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Sciences and Exploration Directorate

Steven Daniel Christe

(RSCH AST, SOLAR & SOLAR TRSTRL STD)

Steven Daniel Christe's Contact Card & Information.
Email: steven.d.christe@nasa.gov
Phone: 301.286.7152
Org Code: 670
Address:
NASA/GSFC
 Mail Code 670
 Greenbelt, MD 20771
Employer:
NASA

Brief Bio

Dr. Steven Christe is a research astrophysicist in the Heliophysics division at the Goddard Space Flight Center in Greenbelt, Maryland. His science interests focus on hard X-ray emission from solar flares and the quiet Sun with particular emphasis on the statistics of small transient bursts such as solar microflares; hard X-ray emission associated with solar radio emission; and the application of hard X-ray focusing optics to solar observations. Dr. Christe completed his Ph.D. in 2007, under the supervision of Dr. S. Krucker and Prof. R. P. Lin. After a short postdoctoral appointment at the Space Sciences Lab, he accepted a permanent position at the NASA Goddard Space Flight Center. He led the first launch of the FOXSI sounding rocket. Short for the Focusing Optics X-ray Solar Imager, FOXSI observed a microflare in hard X-rays for the first time using grazing-incidence optics. He was also the solar PI for HEROES, a joint mission between MSFC and GSFC, which modified and flew an existing astrophysics balloon payload to observe the Sun in hard X-rays for the first time using hard x-ray focusing optics. Dr. Christe was the PI for the FOXSI Small Explorer mission concept which was selected for a Phase A study. Steven served as the Heliophysics Line of Business Manager overseeing all proposals for flight instruments lead by Goddard Space Flight Center. Currently Dr. Christe is the Lead Scientist for the Heliophysics Strategic Technology Office (HESTO), the PI for an X-ray instrument which will fly on a small Sat mission called PADRE to study the acceleration mechanism in solar flares, and leading the Space Weather Science Operations Center (SWxSOC) which will HERMES and PADRE. HERMES is a instrument suite focused on space weather that will fly on the Lunar Gateway.


For more information, see

  • ORCID for a list of all publications
  • Github for a list of software contributions

Research Interests

Particle acceleration and heating in solar eruptions, the drivers of space weather

Heliophysics: Solar Atmosphere

Solar flares are the most energetic explosions that occur in the solar system. They heat plasmas to millions of degrees and accelerate particles to very high energies. Understanding the mystery of how impulsive energy release leads to solar eruptions, the primary drivers of space weather at Earth, and how those eruptions are energized and evolve, enables us to address fundamental questions of energy release and efficient particle acceleration that have importance far beyond their solar application (e.g., planetary magnetospheres, flaring stars, accretion disks). Some of the most important science questions are

  • How are particles accelerated at the Sun?
  • How do solar plasmas get heated to high temperatures?
  • How does magnetic energy released on the Sun produce flares and eruptions?

One of the best ways to address these questions is by observing x-ray emission from the Sun.

Scientific Software and Science Data Processing

Heliophysics: Technology & Missions

Current Projects

FOXSI Sounding Rocket

Transient Events

Short for the Focusing Optics X-ray Solar Imager, FOXSI is a sounding rocket payload to apply hard x-ray grazing incidence optics coupled to solid-state pixelated detectors to solar observations.

The MeDDEA Instrument on the PADRE Smallsat

X-ray Astrophysics

The Measuring Directivity to Determine Electron Anisotropy (MeDDEA) is an innovative system utilizing flight-spare detectors from the Spectrometer/Telescope for Imaging X-rays (STIX) mission, provided by CEA-Saclay. By adapting these state-of-the-art detectors, MeDDEA offers a unique platform for investigating the directivity of solar flare X-ray emissions and advancing our understanding of solar flare electron anisotropy. See the mission page.

The Space Weather Science Operations Center

Data Processing

The Space Weather Science Operations Center is a multi-mission science operations center for the community. For more information see this webpage.

Positions/Employment

Heliophysics Strategic Technology Office (HESTO) Lead Scientist

NASA HQ - NASA Goddard

July 2022 - Present

As the technology program within NASA’s Heliophysics Science Division (HSD), HESTO funds new technologies that can improve Heliophysics science research. We work with researchers and scientists to help solve technological challenges inherent in space-based observations to better understand our heliosphere and the dynamic, interrelated systems contained within it. Through an open and competitive solicitation process, we provide grants to universities, corporations, NASA Centers, and other institutions to explore new instrument designs and technologies.

Education

PhD. in Physics from University of California - Berkeley, 2007

M.S. in Physics, University of California at Berkeley, 2006

B.S. in Physics, State University of New York at Stony Brook, 2001

B.S. in Mathematics, State University of New York at Stony Brook, 2001

Publications

Refereed

2024. "The multiview observatory for solar terrestrial science (MOST).", Journal of Atmospheric and Solar-Terrestrial Physics, 254 106165 [10.1016/j.jastp.2023.106165] [Journal Article/Letter]

2023. "The Solar Particle Acceleration Radiation and Kinetics (SPARK) Mission Concept.", Aerospace, 10 (12): 1034 [10.3390/aerospace10121034] [Journal Article/Letter]

2019. "Ghost-ray reduction and early results from the third FOXSI sounding rocket flight.", Proc. SPIE 11118, UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XXI, 1111812 [10.1117/12.2530029] [Proceedings]

2015. "CdTe focal plane detector for hard x-ray focusing optics.", UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XIX, 9601 960103-960103-12 [10.1117/12.2191617] [Proceedings]

2014. "INVESTIGATING THE DIFFERENTIAL EMISSION MEASURE AND ENERGETICS OF MICROFLARES WITH COMBINED SDO/AIA AND RHESSI OBSERVATIONS.", ASTROPHYSICAL JOURNAL, 789 [10.1088/0004-637X/789/2/116] [Journal Article/Letter]

2014. "FIRST IMAGES FROM THE FOCUSING OPTICS X-RAY SOLAR IMAGER.", ASTROPHYSICAL JOURNAL LETTERS, 793 [10.1088/2041-8205/793/2/L32] [Journal Article/Letter]

2014. "Astrophysical Observations with the HEROES Balloon-borne Payload.", American Astronomical Society Meeting Abstracts, 223 #136.03- [Journal Article/Letter]

2013. "The Focusing Optics X-ray Solar Imager (FOXSI): Instrument and first flight.", SOLAR PHYSICS AND SPACE WEATHER INSTRUMENTATION V, 8862 [10.1117/12.2024277] [Journal Article/Letter]

2013. "The High Energy Replicated Optics to Explore the Sun Mission: A Hard X-Ray Balloon-Borne Telescope.", SOLAR PHYSICS AND SPACE WEATHER INSTRUMENTATION V, 8862 [10.1117/12.2024323] [Journal Article/Letter]

2013. "A Community Python Library for Solar Physics (SunPy).", AAS/Solar Physics Division Meeting, 44 #.1.36- [Journal Article/Letter]

2013. "The High Energy Replicated Optics to Explore the Sun (HEROES).", AAS/Solar Physics Division Meeting, 44 #...76- [Journal Article/Letter]

2013. "High Energy Replicated Optics to Explore the Sun: Hard X-ray balloon-borne telescope.", Proceedings of the 2013 IEEE Aerospace Conference, [-10.1109/AERO.2013.6497198] [Journal Article/Letter]

2013. "Solar Eruptive Events (SEE) 2020 Mission Concept.", ArXiv e-prints, arXiv:1311.5243- [Journal Article/Letter]

2013. "Results from the first flight of the Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket.", AAS/Solar Physics Division Meeting, 44 #200.04- [Journal Article/Letter]

2013. "The Focusing Optics X-ray Solar Imager (FOXSI): Instrument and First Flight.", AAS/High Energy Astrophysics Division, 13 #123.14- [Journal Article/Letter]

2012. "SunPy: Python for Solar Physics Data Analysis.", American Astronomical Society Meeting Abstracts #220, 220 #522.07- [Journal Article/Letter]

2012. "Constraining Differential Emission Measure and Energy Estimates for Microflares and Active Regions by Combining SDO/AIA and RHESSI.", American Astronomical Society Meeting Abstracts #220, 220 #509.05- [Journal Article/Letter]

2011. "Multi-thermal observations of the 2010 October 16 flare:heating of a ribbon via loops, or a blast wave?.", Bulletin of the American Astronomical Society, 2237- [Journal Article/Letter]

2011. "The Relationship Between Solar Radio and Hard X-ray Emission.", Space Science Reviews, 159 225-261 [10.1007/s11214-010-9708-1] [Journal Article/Letter]

2011. "The Focusing Optics X-ray Solar Imager.", Bulletin of the American Astronomical Society, 1511- [Journal Article/Letter]

2011. "The RHESSI Microflare Height Distribution.", Solar Physics, 270 493-502 [10.1007/s11207-011-9777-7] [Journal Article/Letter]

2011. "Solar Eruptive Events (SEE) Mission for the Next Solar Maximum.", Bulletin of the American Astronomical Society, 2204- [Journal Article/Letter]

2011. "Microflares and the Statistics of X-ray Flares.", Space Science Reviews, 159 263-300 [10.1007/s11214-010-9705-4] [Journal Article/Letter]

2011. "Estimates of Densities and Filling Factors from a Cooling Time Analysis of Solar Microflares Observed with RHESSI.", The Astrophysical Journal, 736 [75-10.1088/0004-637X/736/1/75] [Journal Article/Letter]

2011. "Electron Acceleration Associated with Solar Jets.", The Astrophysical Journal, 742 [82-10.1088/0004-637X/742/2/82] [Journal Article/Letter]

2011. "Suzaku/WAM and RHESSI observation of non-thermal electrons in solar microflares.", AGU Fall Meeting Abstracts, A1908- [Journal Article/Letter]

2011. "Transient phenomena and thermal evolution during the Boss' Day flare of 2010 October 16 with AIA, EVE and RHESSI.", AGU Fall Meeting Abstracts, A1902- [Journal Article/Letter]

2011. "Automatic Detection and Characterization of EIT waves observed by AIA Data.", AGU Fall Meeting Abstracts, 1958- [Journal Article/Letter]

2011. "The flare productivity of active regions.", AGU Fall Meeting Abstracts, 1946- [Journal Article/Letter]

2011. "Photospheric Magnetic Evolution in the WHI Active Regions.", Solar Physics, 274 131-157 [10.1007/s11207-011-9759-9] [Journal Article/Letter]

2010. "Science Objectives for an X-Ray Microcalorimeter Observing the Sun.", ArXiv e-prints, arXiv:1011.4052- [Journal Article/Letter]

2010. "The Focusing Optics X-Ray Solar Imager.", LPI Contributions, 1534 30- [Journal Article/Letter]

2010. "SDO and RHESSI Observations of Microflares.", AGU Fall Meeting Abstracts, A1830- [Journal Article/Letter]

2010. "Solar flare impulsive phase observations from SDO and other observatories.", AGU Fall Meeting Abstracts, A1832- [Journal Article/Letter]

2010. "The flare productivity of active regions.", AGU Fall Meeting Abstracts, 1638- [Journal Article/Letter]

2009. "Relationship between flare X-rays and photospheric magnetic fields.", AGU Fall Meeting Abstracts, A1521- [Journal Article/Letter]

2009. "The Focusing Optics X-ray Solar Imager.", Bulletin of the American Astronomical Society, 41 #475.08- [Journal Article/Letter]

2009. "The RHESSI Microflare Height Distribution.", AAS/Solar Physics Division Meeting #40, 40 #19.03- [Journal Article/Letter]

2009. "The Focusing Optics X-ray Solar Imager.", Bulletin of the American Astronomical Society, 41 #475.08- [Journal Article/Letter]

2009. "The Focusing Optics Solar X-ray Imager (FOXSI).", AGU Fall Meeting Abstracts, 1496- [Journal Article/Letter]

2008. "RHESSI Microflare Statistics. II. X-Ray Imaging, Spectroscopy, and Energy Distributions.", The Astrophysical Journal, 677 704-718 [10.1086/529012] [Journal Article/Letter]

2008. "Hard X-Rays Associated with Type III Radio Bursts.", The Astrophysical Journal, 680 L149-L152 [10.1086/589971] [Journal Article/Letter]

2008. "RHESSI Microflare Statistics. I. Flare-Finding and Frequency Distributions.", The Astrophysical Journal, 677 1385-1394 [10.1086/529011] [Journal Article/Letter]

2008. "An intriguing solar microflare observed with RHESSI, Hinode, and TRACE.", Astronomy and Astrophysics, 481 L45-L48 [10.1051/0004-6361:20079019] [Journal Article/Letter]

2008. "Microflares with RHESSI and Hinode/XRT.", First Results From Hinode, 397 169- [Journal Article/Letter]

2008. "Microflares with RHESSI and Hinode/XRT.", First Results From Hinode, 397 169- [Journal Article/Letter]

2008. "Coronal Hard X‐Ray Emission Associated with Radio Type III Bursts.", The Astrophysical Journal, 681 (1): 644-649 [10.1086/588549] [Journal Article/Letter]

2007. "X-ray Microflares with Hinode and RHESSI.", AGU Fall Meeting Abstracts, 7- [Journal Article/Letter]

2007. "RHESSI Microflare Statistics: X-ray Imaging And Spectral Analysis.", Bulletin of the American Astronomical Society, 39 213- [Journal Article/Letter]

2007. "Solar Flare Electron Spectra at the Sun and near the Earth.", The Astrophysical Journal, 663 L109-L112 [10.1086/519373] [Journal Article/Letter]

2007. "RHESSI Hard X-ray Microflare Statistics.", AGU Fall Meeting Abstracts, A849- [Journal Article/Letter]

2007. "X-ray Microflares with Hinode and RHESSI.", AGU Fall Meeting Abstracts, 7- [Journal Article/Letter]

2005. "Solar Impulsive Electron Events and RHESSI Hard X-ray Emission.", AGU Fall Meeting Abstracts, A4- [Journal Article/Letter]

2004. "RHESSI Observations of Hard X-ray Microflares with Interplanetary Type III Radio Bursts.", Bulletin of the American Astronomical Society, 36 758- [Journal Article/Letter]

2004. "The Microflare Frequency Distribution observed by RHESSI.", Bulletin of the American Astronomical Society, 36 818- [Journal Article/Letter]

2004. "Rhessi Microflare Statistics.", SOHO 15 Coronal Heating, 575 259- [Journal Article/Letter]

2004. "Nonthermal X-ray Microflares.", AGU Fall Meeting Abstracts, A3- [Journal Article/Letter]

2003. "RHESSI Observations of Two Occulted Solar Flares.", Bulletin of the American Astronomical Society, 35 841- [Journal Article/Letter]

2003. "Type III Radio Bursts and Microflares.", Bulletin of the American Astronomical Society, 35 830- [Journal Article/Letter]

2003. "First Detection of Hard X-ray Emission From Solar Type III Radio Bursts.", AGU Fall Meeting Abstracts, 1131- [Journal Article/Letter]

2003. "RHESSI Microflares Statistics.", AGU Fall Meeting Abstracts, 167- [Journal Article/Letter]

2002. "Hard X-ray Microflares down to 3~keV.", AGU Fall Meeting Abstracts, A484- [Journal Article/Letter]

2002. "RHESSI Observation of an Occulted Hard X-ray Flare.", AGU Fall Meeting Abstracts, A480- [Journal Article/Letter]

2001. "A single hollow-beam optical trap for cold atoms.", Journal of Optics B: Quantum and Semiclassical Optics, 3 353-357 [10.1088/1464-4266/3/6/301] [Journal Article/Letter]

Contact Us

For general inquiries about the Sciences and Exploration Directorate.

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Project Support Specialist

301-286-6066 jocelyn.m.lynch@nasa.gov
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Project Support Specialist

301-286-6066 ellie.jeffries@nasa.gov
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