AI in creating inclusive work environments for neurodiverse employees
Artificial intelligence; Inclusivity; Neurodivergent; Neurodiversity; Workplace diversity
Purpose This study aims to examine the increased focus on neurodiversity in contemporary businesses. It shows how inclusive policies can capitalize on the special abilities of people with neurodiverse backgrounds, including their extraordinary problem-solving abilities, meticulous attention to detail and creative thinking. These policies benefit the individuals and contribute to a more diverse and innovative workplace. Design/methodology/approach Data was collected through semistructured interviews with HR experts and neurodivergent employees. The qualitative data were manually analyzed and coded, and themes were identified. Findings The results highlight the significant benefits of accepting neurodiversity in the workplace, enlightening the audience about its potential. For instance, artificial intelligence (AI) can be used to anonymize resumes, removing potential biases related to gender, ethnicity or age. In addition, AI can help in identifying the unique skills and strengths of neurodivergent employees, enhancing the fit between job responsibilities and their abilities. This study also emphasizes the wider effects of accepting neurodiversity on employee satisfaction, productivity and organizational innovation. This study promotes a deep learning framework that combines human-centered strategy with strategic methods to maximize the participation of neurodiverse workers and foster a more creative and dynamic corporate culture, convincing the audience of its benefits. Research limitations/implications This study is limited by its qualitative nature and relatively small sample size, comprising 15 HR professionals and 20 neurodivergent employees, which restricts generalizability. The sensitive nature of neurodiversity also made participant recruitment challenging, with some individuals hesitant to disclose their condition. In addition, companies were reluctant to share internal AI practices due to confidentiality concerns. The research focused on a select set of organizations, primarily from specific regions, limiting cross-cultural applicability. Furthermore, the absence of AI developers in the sample means insights into technical tool design and implementation remain unexplored, suggesting a gap for future multidisciplinary research. Practical implications This study provides actionable insights for HR professionals and organizational leaders aiming to improve neurodiverse hiring and support systems. It identifies specific AI tools such as Grammarly, Otter.ai and Pymetrics, that can be integrated into recruitment and workplace settings to enhance communication, reduce sensory overload and match roles to individual strengths. Organizations can use the deep learning framework proposed to design more inclusive policies and infrastructure. Training managers and customizing AI-driven accommodations can improve retention, engagement and performance among neurodiverse talent. This research supports firms in developing more equitable, adaptive and innovative environments aligned with diversity and inclusion goals. Social implications This study promotes a societal shift in how neurodivergent individuals are perceived and supported in the workforce. By emphasizing ability over deficit and proposing inclusive AI integration, it helps reduce stigma and encourages broader acceptance of cognitive diversity. The findings advocate for universal accommodations that do not require self-disclosure, promoting dignity and equity. Improved employment outcomes for neurodiverse individuals contribute to economic inclusion, reduce unemployment rates and challenge ableist norms. The research also aligns with broader Diversity Equity and Inclusion (DEI) movements, inspiring organizations and policymakers to build socially responsible frameworks that reflect the value of every individual, regardless of neurological difference. Originality/value This paper offers original value by exploring the underresearched intersection of AI and neurodiversity inclusion in the workplace. It contributes novel insights through qualitative analysis of HR professionals and neurodivergent employees, highlighting the role of AI in reducing hiring bias, customizing work environments and enhancing employee well-being. By proposing a deep learning framework and cataloging AI tools matched to neurodiverse conditions, this study bridges theory and practice. It uniquely positions AI as both a technological and ethical enabler for inclusive employment, making it highly relevant for scholars, practitioners and policymakers aiming to foster equitable, future-ready workplaces. 2025 Emerald Publishing Limited
George, Ginu; Kulkarni, Mugdha; Varghese, Bindi
Restricted Access; Hardcopy may be available in the library
https://doi.org/10.1108/AIA-05-2025-0046 https://www.scopus.com/pages/publications/105024714959?origin=resultslist
George G., Department of Academics, Westford University College, Sharjah, United Arab Emirates; Kulkarni M., Symbiosis Centre for Information Technology (SCIT), Symbiosis International University, Pune, India; Varghese B., Department of School of Business Management, CHRIST (Deemed to be University), Bangalore, India
A multi-cognitive approach to empowering secondary school teachers' self-efficacy and practices related to education for sustainable development
Classroom practices; Education for sustainable development; Multi-cognitive approach; Quasi-experimental; Secondary school teachers; Self-efficacy
Purpose Education for Sustainable Development (ESD) is vital for addressing global sustainability goals. However, integration in Indian schools faces challenges, particularly due to gaps in teacher preparedness. This study aimed to evaluate the effectiveness of a multi-cognitive approach (MCA) in empowering secondary school teachers' self-efficacy and ESD integration. Design/methodology/approach A quasi-experimental, one-group pretestposttest design was employed with 50 secondary school teachers from marginalized communities in Kerala, India. Participants with over 6years of experience but no prior ESD training underwent a 3-month MCA-based transformative learning program. The intervention addressed content, perspectives, processes and design. Teacher self-efficacy and ESD practices were measured pre- and immediately post-intervention, and three months later, using structured questionnaires. Findings Teachers' self-efficacy significantly improved post-intervention (52.707.61) and was sustained at three months (56.604.59), compared to baseline (49.069.69) (p<0.001). ESD-related practices also improved post-intervention (47.487.16), with further gains at three months (51.863.96), compared to pre-intervention (41.905.91). Research limitations/implications These results support incorporating the MCA into teacher training and professional development programs to foster sustainable education practices. The approach aligns with SDG 4.7 and can guide policy reforms in integrating ESD into mainstream education. Practical implications The study also presents a professional development model for schools, particularly beneficial in resource-constrained contexts, that enables teachers to embed sustainability in their practices. Furthermore, it offers policy guidance for embedding MCA-informed ESD into teacher education and national curricula, supporting Sustainable Development Goal 4.7 and NEP 2020 vision, promoting systemic education reform in sustainability. Social implications This study empirically validates an MCA as an effective framework for ESD. It highlights those engaging teachers across the cognitive, reflective, procedural and design dimensions, simultaneously enhancing their self-efficacy and sustaining ESD practices. The findings extend existing theories by showing that self-efficacy in sustainability is teachable and durable with the right interventions. Originality/value This study highlights MCA as a promising model for building teacher capacity in ESD and recommends future research on its impact on student outcomes. Emerald Publishing Limited
Asian Education and Development Studies;pp.1-20
https://doi.org/10.1108/AEDS-09-2025-0491 https://www.scopus.com/pages/publications/105038971765?origin=resultslist
Varghese S., Department of Social Work, CHRIST (Deemed to be University), Bangalore, India; Mathew P.M., Department of Social Work, CHRIST (Deemed to be University), Bangalore, India
Condensate phases of nuclear matter from AdS hardwall models
This work develops our previous study of confined phases at finite densities in AdS/QCD by systematically exploring the possibility of baryonic condensates. Using phenomenologically motivated boundary conditions in an AdS hardwall model, we show that both baryonic and quark-type condensates dominate the phase diagram at low temperatures. We also undertake a careful scan of the parameter space to extract robust conclusions. (2025), (American Physical Society). All rights reserved.
Physical Review D;Volume;112;Issue;8;Article No.;86016;pp.1-19
https://doi.org/10.1103/n6vx-55bz https://www.scopus.com/pages/publications/105026396531?origin=resultslist
Singh A., Department of Physical Sciences, IISER Mohali, Sector 81, Punjab, Knowledge City, 140306, India; Yogendran K.P., Department of Physical Sciences, IISER Mohali, Sector 81, Punjab, Knowledge City, 140306, India, Department of Physics and Electronics, Christ University, Hosur Road, Bangalore, India
Investigating wave propagation across loosely bonded interfaces in visco-piezo composites with flexoelectricity in LiNbo3 and AlN
aluminium nitride; attenuation coefficients; flexoelectric effect; lanthanum niobate; phase velocity; rheological model
This study compares the transference of surface seismic waves at the loosely bonded interface of a visco-piezo composite structure using two materials, lanthanum niobate (LiNbO 3) and aluminium nitride (AIN). The structure comprises a viscoelastic layer bonded to a piezoelectric substrate, incorporating the flexoelectric effect. The shear response of the upper layer is modelled using three rheological models: Kelvin-Voigt, Maxwell and Newton. An analytical separable variable method is employed to derive complex dispersion relations for both electrically open- and short-circuit conditions. The numerical analysis focuses on the influence of key parameters, such as bonding conditions and interfacial parameters, on phase velocity and attenuation coefficients in both materials. Results indicate that AIN shows higher phase velocities, while LiNbO 3 demonstrates a stronger impact on attenuation, particularly in the Kelvin-Voigt model. In addition, the flexoelectric effect significantly alters the wave behaviour in both materials, impacting both phase velocity and attenuation. This comparison reveals important differences in wave propagation behaviour, which is crucial for the development of devices like sensors, actuators and energy harvesters. The study offers new insights into piezo-flexo coupling and its potential applications in advanced piezoelectric systems. 2025 The Author(s).
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences;Volume;481;Issue;2311;Article No.;20240661;
https://doi.org/10.1098/rspa.2024.0661 https://www.scopus.com/pages/publications/105002021162?origin=resultslist
Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India
Eco-friendly synthesis of NiO and Ag/NiO nanoparticles: Applications in photocatalytic and antibacterial activities
Ag/NiO NPs; Cocos nucifera; dye; H 2 production; NiO NPs; photocatalysis
Herein, NiO and Ag/NiO NPs were produced via the solution combustion method using nickel nitrate and silver nitrate as oxidizers and Cocos nucifera water as a fuel at 450C. The study also explores their applications in photocatalytic dye degradation, H 2 production and antibacterial properties. The primary advantage of using C. nucifera water as a green fuel in the solution combustion method is that it serves a dual purpose - both as a fuel and as a solvent. This eliminates the need for additional water to create a homogeneous redox mixture of fuel and oxidant in the experimental procedure. X-ray diffraction confirmed the existence of Ag in the bunsenite form of rhombohedral structure with a simple cubic system, with particles sized at 31-44 nm. Energy-dispersive X-ray spectroscopy revealed Ni, O and Ag weight percentages of 48.2, 44.5 and 7.3%, respectively. X-ray photoelectron spectroscopy confirmed the formation of Ag in NiO nanostructure. UV-visible spectrometry showed reduced band gap energy of Ag/NiO NPs (3.03-2.87 eV) compared to the bare NiO NPs (3.21 eV), red shift of the optical response towards the visible region after doping Ag into the NiO. The 0.3 wt% Ag/NiO NPs showed the highest quantum efficiency (0.781) among the other synthesized NPs. Fourier-transform infrared spectroscopy revealed absorption bands in the range of 460-900 cm -1 stretching vibrations of Ni-O and Ag-O. Photoluminescence spectroscopy indicated that a doping concentration of 0.3 wt% Ag effectively introduces donor levels, defect levels and surface trap states within the NiO nanocrystalline structure, enhancing charge carrier separation and reducing recombination. Scanning electron microscopy revealed a voluminous, porous surface morphology characterized by numerous voids, resulting from the release of various combustible gases during the combustion process. Transmission electron microscopy images showed that most particles were spherical, irregular in size and well-distributed, with minimal aggregation with an average particle size of 25.8 nm. BET analysis of both NiO and 0.3 wt% Ag/NiO NPs exhibited type IV adsorption isotherms, indicating mesoporous structures and a clear monolayer-multilayer adsorption process, 0.3 wt% Ag/NiO NPs showed the highest surface area (170 m2 g-1) compared to the NiO (130 m2 g-1) NPs. Ag/NiO NPs has demonstrated a promising H2 evolution rate of 1212 ?mol g-1 under visible light illumination in a water/ethanol system. The trypan blue dye degradation reaches up to 98% and has moderate stability for the reusable photocatalysis process. The synthesized NPs exhibited significantly enhanced antibacterial activity against a range of bacterial strains. 2025 The Authors.
Ravishankar, T.N.; Ananda, A.; Shilpa, B.M.; Adarsh, J.R.
Royal Society Open Science;Volume;12;Issue;2;Article No.;241733;
All Open Access; Gold Open Access; Green Open Access
https://doi.org/10.1098/rsos.241733 https://www.scopus.com/pages/publications/85219683034?origin=resultslist
Ravishankar T.N., Department of Chemistry, B.M.S. College of Engineering, Bull Temple Road, Basavanagudi, Karnataka, Bengaluru, 560019, India; Ananda A., Department of Chemistry, Dayananda Sagar Academy of Technology & Management Udayapura, Kanakapura Road, Bengaluru, 560082, India; Shilpa B.M., Department of Psychology, Christ University, Bangalore Kengeri Campus, Karnataka, Bangalore, 560074, India; Adarsh J.R., Department of Chemistry, Global Academy of Technology, RR Nagar, Karnataka, Bangalore, 560098, India
Dispositional Mindfulness and Perceived Stress in Psychiatric and Nonpsychiatric Physicians: A Facet-level Pilot Study
burnout prevention; clinician wellness; dispositional mindfulness; healthcare professionals; perceived stress
OBJECTIVES: Perceived stress is a significant concern among health care professionals, with potential consequences for mental health and clinical performance. This study examined associations between dispositional mindfulness and perceived stress among Indian physicians working in psychiatric and nonpsychiatric specializations within hierarchical systems with limited institutional support. METHODS: In this cross-sectional pilot study, 62 clinicians (39 nonpsychiatric and 23 psychiatric physicians) completed the Perceived Stress Scale and the Five Facet Mindfulness Questionnaire-Short Form. Independent samples t tests compared perceived stress and mindfulness scores between the groups. Correlations and linear regression analyses were conducted to examine relationships between mindfulness and perceived stress. RESULTS: No statistically significant differences were found between psychiatric and nonpsychiatric physicians in perceived stress, t(59)=0.98, P=0.329, d=0.27, or total mindfulness, t(59)=-1.31, P=0.186, d=0.35. Across the sample, higher dispositional mindfulness was strongly associated with lower perceived stress, r(60)=-0.65, P<0.001, r=0.43, particularly for the Describe and Acting with Awareness facets. Linear regression indicated that mindfulness was significantly related to perceived stress, ?=-0.65, t=-6.66, P<0.001, accounting for 42.5% of the variance. CONCLUSIONS: These findings cautiously suggest that dispositional mindfulness may serve as a potential psychological resource for stress regulation and burnout prevention among clinicians. Further research is warranted to validate these associations in larger and more diverse samples and to explore practical applications within wellness initiatives. Copyright 2026 Wolters Kluwer Health, Inc. All rights reserved.
Journal of psychiatric practice;Volume;32;Issue;3;pp.144-152
https://doi.org/10.1097/PRA.0000000000000926 https://www.scopus.com/pages/publications/105038373105?origin=resultslist
Sheikh M.A., School of Psychological Sciences, Christ University, Bangalore, Karnataka, India
Golden orator to tongue cancer survivor: A case study tracing identity transformation through religious coping
Cancer survivorship; Identity transformation; Indian priest; Religious coping
The "survivorship" identity corresponds to a collective identity for individuals that have experienced cancer. While medical labels, culture and personal beliefs influence this label, this case report illuminates the journey of integrating the preillness identity to a postrecovery identity through the long-Term survivorship experience of T.J.J, a nonagenarian cancer survivor and Indian priest belonging to the Syrian Marthomite Christian denomination, focusing on how religious coping mechanisms facilitated identity reintegration. Diagnosed with tongue cancer at age 64 years, T.J.J.Transitioned from a renowned orator to a religious writer, reshaping his identity through eudemonic principles of purpose, self-Actualization, and growth. The influence of religious meaning-making, prayer, and communal support is highlighted, which helped cognitively reframe his experience of loss into a transformative experience that fostered psychological security. Implications for public health policies emphasize incorporating religious coping strategies in culturally relevant survivorship programs for better psychosocial outcomes. 2025 Lippincott Williams and Wilkins. All rights reserved.
Jacob, Layah Liz; Sathiyaseelan, Anuradha
Journal of Psychosocial Oncology Research and Practice;Volume;7;Issue;1;Article No.;e167;
https://doi.org/10.1097/OR9.0000000000000167 https://www.scopus.com/pages/publications/105002217172?origin=resultslist
Jacob L.L., Department of Psychology, CHRIST (Deemed to Be University), Bengaluru, India; Sathiyaseelan A., Department of Psychology, CHRIST (Deemed to Be University), Bengaluru, India
AI-Enabled Early Detection of Chemo-Induced Cardiotoxicity Patterns Using ECG Time Series Data
cardio-oncology; cardiotoxicity; chemotherapy; ECG; precision medicine
Objectives: Chemotherapy-induced cardiotoxicity is still a major clinical problem, usually appearing subclinically before structural or symptomatic cardiac dysfunction appears. Standard surveillance methods use imaging and biomarkers, which are time-intensive and money-intensive and can only identify damage at more advanced levels. Electrocardiography (ECG) provides a low-cost, non-invasive method that can detect early electrophysiological changes but is not fully utilized in cardio-oncology. The present work was designed to build an explainable machine learning model for predicting chemo-like cardiotoxicity patterns at an early stage from single-lead ECG signals. Methods: A public ECG data set (n=4997 segments) underwent preprocessing and was converted to 18 temporal, morphologic, and spectral features. Two ensemble learning algorithmsRandom Forest and XGBoostwere trained and validated with stratified splits. Model performance was assessed with ROCAUC, PRAUC, and F1-score with 1000 bootstrap resampling. Feature interpretability was evaluated through permutation importance and SHAP analysis. Results: Both models scored near-perfect classification (ROCAUC and PRAUC>0.99, F1-score ? 0.986). Spectral entropy, band3 (high-energy frequency), QT surrogate, and peak count were the top features ranking alongside early cardiotoxicity indicators like repolarization instability and autonomic imbalance. Conclusions: The feature-driven, interpretable ML architecture suggested here shows that single-lead ECG has the potential to be an affordable and clinically relevant tool for the early detection of chemotherapy-induced cardiotoxicity. The method provides a feasible route toward implementation in precision cardio-oncology, particularly in resource-poor or ambulatory environments. 2025
Upreti, Kamal; George, Jossy P.; Malik, Khushboo; Radhakrishnan, G. V.; Ga-B?aszczykowska, Agnieszka
American Journal of Clinical Oncology: Cancer Clinical Trials;
https://doi.org/10.1097/COC.0000000000001280 https://www.scopus.com/pages/publications/105029467813?origin=resultslist
Upreti K., Department of Computer Science, Christ University, Delhi NCR, Uttar Pradesh, Ghaziabad, India; George J.P., Department of Computer Science, Christ University, Delhi NCR, Uttar Pradesh, Ghaziabad, India; Malik K., Department of Computer Science, Christ University, Delhi NCR, Uttar Pradesh, Ghaziabad, India; Radhakrishnan G.V., Department of Computer Science, KIIT School of Management (KSOM), Bhubaneswar, India; Ga-B?aszczykowska A., School of Law, War Studies University, Warsaw, Poland
Predicting and Optimizing Synergistic Drug Combinations for Breast Cancer Treatment Using Machine Learning
breast cancer; cell lines; drug discovery; machine learning; prediction; synergy metrics
Objectives: The study aims to identify highly synergistic drug combinations for breast cancer treatment using machine learning models. The primary objective is to predict drug synergy scores accurately and rank combinations with the highest potential for therapeutic efficacy. Methods: Machine learning models, including XGBoost, Random Forest (RF), and CatBoost (CB), were employed to analyze breast cancer drug combination data. Four synergy metricsZIP, Bliss, Loewe, and HSAwere used to quantify drug interaction effects. The models were trained to predict these synergy scores, and their performance was evaluated using normalized root mean squared error (NRMSE) and Pearson correlation coefficient. Predicted top-ranking drug combinations were further validated by comparing observed versus expected dose-response curves and calculating the area under the curve (AUC) for synergy assessment. Results: XGBoost (XGB_5235) outperformed other models, achieving an NRMSE of 0.074 and a Pearson correlation of 0.90 for the Bliss synergy model. Based on average synergy scores, the top 20 drug combinations were identified, with Ixabepilone+Cladribine, SN 38 Lactone+Pazopanib, and Decitabine+Tretinoin emerging as the most promising. These combinations showed high synergy and were supported by biological insights into their mechanisms of action. Conclusions: The study demonstrates the effectiveness of machine learning in predicting synergistic drug combinations for breast cancer. By accelerating the screening process and reducing experimental burden, the approach offers a promising tool for guiding future in vitro and in vivo validation of combination therapies. Copyright 2025 Wolters Kluwer Health, Inc. All rights reserved.
Jain, Dhyanendra; Upreti, Kamal; Tak, Tan Kuan; Date, Saroj S.; Kshirsagar, Pravin R.; Jain, Rituraj; Agrawal, Rashmi
American Journal of Clinical Oncology: Cancer Clinical Trials;Volume;49;Issue;3;pp.113-124
https://doi.org/10.1097/COC.0000000000001244 https://www.scopus.com/pages/publications/105012555411?origin=resultslist
Jain D., Department of CSE-AIML, ABES Engineering College, Ghaziabad; Upreti K., CHRIST (Deemed to be University), Delhi NCR, Uttar Pradesh, Ghaziabad; Tak T.K., Singapore Institute of Technology, Singapore; Date S.S., CSMSS Chh. Shahu College of Engineering, Chh. Sambhajinagar, Aurangabad; Kshirsagar P.R., J D College of Engineering & Management, Nagpur, Maharashtra, United States; Jain R., Department of Information Technology, Marwadi University, Gujarat, Rajkot; Agrawal R., Manav Rachna International Institute of Research and Studies, Haryana, Faridabad, India
A new broad-band atmospheric dispersion corrector for HROS-TMT
atmospheric dispersion corrector; atmospheric effects; instrumentation; instrumentation: spectrographs; surveys; telescopes
Atmospheric dispersion causes light from celestial objects with different wavelengths to refract at varying angles as it passes through Earths atmosphere. This effect results in an elongated image at the focal plane of a telescope and diminishes fibre coupling efficiency into spectrographs. We propose an optical design that incorporates a Rotational Atmospheric Dispersion Corrector (RADC) to address the broad-band dispersion for the multi-object mode of the High-Resolution Optical Spectrograph (HROS) on the Thirty Meter Telescope (TMT). The RADC corrects the dispersion across the entire wavelength range (0.311 ?m), using Amici prisms optimized for over 90 per cent transmission efficiency and minimal angular deviation of the beam from the optical axis after dispersion correction. For enhanced accuracy, particularly in the blue region, we have, for the first time, implemented the Filippenko model in Zemax via a custom Dynamic-Link Library (DLL) file. The Author(s) 2025. Published by Oxford University Press on behalf of Royal Astronomical Society.
Bestha, Manjunath; Sivarani, Thirupathi; Wehbe, Bachar; Hasan, Amirul; Chandra, Bharat; Divakar, Devika K.; Unni, Athira; Menon, Parvathy; Surya, Arun; Saraf, Pallavi
RAS Techniques and Instruments;Volume;4;Issue;;Article No.57
https://doi.org/10.1093/rasti/rzaf057 https://www.scopus.com/pages/publications/105029392026?origin=resultslist
Bestha M., Indian Institute of Astrophysics, Bangalore, P-560034, India, Department of Applied Optics and Photonics, University of Calcutta, Kolkata, P-700106, India; Sivarani T., Indian Institute of Astrophysics, Bangalore, P-560034, India; Wehbe B., Instituto de Astrofica e Cicias do Espa, Universidade de Lisboa, Campo Grande, Lisboa, P-1749-016, Portugal, Departamento de Fica, Faculdade de Cicias, Universidade de Lisboa, Campo Grande, Lisboa, P-1749-016, Portugal; Hasan A., Indian Institute of Astrophysics, Bangalore, P-560034, India, Department of Physics and Electronics, Christ University, Bangalore, P-560029, India; Chandra P.B., Indian Institute of Astrophysics, Bangalore, P-560034, India; Divakar D.K., McDonald Observatory, University of Texas, Austin, P-78712, United States; Unni A., Department of Astronomy and Astrophysics, University of California, Santa Cruz, P-95064, United States; Menon P., Indian Institute of Astrophysics, Bangalore, P-560034, India, Department of Applied Optics and Photonics, University of Calcutta, Kolkata, P-700106, India; Surya A., Indian Institute of Astrophysics, Bangalore, P-560034, India; Saraf P., Indian Institute of Astrophysics, Bangalore, P-560034, India, Physical Research Laboratory, Astronomy and Astrophysics Division, Ahmadabad, P-380058, India
Evidence fora slim accretion disc in GX 17+2: a polarimetric study of super-Eddington flows
accretion, accretion discs; polarization; stars: neutron; X-rays: binaries; X-rays: individual: GX 17+2
This study presents a time-resolved spectro-polarimetric analysis of GX 17+2 using IXPE, NICER, and NuSTAR observations. Spectral modelling with (Formula presented) (Formula presented) (Formula presented) (Formula presented) (Formula presented) (Formula presented) (Formula presented) (Formula presented) (Formula presented) ) indicates that the source was in a soft spectral state, and accreting at super-Eddington luminosity. Time-resolved PCUBE analysis shows that the polarization degree (PD) and polarization angle (PA) remain nearly constant across the 2.0(Formula presented) 8.0?keV energy range, suggesting an aligned geometry between the spin and the binary orbital axes of the neutron star. Energy-resolved PCUBE analysis further indicates that the blackbody emission component most likely originates from the boundary layer. The spectro-polarimetric analysis confirms that the reflected emission contributes a PD <20per?cent, consistent with theoretical expectations. In contrast, the Comptonizing medium exhibits a PD of (Formula presented) 1.4per?cent, while the accretion disc shows a PD of (Formula presented) 3.2per?cent in the 2.0(Formula presented) 8.0?keV energy range, exceeding theoretical predictions. Energy-resolved spectro-polarimetric analysis hints at excess disc polarization, possibly associated with the formation of a slim disc and the presence of disc wind under super-Eddington accretion conditions. Both time- and energy-resolved polarization measurements reveal a rotation of the PA for the (Formula presented) and (Formula presented) components in the 3.5(Formula presented) 8.0?keV energy range, suggesting a coupling between the soft and hard polarized emission components. Our results indicate that while the geometry of GX 17+2 is aligned, the emergent hard X-ray emission is significantly influenced by inner disc outflows. The nearly constant PD across energy and time further points to a complex interplay among the accretion disc, Comptonization, and reflection components. The Author(s) 2026. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Lavanya, S.; Thomas, Neal Titus; Gudennavar, S.B.; Bubbly, S.G.
Monthly Notices of the Royal Astronomical Society;Volume;549;Issue;2;Article No.;stag900;
https://doi.org/10.1093/mnras/stag900 https://www.scopus.com/pages/publications/105039995953?origin=resultslist
Lavanya S., Department of Physics and Electronics, CHRIST University, Karnataka, Bengaluru, 560029, India; Thomas N.T., Department of Physics and Electronics, CHRIST University, Karnataka, Bengaluru, 560029, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST University, Karnataka, Bengaluru, 560029, India; Bubbly S.G., Department of Physics and Electronics, CHRIST University, Karnataka, Bengaluru, 560029, India
The broad-band spectral energy distribution of candidate neutrino blazars
(galaxies:)BL Lacertae objects: individual: TXS 0506+056; galaxies: active; galaxies: jets; gamma-rays: general
Blazars, the jet-dominated class of active galactic nuclei comprising flat-spectrum radio quasars (FSRQs) and BL Lacertae objects (BL Lacs), are now increasingly identified as potential sources of high-energy neutrinos. Such neutrino blazars are ideal targets to investigate the high-energy emission processes and to understand their role as neutrino sources. We report results on four candidate neutrino blazars, PKS 0446+112, TXS 0506+056, PKS 1424(Formula presented) 418, and PKS 1502+106. We carried out (Formula presented) -ray spectral and timing analysis on three time periods that comprise a quiescent epoch, an epoch that corresponds to neutrino detection, and a flaring epoch. We also carried out modelling of the broad-band spectral energy distribution (SED) on those three epochs. We found that the (Formula presented) -ray spectra of the BL Lac TXS 0506+056 can be adequately described by a power law, while the spectra of the other three FSRQs require a log-parabola model. On shorter time-scales, we observed flux variability with doubling/halving time-scales of 4.70, 9.24, 30.76, and 15.42 h for PKS 0446+112, TXS 0506+056, PKS 1424(Formula presented) 418, and PKS 1502+106, respectively. The SEDs of most of the epochs for the sources are well explained by a leptonic scenario. However, the quiescent epoch of PKS 1502+106 and the neutrino-emission epoch of PKS 0446+112 required an additional hadronic component to reproduce the observed SEDs. Our analysis reveals a complex interplay of leptonic and hadronic processes. While certain neutrino-associated epochs align with a leptonic model, others necessitate a hadronic component to explain the emission features. The Author(s) 2026. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Bharathan, Athira M; Stalin, C.S.; Btcher, Markus; Sahayanathan, S.; Mathew, Blesson; Bhattacharyya, Subir
Monthly Notices of the Royal Astronomical Society;Volume;548;Issue;2;Article No.;stag674;
https://doi.org/10.1093/mnras/stag674 https://www.scopus.com/pages/publications/105038207876?origin=resultslist
Bharathan A.M., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India, Centre for Space Research, North-West University, Potchefstroom, 2531, South Africa; Stalin C.S., Indian Institute of Astrophysics, Block II, Koramangala, Bangalore, 560 034, India; Btcher M., Centre for Space Research, North-West University, Potchefstroom, 2531, South Africa; Sahayanathan S., Astrophysical Sciences Division, Bhabha Atomic Research Centre, Mumbai, 400085, India, Homi Bhabha National Institute, Mumbai, 400094, India; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Bhattacharyya S., Astrophysical Sciences Division, Bhabha Atomic Research Centre, Mumbai, 400085, India, Homi Bhabha National Institute, Mumbai, 400094, India
Revisiting wideband pulsar timing measurements
methods: data analysis; pulsars: general
In the wideband paradigm of pulsar timing, the time of arrival of a pulsar pulse is measured simultaneously with the corresponding dispersion measure from a frequency-resolved integrated pulse profile. We present a new method for performing wideband measurements that rigorously accounts for measurement noise. We demonstrate this method using observations of PSR J2124?3358 made as part of the Indian Pulsar Timing Array experiment using the upgraded Giant Metre-wave Radio Telescope, and show that our method produces more realistic measurement uncertainty estimates compared to the existing wideband measurement method. The Author(s) 2026. Published by Oxford University Press on behalf of Royal Astronomical Society.
Susobhanan, Abhimanyu; Paladi, Avinash Kumar; Desmecht, Ra; Amarnath; Bagchi, Manjari; Chakraborty, Manoneeta; Chowdhury, Shaswata; Das, Suruj Jyoti; Deb, Debabrata; Desai, Shantanu; Dwivedi, Churchil; Grover, Himanshu; Jose, Jibin; Joshi, Bhal Chandra; Kala, Shubham; Kareem, Fazal; Meena, Kuldeep; Mondal, Sushovan; Nobleson, K.; Pandian, B Arul; Rai, Kaustubh; Shukla, Adya; Singh, Manpreet; Srivastava, Aman; Surnis, Mayuresh; Tahbildar, Hemanga; Takahashi, Keitaro; Tarafdar, Pratik; Vara, Kunjal; Vyasraj, Vaishnavi; Zuraiq, Zenia
Monthly Notices of the Royal Astronomical Society;Volume;547;Issue;4;
https://doi.org/10.1093/mnras/stag444 https://www.scopus.com/pages/publications/105036690637?origin=resultslist
Susobhanan A., MaxPlanckInstitut f Gravitationsphysik (AlbertEinsteinInstitut), Liebniz Universit Hannover, Callinstra 38, Hannover, D-30167, Germany, School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Kerala, Thiruvananthapuram, 695551, India; Paladi A.K., MaxPlanckInstitut f Gravitationsphysik (AlbertEinsteinInstitut), Liebniz Universit Hannover, Callinstra 38, Hannover, D-30167, Germany, Department of Physics, Indian Institute of Science, C. V. Raman Avenue, Karnataka, Bengaluru, 560012, India; Desmecht R., MaxPlanckInstitut f Gravitationsphysik (AlbertEinsteinInstitut), Liebniz Universit Hannover, Callinstra 38, Hannover, D-30167, Germany, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, B-1050, Belgium; Amarnath, Raman Research Institute, Karnataka, Bengaluru, 560080, India; Bagchi M., The Institute of Mathematical Sciences, C. I. T. Campus, Taramani, Tamil Nadu, Chennai, 600113, India, Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Maharashtra, Mumbai, 400094, India; Chakraborty M., Department of Astronomy, Astrophysics, and Space Engineering, Indian Institute of Technology Indore, Madhya Pradesh, Indore, 453552, India; Chowdhury S., The Institute of Mathematical Sciences, C. I. T. Campus, Taramani, Tamil Nadu, Chennai, 600113, India; Das S.J., Particle Theory and Cosmology Group, Center for Theoretical Physics of the Universe, Institute for Basic Science, Daejeon, 34126, South Korea; Deb D., Centre for Space Research, NorthWest University, Private Bag X6001, Potchefstroom, 2520, South Africa; Desai S., Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Telangana, 502284, India; Dwivedi C., Astronomy and Astrophysics Division, Physical Research Laboratory, Thaltej Campus, Gujarat, Ahmedabad, 380059, India; Grover H., Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India; Jose J., Department of Astronomy, Astrophysics, and Space Engineering, Indian Institute of Technology Indore, Madhya Pradesh, Indore, 453552, India; Joshi B.C., Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India, National Centre for Radio Astrophysics, Savitribhai Phule Pune University Campus, Maharashtra, Pune, 411007, India; Kala S., The Institute of Mathematical Sciences, C. I. T. Campus, Taramani, Tamil Nadu, Chennai, 600113, India; Kareem F., MaxPlanckInstitut f Radioastronomie, Auf dem Hel 69, Bonn, D-53121, Germany; Meena K., UM DAE Centre for Excellence in Basic Sciences, University of Mumbai, Vidyanagari, Maharashtra, Mumbai, 400098, India; Mondal S., The Institute of Mathematical Sciences, C. I. T. Campus, Taramani, Tamil Nadu, Chennai, 600113, India, Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Maharashtra, Mumbai, 400094, India; Nobleson K., Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan; Pandian B.A., Raman Research Institute, Karnataka, Bengaluru, 560080, India, Department of Physics and Electronics, CHRIST (Deemed to be University), Karnataka, Bengaluru, 560029, India; Rai K., Department of Physics, Indian Institute of Science Education and Research Bhopal, Madhya Pradesh, Bhopal, 462066, India; Shukla A., Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India; Singh M., Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Punjab, Mohali, 140306, India; Srivastava A., Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Telangana, 502284, India, Department of Physics, GLA University, Uttar Pradesh, Mathura, 281406, India; Surnis M., Department of Physics, Indian Institute of Science Education and Research Bhopal, Madhya Pradesh, Bhopal, 462066, India; Tahbildar H., Department of Physics, Indian Institute of Science Education and Research Bhopal, Madhya Pradesh, Bhopal, 462066, India; Takahashi K., Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan; Tarafdar P., INAF Osservatorio Astronomico di Cagliari, via della Scienza 5, CA, Selargius, 09047, Italy; Vara K., Department of Physics, Indian Institute of Science Education and Research Bhopal, Madhya Pradesh, Bhopal, 462066, India; Vyasraj V., Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Telangana, 502284, India; Zuraiq Z., Department of Physics, Indian Institute of Science, C. V. Raman Avenue, Karnataka, Bengaluru, 560012, India
DESI DR2 meets cosmography: a comparative study of Pad Chebyshev, and Taylor expansions
cosmological parameters; observations; theory
We perform a comprehensive cosmographic analysis of the late-time Universe using the latest Dark Energy Spectroscopic Instrument (DESI) Data Release 2 (DR2) baryon acoustic oscillation (BAO) measurements, comparing Taylor, Pad and Chebyshev expansions as model-independent reconstructions of the background expansion. We consider Padapproximants of order (2,1) and (2,2), a Chebyshev expansion, and a third-order Taylor series. Due to its limited radius of convergence, the Taylor expansion is constrained using only the low-redshift DESI sub-set (z < 1), while the rational Padforms and the Chebyshev expansion are applied over the full DESI DR2 redshift range. Cosmographic parameters are inferred through a Bayesian Markov chain Monte Carlo (MCMC) analysis, and the resulting best-fitting reconstructions of H(z), dL(z), and BAO distance indicators are compared with the predictions of the Lambda cold dark matter (CDM) model. All methods are consistent with CDM at low redshift, but the Chebyshev expansion exhibits noticeable deviations at higher redshifts, while the Pad2,1) and Pad2,2) reconstructions remain closely aligned with CDM across the DESI DR2 range. A model-selection analysis based on Akaike Information Criterion and Bayesian Information Criterion shows a clear statistical preference for the Taylor expansion over low-zCDM, and a strong preference for Padcosmography over CDM when the full DESI DR2 data set is used. These results demonstrate the constraining power of DESI DR2 for cosmographic studies and highlight the utility of rational approximants, especially Padforms, in extending cosmography reliably to higher redshifts beyond the domain of traditional Taylor series. The Author(s) 2026. Published by Oxford University Press on behalf of Royal Astronomical Society.
Mishra, Sai Swagat; Kavya, N.S.; Sahoo, P.K.; Bamba, Kazuharu
Monthly Notices of the Royal Astronomical Society;Volume;546;Issue;4;Article No.;stag197;
https://doi.org/10.1093/mnras/stag197 https://www.scopus.com/pages/publications/105030931293?origin=resultslist
Mishra S.S., Department of Mathematics, School of Computer Science and Artificial Intelligence, SR University, Telangana, Warangal, 506371, India, Department of Mathematics, Birla Institute of Technology and Science, Hyderabad Campus, Jawahar Nagar, Kapra Mandal, Medchal District, Telangana, Pilani, 500078, India; Kavya N.S., Centre for Mathematical Needs, Department of Mathematics, CHRIST (Deemed to be University), Bengaluru, 560029, India; Sahoo P.K., Department of Mathematics, Birla Institute of Technology and Science, Hyderabad Campus, Jawahar Nagar, Kapra Mandal, Medchal District, Telangana, Pilani, 500078, India; Bamba K., Faculty of Symbiotic Systems Science, Fukushima University, Fukushima, 960-1296, Japan
Analysis of forbidden neon emission lines in HAeBe stars using Spitzer IRS spectra
infrared: stars; protoplanetary discs; stars: variables: T Tauri, Herbig Ae/Be
We analysed high-resolution mid-infrared spectra of 78 well-known Herbig Ae/Be (HAeBe) stars using Spitzer InfraRed Spectrograph data, focusing on the detection of [Ne ii] and [Ne iii] emission lines as indicators of ionized outflows or disc winds. Emission from [Ne ii] at 12.81 m or [Ne iii] at 15.55 m was identified in 25 sources, constituting the largest sample of HAeBe stars with these detected lines. Our analysis revealed a higher detection frequency of [Ne ii] in sources with lower relative accretion luminosity (Lacc/L?< 0.1), suggesting a connection to the disc dispersal phase. We examined correlations between neon lines and various spectral features and investigated [Ne iii]-to-[Ne ii] line flux ratios to explore potential emission mechanisms. Neon emission is predominantly observed in Group I sources (75 per cent), where their flared disc geometry likely contributes to the observed emission, potentially originating from the irradiated disc atmosphere. Interestingly, we also find that Group II sources exhibit a higher median relative [Ne ii] line luminosity (L/L), suggesting enhanced photoevaporation rates possibly associated with their more settled disc structures. However, larger samples and higher-resolution spectra are required to confirm this trend definitively. The high detection rate of the [Fe ii] and [S iii] lines, commonly associated with EUV-dominated regions, alongside a [Ne iii]-to-[Ne ii] emission ratio greater than 0.1 in sources where both lines detected, suggests that EUV radiation is the primary driver of neon emission in our sample. 2025 The Author(s).
Akhila, D.; Mathew, Blesson; Nidhi, S.; Shridharan, B.; Arun, R.; Anilkumar, Hema; Maheswar, G.; Kartha, Sreeja S.; Manoj, P.; Bhattacharyya, Suman
Monthly Notices of the Royal Astronomical Society;Volume;540;Issue;4;pp.3330-3349
https://doi.org/10.1093/mnras/staf914 https://www.scopus.com/pages/publications/105009126129?origin=resultslist
Akhila D., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore, 560029, India, Instituto de Astronom y Ciencias Planetarias, Universidad de Atacama, Copayapu 485, Copiap Chile; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore, 560029, India; Nidhi S., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore, 560029, India, The Oxford College of Science, 19th Main road, Sector 4, HSR Layout, Karnataka, Bengaluru, 560102, India; Shridharan B., Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400005, India; Arun R., Indian Institute of Astrophysics, 2nd Block Koramangala, Bangalore, 560034, India; Anilkumar H., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore, 560029, India; Maheswar G., Indian Institute of Astrophysics, 2nd Block Koramangala, Bangalore, 560034, India; Kartha S.S., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore, 560029, India; Manoj P., Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400005, India; Bhattacharyya S., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore, 560029, India
Kinematic study of molecular gas in cometary globule - LBN 437
H ii regions; ISM: kinematics and dynamics; ISM: molecules; stars: formation - ISM: clouds
Bright-rimmed, cometary-shaped star-forming globules, associated with H ii regions, are remnants of compressed molecular shells exposed to ultraviolet radiation from central OB-type stars. The interplay between dense molecular gas and ionizing radiation, analysed through gas kinematics, provides significant insights into the nature and dynamic evolution of these globules. This study presents the results of a kinematic analysis of the cometary globule, Lynds' Bright Nebula (LBN) 437, focusing on the first rotational transition of CO and CO molecular lines observed using the Taeduk Radio Astronomy Observatory. The averaged CO spectrum shows a slightly skewed profile, suggesting the possibility of a contracting cloud. The molecular gas kinematics reveals signatures of infalling gas in the cometary head of LBN 437, indicating the initial stages of star formation. The mean infall velocity and mass infall rate towards the cometary head of LBN 437 are 0.25 km s and 5.08 10 M yr, respectively, which align well with the previous studies on intermediate or high-mass star formation. 2025 The Author(s).
Aardra, S.; Issac, Namitha; Soam, Archana; Mathew, Blesson; Lee, Chang Won
Monthly Notices of the Royal Astronomical Society;Volume;540;Issue;3;pp.2279-2288
https://doi.org/10.1093/mnras/staf822 https://www.scopus.com/pages/publications/105008371881?origin=resultslist
Aardra S., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore, 560029, India, Indian Institute of Astrophysics (IIA), Koramangala, Bangalore, 560034, India; Issac N., Indian Institute of Astrophysics (IIA), Koramangala, Bangalore, 560034, India, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030, China; Soam A., Indian Institute of Astrophysics (IIA), Koramangala, Bangalore, 560034, India; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore, 560029, India; Lee C.W., Korea Astronomy and Space Science Institute (KASI), 776 Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348, South Korea, University of Science & Technology, 176 Gajeong-dong, Yuseong-gu, Daejeon, 34113, South Korea
Unveiling the bulge-disc structure, AGN feedback, and baryon landscape in a massive spiral galaxy with Mpc-scale radio jets
galaxies: formation; galaxies: fundamental parameters; galaxies: individual: 2MASX J23453268-0449256; galaxies: ISM; galaxies: spiral
We study the bulge-disc components and stellar mass distribution in the fast-rotating, highly massive spiral galaxy 2MASX J23453268-0449256, which is distinguished by extraordinary radio jets extending to Mpc scales. Using high-resolution multiwavelength Hubble Space Telescope (HST) observations and multiparameter panchromatic spectral energy distribution (SED) fitting, we derive estimates of key properties, such as the star formation rate, total baryonic mass in stars, and the characteristics of warm dust. Our findings, validated at a spatial resolution of approximately 100 pc, reveal a pseudo-bulge rather than a classical bulge, as well as a small nuclear bar and resonant ring, challenging traditional models of galaxy formation. Furthermore, the absence of tidal debris and the highly symmetric spiral arms within a rotationally supported stellar disc suggest a peaceful co-evolution of the galactic disc and its central supermassive black hole (SMBH). Notably, the galaxy exhibits suppressed star formation in its central region, which may be influenced by feedback from the central accreting SMBH, producing powerful radio jets. Detailed multiwavelength studies of potential star-forming gas show that while hot X-ray gas cools in the galaxy's halo, new stars do not form in the centre, likely due to this feedback. This study raises important questions about the efficient fuelling and sustained collimated jet activity in J2345-0449, highlighting the need for a better understanding of the central black hole's properties. The exceptional rarity of galaxies like 2MASX J23453268-0449256 presents intriguing challenges in uncovering the physical processes behind their unique characteristics. 2025 The Author(s).
Bagchi, Joydeep; Ray, Shankar; Dhiwar, Suraj; Pandge, Mahadev B; Dabhade, Pratik; Barth, Aaron J; Ho, Luis C; Mirakhor, Mohammad S; Walker, Stephen A; Nesvadba, Nicole; Combes, Francoise; Fabian, Andrew; Jacob, Joe
Monthly Notices of the Royal Astronomical Society;Volume;538;Issue;3;pp.1628-1652
https://doi.org/10.1093/mnras/staf229 https://www.scopus.com/pages/publications/105000634832?origin=resultslist
Bagchi J., Department of Physics and Electronics, CHRIST (Deemed to Be University), Hosur Road, Bengaluru, 560029, India; Ray S., Department of Physics and Electronics, CHRIST (Deemed to Be University), Hosur Road, Bengaluru, 560029, India; Dhiwar S., Inter-University Centre for Astronomy and Astrophysics (IUCAA), Post Bag 4, Ganeshkhind, Pune, 411007, India, Department of Physics, Savitribai Phule Pune University, Ganeshkhind, Pune, 411007, India; Pandge M.B., Department of Physics and Electronics, Dayanand Science College, Barshi Road, Latur, 413512, India; Dabhade P., Instituto de Astrofica de Canarias, Calle V Ltea, s/n, E-38205, La Laguna, Tenerife, Spain, Departamento de Astrofisica, Universidad de la Laguna (ULL), Tenerife, E-38206, Spain, Astrophysics Division, National Centre for Nuclear Research, Pasteura 7, Warsaw, PL-02-093, Poland; Barth A.J., Department of Physics and Astronomy, University of California, 4129 Frederick Reines Hall, Irvine, 92697-4575, CA, United States; Ho L.C., Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, 100871, China, Department of Astronomy, School of Physics, Peking University, Beijing, 100871, China; Mirakhor M.S., Department of Physics and Astronomy, University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, 35899, AL, United States; Walker S.A., Department of Physics and Astronomy, University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, 35899, AL, United States; Nesvadba N., Institut d'Astrophysique Spatiale, Centre Universitaire d'Orsay, Orsay, F-91405, France; Combes F., LERMA, Observatoire de Paris, PSL Research University, College de France, CNRS, Sorbonne University, Paris, 75006, France; Fabian A., Institute of Astronomy, Cambridge University, Madingly Road, Cambridge, CB3 0HA, United Kingdom; Jacob J., Department of Physics, Newman College, Idukki District, Kerala, Thodupuzha, 685585, India
High-resolution spectroscopy of HE 0225?0546 and HE 1153?0518: probing the progenitors through abundance patterns and kinematics
stars: abundances; stars: carbon; stars: chemically peculiar; stars: kinematics and dynamics; stars: Population II
We present the results of a high-resolution (SUBARU/HDS, R ? 50 000) spectroscopic study of two metal-poor stars, HE 0225 ?0546 and HE 1153 ?0518. This marks the first such detailed analysis for both objects. Our findings reveal that HE 0225 ?0546 is extremely metal-poor with [Fe/H] ??3.03, while HE 1153 ?0518 is very metal-poor with [Fe/H] ??2.80. Both stars exhibit enhancements in carbon and neutron-capture elements and formally satisfy the criteria for carbon-enhanced metal- poor (CEMP) classification. Although their [Ba/Eu] and [La/Eu] ratios do not allow a secure assignment to any specific CEMP sub-class, the estimated [Ba/Eu] and [Eu/Fe] ratios indicate that both stars fall into the r-II star category. Distinct abundance patterns between the two stars suggest different nucleosynthetic histories. HE 0225 ?0546 shows strong enhancement in Fe-peak elements, while HE 1153 ?0518 is mildly deficient in the same. Both stars are ?-enhanced, though the level of enhancement varies. These results indicate pollution by multiple progenitor channels. Abundance ratios imply that HE 0225 ?0546 is likely enriched by fast-rotating massive stars (FRMS), whereas HE 1153 ?0518 shows signatures consistent with asymptotic giant branch (AGB) star enrichment. Kinematic analyses place both stars in the high-energy, prograde component of the Galactic halo. HE 0225 ?0546 has an apogalactic distance (rapo ) of ?31.8 kpc, placing it in the outer halo, while HE 1153 ?0518 lies closer to the boundary of the inner and outer halo with rapo ?13.8 kpc. Both stars show kinematic coherence with the Sagittarius substructure, suggesting a possible extragalactic origin. The Author(s) 2025. Published by Oxford University Press on behalf of Royal Astronomical Society.
Purandardas, Meenakshi; Aroli-Veettil, Sidharth; Ray, Shankar; Mathew, Blesson; Kartha, Sreeja S.; Sreeshma, N.M.; Haridas, Sreelakshmi
Monthly Notices of the Royal Astronomical Society;Volume;546;Issue;1;Article No.;staf2215;
https://doi.org/10.1093/mnras/staf2215 https://www.scopus.com/pages/publications/105028243223?origin=resultslist
Purandardas M., Department of Physics and Electronics, Christ (Deemed to be University), Bengaluru, 560029, India; Aroli-Veettil S., Instituto de Astrofica, Pontificia Universidad Catica de Chile, Vicu Mackenna 4860, Santiago, Chile; Ray S., Department of Physics and Electronics, Christ (Deemed to be University), Bengaluru, 560029, India; Mathew B., Department of Physics and Electronics, Christ (Deemed to be University), Bengaluru, 560029, India; Kartha S.S., Department of Physics and Electronics, Christ (Deemed to be University), Bengaluru, 560029, India; Sreeshma N.M., Department of Physics, Vimala college, Kerala, Thrissur, 680009, India; Haridas S., Department of Physics, Vimala college, Kerala, Thrissur, 680009, India
Discovery of fullerenes in the shell of candidate luminous blue variable WRAY 16-232
astrochemistry; circumstellar matter; infrared: stars; stars: variables: general; stars: winds, outflows
We report the discovery of fullerene in the circumstellar environment of WRAY 16-232, a strong candidate luminous blue variable. Multiple pointings of archival Spitzer Infrared Spectrograph spectra reveal, for the first time, the presence of prominent vibrational bands of C60 at 17.4 and 18.9 ?m in a luminous blue variable (LBV) envelope, along with the strong polycyclic aromatic hydrocarbon features. These observations suggest that, despite the harsh radiative conditions, large carbonaceous molecules can form, process, and survive in the ejecta of massive stars. Complementary optical spectroscopy with South African Large Telescope High-Resolution Spectrograph shows multiple P Cygni profiles in H ?, He i, and Fe ii lines, which are indicative of a dense, expanding wind and substantial mass-loss. Furthermore, analysis of decade long photometric data shows short-term brightness variations of ?0.5 mag. These results not only reinforce the classification of WRAY 16-232 as a strong LBV candidate but also provide new insights into the mechanisms of dust formation and the chemical enrichment of the interstellar medium by massive stars. We discuss various scenarios for fullerene formation in such environments, and find that shock processing due to wind-wind interactions could be playing a vital role. The shell of WRAY 16-232 has an ideal UV field strength and the time-scales appear to match with shock processing time-scales. The results highlight the need for further high spatial/spectral resolution and temporal observations to confirm the formation and survival scenario of C60 in its shell. The Author(s) 2025. Published by Oxford University Press on behalf of Royal Astronomical Society.
Arun, R.; Prasoon, S.A.; Mathew, Blesson; Akhila, D.; Banerjee, Gourav; Shridharan, B.; Maheswar, G.; Surya, Arun
Monthly Notices of the Royal Astronomical Society;Volume;543;Issue;4;pp.3214-3228
https://doi.org/10.1093/mnras/staf1676 https://www.scopus.com/pages/publications/105018861328?origin=resultslist
Arun R., Indian Institute of Astrophysics, Sarjapur Road, Koramangala, Bangalore, 560034, India; Prasoon S.A., Indian Institute of Astrophysics, Sarjapur Road, Koramangala, Bangalore, 560034, India, Center of Excellence in Astronomy and Astrophysics, Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Mathew B., Center of Excellence in Astronomy and Astrophysics, Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Akhila D., Center of Excellence in Astronomy and Astrophysics, Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India, Instituto de Astronom y Ciencias Planetarias, Universidad de Atacama, Copayapu 485, Copiap Chile; Banerjee G., Indian Institute of Astrophysics, Sarjapur Road, Koramangala, Bangalore, 560034, India; Shridharan B., Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India; Maheswar G., Indian Institute of Astrophysics, Sarjapur Road, Koramangala, Bangalore, 560034, India; Surya A., Indian Institute of Astrophysics, Sarjapur Road, Koramangala, Bangalore, 560034, India
Thermonuclear X-ray bursts across the eclipse transitions in the LMXBs EXO 0748?676 and XTE J1710?281
accretion, accretion discs; stars: neutron; X-rays: binaries; X-rays: individual: EXO 0748?676
The primary radiation from thermonuclear X-ray bursts observed in the neutron star low-mass X-ray binary (LMXB) systems can interact with various parts of the binary system. This interaction gives rise to secondary radiation in different wavelength ranges, known as reprocessed emission. In eclipsing LMXBs, the reprocessed emission from the bursts can be examined during eclipses, as the primary emission is blocked and only the reprocessed emission is visible. We searched for bursts during eclipses in the archival RXTE data of the eclipsing LMXBs and found them in EXO 0748?676 and XTE J1710?281. In EXO 0748?676, seven bursts were found to occur near eclipse egress, with their tails extending beyond the eclipse, and one such burst was found for XTE J1710?281. We estimate the reprocessing fraction at orbital phases near eclipse egress by modelling the peculiar eclipse bursts detected in both systems, which have tails extending beyond the eclipses. We observe an increasing trend in reprocessing fraction as these eclipse bursts occur closer to the eclipse egress. We discuss the possibilities of reprocessing in the ablated wind from the companion star, the accretion disc, and the disc wind in EXO 0748?676 and XTE J1710?281. Additionally, we observe two decay components in the bursts in EXO 0748?676, which could suggest a complex composition of the accreting fuel. From the burst rise time-scales, we place an upper limit on the size of the reprocessing regions in both EXO 0748?676 and XTE J1710?281, finding it comparable to the size of the respective X-ray binaries. The Author(s) 2025. Published by Oxford University Press on behalf of Royal Astronomical Society.
Rikame, Ketan; Paul, Biswajit; Sharma, Rahul; Jithesh, V.
Monthly Notices of the Royal Astronomical Society;Volume;544;Issue;1;pp.13-23
https://doi.org/10.1093/mnras/staf1611 https://www.scopus.com/pages/publications/105020016441?origin=resultslist
Rikame K., Department of Physics and Electronics, Christ University, Karnataka, Bangalore, 560029, India, Raman Research Institute, C.V. Raman Avenue, Karnataka, Bangalore, 560080, India; Paul B., Raman Research Institute, C.V. Raman Avenue, Karnataka, Bangalore, 560080, India; Sharma R., Raman Research Institute, C.V. Raman Avenue, Karnataka, Bangalore, 560080, India, Inter-University Centre for Astronomy and Astrophysics, Post Box No. 4, Ganeshkhind, Maharashtra, Pune, 411007, India; Jithesh V., Department of Physics and Electronics, Christ University, Karnataka, Bangalore, 560029, India