Dr. Harold W. Yorke Profile

Dr. Harold W. Yorke

Sr Research Scientist, Sr Manager at SOFIA / USRA

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Author

Publications (15)

Proceedings Article | 6 July 2018 Presentation + Paper

SOFIA in the era of JWST and ALMA

Harold Yorke, Erick Young, Eric Becklin

Proceedings Volume 10700, 107000E (2018) https://doi.org/10.1117/12.2314222

KEYWORDS: Stars, James Webb Space Telescope, Galactic astronomy, Astronomy, Telescopes, Space telescopes, Imaging spectroscopy, Spectroscopy, Terahertz radiation, Magnetism

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Proceedings Article | 28 July 2010 Paper

The Stratospheric THz Observatory (STO)

C. Walker, C. Kulesa, P. Bernasconi, H. Eaton, N. Rolander, C. Groppi, J. Kloosterman, T. Cottam, D. Lesser, C. Martin, A. Stark, D. Neufeld, C. Lisse, D. Hollenbach, J. Kawamura, P. Goldsmith, W. Langer, H. Yorke, J. Sterne, A. Skalare, I. Mehdi, S. Weinreb, J. Kooi, J. Stutzki, U. Graf, M. Brasse, C. Honingh, R. Simon, M. Akyilmaz, P. Puetz, Mark Wolfire

Proceedings Volume 7733, 77330N (2010) https://doi.org/10.1117/12.857765

KEYWORDS: Telescopes, Terahertz radiation, Receivers, Observatories, Spectroscopy, Electronics, Signal processing, Stars, Clouds, Control systems

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Proceedings Article | 15 July 2010 Paper

Large format heterodyne arrays for observing far-infrared lines with SOFIA

C. Walker, C. Kulesa, J. Kloosterman, D. Lesser, T. Cottam, C. Groppi, J. Zmuidzinas, M. Edgar, S. Radford, P. Goldsmith, W. Langer, H. Yorke, J. Kawamura, I. Mehdi, D. Hollenbach, J. Stutzki, H. Huebers, J. R. Gao, C. Martin

Proceedings Volume 7741, 77410Z (2010) https://doi.org/10.1117/12.857811

KEYWORDS: Heterodyning, Terahertz radiation, Receivers, Spectroscopy, Stars, Spectral resolution, Oscillators, Cryogenics, Astronomy, Micromachining

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In the wavelength regime between 60 and 300 microns there are a number of atomic and molecular emission lines that are key diagnostic probes of the interstellar medium. These include transitions of [CII], [NII], [OI], HD, H₂D+, OH, CO, and H₂O, some of which are among the brightest global and local far-infrared lines in the Galaxy. In Giant Molecular Clouds (GMCs), evolved star envelopes, and planetary nebulae, these emission lines can be extended over many arc minutes and possess complicated, often self absorbed, line profiles. High spectral resolution (R> 10⁵) observations of these lines at sub-arcminute angular resolution are crucial to understanding the complicated interplay between the interstellar medium and the stars that form from it. This feedback is central to all theories of galactic evolution. Large format heterodyne array receivers can provide the spectral resolution and spatial coverage to probe these lines over extended regions. The advent of large format (~100 pixel) spectroscopic imaging cameras in the far-infrared (FIR) will fundamentally change the way astronomy is performed in this important wavelength regime. While the possibility of such instruments has been discussed for more than two decades, only recently have advances in mixer and local oscillator technology, device fabrication, micromachining, and digital signal processing made the construction of such instruments tractable. These technologies can be implemented to construct a sensitive, flexible, heterodyne array facility instrument for SOFIA. The instrument concept for StratoSTAR: Stratospheric Submm/THz Array Receiver includes a common user mounting, control system, IF processor, spectrometer, and cryogenic system. The cryogenic system will be designed to accept a frontend insert. The frontend insert and associated local oscillator system/relay optics would be provided by individual user groups and reflect their scientific interests. Rapid technology development in this field makes SOFIA the ideal platform to operate such a modular, continuously evolving instrument.

Proceedings Article | 12 July 2008 Paper

CALISTO: the Cryogenic Aperture Large Infrared Space Telescope Observatory

Paul Goldsmith, Matt Bradford, Mark Dragovan, Chris Paine, Celeste Satter, Bill Langer, Harold Yorke, Kevin Huffenberger, Dominic Benford, Dan Lester

Proceedings Volume 7010, 701020 (2008) https://doi.org/10.1117/12.788412

KEYWORDS: Space telescopes, Stars, Telescopes, Astronomy, Galactic astronomy, Infrared telescopes, Infrared radiation, Space operations, Observatories, Spectroscopy

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CALISTO, the Cryogenic Aperture Large Infrared Space Telescope Observatory, will enable extraordinarily high sensitivity far-infrared continuum and moderate (R ~ 1000) resolution spectroscopic observations at wavelengths from ~30µm to ~300 μm - the wavelengths between those accessible by JWST and future ground based facilities. CALISTO's observations will provide vital information about a wide range of important astronomical questions including (1) the first stars and initial heavy element production in the universe; (2) structures in the universe traced by H2 emission; (3) the evolution of galaxies and the star formation within them (4) the formation of planetary systems through observations of protostellar and debris disks; (5) the outermost portions of our solar system through observations of Trans-Neptunian Objects (TNOs) and the Oort cloud. With optics cooled to below 5 K, the photon fluctuations from the astronomical background (Zodiacal, Galactic, and extragalactic) exceed those from the telescope. Detectors with a noise equivalent power below that set by the background will make possible astronomical-background-limited sensitivity through the submillimeter/far-infrared region. CALISTO builds on studies for the SAFIR (Single Aperture Far Infrared) telescope mission, employing a 4m x 6m off-axis Gregorian telescope which has a simple deployment using an Atlas V launch vehicle. The unblocked telescope with a cold stop has minimal sidelobes and scattering. The clean beam will allow astronomical background limited observations over a large fraction of the sky, which is what is required to achieve CALISTO's exciting science goals. The maximum angular resolution varies from 1.2" at 30 µm to 12" at 300 μm. The 5σ 1 hr detectable fluxes are ▵S(dν/ν = 1.0) = 2.2x10^-20 Wm^-2, and ▵S(dν/ν = 0.001) = 6.2x10^-22 Wm^-2. The 8 beams per source confusion limit at 70 μm is estimated to be 5 μJy. We discuss CALISTO optics, performance, instrument complement, and mission design, and give an overview of key science goals and required technology development to enable this promising far IR/submm mission.

Proceedings Article | 18 October 2007 Paper

Instrumentation for the next generation cryogenic spaceborne far-IR observatories

C. Matt Bradford, Paul Goldsmith, Mark Dragovan, Matt Kenyon, Warren Holmes, Harold Yorke

Proceedings Volume 6687, 66870O (2007) https://doi.org/10.1117/12.732657

KEYWORDS: Galactic astronomy, Sensors, Bolometers, Spectroscopy, Space telescopes, Telescopes, Cameras, Cryogenics, Stars, Spectrographs

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Proceedings Article | 20 September 2007 Paper

CALISTO: a cryogenic far-infrared/submillimeter observatory

P. Goldsmith, C. M. Bradford, M. Dragovan, B. Khayatian, K. Huffenberger, I. O'Dwyer, K. Górski, H. Yorke, J. Zmuidzinas, C. Paine, C. Satter, R. Lee

Proceedings Volume 6687, 66870P (2007) https://doi.org/10.1117/12.731049

KEYWORDS: Telescopes, Reflectors, Space telescopes, Astronomy, Sensors, Diffraction, Infrared radiation, Space operations, Observatories, Infrared telescopes

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Proceedings Article | 7 July 2006 Paper

Science promise and conceptual mission design for SAFIR: the single aperture far-infrared observatory

Dan Lester, Dominic Benford, Harold Yorke, C. Bradford, K. Parrish, H. Stahl

Proceedings Volume 6265, 62651X (2006) https://doi.org/10.1117/12.671995

KEYWORDS: James Webb Space Telescope, Space telescopes, Telescopes, Mirrors, Galactic astronomy, Observatories, Far infrared, Stars, Spectrometers, Cameras

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Proceedings Article | 7 July 2006 Paper

A parametric design tool for large space telescope sunshields

Christopher Paine, Charles Bradford, Mark Dragovan, Harold Yorke

Proceedings Volume 6265, 62652R (2006) https://doi.org/10.1117/12.672151

KEYWORDS: Space telescopes, Thermal modeling, Telescopes, Black bodies, Performance modeling, Radiative transfer, Optical instrument design, Space operations, Optical properties, Solar radiation models

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Proceedings Article | 16 June 2006 Paper

Analysis of the optical design for the SAFIR telelscope

Paul Goldsmith, Behrouz Khayatian, Matt Bradford, Mark Dragovan, Daniel Hoppe, William Imbriale, Roger Lee, Chris Paine, Philip Turner, Harold Yorke, Jonas Zmuidzinas

Proceedings Volume 6265, 62654A (2006) https://doi.org/10.1117/12.670051

KEYWORDS: Reflectors, Telescopes, Space telescopes, Diffraction, Antennas, Scattering, Astronomy, Solar system, Earth's atmosphere, Reflection

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SAFIR, the Single Aperture Far Infra Red Observatory, is a very powerful space mission that will achieve background-limited sensitivity in the far infrared-submillimeter spectral region. Many processes of enormous interest to astronomers can best be studied in this wavelength range, but require the demanding combination of high sensitivity, good angular resolution, and spectroscopic capability. SAFIR is a 10m class telescope offering good angular resolution, cooled to below 5 K in order to achieve background-limited sensitivity, and equipped with a complement of large-format cameras and broadband spectrometers. Successful operation of such a facility is critically dependent on achieving the level of sensitivity expected, but this is rendered difficult by potential pickup from unwanted sources of radiation. This problem is exacerbated by the fact that the emission from the optical system itself is minimal due to its low temperature, thus emphasizing the importance of minimizing pickup from unwanted astronomical sources of radiation, including the emission from dust in our solar system (analogous to the zodiacal light, hence "zodi"), and the emission from warm dust in the Milky Way (Galactic "cirrus"). The extreme sensitivity of SAFIR to these unwanted sources of radiation makes it essential to understand the relative sensitivity of the telescope/detector system to radiation coming from angles far outside the main beam, and to develop designs which minimize this pickup. In this paper we analyze in some detail the relative telescope sensitivity (referred to as the antenna pattern by microwave engineers) for different designs of SAFIR. These calculations include edge diffraction from the secondary and primary reflector, and also the effect of blockage by the secondary and blockage and scattering by support legs in a symmetric system. By convolving the antenna pattern with the brightness of the sky due to the zodi and cirrus, we can calculate the power received when the antenna is pointed in any specified direction. We can also compare the undesired pickup for different designs, in particular symmetric vs. asymmetric (off-axis or unblocked) antenna configurations. These considerations are vital for achieving the most efficient SAFIR design possible, in terms of achieving maximum sensitivity while being able to observe over a large fraction of the sky.

Proceedings Article | 20 October 2004 Paper

A SPECS update: engineering and technology requirements for a space-based far-IR imaging interferometer

David Leisawitz, Ronald Allen, Charles Baker, Dominic Benford, Claudio Bombardelli, Michael DiPirro, Pascale Ehrenfreund, Neal Evans, Martin Harwit, Tristram Hyde, Antoine Labeyrie, Jesse Leitner, Alice Liu, Enrico Lorenzini, Richard Lyon, Anthony Martino, John Mather, Karl Menten, S. Harvey Moseley, Lee Mundy, Takao Nakagawa, Stanford Ollendorf, John Pearson, Dave Quinn, Stephen Rinehart, Juan Roman, Shobita Satyapal, Robert Silverberg, H. Philip Stahl, Mark Swain, Theodore Swanson, Wesley Traub, Edward Wright, Harold Yorke

Proceedings Volume 5491, (2004) https://doi.org/10.1117/12.552104

KEYWORDS: Space telescopes, Telescopes, Interferometers, Sensors, Interferometry, Mirrors, Spatial resolution, Infrared telescopes, Detector arrays, Beam splitters

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Proceedings Article | 12 October 2004 Paper

Thermal design trades for SAFIR architecture concepts

Harold Yorke, Christopher Paine, Charles Bradford, Mark Dragovan, Al Nash, Jennifer Dooley, Charles Lawrence

Proceedings Volume 5487, (2004) https://doi.org/10.1117/12.551995

KEYWORDS: Telescopes, Space telescopes, Reflectors, James Webb Space Telescope, Mirrors, Stars, Reflector telescopes, Far infrared, Galactic astronomy, Space operations

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Proceedings Article | 12 October 2004 Paper

SPECS: the kilometer-baseline far-IR interferometer in NASA's space science roadmap

David Leisawitz, Tom Abel, Ronald Allen, Dominic Benford, Andrew Blain, Claudio Bombardelli, Daniela Calzetti, Michael DiPirro, Pascale Ehrenfreund, Neal Evans, Jacqueline Fischer, Martin Harwit, Tristram Hyde, Marc Kuchner, Jesse Leitner, Enrico Lorenzini, John Mather, Karl Menten, Samuel Moseley, Lee Mundy, Takao Nakagawa, David Neufeld, John Pearson, Stephen Rinehart, Juan Roman, Shobita Satyapal, Robert Silverberg, H. Philip Stahl, Mark Swain, Theodore Swanson, Wesley Traub, Edward Wright, Harold Yorke

Proceedings Volume 5487, (2004) https://doi.org/10.1117/12.552150

KEYWORDS: Space telescopes, Telescopes, Interferometers, Galactic astronomy, Stars, Interferometry, Spatial resolution, Astronomy, Infrared telescopes, Planets

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Proceedings Article | 12 October 2004 Paper

The science case and mission concept for the Single Aperture Far-Infrared (SAFIR) Observatory

Daniel Lester, Dominic Benford, Andrew Blain, Charles Bradford, Mark Dragovan, William Langer, Charles Lawrence, David Leisawitz, John Mather, Samuel Moseley, Lee Mundy, George Rieke, Gordon Stacey, Harold Yorke, Erick Young

Proceedings Volume 5487, (2004) https://doi.org/10.1117/12.551335

KEYWORDS: Observatories, Stars, Space telescopes, James Webb Space Telescope, Telescopes, Galactic astronomy, Mirrors, Infrared telescopes, Spatial resolution, Infrared radiation

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Proceedings Article | 28 July 2000 Paper

Scientific motivation and technology requirements for the SPIRIT and SPECS far-infrared/submillimeter space interferometers

David Leisawitz, William Danchi, Michael DiPirro, Lee Feinberg, Daniel Gezari, Mike Hagopian, William Langer, John Mather, Samuel Moseley, Michael Shao, Robert Silverberg, Johannes Staguhn, Mark Swain, Harold Yorke, Xiaolei Zhang

Proceedings Volume 4013, (2000) https://doi.org/10.1117/12.393957

KEYWORDS: Space telescopes, Galactic astronomy, Interferometers, Telescopes, Mirrors, Spatial resolution, Stars, Interferometry, Sensors, Far infrared

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Proceedings Article | 5 July 2000 Paper

Space-based interferometric telescopes for the far infrared

Michael Shao, William Danchi, Michael DiPirro, Mark Dragovan, Lee Feinberg, Mike Hagopian, William Langer, Charles Lawrence, Peter Lawson, David Leisawitz, John Mather, Samuel Moseley, Mark Swain, Harold Yorke, Xiaolei Zhang

Proceedings Volume 4006, (2000) https://doi.org/10.1117/12.390278

KEYWORDS: Sensors, Mirrors, Space telescopes, Interferometers, Telescopes, Stars, Cryogenics, Interferometry, Infrared telescopes, Far infrared

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