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Browsing by Author "Subramanian, S"

Browsing by Author "Subramanian, S"

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  • Line of sight depth of the large and small magellanic clouds 
    Subramaniam, A; Subramanian, S (Cambridge University Press, 2009-03)
    We used the red clump stars from the Optical Gravitational Lensing Experiment (OGLE II) survey and the Magellanic Cloud Photometric Survey (MCPS), to estimate the line-of-sight depth. The observed dispersion in the magnitude ...
  • More insights into bar quenching: Multi-wavelength analysis of four barred galaxies 
    George, K; Joseph, P; Mondal, C; Subramanian, S; Subramaniam, A; Paul, K. T (EDP Sciences, 2020-12)
    The underlying nature of the process of star formation quenching in the central regions of barred disc galaxies that is due to the action of stellar bar is not fully understood. We present a multi-wavelength study of four ...
  • The mysterious bar of the large magellanic cloud: what is it? 
    Subramaniam, A; Subramanian, S (Institute of Physics, 2009-09)
    The bar of the Large Magellanic Cloud (LMC) is one of the prominent, but controversial, features regarding its location with respect to the disk of the LMC. In order to study the relative location of the bar with respect ...
  • The Nature of jets in double-peaked emission-line AGN in the KISSR sample 
    Kharb, P; Subramanian, S; Mousumi Das; Vaddi, S; Paragi, Z (IOP Publishing, 2021-10-01)
    Double-peaked emission-line AGN (DPAGN) have been regarded as binary black hole candidates. We present here results from parsec-scale radio observations with the Very Long Baseline Array (VLBA) of five DPAGN belonging to ...
  • Nature of quiet Sun oscillations using data from the hinode, TRACE, and SOHO spacecraft 
    Gupta, G. R; Subramanian, S; Banerjee, D; Madjarska, M. S; Doyle, J. G (Springer, 2013-01)
    We study the nature of quiet-Sun oscillations using multi - wavelength observations from TRACE, Hinode, and SOHO. The aim is to investigate the existence of propagating waves in the solar chromosphere and the transition ...
  • Presence of red giant population in the foreground stellar substructure of the Small Magellanic Cloud 
    James, Dizna; Subramanian, S; Omkumar, Abinaya O; Mary, Adhya; Bekki, Kenji; Cioni, Maria-Rosa L; Grijs, Richard de; Youssouf, Dalal El; Kartha, Sreeja S; Niederhofer, Florian; Loon, Jacco Th. van (Oxford University Press on behalf of Royal Astronomical Society, 2021-12)
    The eastern region of the Small Magellanic Cloud (SMC) is found to have a foreground stellar substructure, which is identified as a distance bimodality (∼12 kpc apart) in the previous studies using red clump (RC) stars. ...
  • Relativistic Jet Motion in the Radio-quiet LINER Galaxy KISSR 872 
    Kharb, Preeti; Blackman, Eric G; Clausen-Brown, Eric; Mousumi Das; Schwartz, Daniel A; Siemiginowska, Aneta; Subramanian, S; Vaddi, Sravani (American Astronomical Society, 2024-02-20)
    We report superluminal jet motion with an apparent speed of βapp = 1.65 ± 0.57 in the radio-quiet (RQ) lowionization nuclear emission-line region (LINER) galaxy KISSR 872. This result comes from two-epoch phasereferenced ...
  • A road map for the generation of a near-infrared guide star catalog for thirty meter telescope observations 
    Subramanian, S; Subramaniam, A; Sivarani, T; Simard, Luc; Anupama, G. C; Gillies, Kim; Ramaprakash, A. N; Reddy, B. E (Indian Academy of Sciences, 2016-09)
    The near-infrared instruments in the upcoming Thirty Meter Telescope (TMT) will be assisted by a multi conjugate Adaptive Optics (AO) system. For the efficient operation of the AO system, during observations, a near-infrared ...
  • RR Lyrae stars in the inner LMC: Where did they form? 
    Subramaniam, A; Subramanian, S (EDP Sciences, 2009-08)
    RR Lyrae stars (RRLS) belong to population II and are generally used as a tracer of the host galaxy halo. The surface as well as vertical distribution of RRLS in the inner Large Magellanic Cloud (LMC) are studied to ...
  • The search for binary black holes in Seyferts with double peaked emission lines 
    Kharb, P; Mousumi Das; Subramanian, S; Paragi, Z (Astronomical Society of India, 2015-04)
    We discuss results from very long baseline interferometry (VLBI) observations of two Seyfert galaxies with double peaked emission lines in their SDSS optical spectra. Such AGN are potential candidates for the presence ...
  • Shape of the outer stellar warp in the Large Magellanic Cloud disk 
    Saroon, S; Subramanian, S (EDP Sciences, 2022-10)
    Warps are vertical distortions of the stellar or gaseous disks of galaxies. One of the proposed scenarios for the formation of warps involves tidal interactions among galaxies. A recent study identified a stellar warp in ...
  • Significance of bar quenching in the global quenching of star formation 
    George, K; Subramanian, S; Paul, K. T (EDP Sciences, 2019-08)
    The suppression of star formation in the inner kiloparsec regions of barred disk galaxies due to the action of bars is known as bar quenching. We investigate here the significance of bar quenching in the global quenching ...
  • Smallest Scale Clumpy Star Formation in Stephan's Quintet Revealed from UV and IR Imaging 
    Joseph, P; George, K; Subramanian, S; Mondal, C; Subramaniam, A (IOP Publishing, 2022-09)
    The spatial distribution and physical sizes of star-forming clumps at the smallest scales provide valuable information on hierarchical star formation (SF). In this context, we report the sites of ongoing SF at ∼120 pc along ...
  • Spatiotemporal map of star clusters in the Magellanic Clouds using Gaia: synchronized peaks and radial shrinkage of cluster formation 
    Dhanush, S. R; Subramaniam, A; Nayak, Prasanta K; Subramanian, S (Oxford University Press on behalf of Royal Astronomical Society, 2024-02)
    We present a detailed view of cluster formation (CF) to trace the evolution and interaction history of the Magellanic Clouds (MCs) in the last 3.5 Gyr. Using the Gaia DR3 data, we parametrized 1710 and 280 star clusters ...
  • Stellar populations in the magellanic clouds 
    Subramanian, S; Subramaniam, A (Astronomical Society of India, 2013)
    The structural parameters of the Large Magellanic Cloud and the Small Magellanic Cloud are derived from the study of di erent stellar populations, such as, Cepheids (age 100 Myr), Red Clump stars (age 2-9 Gyr) and RR ...
  • Stellar substructures in the periphery of the Magellanic Clouds with the VISTA hemisphere survey from the red clump and other tracers 
    El Youssouf, Dalal; Cioni, Maria-Rosa L; Bell, C. P. M; de Grijs, Richard; Groenewegen, M. A. T; Ivanov, Valentin D; Matijevic, Gal; Niederhofer, Florian; Oliveira, Joana M; Ripepi, Vincenzo; Schmidt, Thomas; Subramanian, S; Sun, Ning-Chen; van Loon, Jacco Th (Oxford University Press on behalf of the Royal Astronomical Society, 2021-08)
    We study the morphology of the stellar periphery of the Magellanic Clouds in search of substructure using near-infrared imaging data from the Visible and Infrared Survey Telescope for Astronomy Hemisphere Survey. Based on ...
  • Structure of the Large Magellanic Cloud from near infrared magnitudes of red clump stars 
    Subramanian, S; Subramaniam, A (EDP Sciences, 2013-04)
    Context. The structural parameters of the disk of the Large Magellanic Cloud (LMC) are estimated. Aims. We used the JH photometric data of red clump (RC) stars from the Magellanic Cloud Point Source Catalog (MCPSC) ...
  • The Three-dimensional Structure of the Small Magellanic Cloud 
    Subramanian, S; Subramaniam, A (IOP Publishing, 2012-01-10)
    The three-dimensional structure of the inner Small Magellanic Cloud (SMC) is investigated using the red clump (RC) stars and the RR Lyrae stars (RRLS), which represent the intermediate-age and the old stellar populations ...
  • Towards the development of the Infrared Guide Star Catalogue for the adaptive optics observations by the Thirty Meter Telescope 
    Shah, Sarang; Subramanian, S; Anupama, G. C; Delgado, Francisco; Gillies, Kim; Maheswar, G; Narayanan, Rajalakshmi; Ramaprakash, A. N; Rao, Suhasini; Reddy, B. E; Skidmore, Warren; Sivarani, T; Subramaniam, A (SPIE-The International Society for Optical Engineering, 2022-08)
    At first light, the NIR instruments of TMT will be assisted by a multi-conjugate adaptive optics instrument, known as the Narrow Field Infrared Adaptive Optics System (NFIRAOS). NFIRAOS will use laser guide stars for ...
  • Tracing young star-forming clumps in the nearby flocculent spiral galaxy NGC 7793 with UVIT imaging 
    Mondal, Chayan; Subramaniam, A; George, Koshy; Postma, Joseph E; Subramanian, S; Barway, Sudhanshu (IOP Publishing, 2021-03-10)
    Star formation in galaxies is a hierarchical process with a wide range of scales, from smaller clusters to larger stellar complexes. Here, we present an ultra-violet imaging study of the nearby flocculent spiral galaxy NGC ...

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