IIA Institutional Repository: Recent submissions

  • Modification of Newtonian gravity: Implications for hot gas in clusters and galactic angular momentum 
    Rebecca, Louise; Sebastian, Dominic; Sivaram, C; Arun, K (World Scientific Publishing, 2025-05-30)
    In view of the negative results from various dark matter detection experiments, we had earlier proposed an alternate theoretical framework through modification of Newtonian gravity (MONG). Here, the Poison’s equation is ...
  • Warm ionized gas outflows in Active Galactic Nuclei: What causes them? 
    Nandi, Payel; Stalin, C. S; Saikia, D. J (American Astronomical Society, 2025-05-01)
    The driving force behind outflows, often invoked to understand the correlation between the supermassive black holes powering active galactic nuclei (AGN) and their host galaxy properties, remains uncertain. We provide new ...
  • The Lyα sky as observed by New Horizons at 57 AU 
    Gladstone, G. Randall; Shull, J. Michael; Pryor, Wayne R; Slavin, Jonathan; Kammer, Joshua A; Becker, Tracy M; Lauer, Tod R; Postman, Marc; Spencer, John R; Parker, Joel Wm; Retherford, Kurt D; Velez, Michael A; Versteeg, Maarten H; Davis, Michael W; Froning, Cynthia S; Ertley, Camden D; Cunningham, Nathaniel; Murthy, J; Henry, Richard C; Redfield, Seth; Lisse, Carey M; Singer, Kelsi N; Verbiscer, Anne J; Brandt, Pontus C; Stern, S. Alan (American Astronomical Society, 2025-05)
    During 2023 September the Alice ultraviolet spectrograph on the New Horizons (NH) spacecraft was used to map diffuse Lyα emission over most of the sky, at a range of ∼56.9 au from the Sun. At that distance, models predict ...
  • The long-term optical flux variations of Compact Symmetric Objects 
    Swain, Subhashree; Paliya, Vaidehi S; Saikia, D. J; Stalin, C. S; Venugopal, Arya; Bhavya, A. K; Ravikumar, C. D (Springer Nature, 2025-05)
    Compact Symmetric Objects (CSOs) are a distinct category of jetted active galactic nuclei (AGN) whose optical variability characteristics have not been well investigated. We present here the results of our investigation ...
  • Solar cycle variations in meridional flows and rotational shear within the sun's near-surface shear layer 
    Sen, Anisha; Rajaguru, S. P; Iyer, Abhinav G; Chen, Ruizhu; Zhao, Junwei; Kholikov, S (American Astronomical Society, 2025-05-01)
    Using solar cycle–long helioseismic measurements of meridional and zonal flows in the near-surface shear layer (NSSL) of the Sun, we study their spatiotemporal variations and connections to active regions. We find that ...
  • Visible Emission Line Coronagraph (VELC) on board Aditya-L1 
    Singh, J; Ramesh, R; Prasad, B. R; Priyal, M; Sasikumar Raja, K; Venkata, S. N; Kamath, P. U; Natarajan, V; Pawan Kumar, S; Sanal Krishnan, V. U; Savarimuthu, P; Mishra, Shalabh; Kumar, Varun; Sumana, Chavali; Hegde, Bhavana; Utkarsha, D; Kumar, Amit; Nagabhushana, S; Kathiravan, S; Vemareddy, P; Kathiravan, C; Nagaraju, K; Ravindra, B; Mishra, Wageesh (Springer Nature, 2025-05)
    Aditya-L1, India’s first dedicated mission to study the Sun and its atmosphere from the Sun-Earth Lagrangian L1 location was successfully launched on September 2, 2023. It carries seven payloads. The Visible Emission Line ...
  • Statistical insights into flux and photon index distributions of VHE FSRQs from Fermi-LAT observations 
    Malik, Zahoor; Akbar, Sikandar; Shah, Zahir; Misra, Ranjeev; Dar, Athar A; Manzoor, Aaqib; Ahanger, Sajad; Nazir, Zeeshan; Iqbal, Naseer; Rubab, Seemin; Tantry, Javaid (Oxford University Press on behalf of Royal Astronomical Society, 2025-05)
    This study examines the flux and photon index distributions of 11 Very High Energy (VHE) Flat Spectrum Radio Quasars (FSRQs) using over 16 yr of Fermi-LAT γ -ray data. The distributions reveal double lognormal profiles in ...
  • The Detectability of coronal mass ejections in the low corona using multislit extreme-ultraviolet spectroscopy 
    Chan, Lami; Bai, Xianyong; Tian, Hui; Feng, Yufei; Xu, Yu; Torok, Tibor; Gao, Yuhang; Samanta, T; Sun, Zheng (American Astronomical Society, 2025-05-10)
    The spectra of coronal mass ejections (CMEs) in the low corona play a crucial role in understanding their origins and physical mechanisms and enhancing space weather forecasting. However, capturing these spectra faces ...
  • Structure and dynamics of the sun’s interior revealed by the helioseismic and magnetic Imager 
    Kosovichev, A. G; Basu, S; Bekki, Y; Buitrago-Casas, Juan Camilo; Chatzistergos, Theodosios; Chen, Ruizhu; Christensen-Dalsgaard, J; Donea, Alina; Fleck, Bernhard; Fournier, Damien; Garcia, R. A; Getling, Alexander V; Gizon, L; Gough, Douglas O; Hanasoge, S. M; Hanson, Chris S; Webber, Shea A. Hess; Hoeksema, J. Todd; Howe, Rachel; Jain, K; Kasapis, Spiridon; Kashyap, Samarth G; Kitiashvili, I. N; Komm, R; Korzennik, S. G; Krivova, Natalie A; Kuhn, Jeffrey R; Liang, Zhi-Chao; Lindsey, Charles; Mahajan, Sushant S; Mandal, K; Mani, Prasad; Oliveros, Juan Carlos Martinez; Mathur, S; Soares, M. Cristina Rabello; Rajaguru, S. P; Reiter, Johann; Rhodes Jr., Edward J; Rozelot, J. P; Scherrer, P. H; Solanki, S. K; Stefan, John T; Toomre, Juri; Tripathy, S. C; Upton, Lisa A; Zhao, Junwei (Springer Nature, 2025-05)
    High-resolution helioseismology observations with the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) provide a unique three-dimensional view of the solar interior structure and dynamics, ...
  • Computational astrophysics, data science and AI/ML in astronomy: A perspective from Indian community 
    Sharma, Prateek; Vaidya, Bhargav; Wadadekar, Y; Bagla, Jasjeet Singh; Chatterjee, Piyali; Hanasoge, S. M; Kumar, Prayush; Mukherjee, Dipanjan; Philip, Ninan Sajeeth; Singh, Nishant (Springer Nature, 2025-06)
    In contemporary astronomy and astrophysics (A&A), the integration of high-performance computing (HPC), big data analytics, and artificial intelligence/machine learning (AI/ML) has become essential for advancing research ...
  • Quiet Sun Ellerman bombs as a possible proxy for reconnection-driven spicules 
    Sand, Mats Ola; van der Voort, Luc Rouppe; Joshi, Jayant; Bose, Souvik; Nobrega-Siverio, Daniel; Grinon-Marin, Ana Belen (EDP Sciences, 2025-05)
    Context. Spicules are elongated, jet-like structures that populate the solar chromosphere and are rooted in the lower solar atmosphere. In recent years, high-resolution observations and advanced numerical simulations have ...
  • Kinematic study of molecular gas in cometary globule – LBN 437 
    Aardra, S; Issac, Namitha; Archana Soam; Mathew, B; Lee, Chang Won (Oxford University Press on behalf of Royal Astronomical Society, 2025-07)
    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 ...
  • Ultraviolet Background Radiation from Not-So-Dark Matter in the Galactic Halo 
    Henry, R. C; Murthy, J; Overduin, James (Multidisciplinary Digital Publishing Institute, 2025-05)
    Murthy et al. (2025) (hereafter Paper I) have recently reported the discovery of unexpectedly bright diffuse extreme-ultraviolet radiation at high latitudes in both the Northern and Southern Galactic Hemispheres. After ...
  • Global 21 cm signal: A promising probe of primordial features 
    Naik, Suvedha Suresh; Pravabati, C; Singh, Saurabh; Mesinger, Andrei; Furuuchi, Kazuyuki (IOP Publishing, 2025-05)
    Inflationary models that involve bursts of particle production generate bump-like features in the primordial power spectrum of density perturbations. These features influence the evolution of density fluctuations, leaving ...
  • Proton heating estimates from near-Earth observations of coronal mass ejections in solar cycle 24 
    Bhattacharjee, Debesh; Subramanian, P; Majumder, Saikat; Mishra, Wageesh (Oxford University Press on behalf of Royal Astronomical Society, 2025-07)
    As solar coronal mass ejections (CMEs) propagate through the heliosphere, they expend energy in heating protons to compensate for the cooling that occurs due to expansion. CME propagation models usually treat energy ...
  • Can Hubble tension be eased by invoking a finite range for gravity? 
    Rebecca, Louise; Sivaram, C; Sebastian, Dominic; Kenath, Arun (World Scientific Publishing, 2024-06)
    The estimation of the Hubble constant in the past few decades has increasingly become more accurate with the advancement of new techniques. However, its value seems to depend on the epoch at which the measurements are made. ...
  • High-resolution spectral analysis of three high-latitude carbon stars 
    Meenakshi, P; Dutta, Debasish; Goswami, A; Kartha, Sreeja S (Cambridge University Press on behalf of Astronomical Society of Australia, 2025-04)
    We present the results of a detailed high-resolution spectroscopic analysis (SUBARU/HDS spectra, R ∼50,000) of three faint high-latitude carbon stars HE 1104 − 0957, HE 1205 − 0521, and HE 1244 − 3036. Our estimated ...
  • Test and Calibration of the Solar Ultraviolet Imaging Telescope (SUIT) on Board Aditya-L1 
    Sarkar, Janmejoy; Nived, V. N; Roy, Soumya; Deogaonkar, Rushikesh; Padinhatteeri, Sreejith; Bayanna, A. R; Kesharwani, Ravi; Ramaprakash, A. N; Tripathi, Durgesh; Gopalakrishnan, Rahul; Joshi, Bhushan; Sinha, Sakya; Burse, Mahesh; Varma, Manoj; Tyagi, Anurag; Yadav, Reena; Rajarshi, Chaitanya; Adithya, H. N; Adoni, A. A; Ahmed, Gazi A; Banerjee, D; Bhandare, Rani; Bhargava Ram, B. S; Chillal, Kalpesh; Chordia, Pravin; Ghosh, Avyarthana; Gowda, Girish; Jain, Anand; James, Melvin K; Justin, Evangeline Leeja; Kathait, Deepak; Khan, Aafaque; Khodade, Pravin; Kohok, A; Kulkarni, Akshay; Kumar, Ghanshyam; Mehandiratta, Nidhi; Mestry, V. B; Modi, Deepa; Motamarri, Srikanth; Nagaraju, K; Nandy, D; Narendra, S; Navle, Sonal; Parate, Nashiket; Punnadi, Sujit; Ravi, A; Sankarasubramanian, K; Sarvar, Ghulam; Shaji, Nigar; Solanki, S. K; Rethika, T; Vadodariya, Kaushal; Veeresha, D. R; Venkateswaran, R (Springer Nature, 2025-05)
    The Solar Ultraviolet Imaging Telescope (SUIT) on board the Aditya-L1 mission observes the Sun in the 200 – 400 nm wavelength range. This paper presents the results of various on ground and on-board tests and their ...
  • Square Kilometre Array—India consortium: Education and public outreach 
    Ramanujam, N. M; Dutta, Prasun; Indulekha, K; Chakraborty, Manoneeta; Dhurde, Samir; Hota, A; Konar, Chiranjib; Oberoi, Divya; Pandey-Pommier, Mamta; Rao, Mayuri Sathyanarayana (Indian Academy of Sciences, 2024-06)
    This paper presents a report on the activities and the proposed action plan of the Education and Public Outreach Working Group (EPO WG) of Square Kilometre Array–India Consortium (SKAIC). Details of a set of flagship ...
  • Optical design studies for national large optical-IR telescope 
    Padikal, Varun; Hasan, Amirul; Valsan, Vineeth; Sriram, S; Kurian, Athul; Vishnu, Unni. C; Basheer, Alikhan; Panchal, Pramod; Maheswar, G; Remya, B. S; Chand, Totan (Indian Academy of Sciences, 2024-06)
    A 10–12 m class national large optical-IR telescope (NLOT) is envisaged to meet the growing scientific requirements in astronomy and astrophysics. Telescopes of such dimensions can only be made by segmenting the primary ...

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