Jeonghee Rho

Dust and Molecule formation in Supernovae

Dr. Jeonghee Rho studies supernovae and their remnants to investigate the origin of dust and molecules in the early and local Universe. Supernovae play a key role in the chemical and dust budget of galaxies, producing heavy elements and dust in their ejecta and processing dust. These explosions light up regions of stellar birth, trigger the next generation of star formation, return solid material to the gas phase and create the elements necessary for life. Infrared imaging and spectroscopy provide direct information on the composition, amount, and distribution of molecules and dust in the remnants of supernovae.

Dr. Rho and her collaborators have performed infrared observations of young nearby supernova remnants using the Spitzer and Herschel space telescopes. These observations, as well as grounds-based observations, have demonstrated the presence of significant amounts of molecules and dust in SN ejecta. One potential project for a student working with Dr. Rho is to study molecule formation and destruction in SN ejecta and heating and cooling in the interstellar medium by using near-infrared observations of a more varied sample of supernova remnants. The data analysis component includes data from ground-based telescopes such as Palomar (http://www.astro.caltech.edu/palomar/hale.html), Cerro Tololo Inter-American Observatory in Chile (CTIO; http://www.ctio.noao.edu/noao/) and the Anglo-Australian Telescope (AAT; http://www.aao.gov.au/).

• NASA Group Award as a member of Two Micron All Sky Survey project at IPAC/Caltech (2000)
• NASA Group Award as a member of Spitzer Space Telescope MIPS group at Spitzer Science Center,Caltech (2005) 
• NASA Group Award as a member of SOFIA Outreach group at NASA Ames Research Center (2012 and 2014)

• Akari finds carbon monoxide molecules embedded in ten million degree gas
• Spitzer Finds Stellar 'Incubators' With Massive Star Embryos
• Exploding Stars Make Key Ingredient in Sand, Glass 
• Fall 2021 Supernovae and Dust Tele-Talks schedule and speakers and archived talks, hosted by Jeonghee Rho

• Rho, J., Geballe, T. R., Banerjee, D. P., Joshi, V., Evans, A., Dessart, L., Near-Infrared Spectroscopy of SN 2017eaw in 2017: Carbon Monoxide and Dust Formation in a Type II-P Supernova, 2018, ApJL, 864, 20 
   
• Rho, J., Gomez, H.L., Boogert, A., Smith, M.W.L., Lagage, P.-O., Dowell, D., & Clark, C. J.R., A Dust Twin of Cas A: Cold Dust and Silica and Silicon Carbide Pre-Solar Grains Revealed in the Supernova Remnant G54.1+0.3, 2018, MNRAS, 479, 5101 
   
• Rho, J., Hewitt, J., Bieging, J., Reach, W.T., Andersen, M., & Gu ̈sten, R., Discovery of Shocked Molecular Gas From the Supernova Remnant G357.7+0.3: HHSMT, APEX, Spitzer, and SOFIA Observations, 2017, ApJ , 834, 12 
   
• Rho, J., Hewitt, J., Boogert, A., & Kaufman, M., Gusdorf, A. Detection of Extremely Broad 1
  Water Emission from the Molecular Cloud Interacting Supernova Remnant G349.7+0.2, 2015, ApJ, 812, 44
   
• Rho, J.,, Cami, J., Onaka, T., & Reach, W. T. Spectroscopic detection of the Carbon Monoxide Fundamental Band in the Young Supernova Remnant Cassiopeia A, 2012, ApJ Letter, 747, 6 
   
• Gomez, H. L including Rho, J., 2012, A Cool Dust Factory in the Crab Nebula: A Herschel Study of the Filaments, A&A, 760, 92
   
• Tappe, A., Rho, J., Boersma, C., and Micelotta, E. R., Polycyclic Aromatic Hydrocarbon Processing in the Blast Wave of the Supernova Remnant N132D, ApJ, 754, 132 
   
• Andersen, M., Rho, J., Reach, W. T., Hewitt, J. W., & Bernard, J. P., 2011, Dust processing in Supernova Remnants: Spitzer MIPS SED and IRS Observations, ApJ, 742, 7
   
• Rho, J., Reach, W.T., Tappe, A., Hwang, U., Kozasa, T., Dunne, L., Spitzer Observations of the Young Core-collapse Supernova Remnant 1E0102-72.3: Infrared Ejecta Emission and Dust Formation, 2009, ApJ, 700, 579 
   
• Rho, J., Jarrett, T. H., Reach, W. T., Gomez, H., & Andersen, M., Carbon Monoxide in the Cassiopeia A Supernova Remnant, 2009, ApJLetter, 693, 39.
   
• Hewitt, J. W., Rho, J., Andersen, M., & Reach, W. T., Spitzer Observations of Molecular Hydrogen in Interacting Supernova Remnants, 2009, ApJ, 694, 1266
   
• Rho, J., Kozasa, T., Reach, W. T., Smith, J. D., Rudnick, L., DeLaney, T., Ennis, J. A., & Gomez, H., Freshly Formed Dust in the Cassiopeia A Supernova Remnant as Revealed by the 3 Spitzer Space Telescope, 2008, ApJ, 673, 271
   
• Rho, J., Jarrett, T.H., Chugai, N. N., & Chevalier, R. A. Chandra observations of SN 2004et and the early X-ray emission of Type IIP supernovae, 2007, ApJ, 666, 1108
   
• Reach, W. T., Rho, J. , Tappe, A., Pannuti, T., Brogan, C. L., Churchwell, E.D. et al., 2006, A Spitzer Space Telescope Infrared Survey of Supernova Remnants in the Inner Galaxy, AJ, 131, 1479
   
• Rho, J., Reynolds, S.P., Reach, W. T., Jarrett, T. H., Allen, G. E. and Wilson, J., 2003, “Near-Infrared Synchrotron Emission from Cas A”, Astrophysical Journal, 592, 299
   
• Rho, J., and Petre, R., 1998, “Mixed Morphology Supernova Remnants”, Astrophysical Journal 6 (letter), 503, 167L

Supernova Remnants and ISM 

Supernovae are among the most violent events in the Universe, ejecting gas on galactic scales and returning material from dense molecular clouds into the more diffuse interstellar medium (ISM) and the galactic halo. When the expanding blast wave encounters a dense molecular cloud, a strong shock wave develops, compressing, heating and chemically altering the ISM, and accelerating the ambient gas. Interstellar shocks are ubiquitous in the ISM including supernova blast waves, jets and outflows in protostars and spiral arms. The shocks have a strong impact on the local physical conditions, the gas chemistry and they regulate dust grains through sputtering and shattering. Our Spitzer observations reveal 18 supernova remnants interacting with molecular clouds (MSNRs) using infrared colors from the Galactic Survey data, and our follow-up spectroscopy confirmed that the bright IR emission detected is from shocked molecular lines, ionic fine-structure lines, and shock-processed dust. 

Dr. Rho studies astrochemical processes and dust processing in molecular SNRs with SOFIA, Herschel, Spitzer, WISE, and Herschel observations. The study includes examining cycles of water and oxygen chemistry, dynamic motions from molecular and atomic lines, and their energy budget. Dr. Rho also studies star formation activities around supernova remnants and the impact of shocks on star-formation. 

Star Formation: Understanding Massive-star formation

In the study of massive-star formation, a fundamental open question is how clusters are formed. Do massive dense cores have internal substructures? Do clumps evolve independently to produce stars, or do they share a common evolutionary process? Are apparent-single stars born single, or are they born in groups and subsequently ejected? While low-mass stars are believed to be produced mainly through accretion, there are two main scenarios to explain high-mass star formation. One scenario is through accretion, like that of low-mass stars but with higher accretion rates; the other scenario is through formation of high-mass stars through coalescence of lower-mass protostars.  An example is Rho et al. (2006); Spectacular Spitzer Images of the Trifid Nebula: Protostars in a Young, Massive-Star-forming Region at http://adsabs.harvard.edu/abs/2006ApJ...643..965R link to http://www.nasa.gov/vision/universe/starsgalaxies/spitzer-011205.html

Current Work

SOFIA Science Outreach Scientist: I advocate and promote SOFIA for scientific observations and discoveries by the astronomical community. I send regular science e-Newsletters, organize and participate conferences related to SOFIA, and give colloquium and talks at Universities. I also test various SOFIA software and contribute documentation of SOFIA data analysis.

Dr. Rho's Recent Observational Projects

• Current SOFIA projects.
  • Velocity-Resolved [OI] Line Survey of Supernova Remnants Interacting with Molecular Clouds (Cycle 6; PI: Dr. Rho, J.) Collaborators: Prof. J. Hewitt (North Florida University), Dr.Morten Andersen (Gemini Observatory), Prof. Thomas Pannuti (Morehead State University)
  • Dust polarisation properties in the Crab Nebula (Cycle 6; PI: Dr. Ilse De Looze) Collaborators: Dr. J. Rho (SOFIA Science Center), Prof. M. Barlow (University College London), Prof. H. Gomez (Cardiff U.), Prof. Mikako Matsuura (Cardiff U.), Dr. Roger, Wesson (University College London), Prof. Anthony Jones (Institut d’Astrophysique Spatiale, CNRS, Orsay)
• LSST Collaborations;

SN Science Collaboration LSST Dark Energy Science Collaboration Team: Type Ia Supernova Cosmology  see my contribution to the LSST Observing Strategy: 9.5 Supernova Cosmology and Physics at http://adsabs.harvard.edu/abs/2017arXiv170804058L

• Global Supernova Project:

Novel wide-field synoptic surveys of the sky using LCOGT (worldwide network of robotic telescopes Las Cumbres Observatory (https://lco.global/about/), combined with multi-wavelength and multi-messenger experiments, mean we have now entered a golden age in transient astronomy. This program will give the opportunity to a large US community interested in transients to join the LCO Global Supernova Project and follow the most interesting transients in an efficient way.  I have recently joined the LCOGT SN project (NOAO proposal PI: Stefano Valenti).

• Gemini Observation of Type IIP  SN2017eaw (DDT proposal):

Collaborators:Jeonghee Rho (SOFIA Science Center and SETI Institute), Thomas R. Geballe (Gemini Observatory), Dipankar P. K. Banerjee and Vishal Joshi (Physical Research Lab., Ahmedabad, India), Aneurin Evans (Keele U., UK) and Luc Dessart (UMI 3386, CNRS, Universidad de Chile) see ATel #10765 at http://www.astronomerstelegram.org/?read=10765

• JWST ERS (Director’s Discretionary Early Release Science Program)

I participate in "Radiative Feedback from Massive Stars as Traced by Multiband Imaging and Spectroscopic Mosaics (PI: Olivier Berne (Universite Toulouse) CoPIs: Emilie Habart (Institut d'Astrophysique Spatiale) and Els Peeters (University of Western Ontario)

Research Area

Dr. Jeonghee Rho studies Supernova Remnants, Supernovae, Shock Physics, Pulsars, Massive Star Formation, HII regions, and Interstellar Medium. Nucleosynthetic products, Dust and Molecule Formation in Supernovae to probe the Early Universe. Expert in Infrared observation and experience of Millimeter and X-ray Observations.