Juna Kollmeier

Last updated
Juna Kollmeier
Alma mater Ohio State University
California Institute of Technology
Scientific career
Institutions Carnegie Institution for Science
Thesis The Intergalactic Medium: Absorption, Emission, Disruption  (2006)
Doctoral advisor David H. Weinberg

Juna Kollmeier is an astrophysicist from the US. She is currently employed at the Carnegie Institution for Science and is the director of the fifth phase of the Sloan Digital Sky Survey, which made its first observations in October, 2020. [1] She served as the director of the Canadian Institute for Theoretical Astrophysics, located at the University of Toronto, from 2021 to 2024. [2]

Contents

Early life and education

Kollmeier was going to become a lawyer, until she attended a summer camp and learned how to classify stars. [3] She earned a bachelor's degree in physics from the California Institute of Technology in 2000. [4] She moved to Ohio State University for her doctoral studies on the intergalactic medium, which she completed in 2006. [4] [5]

Research and career

Kollmeier's research focuses on the formation of structure within the universe. [6] She combines a use of cosmological hydrodynamic simulations with analytic theory to understand how galaxies and black holes formed from fluctuations in the density of the early universe. [5] She studies everything from the Intergalactic medium to the Milky Way and supermassive black holes. [5]

After graduating Ohio State University, Kollmeier was a Hubble Fellow and a Carnegie Princeton Fellow. [7] She joined the staff at Carnegie Institution for Science in 2008. [8] In 2014 she reported the photon underproduction crisis, a deficit between the observations of intergalactic hydrogen and ionized hydrogen gas. [9] [10] [11] [12] [13]

In 2015 she was a visiting professor at the Institute for Advanced Study. [14] Today she is a researcher at Carnegie Observatories. [15] She gives regular invited talks. [16] [6] In 2017 it was announced that Kollmeier would lead the Sloan Digital Sky Survey. [8] [17]

She featured on the PBS documentary "Genius". [7]

See also

Related Research Articles

<span class="mw-page-title-main">Cosmic microwave background</span> Trace radiation from the early universe

The cosmic microwave background is microwave radiation that fills all space in the observable universe. It is a remnant that provides an important source of data on the primordial universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dark. However, a sufficiently sensitive radio telescope detects a faint background glow that is almost uniform and is not associated with any star, galaxy, or other object. This glow is strongest in the microwave region of the radio spectrum. The accidental discovery of the CMB in 1965 by American radio astronomers Arno Penzias and Robert Wilson was the culmination of work initiated in the 1940s.

<span class="mw-page-title-main">Extragalactic astronomy</span> Study of astronomical objects outside the Milky Way Galaxy

Extragalactic astronomy is the branch of astronomy concerned with objects outside the Milky Way galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy.

<span class="mw-page-title-main">Sandra Faber</span> American astrophysicist

Sandra Moore Faber is an American astrophysicist known for her research on the evolution of galaxies. She is the University Professor of Astronomy and Astrophysics at the University of California, Santa Cruz, and works at the Lick Observatory. She has made discoveries linking the brightness of galaxies to the speed of stars within them and was the co-discoverer of the Faber–Jackson relation. Faber was also instrumental in designing the Keck telescopes in Hawaii.

<span class="mw-page-title-main">Observable universe</span> All of space observable from the Earth at the present

The observable universe is a ball-shaped region of the universe consisting of all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time; the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. Initially, it was estimated that there may be 2 trillion galaxies in the observable universe. That number was reduced in 2021 to only several hundred billion based on data from New Horizons. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe is a spherical region centered on the observer. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth.

<span class="mw-page-title-main">Reionization</span> Process that caused matter to reionize early in the history of the Universe

In the fields of Big Bang theory and cosmology, reionization is the process that caused electrically neutral atoms in the universe to reionize after the lapse of the "dark ages".

<span class="mw-page-title-main">Dwarf galaxy</span> Small galaxy composed of up to several billion stars

A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars. The Large Magellanic Cloud, which closely orbits the Milky Way and contains over 30 billion stars, is sometimes classified as a dwarf galaxy; others consider it a full-fledged galaxy. Dwarf galaxies' formation and activity are thought to be heavily influenced by interactions with larger galaxies. Astronomers identify numerous types of dwarf galaxies, based on their shape and composition.

<span class="mw-page-title-main">Kappa Andromedae</span> Star in the constellation of Andromeda

Kappa Andromedae, Latinized from κ Andromedae, is the Bayer designation for a bright star in the northern constellation of Andromeda. It is visible to the naked eye with an apparent visual magnitude of 4.1. Based on the star's ranking on the Bortle Dark-Sky Scale, it is luminous enough to be visible from the suburbs and from urban outskirts, but not from brightly lit inner city regions. Parallax measurements made during the Hipparcos mission place it at a distance of approximately 168 light-years from the Sun. It is drifting closer with a radial velocity of −15 km/s, and there is a high likelihood (86%) that it is a member of the Beta Pictoris moving group. The star has one known companion exoplanet, Kappa Andromedae b.

<span class="mw-page-title-main">Canadian Institute for Theoretical Astrophysics</span> Research institute in Toronto, Canada

The Canadian Institute for Theoretical Astrophysics (CITA) is a national research institute funded by the Natural Sciences and Engineering Research Council, located at the University of Toronto in Toronto, Ontario, Canada. CITA's mission is "to foster interaction within the Canadian theoretical Astrophysics community and to serve as an international center of excellence for theoretical studies in astrophysics." CITA was incorporated in 1984.

<span class="mw-page-title-main">Cosmic Origins Spectrograph</span> Instrument installed on the Hubble Space Telescope

The Cosmic Origins Spectrograph (COS) is a science instrument that was installed on the Hubble Space Telescope during Servicing Mission 4 (STS-125) in May 2009. It is designed for ultraviolet (90–320 nm) spectroscopy of faint point sources with a resolving power of ≈1,550–24,000. Science goals include the study of the origins of large scale structure in the universe, the formation and evolution of galaxies, and the origin of stellar and planetary systems and the cold interstellar medium. COS was developed and built by the Center for Astrophysics and Space Astronomy (CASA-ARL) at the University of Colorado at Boulder and the Ball Aerospace and Technologies Corporation in Boulder, Colorado.

The Carnegie Institution for Science, also known as Carnegie Science and the Carnegie Institution of Washington, is an organization in the United States established to fund and perform scientific research. The institution is headquartered in Washington, D.C. As of June 30, 2020, the Institution's endowment was valued at $926.9 million. In 2018 the expenses for scientific programs and administration were $96.6 million. Eric Isaacs is president of the institution.

<span class="mw-page-title-main">Wendy Freedman</span> Canadian-American astronomer

Wendy Laurel Freedman is a Canadian-American astronomer, best known for her measurement of the Hubble constant, and as director of the Carnegie Observatories in Pasadena, California, and Las Campanas, Chile. She is now the John & Marion Sullivan University Professor of Astronomy and Astrophysics at the University of Chicago. Her principal research interests are in observational cosmology, focusing on measuring both the current and past expansion rates of the universe, and on characterizing the nature of dark energy.

<span class="mw-page-title-main">Neta Bahcall</span> Israeli astrophysicist and cosmologist

Neta Bahcall is an Israeli astrophysicist and cosmologist specializing in dark matter, the structure of the universe, quasars, and the formation of galaxies. Bahcall is the Eugene Higgins Professor of Astronomy at Princeton University.

The photon underproduction crisis is a cosmological discussion concerning the purported deficit between observed photons and predicted photons.

<span class="mw-page-title-main">Mercedes López-Morales</span> Spanish-American astrophysicist

Mercedes López-Morales is a Spanish-American astrophysicist at the Center for Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Massachusetts, who works on detection and characterization of exoplanet atmospheres.

<span class="mw-page-title-main">Renée Hložek</span> South African cosmologist

Renée Hložek is a South African cosmologist, Professor of Astronomy & Astrophysics at the Dunlap Institute for Astronomy & Astrophysics at the University of Toronto, and an Azrieli Global Scholar within the Canadian Institute for Advanced Research. She studies the cosmic microwave background, Type Ia supernova and baryon acoustic oscillations. She is a Sloan Research Fellow in 2020. Hložek identifies as bisexual.

<span class="mw-page-title-main">Erika Hamden</span> American astrophysicist

Erika Tobiason Hamden is an American astrophysicist and associate professor at the University of Arizona and Steward Observatory. Her research focuses on developing ultraviolet (UV) detector technology, ultraviolet–visible spectroscopy (UV/VIS) instrumentation and spectroscopy, and galaxy evolution. She served as the project scientist and project manager of a UV multi-object spectrograph, FIREBall-2, that is designed to observe the circumgalactic medium (CGM). She is a 2019 TED fellow.

Blakesley Burkhart is an astrophysicist. She is the winner of the 2017 Robert J. Trumpler Award awarded by the Astronomical Society of the Pacific, which recognizes a Ph.D. thesis that is "particularly significant to astronomy." She also is the winner of the 2019 Annie Jump Cannon Award in Astronomy and the 2022 winner of The American Physical Society's Maria Goeppert-Mayer Award. The awards both cited her work on magnetohydrodynamic turbulence, and for developing innovative techniques for comparing observable astronomical phenomena with theoretical models.

Barbara Sue Ryden is an American astrophysicist who is a Professor of Astronomy at Ohio State University. Her research considers the formation, shape and structure of galaxies. She was elected a fellow of the American Association for the Advancement of Science in 2016.

Hsiao-Wen Chen is a Taiwanese-American astronomer who uses a combination of absorption spectroscopy and emission-line mapping to study diffuse baryonic "normal matter" in the intergalactic medium and galactic halos, and the connections between this matter and the matter in star-forming regions of galaxies. The circumgalactic medium resides in the interface between star-forming regions and intergalactic space contains the majority of baryonic mass as well as the critical record of gas circulation in and out of galaxies. Chen, a professor of astronomy and astrophysics at the University of Chicago, has been leading efforts to decipher how the growth and evolution of galaxies over cosmic time are connected and/or regulated by the physical properties of the circumgalactic gas.

References

  1. "Next-gen astronomical survery makes its first observations toward a new understanding of the cosmos". 2 November 2020. Retrieved 2021-03-31.
  2. "U of T names prominent astrophysics scholar, Juna Kollmeier, new director of the Canadian Institute for Theoretical Astrophysics (CITA)". 30 March 2021. Retrieved 2021-03-31.
  3. "Meet the Woman Who Wants to Solve the Universe's Mysteries" . Retrieved 2018-04-20.
  4. 1 2 "Juna Kollmeier | Simons Foundation". www.simonsfoundation.org. Retrieved 2018-04-20.
  5. 1 2 3 Science, Carnegie. "Juna Kollmeier | Carnegie Institution for Science". carnegiescience.edu. Retrieved 2018-04-20.
  6. 1 2 Carnegie Science (2015-06-05), At the Edge of Reason: The Black Holes in the Universe , retrieved 2018-04-20
  7. 1 2 "Juna Kollmeier | Meet the Experts | Genius by Stephen Hawking". Juna Kollmeier | Meet the Experts | Genius by Stephen Hawking. Retrieved 2018-04-20.
  8. 1 2 "Juna Kollmeier | The Kavli Institute for Astronomy and Astrophysics at Peking University (KIAA-PKU)". kiaa.pku.edu.cn. Archived from the original on 2018-04-21. Retrieved 2018-04-20.
  9. Kollmeier, Juna A.; Weinberg, David H.; Oppenheimer, Benjamin D.; Haardt, Francesco; Katz, Neal; Davé, Romeel A.; Fardal, Mark; Madau, Piero; Danforth, Charles (2014-06-25). "The Photon Underproduction Crisis". The Astrophysical Journal. 789 (2): L32. arXiv: 1404.2933 . Bibcode:2014ApJ...789L..32K. doi:10.1088/2041-8205/789/2/L32. ISSN   2041-8205. S2CID   73665428.
  10. Rodgers, Paul. "An Intergalactic Light That Shines Too Bright". Forbes. Retrieved 2018-04-20.
  11. "Strange dark stuff is making the universe too bright". New Scientist. Retrieved 2018-04-20.
  12. "Cosmic accounting reveals missing light crisis" . Retrieved 2018-04-20.
  13. redOrbit (2017-09-15). "Researcher puts his own body on the line to test eel's shock power - Redorbit". Redorbit. Retrieved 2018-04-20.
  14. "Juna Kollmeier". Institute for Advanced Study. Retrieved 2018-04-20.
  15. "The Carnegie Observatories". obs.carnegiescience.edu. Retrieved 2018-04-20.
  16. AstronomyHeidelberg (2015-11-03), Juna Kollmeier: The Nature of the IGM and the Photon Underproduction Crisis , retrieved 2018-04-20
  17. "Astrophysical Research Consortium". sloan.org. Retrieved 2018-04-20.