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Browsing by Author "Subramaniam, A"

Browsing by Author "Subramaniam, A"

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  • Spectroscopic survey of emission line stars in open clusters 
    Subramaniam, A; Mathew, B (Springer, 2010)
    We summarize a study of emission-line stars in young open clusters. The study was done in two phases. The first phase was the survey, where the emission stars in young open clusters were identified using the slitless ...
  • Spectroscopy of Be stars in young open clusters 
    Mathew, B; Subramaniam, A (Astronomical Society of India, 2010)
    A spectroscopic study of 152 Classical Be stars in 42 young open clusters was performed using medium resolution spectra in 3700-9000 A range, to understand the Be phenomenon. The Balmer decrement is found to have a ...
  • Star clusters in the magellanic clouds II. age-dating, classification, and spatio-temporal distribution of the SMC clusters 
    Nayak, P. K; Subramaniam, A; Choudhury, S; Sagar, R (EDP Sciences, 2018-08)
    Aims. We aim to estimate the age and reddening parameters of already identified star clusters within the Small Magellanic Cloud (SMC) in a consistent way using available photometric data, classify them based on their mass ...
  • Star clusters in the magellanic clouds-1: parameterisation and classification of 1072 clusters in the LMC 
    Nayak, P. K; Subramaniam, A; Choudhury, S; Indu, G; Sagar, R (Oxford University Press on behalf of the Royal Astronomical Society, 2016-12-01)
    We have introduced a semi-automated quantitative method to estimate the age and reddening of 1072 star clusters in the Large Magellanic Cloud (LMC) using the Optical Gravitational Lensing Experiment III survey data. This ...
  • Star formation in the region of young open cluster - NGC 225 
    Subramaniam, A; Mathew, B; Sreeja S. K (Astronomical Society of India, 2006-12)
    NGC 225 is believed to be a 120 Myr old open cluster located at tilda 650 pc. Eight stars with H alphaemission are found to be located around the cluster, of which two are probable Herbig Be stars, indicating a very young ...
  • Stara -Disk Interactions in Multiband Photometric Monitoring of the Classical T Tauri Star GI Tau 
    Guo, Zhen; Herczeg, Gregory J; Jose, J; Fu, Jianning; Chiang, Po-Shih; Grankin, Konstantin; Michel, R; Yadav, Ram Kesh; Liu, Jinzhong; Chen, Wen-Ping; Li, Gang; Xue, Huifang; Niu, Hubiao; Subramaniam, A; Sharma, Saurabh; Prasert, Nikom; Flores-Fajardo, Nahiely; Castro, Angel; Altamirano, Liliana (IOP Publishing, 2018-01)
    The variability of young stellar objects is mostly driven by star – disk interactions. In long-term photometric monitoring of the accreting T Tauri star GI Tau, we detect extinction events with typical depths ...
  • 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 ...
  • Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 6: Variability of NGC 3783 from ground-based data 
    Stirpe, G. M; Winge, C; Altieri, B; Alloin, D; Aguero, E. L; Anupama, G. C; Ashley, R; Bertram, R; Calderon, J. H; Catchpole, R. M; Corradi, R. L. M; Covino, E; Dottori, H. A; Feast, M. W; Ghosh, K. K; Hutton, R. Gil; Glass, I. S; Grebel, E. K; Jorda, L; Koen, C; Laney, C. D; Maia, M; Marang, F; Mayya, Y. D; Morrell, N; Nakada, Y; Pastoriza, M. G; Pati, A. K; Pelat, D; Peterson, B. M; Prabhu, T. P; Roberts, G; Sagar, R; Salamanca, I; Sekiguchi, K; Storchi-Bergmann, T; Subramaniam, A; Van Winckel, H; Van Wyk, F; Villada, M; Wagner, R. M; Whitelock, P. A; Winkler, H; Clavel, J; Dietrich, M; Kollatschny, W; O'Brien, P. T; Perola, G. C; Recondo-Gonzalez, M. C; Rodriguez-Pascual, P; Santos-Lleo, M (The American Astronomical Society, 1994-04)
    The Seyfert 1 galaxy NGC 3783 was intensely monitored in several bands between 1991 December and 1992 August. This paper presents the results from the ground-based observations in the optical and near-IR bands, which ...
  • 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) ...
  • Studies of a possible new Herbig Ae/Be star in the open cluster NGC 7380 
    Mathew, B; Banerjee, D. P. K; Ashok, N. M; Subramaniam, A; Bhavya, B; Joshi, V (Chinese Academy of Sciences, 2012-02)
    We present a study of the star 2MASS J22472238+5801214 with the aim of identifying its true nature which has hitherto been uncertain. This object, which is a member of the young cluster NGC 7380, has been variously proposed ...
  • Study of candidate be stars in the magellanic clouds using near-infrared photometry and optical spectroscopy 
    Paul, K. T; Subramaniam, A; Mathew, B; Mennickent, R. E; Sabogal, B (Wiley-Blackwell, 2012-04)
    Mennickent et al. and Sabogal et al. identified a large number of classical Be (CBe) candidates (∼3500) in the Large and Small Magellanic Clouds (LMC and SMC) based on their photometric variability using the OGLE II data ...
  • Study of classical Be stars in open clusters older than 100 Myr 
    Jagadeesh, Madhu Kashyap; Blesson, Mathew; Paul, K. T; Banerjee, Gourav; Subramaniam, A; Arun, R (Springer, 2021-10)
    We performed the slitless spectroscopic survey to identify classical Be (CBe) stars in open clusters older than 100 Myr. Observing a sample of 71 open clusters, we identified 13 CBe stars in 11 open clusters, one of, ...
  • Study of dynamical status of the globular cluster NGC 1851 using ultraviolet imaging telescope 
    Singh, Gaurav; Yadav, R. K. S; Snehalata Sahu; Subramaniam, A (Indian Academy of Sciences, 2021-10)
    We present the study of dynamical status of the globular cluster NGC 1851. A combination of multi-wavelength space and ground-based data sets are used for the present analysis. In order to select the genuine cluster members, ...
  • Study of emission line stars in young open clusters 
    Mathew, B; Subramaniam, A (Astronomical Society of India, 2011)
    Emission-line stars in young open clusters are identified to study their properties, as a function of age, spectral type and evolutionary state. 207 open star clusters were observed using the slitless spectroscopy method ...
  • A study of the local environment of novae in the Large Magellanic Cloud 
    Subramaniam, A; Anupama, G. C (Astronomical Society of India, 2001)
  • A Study of the Role of Lyβ Fluorescence on O I Line Strengths in Be Stars 
    Blesson, M; Banerjee, D. P. K; Subramaniam, A; Ashok, N. M (IOP Publishing, 2012-07-01)
    The possibility of the Lyβ fluorescence mechanism being operational in classical Be (CBe) stars and thereby contributing to the strength of the O I λ8446 line has been recognized for long. However, this supposition needs ...
  • Study of transient nature of classical Be stars using multi-epoch optical spectroscopy 
    Banerjee, Gourav; Mathew, Blesson; Paul, K. T; Subramaniam, A; Balan, Anjusha; Bhattacharyya, Suman; Anusha, R; Moosa, Deeja; Dheeraj, C. S.; Charly, Aleeda; Raghu, Megha (Indian Academy of Sciences, 2022-12)
    Variability is a commonly observed property of classical Be stars (CBe) stars. In extreme cases, complete disappearance of the Hα emission line occurs, indicating a disc-less state in CBe stars. The disc-loss and reappearing ...
  • Study of UV-bright stellar populations in the globular cluster NGC 1261 using Astrosat 
    Sharmila Rani; Pandey, G; Subramaniam, A; Snehalata Sahu; Kameswara Rao, N (Oxford University Press on behalf of the Royal Astronomical Society, 2021-02)
    We present UV photometry of the globular cluster NGC 1261 using images acquired with the Ultraviolet Imaging Telescope (UVIT) on board Astrosat. We performed point-spread function (PSF) photometry on four near-UV (NUV) and ...
  • Study of Young Stellar Objects and Associated Filamentary Structures in the Inner Galaxy 
    Bhavya, B; Subramaniam, A; Kuriakose, V. C (Oxford University Press on behalf of the Royal Astronomical Society, 2013-10-11)
    Young stellar objects in the inner Galactic region 10° < l < 15° and −1° < b < 1° were studied using GLIMPSE images and the GLIMPSE data catalogue. A total of 1107 Class I and 1566 Class II sources were identified in this ...
  • A tale of two nearby dwarf irregular galaxies WLM and IC 2574: As revealed by UVIT 
    Mondal, Chayan; Subramaniam, A; George, Koshy (Indian Academy of Sciences, 2021-10)
    We present an ultra-violet study of two nearby dwarf irregular galaxies WLM and IC 2574, using the Far-UV and Near-UV data from the Ultra-Violet Imaging Telescope (UVIT). We used the F148W band Far-UV images and identified ...

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