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 Interstellar and Heliospheric Physics (3263): People
Thangasamy  Velusamy's Picture
Jet Propulsion Laboratory
M/S 169-506
4800 Oak Grove Drive
Pasadena, CA 91109
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Thangasamy Velusamy

  • B.Sc, Physics, St.John's College (Madras University), Palayamkottai, India (1961)
  • M.Sc, Physics, Madras Christian College (Madras University), Madras, India (1964)
  • Ph.D, Astronomy, University of Maryland, College Park, Md (1973)

Research Interests
  • Milky Way Galaxy-interstellar medium - ISM phases and atomic to molecular cloud transitions - Herschel HIFI observations of THz C+ line emission
  • Star and planet formation - physical and chemical structure & evolution of star-forming cores and protostellar disks
  • Observational studies of circumstellar disks and young stellar infall/outflows at radio, mm/submm wavelengths
  • High contrast imaging for direct detection of extrasolar planets - design and performance analysis of infrared nulling interferometers
  • Image reconstruction, deconvolution and spatial resolution enhancement

Professional Experience
  • Jet Propulsion Laboratory (1992-Present)
    • Principal Scientist, Astrophysics (2001-Present)
    • Research Scientist, Astrophysics (1995-2001)
    • NRC Senior Research Associate (1992-1995)
  • Tata Institute of Fundamental Research (TIFR), Bombay (1965-1992)
    • Professor & Director of Ooty Radio Observatory (1989-1992)
    • Research Associate/Reader/Associate Professor (1965-1988)
  • University of Maryland, College Park, MD
    • Research Associate (1979-1981)
    • Graduate Student & Research Assistant (1969-1973)
  • Radio Sterrenwacht Dwingeloo, The Netherlands, Visiting Scientist (Fall 1977)
  • Lawrence Livermore National Laboratory Livermore, CA, Visiting Scientist (Summer 1987 & 1989)
  • Department of Terrestrial Magnetism Carnegie Institution, Washington D.C, Visiting Scientist (Summer 1973)

Selected Awards
  • Team Award: "Center for Long Wavelength Astrophsyics Team", 2008
  • Team Award: "HiResTeam" for developing tool for HiRes Deconvolution of Spitzer IR images, 2004
  • Senior Research Associateship, National Research Council, 1992-1995
  • Atomic Energy Commission Merit Scholarship (M.Sc. Physics), 1962-64

Selected Publications


  1. RAY, A. & Velusamy, T., eds, "Supernovae and Stellar Evolution," Proc. Of International Workshop, Goa, 1989, World Scientific, Singapore (1991).

Papers, Chapters, and Articles

  1. Velusamy, T.; Langer, W. D.; Goldsmith, P. F.; Pineda, J. L (2015) “Internal structure of spiral arms traced with [CII]: Unraveling the WIM, HI, and molecular emission lanes”, A&A, 578, A135
  2. Langer, W. D.; Goldsmith, P. F.; Pineda, J. L.; Velusamy, T.; Requena-Torres, M. A.; Wiesemeyer, H., (2015) “Ionized gas at the edge of the central molecular zone”, A&A 576, 1L
  3. Velusamy, T.  & Langer, W. D. (2014) “Origin and z-distribution of [CII] emission from Galactic diffuse and ionized gas”, A&A, 572A, 45V
  4. Velusamy, T., Langer, W. D. (2014) “Origin and z–distribution of Galactic diffuse [C ii] emission”, A&A in press.
  5. Langer, W. D.; Pineda, J. L.; Velusamy, T, (2014) “The scale height of gas traced by [CII] in the Galactic plane”, A&A  564, A101.
  6. Velusamy, T.; Langer, W. D.; Thompson, T.(2014) “HiRes Deconvolved Spitzer Images of 89 Protostellar Jets and Outflows: New Data on the Evolution of the Outflow Morphology”, ApJ 783, 6v.
  7. Langer, W. D.; Velusamy, T.; Pineda, J. L.; Willacy, K.; Goldsmith, P. F.(2014), “A Herschel [C ii] Galactic plane survey. II. CO-dark H2 in clouds”, A&A 561, 122.
  8. Pineda, J. L.; Langer, W. D.; Velusamy, T.; Goldsmith, P. F., (2013) “A Herschel [C ii] Galactic plane survey. I. The global distribution of ISM gas components”, A&A,  554, 103.
  9. P. F. Goldsmith, W. D. Langer, J. L. Pineda, T. Velusamy, (2012) Collisional Excitation of the [CII] Fine-Structure Transition in Interstellar Clouds, APJS 203, 13.
  10. T. Velusamy, W. D. Langer, J. L. Pineda, P. F. Goldsmith, (2012) [CII] 158 micron line detection of the warm ionized medium in the Scutum-Crux spiral arm tangency, A&A (Lett) 541, L10.
  11. T. Velusamy, W. D. Langer, M. S. N. Kumar, J. M. C. Grave, (2011) Jets and Wide-angle Outflows in Cepheus E: New Evidence from Spitzer, ApJ, 741, 60.
  12. W. D. Langer, T. Velusamy, J. L. Pineda, P. F. Goldsmith, D. Li, H. W. Yorke, (2010) C+ Detection of Warm Dark Gas in Diffuse Clouds, A&A 521, 17.
  13. T. Velusamy, W. D. Langer, J. L. Pineda, P. F. Goldsmith, D. Li, H. W. Yorke, (2010) [CII] Observations of H2 Molecular Layers in Transition Clouds, A&A 521, 18.
  14. J. L. Pineda, T. Velusamy, W. D. Langer, P. F. Goldsmith, D. Li, H. W. Yorke, (2010) A Sample of [CII] Clouds Tracing Dense Clouds in Weak UV Fields Observed by Herschel, A&A 521, 19.
  15. P. F. Goldsmith, T. Velusamy, D. Li, W. D. Langer, (2010) Molecular Hydrogen Emission from the Boundaries of the Taurus Molecular Cloud, ApJ, 715, 1370.
  16. T. Velusamy and W. D. Langer, (2008) Polycyclic Aromatic Hydrocarbon and H2 Emissions in the Ultraviolet-Dominated Region in NGC 2316, AJ 136, 602.
  17. T. Velusamy, R. Peng, D. Li, P. F. Goldsmith, W. D. Langer, (2008) Dichotomy in the Dynamical Status of Massive Cores Orion, ApJ (Lett) 688,L 87.
  18. Velusamy, T., Marsh, K.A., Beichman, C.A., Backus, C.R., (2008) "HiRes Deconvolution of Spitzer IR images", AJ 136, 197.
  19. T. Velusamy, W. D. Langer, K. A. Marsh, (2007) Highly Collimated Jets and Wide-Angle Outflows in HH 46/47: New Evidence from Spitzer Infrared Images, ApJ (Lett) 668, L159.
  20. D. Li, T. Velusamy, P. F. Goldsmith, W. D. Langer, (2007) Massive Quiescent Cores in Orion II. Core Mass Function, ApJ, 655, 351.
  21. Marsh, K. A.; Dowell, C. D.; Velusamy, T.; Grogan, K.; Beichman, C. A. (2006) "Images of the Vega Dust Ring at 350 and 450 µm: New Clues to the Trapping of Multiple-Sized Dust Particles in Planetary Resonances", ApJ (Lett) 646, L77.
  22. Marsh,K.A.; Velusamy,T.; Dowell, C.D.; Grogan,K.; Beichman,C.A. (2005) "Image of Fomalhaut Dust Ring at 350 Microns: The Relative Column Density Map Shows Pericenter-Apocenter Asymmetry", ApJ (Lett) 620, 47.
  23. Takeuchi,Taku; Velusamy,T.; Lin,D.N.C. (2005) "Apparent Stellar Wobble by a Planet in a Circumstellar Disk: Limitations on Planet Detection by Astrometry ", ApJ 618,987.
  24. Lai, S-P., Velusamy, T., & Langer, W.D. (2003) "High Angular Resolution Study of the Ion and Neutral Spectra as a Probe of the Magnetic Field Structure," ApJ (Letters), 596, L239.
  25. Velusamy, T., Angel. R.P., Eatchel, A., Tenerelli, D., & Woolf, N.J. (2003) "Single and Double Bracewell Nulling Interferometry in Space," in Proc. "Towards Other Earths," ESA SP-539, p631.
  26. Lai, S-P., Velusamy, T., Langer, W. D., & Kuiper, T.B.H., (2003) "Physical and Chemical Status of Prestellar Core B68," Astron J. 126, 311.
  27. Velusamy, T., Langer, W. D., & Goldsmith, P. F. (2002) "Tracing the Infall and the Accretion Shock in the Protostellar Disk: L1157," Astrophy J. (Letters), 565, L43.
  28. Velusamy, T., & Langer, W.D., (1998) "Outflow-Infall Interactions as a Mechanism for Terminating Accretion in Protostars," Nature, 392, 685.
  29. Velusamy, T., Kuiper, T. B. H. & Langer, W. D. (1995) "Imaging Infall: CCS observations of the protostellar envelope of B335." ApJ, 451, L75.
  30. Velusamy, T. (1984), "Radio detection of a jet in the Crab Nebula," Nature, 308..251.

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