circumstantial evidence that the companion and disc may not share the same orbital plane. Whether the companion severely disrupts the disc, truncates it, or has little effect at all, will require further observations of both the companion and disc., Comment: MNRASL in press

Context: The Galilean satellites are thought to have formed from a circumplanetary disk (CPD) surrounding Jupiter. When it reached a critical mass, Jupiter opened an annular gap in the solar protoplanetary disk (PPD) that might have exposed the CPD to radiation from the young Sun or from the stellar cluster in which the Solar System formed. Aims: We investigate the radiation field to which the Jovian CPD was exposed during the process of satellite formation. The resulting photoevaporation of the CPD is studied in this context to constrain possible formation scenarios for the Galilean satellites and explain architectural features of the Galilean system. Methods: We constructed a model for the stellar birth cluster to determine the intracluster far-ultraviolet (FUV) radiation field. We employed analytical annular gap profiles informed by hydrodynamical simulations to investigate a range of plausible geometries for the Jovian gap. We used the radiation thermochemical code ProDiMo to evaluate the incident radiation field in the Jovian gap and the photoevaporation of an embedded 2D axisymmetric CPD. Results: We derive the time-dependent intracluster FUV radiation field for the solar birth cluster over 10 Myr. We find that intracluster photoevaporation can cause significant truncation of the Jovian CPD. We determine steady-state truncation radii for possible CPDs, finding that the outer radius is proportional to the accretion rate $\dot{M}^{0.4}$. For CPD accretion rates $\dot M < 10^{-12} M_{\odot}$ yr$^{-1}$, photoevaporative truncation explains the lack of additional satellites outside the orbit of Callisto. For CPDs of mass $M_{\rm CPD} < 10^{-6.2 M_{\odot}}$ , photoevaporation can disperse the disk before Callisto is able to migrate into the Laplace resonance. This explains why Callisto is the only massive satellite that is excluded from the resonance., Comment: 17 pages, 13 figures, accepted by A&A

To ensure the security of the general mass, crime prevention is one of the most higher priorities for any government. An accurate crime prediction model can help the government, law enforcement to prevent violence, detect the criminals in advance, allocate the government resources, and recognize problems causing crimes. To construct any future-oriented tools, examine and understand the crime patterns in the earliest possible time is essential. In this paper, I analyzed a real-world crime and accident dataset of Denver county, USA, from January 2014 to May 2019, which containing 478,578 incidents. This project aims to predict and highlights the trends of occurrence that will, in return, support the law enforcement agencies and government to discover the preventive measures from the prediction rates. At first, I apply several statistical analysis supported by several data visualization approaches. Then, I implement various classification algorithms such as Random Forest, Decision Tree, AdaBoost Classifier, Extra Tree Classifier, Linear Discriminant Analysis, K-Neighbors Classifiers, and 4 Ensemble Models to classify 15 different classes of crimes. The outcomes are captured using two popular test methods: train-test split, and k-fold cross-validation. Moreover, to evaluate the performance flawlessly, I also utilize precision, recall, F1-score, Mean Squared Error (MSE), ROC curve, and paired-T-test. Except for the AdaBoost classifier, most of the algorithms exhibit satisfactory accuracy. Random Forest, Decision Tree, Ensemble Model 1, 3, and 4 even produce me more than 90% accuracy. Among all the approaches, Ensemble Model 4 presented superior results for every evaluation basis. This study could be useful to raise the awareness of peoples regarding the occurrence locations and to assist security agencies to predict future outbreaks of violence in a specific area within a particular time.

There are many award-winning pre-trained Convolutional Neural Network (CNN), which have a common phenomenon of increasing depth in convolutional layers. However, I inspect on VGG network, which is one of the famous model submitted to ILSVRC-2014, to show that slight modification in the basic architecture can enhance the accuracy result of the image classification task. In this paper, We present two improve architectures of pre-trained VGG-16 and VGG-19 networks that apply transfer learning when trained on a different dataset. I report a series of experimental result on various modification of the primary VGG networks and achieved significant out-performance on image classification task by: (1) freezing the first two blocks of the convolutional layers to prevent over-fitting and (2) applying different combination of dilation rate in the last three blocks of convolutional layer to reduce image resolution for feature extraction. Both the proposed architecture achieves a competitive result on CIFAR-10 and CIFAR-100 dataset.