Peter Capak

Last updated
Peter Lawrence Capak
Peter Capak.jpg
Alma mater University of Hawaii at Manoa
University of British Columbia
Known for Cosmology, Structure Formation, Dark Matter, Dark Energy Galaxy Evolution
Scientific career
Fields Astronomy, Machine Learning, Space Sciences
InstitutionsFacebook Reality Labs
California Institute of Technology
Cosmic DAWN Center
Website petercapak.com

Peter Lawrence Capak is currently the Architect of Perception Systems at the Oculus division of Facebook. [1] His current focus is developing machine perception technologies, sensors, displays, and compute architectures for the next generation of augmented (AR), mixed (MR) and virtual reality (VR) systems. His research has focused on using physical modeling and advanced statistical methods including artificial intelligence and machine learning to extract information from very large multi-wavelength (hyper-spectral) data sets. He has primarily used this to study structure formation in the universe, cosmology, and the nature of dark matter [2] and dark energy.

Contents

Early life and education

Capak grew up in a rural area near Smithers, British Columbia, Canada, where he graduated from Smithers Secondary School.[ citation needed ] He received his bachelor of science in physics and astronomy with honors from the University of British Columbia in 1999. [3] He then earned a masters in astronomy in 2002, and a Ph.D. in astronomy in 2004 both from the University of Hawaii. [4] In his Ph.D. thesis, he focused on measuring the growth of structure and history of star formation in the universe using several data sets including the GOODS survey.

Scientific career

Capak is currently the Architect of Perception Systems at the Oculus division of Facebook. Until 2020 he was a senior research scientist and lead of the SPHEREx [5] [6] science center at the Infrared Processing and Analysis Center (IPAC), Caltech and a member of the NASA Euclid Science Center at IPAC. He previously was a member of the Spitzer Science Center where he led the Spitzer Enhanced Imaging Products pipeline team and the Spitzer Frontiers Field Initiative. [7] He was also a principal investigator on the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH) project. [8] Before joining IPAC, he was a postdoctoral fellow on the Cosmic Evolution Survey (COSMOS) and a graduate student at the University of Hawaii at Manoa.

Capak joined Caltech, in 2004, to work on the COSMOS project where he led the multi-wavelength data processing and analysis effort. [9] [10] As part of this work he developed a way of estimating redshifts from photometry (photometric redshifts) that accounted for the signal strength of weak lensing, enabling the first 3-dimensional map of dark matter. He subsequently led the development of new technique based on manifold learning that significantly reduced the number of observations required to calibrate photometric redshifts for dark energy measurements. [11] [12] This made it practical to carry out the calibration observations in a reasonable amount of time on the Keck and VLT telescopes with the C3R2 survey. [13] [14] Capak has also worked on improving galaxy modeling techniques using more advanced statistical methods and machine learning [15] [16] [17] including leading the development of the fitting pipeline for the SPHEREx mission. [18]

In 2010, Capak took over leadership of the COSMOS collaboration which he led until 2018. The COSMOS data set helped to develop the concept behind several experiments to measure the properties of dark matter and dark energy including the Dark Universe Explorer (DUNE), [19] which was incorporated into the Euclid mission. Capak consulted [20] on the design of NASA's Wide Field Infrared Survey Telescope (later renamed the Nancy Grace Roman Space Telescope). He was also a co-investigator on the team that developed NASA's SPHEREx mission.

Capak's work has been featured in the media including his work on Abell 520, the Baby Boom Galaxy. He also discovered the most distant known cluster of galaxies [21] [22] and carried out the first large study of the interstellar medium in the distant universe. [23] [24] In 2017-2019, he was identified as one of the top 1% of cited researchers in space sciences. [25] [26] [27] Since 2017, Capak has been an associate of the Cosmic Dawn Center (DAWN) [28] in Copenhagen, Denmark, a center focused on high-z research.

Related Research Articles

<span class="mw-page-title-main">Redshift</span> Change of wavelength in photons during travel

In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation. The opposite change, a decrease in wavelength and simultaneous increase in frequency and energy, is known as a blueshift, or negative redshift. The terms derive from the colours red and blue which form the extremes of the visible light spectrum. The main causes of electromagnetic redshift in astronomy and cosmology are the relative motions of radiation sources, which give rise to the relativistic Doppler effect, and gravitational potentials, which gravitationally redshift escaping radiation. All sufficiently distant light sources show cosmological redshift corresponding to recession speeds proportional to their distances from Earth, a fact known as Hubble's law that implies the universe is expanding.

Infrared astronomy is a sub-discipline of astronomy which specializes in the observation and analysis of astronomical objects using infrared (IR) radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers, and falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter waves.

The Sunyaev–Zeldovich effect is the spectral distortion of the cosmic microwave background (CMB) through inverse Compton scattering by high-energy electrons in galaxy clusters, in which the low-energy CMB photons receive an average energy boost during collision with the high-energy cluster electrons. Observed distortions of the cosmic microwave background spectrum are used to detect the disturbance of density in the universe. Using the Sunyaev–Zeldovich effect, dense clusters of galaxies have been observed.

<span class="mw-page-title-main">Stephan's Quintet</span> Visual grouping of five galaxies

Stephan's Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered. The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory. The group is the most studied of all the compact galaxy groups. The brightest member of the visual grouping is NGC 7320, which has extensive H II regions, identified as red blobs, where active star formation is occurring.

<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".

Observational cosmology is the study of the structure, the evolution and the origin of the universe through observation, using instruments such as telescopes and cosmic ray detectors.

<span class="mw-page-title-main">Coma Cluster</span> Cluster of galaxies in the constellation Coma Berenices

The Coma Cluster is a large cluster of galaxies that contains over 1,000 identified galaxies. Along with the Leo Cluster, it is one of the two major clusters comprising the Coma Supercluster. It is located in and takes its name from the constellation Coma Berenices.

Lauro Moscardini is an Italian astrophysicist and cosmologist. Moscardini has studied N-body cosmological simulations with non-Gaussian initial conditions. The research activity is mainly focussed in the field of theoretical and observational cosmology, in particular with the application of numerical techniques in astrophysics and the study of the formation of large cosmic structures. Moscardini's research is a mixture of observations and building models of large scale structures in the universe.

<span class="mw-page-title-main">Dark Energy Survey</span> Project to measure the expansion of the universe

The Dark Energy Survey (DES) is an astronomical survey designed to constrain the properties of dark energy. It uses images taken in the near-ultraviolet, visible, and near-infrared to measure the expansion of the universe using Type Ia supernovae, baryon acoustic oscillations, the number of galaxy clusters, and weak gravitational lensing. The collaboration is composed of research institutions and universities from the United States, Australia, Brazil, the United Kingdom, Germany, Spain, and Switzerland. The collaboration is divided into several scientific working groups. The director of DES is Josh Frieman.

<span class="mw-page-title-main">Cosmic Evolution Survey</span> Hubble Space Telescope Treasury Project

The Cosmic Evolution Survey (COSMOS) is a Hubble Space Telescope (HST) Treasury Project to survey a two square degree equatorial field with the Advanced Camera for Surveys (ACS). The largest survey ever undertaken by HST, the project incorporates commitments from observatories around the world, such as the Very Large Array radio observatory, the European Space Agency's XMM-Newton satellite, and Japan's eight meter Subaru telescope. At the moment, more than 150 astronomers around the world actively contribute to the project.

<span class="mw-page-title-main">Abell 520</span> Galaxy cluster in the constellation of Orion

Abell 520 is a galaxy cluster in the Orion constellation, located at a co-moving radial distance of 811 Mpc (2,645 Mly) and subtends 25 arcminutes on the Earth sky.

<span class="mw-page-title-main">ULAS J1120+0641</span> One of the most distant quasars known

ULAS J1120+0641 was the most distant known quasar when discovered in 2011, surpassed in 2017 by ULAS J1342+0928. ULAS J1120+0641 was the first quasar discovered beyond a redshift of z = 7. Its discovery was reported in June 2011.

Tim Richard Walter Schrabback–Krahe is KIPAC Fellow at the Kavli Institute of Particle Astrophysics and Cosmology, which is based at Stanford University. He is working within the X-ray Astronomy and Observational Cosmology Group. His research focuses on weak gravitational lensing and its applications for cosmology and astrophysics.

<span class="mw-page-title-main">MACS0647-JD</span> The farthest known galaxy from the Earth in the constellation Camelopardalis

MACS0647-JD is a galaxy with a redshift of about z = 10.7, equivalent to a light travel distance of 13.26 billion light-years. If the distance estimate is correct, it formed about 427 million years after the Big Bang.

In cosmology, intensity mapping is an observational technique for surveying the large-scale structure of the universe by using the integrated radio emission from unresolved gas clouds.

<span class="mw-page-title-main">Simon Lilly</span>

Simon John Lilly FRS is a professor in the Department of Physics at ETH Zürich.

<span class="mw-page-title-main">SPHEREx</span> NASA near-infrared space observatory

SPHEREx is a future near-infrared space observatory that will perform an all-sky survey to measure the near-infrared spectra of approximately 450 million galaxies. In February 2019, SPHEREx was selected by NASA for its next Medium-Class Explorers mission, beating out two competing mission concepts: Arcus and FINESSE. As of August 2022, SPHEREx is targeted to launch no earlier than April 2025 on a Falcon 9 launch vehicle from Vandenberg Space Force Base. The principal investigator is James Bock at California Institute of Technology (Caltech) in Pasadena, California.

Jeyhan Sevim Kartaltepe is an American astronomer, Associate Professor and Director of the Rochester Institute of Technology Laboratory for Multiwavelength Astrophysics. Her research considers observational astronomy and galaxy evolution. She is a lead investigator on the Cosmic Evolution Early Release Science Survey and the COSMOS-Webb Survey conducted on the James Webb Space Telescope.

References

  1. ↑ "Dr. Peter L. Capak". petercapak.com. Retrieved 2020-04-23.
  2. ↑ "Big Unknowns: what is dark matter? – Science Weekly podcast". The Guardian. 22 Nov 2016.
  3. ↑ "PHYSICS 449/ ASTR 449 THESIS". Physics Astronomy, University of British Columbia. Retrieved 7 Aug 2019.
  4. ↑ "Alumni (alphabetical listing)". Institute for Astronomy, University of Hawaii. Retrieved 7 Aug 2019.
  5. ↑ "SPHEREx Science Team". SPHEREx. Retrieved 7 Aug 2019.
  6. ↑ "IPAC Organization". IPAC. Retrieved 8 Aug 2019.
  7. ↑ "The Frontier Fields: where primordial galaxies lurk". Astronomy Now. 29 Sep 2016.
  8. ↑ "Spitzer's SPLASH Project Dives Deep for Galaxies". JPL NASA. 9 Sep 2014.
  9. ↑ "Dark matter maps reveal cosmic scaffolding" (PDF). Hubble Space Telescope. 12 Nov 2006.
  10. ↑ "First 3D map of the Universe's Dark Matter scaffolding". Hubble Space Telescope. 7 Jan 2007.
  11. ↑ Masters, Daniel; Capak, Peter; Stern, Daniel; Ilbert, Olivier; Salvato, Mara; Schmidt, Samuel; Longo, Giuseppe; Rhodes, Jason; Paltani, Stephane; Mobasher, Bahram; Hoekstra, Henk; Hildebrandt, Hendrik; Coupon, Jean; Steinhardt, Charles; Speagle, Josh; Faisst, Andreas; Kalinich, Adam; Brodwin, Mark; Brescia, Massimo; Cavuoti, Stefano (28 Oct 2015). "Mapping the Galaxy Color-Redshift Relation: Optimal Photometric Redshift Calibration Strategies for Cosmology Surveys". The Astrophysical Journal. 813 (1): 53. arXiv: 1509.03318 . Bibcode:2015ApJ...813...53M. doi:10.1088/0004-637X/813/1/53. hdl:1721.1/100755. S2CID   6200986.
  12. ↑ Hemmati, Shoubaneh; Capak, Peter; Masters, Daniel; Davidzon, Iary; Dorè, Olivier; Kruk, Jeffrey; Mobasher, Bahram; Rhodes, Jason; Scolnic, Daniel; Stern, Daniel (2019). "Photometric Redshift Calibration Requirements for WFIRST Weak Lensing Cosmology: Predictions from CANDELS". The Astrophysical Journal. 877 (2): 117. arXiv: 1808.10458 . Bibcode:2019ApJ...877..117H. doi: 10.3847/1538-4357/ab1be5 . S2CID   119040241.
  13. ↑ "The C3R2 Survey: Mapping the Galaxy Color-Redshift Relation for Weak Lensing Cosmology" . Retrieved 12 Aug 2019.
  14. ↑ Masters, Daniel; Stern, Daniel; Cohen, Judith; Capak, Peter; Rhodes, Jason; Castander, Francisco; Paltani, Stephane (2017). "The Complete Calibration of the Color-Redshift Relation (C3R2) Survey: Survey Overview and Data Release 1". The Astrophysical Journal. 841 (2): 111. arXiv: 1704.06665 . Bibcode:2017ApJ...841..111M. doi: 10.3847/1538-4357/aa6f08 . S2CID   12643344.
  15. ↑ Speagle, Joshua S.; Capak, Peter L.; Eisenstein, Daniel J.; Masters, Daniel C.; Steinhardt, Charles L. (2016). "Exploring Photometric Redshifts as an Optimization Problem: An Ensemble MCMC and Simulated Annealing-Driven Template-Fitting Approach". Monthly Notices of the Royal Astronomical Society. 461 (4): 3432–3442. arXiv: 1508.02484 . doi:10.1093/mnras/stw1503.
  16. ↑ Hemmati, Shoubaneh; Capak, Peter; Pourrahmani, Milad; Nayyeri, Hooshang; Stern, Daniel; Mobasher, Bahram; Darvish, Behnam; Davidzon, Iary; Ilbert, Olivier; Masters, Daniel; Shahidi, Abtin (2019). "Bringing manifold learning and dimensionality reduction to SED fitters". The Astrophysical Journal. 881 (1): L14. arXiv: 1905.10379 . Bibcode:2019ApJ...881L..14H. doi: 10.3847/2041-8213/ab3418 . S2CID   166228692.
  17. ↑ Davidzon, I.; Laigle, C.; Capak, P. L.; Ilbert, O.; Masters, D. C.; Hemmati, S.; Apostolakos, N.; Coupon, J.; de la Torre, S.; Devriendt, J.; Dubois, Y.; Kashino, D.; Paltani, S.; Pichon, C. (2019). "Horizon-AGN virtual observatory - 2: Template-free estimates of galaxy properties from colours". Monthly Notices of the Royal Astronomical Society. 489 (4): 4817. arXiv: 1905.13233 . Bibcode:2019MNRAS.489.4817D. doi:10.1093/mnras/stz2486.
  18. ↑ Stickley, Nathaniel R.; Capak, Peter; Masters, Daniel; De Putter, Roland; Doré, Olivier; Bock, Jamie (2016). "An Empirical Approach to Cosmological Galaxy Survey Simulation: Application to SPHEREx Low-Resolution Spectroscopy". arXiv: 1606.06374 [astro-ph.IM].
  19. ↑ Refregier, A.; the DUNE collaboration (2009). "The Dark UNiverse Explorer (DUNE): Proposal to ESA's Cosmic Vision". Experimental Astronomy. 23 (1): 17–37. arXiv: 0802.2522 . Bibcode:2009ExA....23...17R. doi:10.1007/s10686-008-9106-9. S2CID   14070433.
  20. ↑ Spergel, D.; Gehrels, N.; Baltay, C.; Bennett, D.; Breckinridge, J.; Donahue, M.; Dressler, A.; Gaudi, B. S.; Greene, T.; Guyon, O.; Hirata, C.; Kalirai, J.; Kasdin, N. J.; Macintosh, B.; Moos, W.; Perlmutter, S.; Postman, M.; Rauscher, B.; Rhodes, J.; Wang, Y.; Weinberg, D.; Benford, D.; Hudson, M.; Jeong, W. -S.; Mellier, Y.; Traub, W.; Yamada, T.; Capak, P.; Colbert, J.; Masters, D.; et al. (12 March 2015). "Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report". arXiv: 1503.03757 [astro-ph.IM].
  21. ↑ Clavin, Whitney (11 Jan 2011). "NASA Telescopes Help Identify Most Distant Galaxy Cluster". JPL NASA.
  22. ↑ Capak, P. L.; Riechers, D.; Scoville, N. Z.; Carilli, C.; Cox, P.; Neri, R.; Robertson, B.; Salvato, M.; Schinnerer, E.; Yan, L.; Wilson, G. W.; Yun, M.; Civano, F.; Elvis, M.; Karim, A.; Mobasher, B.; Staguhn, J. G. (12 Jan 2011). "A massive protocluster of galaxies at a redshift of z ≈ 5.3". Nature. 470 (7333): 233–5. arXiv: 1101.3586 . Bibcode:2011Natur.470..233C. doi:10.1038/nature09681. PMID   21228776. S2CID   205223398.
  23. ↑ Choi, Charles (24 June 2015). "Ancient Carbon Haze Offers Clues to Galaxy Evolution". Space.com.
  24. ↑ Capak, P. L.; Carilli, C.; Jones, G.; Casey, C. M.; Riechers, D.; Sheth, K.; Carollo, C. M.; Ilbert, O.; Karim, A.; Lefevre, O.; Lilly, S.; Scoville, N.; Smolcic, V.; Yan, L. (24 June 2015). "Galaxies at redshifts 5 to 6 with systematically low dust content and high [C II] emission". Nature. 522 (7557): 455–458. arXiv: 1503.07596 . Bibcode:2015Natur.522..455C. doi:10.1038/nature14500. PMID   26108853. S2CID   56110132.
  25. ↑ "2017 Highly Cited Researchers". Clarivate Analytics. Archived from the original on 14 September 2018. Retrieved 9 Aug 2019.
  26. ↑ "Highly Cited Researchers 2018". Web of Science Group. Archived from the original on 20 February 2019. Retrieved 9 Aug 2019.
  27. ↑ "Highly Cited Researchers". publons.com. Retrieved 2020-04-23.
  28. ↑ "Cosmic Dawn Center Staff and Students". Cosmic Dawn Center. 25 March 2019. Retrieved 30 Jan 2020.
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