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 Interstellar and Heliospheric Physics (3263): People
Raghvendra Sahai's Picture
Address:
Jet Propulsion Laboratory
M/S 183-900
4800 Oak Grove Drive
Pasadena, CA 91109
Phone:
818.354.0452
Fax:
818.393.9088
Email Contact:
Curriculum Vitae:

Raghvendra Sahai

Dr. Sahai's research has focused on the physics and chemistry of mass-loss in dying stars, using both spectroscopic and continuum techniques, radio and infrared wavelengths. He has over 80 published articles in these areas.

Dr. Sahai's current focus of research is on using NASA's Great Observatories (Hubble Space Telescope, Chandra X-Ray Observatory and Spitzer Space Telescope) to study dying stars with high angular resolution and/or at wavelengths only accesible from space, and modeling of multiwavelength data for detailed object studies.

Dr. Sahai has contributed to the science justification for an infrared high-contrast coronagraphic imaging camera to search for planetary and brown dwarf companions around nearby stars, and circumstellar matter in young, main-sequence and dying stars, as part of the Design Reference Mission for the JWST. He is a member of the Science Team for the ECLIPSE coronagraphic telescope concept for a DISCOVERY-class mission to search for extra-solar giant planets.

He is a full member of the American Astronomical Society and the International Astronomical Union, and a founding member of the European Astronomical Society.


Education
  • Ph.D., California Institute of Technology (1985)
  • MS (Physics, First Class with Distinction), Indian Institute of Technology, Kanpur, India (1978)

Professional Experience
  • Jet Propulsion Laboratory / California Institute of Technology (1992-Present)
    • Principal Research Scientist (2008-Present)
    • Research Scientist, Senior A (2002-2008)
    • Research Scientist (1995-2001)
    • NHST Science Working Group (2002-2003)
    • Member, Science Team, HST's Wide Field and Planetary Camera 2 (1995-1999)
    • National Research Council Senior Resident Research Associate (1992-1995)
  • University of Gothenburg, Sweden (1986-1992)
    • Docent (1990-1992)
    • Post-doctoral Research Associate (1986-1990)
  • University of Texas, Austin, Post-doctoral Research Associate (1985-1986)
  • University of Texas, Austin, Robert A. Welch Foundation Fellow (1984-1985)

Funded Proposals

  • 2 JPL Research & Technology Development Awards (2013, 2014)
  • 4 PI and 2 co-I XMM-Newton (ESA/NASA) GO program awards (2007-2016)
  • 23 PI and 8 co-I NASA Hubble Space Telescope GO program awards (1998-2013)
  • 9 PI and 2 co-I NASA Chandra X-Ray Observatory GO program awards (2001-2015)
  • 3 PI and 1 co-I ESA/NASA Herschel Space Observatory GO program awards (2010-2012)
  • 3 PI and 5 co-I NASA Spitzer Space Telescope GO program awards (2004-2006)
  • PI 2 NASA Long Term Space Astrophysics 5-yr awards (1998-2003, 2005-2010)
  • PI 2 NASA GALEX GO program awards (2004,2008)
  • PI 3 NASA Astrophysics Data Program 3-yr awards (2004-07, 2010-14, 2013-16)

Mentoring and Supervision

  • Dr. M. Stute, Caltech Postdoctoral Scholar at JPL (2005-present)
  • Samantha Scibelli (Stony Brook University), NASA UI program (2015)
  • Ryan McPeters (College of the Canyons), SIRI and JPL Summer Internship program (2015)
  • Kelechi Ikegwu (North Carolina A & T State University), NASA MUREP program (2015)
  • Benjamin Stenger (Cal State University, Fullerton), MSP in STEM program (2015)
  • Galen Mack-Crane (Occidental College), SIRI program (2014)
  • Alexandra Gruson (Santa Monica Community College, Santa Monica, CA), SIRI program & JPL Research Apprentice program (2011-2014)
  • Skyler Saleebyan (Glendale Community College, Glendale, CA), SIRI program (2013)
  • Stoyan Ivanova (Georgia Tech., Georgia), NASA/USRP Internship program (2013)
  • Alyx Stevens (U. Texas, Austin), NASA/USRP Internship program (2012)
  • Jorge Munoz (Occidental College, Los Angeles, Ca), SIRI & Caltech SURF program (2012-2013)
  • Gregory Villar (CSU, Pomona), Minority Initiatives Internship Summer Student (2008)
  • Rachael Ainsworth (U. Tennessee, Knoxville), USRP Internship program, (Sep-Dec 2008)
  • Mark Rubin (CSU, Northridge), Academic Part Time, (2007)
  • Dr. M. Stute, Caltech Postdoctoral Scholar at JPL (2005-2007)
  • Dr. C-F. Lee, National Research Council Postdoctoral Scholar (2001-2003)
  • Dr. C. Sanchez Contreras, Caltech Postdoctoral Scholar at JPL (2000-2002)
  • Dr. A. Dayal , Caltech Postdoctoral Scholar at JPL (1997-1999)

Service

  • Frequent Referee for papers submitted to Astrophysical Journal, Astronomy and Astrophysics & Monthly Notices of the Royal Astronomical Society (1985-present)
  • Chandra Peer Proposal Review Panel Cycle 17 (2015)
  • Herschel Observing Time Allocation Committee (2010, 2011)
  • National Optical Astronomy Observatory (NOAO), Telescope Allocation Committee Member, Scientific Organizing Committee, International Conferences on"Asymmetric Planetary Nebulae VI, IV, and III" (2002-2013)
  • NASA Astrophysics Data Analysis Program [ADAP] Review (2011)
  • JPL Group Supervisor Alternate (2005-2008)
  • JPL Section Promotion Advisory Board Reviews (2002-2005)
  • JPL Research and Technology Development Review (2005)
  • Hubble Space Telescope Proposal Review Panel Cycles 10, 12, 15, 23 (2001-2015)
  • Spitzer Space Telescope Proposal Review Panel Cycle 2 (2005)
  • National Optical Astronomy Observatory (NOAO), Proposal Review Panel (2008)
  • JPL Annual Open House Wide Field Planetary Camera 2 Booth (1995-1998)

Teaching Experience

  • Advanced Undergraduate Course in "Stars and Stellar Atmospheres," Chalmers University of Technology and University of Gothenburg, Sweden (1988-1992)
  • Advanced Undergraduate Course in "Astronomical Techniques," Chalmers University of Technology and University of Gothenburg, Sweden (1990-1992)

Selected Awards
  • President's Gold Medal, Best Outgoing Undergraduate Student, Indian Institute of Technology, Kanpur, India (1978)

Selected Publications
  1. A new self-consistent model of circumstellar CO emission for deriving mass-loss rates in red giants. I - The carbon-rich star U Camelopardalis", Sahai, R. 1990, ApJ, 362, 652
  2. Imaging of the Egg Nebula (CRL 2688) with WFPC2/HST: A History of AGB/Post–AGB Mass Loss", Sahai, R., Trauger, J.T., Watson, A.M., Stapelfeldt, K.R. et al. 1998, ApJ, 493, 301
  3. The Etched Hourglass Nebula MYCN 18. I. HUBBLE SPACE TELESCOPE Observations", Sahai, R., Dayal, A., Watson, A.M., Trauger, J.T., et al. 1999, AJ, 118, 468
  4. The Starfish Twins: Two Young Planetary Nebulae with Extreme Multipolar Morphology", Sahai, R. 2000, ApJ, 537, L43
  5. Shaping Proto-Planetary and Young Planetary Nebulae with Collimated Fast Winds", Lee, C-F. & Sahai, R. 2003, ApJ, 586, 319
  6. A collimated, high-speed outflow from the dying star V Hydrae", Sahai, R.; Morris, M., Knapp, G. R., Young, K., Barnbaum, C. 2003, Nature, 426, 261
  7. X-Ray Emission from the Preplanetary Nebula He3-1475", Sahai, R., Kastner, J.H., Morris, M., Frank, A., Blackman, E.G. 2003, ApJ, 599, L87
  8. Magnetohydrodynamic Models of the Knotty, Collimated Jet in He2-90", Lee, C-F. & Sahai, R. 2004, ApJ, 606, 483
  9. Sculpting a Pre-planetary Nebula with a Precessing Jet: IRAS 16342-3814", Sahai, R.; Le Mignant, D., Sánchez Contreras, C., Campbell, R. D., Chaffee, F. H. 2005, ApJ, 622, L53.
  10. A Starfish Preplanetary Nebula: IRAS 19024+0044", Sahai, R.; Sánchez Contreras, C., Morris, M. 2005, ApJ, 620, 948
  11. A Massive Bipolar Outflow and a Dusty Torus with Large Grains in the Pre-Planetary Nebula IRAS 22036+5306", Sahai, R., Young, K., Patel, N.A., Sánchez Contreras, C. and Morris, M. 2006, ApJ, 653, 1241
  12. Hydrodynamical Simulations of the Jet in the Symbiotic Star MWC 560. III. Application to X-Ray Jets in Symbiotic Stars", Stute, M., & Sahai, R. 2007, ApJ, 665, 698
  13. Preplanetary Nebulae: An HST Imaging Survey and a New Morphological Classification System", Sahai, R., Morris, M., Sánchez Contreras, C., & Claussen, M. 2007, AJ, 134, 2200
  14. High-Velocity Interstellar Bullets in IRAS05506+2414: A Very Young Protostar?", Sahai, R., Claussen, M., Sánchez Contreras, C., Morris, M. & Sarkar, G. 2008, ApJ, 680, 483
  15. Binarity in Cool Asymptotic Giant Branch Stars: A Galex Search for Ultraviolet Excesses", Sahai, R., Findeisen, K., Gil de Paz, A., & Sánchez Contreras, C. 2008, ApJ, 689, 1274
  16. The Motion of Water Masers in the Pre-Planetary Nebula IRAS 16342-3814", Claussen, M.J., Sahai, R., & Morris, M., 2009, ApJ, 691, 219
  17. Collimated Fast Wind in the Pre-Planetary Nebula CRL 618", Lee, C-F., Hsu, M-C., & Sahai, R. 2009, ApJ, 696, 1630
  18. Sculpting an AGB Mass-Loss Envelope into a Bipolar Planetary Nebula: High-Velocity Outflows in V Hydrae", Sahai, R., Sugerman, B.E.K, Hinkle, K. 2009, ApJ, 699, 1015
  19. The Astrosphere of the Asymptotic Giant Branch Star IRC+10216", Sahai, R., & Chronopoulos, C. K.2010, ApJ, 711, L53
  20. The Dusty Circumstellar Disks of B[e] Supergiants in the Magellanic Clouds", Kastner, J. H., Buchanan, C., Sahai, R., Forrest, W. J., & Sargent, B. A. 2010, AJ, 139, 1993
  21. Young Planetary Nebulae: Hubble Space Telescope Imaging and a New Morphological Classification System", Sahai, R., Morris, M. R., & Villar, G. G. 2011, AJ, 141, 134
  22. An EVLA and CARMA study of dusty disks and torii with large grains in dying stars", Sahai, R., Claussen, M. J., Schnee, S., Morris, M. R., & Sánchez Contreras, C. 2011, ApJ, 739, L3
  23. Strong Variable Ultraviolet Emission from Y Gem: Accretion Activity in an AGB Star with a Binary Companion?", Sahai, R., Neill, J.D., Gil de Paz, A., & Sánchez Contreras, C. 2011, ApJ, 740, L39
  24. Shocked and Scorched: The Tail of a Tadpole in an Interstellar Pond", Sahai, R., Morris, M. R., & Claussen, M. J. 2012, ApJ, 751, 69
  25. Probing the mass and structure of the Ring Nebula in Lyra with SOFIA/GREAT observations of the [CII] 158 micron line", Sahai, R., Morris, M. R., Werner, M. W., Guesten, R., Wiesemeyer, H., & Sandell, G. 2012, A & A, 542, L20
  26. Are Large, Cometary-shaped Proplyds Really (Free-floating) Evaporating Gas Globules?", Sahai, R., Güsten, R., & Morris, M. R. 2012, ApJ Let, 761, L21
  27. OPACOS: OVRO Post-AGB CO (1-0) Emission Survey. I. Data and Derived Nebular Parameters", Sánchez Contreras, C., & Sahai, R. 2012, ApJS, 203, 16
  28. IRAS 19520+2759: a 105Lsun massive young stellar object driving a collimated outflow", Palau, A., Sánchez Contreras, C., Sahai, R., Sánchez-Monge, Á., & Rizzo, J. R. 2013, MNRAS, 428, 1537
  29. Mapping the Central Region of the PPN CRL 618 at Sub-arcsecond Resolution at 350 GHz", Lee, C.-F., Yang, C.-H., Sahai, R., & Sanchez Contreras, C. 2013, ApJ, 770, 153
  30. Multiple Fast Molecular Outflows in the Pre-planetary Nebula CRL 618 ", Lee, C.-F., Sahai, R., Sánchez Contreras, C., Huang, P.-S., & Hao Tay, J. J. 2013, ApJ, 777, 37
  31. ALMA Observations of the Coldest Place in the Universe: The Boomerang Nebula", Sahai, R., Vlemmings, W. H. T., Huggins, P. J., Nyman, L.-Å., & Gonidakis, I. 2013, ApJ, 777, 92
  32. Mid-infrared Imaging of the Bipolar Planetary Nebula M2-9 from SOFIA", Werner, M. W., Sahai, R., Davis, J., et al. 2014, ApJ, 780, 156
  33. The Astrosphere of the Asymptotic Giant Branch Star CIT 6", Sahai, R., & Mack-Crane, G. P. 2014, AJ, 148, 74
  34. A Pilot Deep Survey for X-Ray Emission from fuvAGB Stars", Sahai, R., Sanz-Forcada, J., Sanchez Contreras, C., & Stute, M. 2015, ApJ, 810, 77
  35. Sahai, R. 2013, “From AGB Stars to Aspherical Planetary Nebulae An Observational Per- spective”, invited review, in Asymmetric Planetary Nebulae VI, conference held Nov. 4–8, 2013, Riviera Maya, Mexico (http://adsabs.harvard.edu/abs/2014apn6.confE..87S)

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