Dr. Ian N. Evans Profile

Dr. Ian N. Evans

Astrophysicist

SPIE Involvement:

Editorial Board Member: Journal of Astronomical Telescopes, Instruments, and Systems | Author

Area of Expertise:

Astrophysics , Astronomical data processing and data analysis techniques , Astronomical data system architecture

Websites:

Company Website

Profile Summary

End-to-End Scientist for the Chandra X-ray Center Data System (CXCDS), with overall responsibility for the end-to-end scientific integrity of the CXCDS. The CXCDS provides science software functionality for NASA's Chandra X-ray Observatory (CXO) mission, and supports proposal planning, science mission scheduling, standard data processing, archiving, and a distributable data analysis package (CIAO).

Develop architectures for space- and ground-based astronomical data systems. Review/evaluate proposed data system designs.

Project scientist for the Chandra Source Catalog (CSC), which is the definitive catalog of X-ray sources detected by the CXO. The second major release of the CSC, includes measured and derived properties for 317,167 unique X-ray sources, extracted from 928,280 individual detections.

Project scientist for the G-CLEF precision radial velocity echelle spectrograph, the first major instrument being developed for the Giant Magellan Telescope. Responsibilities include the science requirements and architecture of the operations, observation, and data reduction software, and hardware/software/science systems integration.

Publications (31)

Proceedings Article | 29 August 2022 Paper

Paper

The opto-mechanical design of the GMT-Consortium Large Earth Finder (G-CLEF) spectrograph adapted for the Magellan Telescope

Mark Mueller, Andrew Szentgyorgyi, Stuart McMuldroch, Sagi Ben-Ami, Kang-Min Kim, Chan Park, Daniel Baldwin, Daniel Catropa, Moo-Yung Chun, Jeffrey Crane, Daniel Durusky, Jason Eastman, Harland Epps, Ian Evans, Thomas Gauron, Ofir Hershko, Colby Jurgenson, Kenneth McCracken, Cem Onyuksel, William Podgorski, Matthew Smith, Alan Uomoto

Proceedings Volume 12184, 121843H (2022) https://doi.org/10.1117/12.2630238

KEYWORDS: Spectrographs, Telescopes, Cameras, Mirrors, Control systems, Spectral resolution, Sensors, Optomechanical design, Optical mounts, Electronics

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Proceedings Article | 29 August 2022 Presentation

Presentation

G@M: Design of the Giant Magellan Telescope Consortium Large Earth Finder (G-CLEF) for operations at the Magellan telescopes.

Andrew Szentgyorgyi, Stuart McMuldroch, Sagi Ben-Ami, Kang-Min Kim, Chan Park, Daniel Baldwin, Stuart Barnes, Daniel Bednarski, Jacob Bean, Patricia Brennan, Baptiste Callendret, Daniel Catropa, Moo-Young Chun, Laird Close, Jeffrey Crane, Daniel Durusky, Jason Eastman, Harland Epps, Ian Evans, Janet DePonte Evans, Thomas Gauron, Vitor Hartmann, Ofir Hershko, Bi Ho Jang, Jeong-Gyun Jang, Ueejeong Jeong, Andres Jordan, Colby Jurgenson, Jan Kansky, Jihun Kim, Sanghyuk Kim, Yunjong Kim, Sungho Lee, Henrique Lupinari, Jared Males, Kenneth McCracken, Michael McQuade, Claudia Mendes de Oliveira, Rafael Millan-Gabet, Mark Mueller, Jae Sok Oh, Cem Onyuksel, Byeong-Gon Park, Sung-Joon Park, Priscila Pires, William Podgorski, Andreas Seifahrt, Matthew Smith, Joao Steiner, Alan Uomoto, Young-Sam Yu, Joseph Zajac, Rafael Brahm

Proceedings Volume 12184, 121841N (2022) https://doi.org/10.1117/12.2629045

KEYWORDS: Telescopes, Spectrographs, Exoplanets, Stars, Optical instrument design, Spectral resolution, Velocity measurements, Sun, Solar system, Oxygen

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Proceedings Article | 13 July 2018 Paper

Paper

Precision thermal control of the GMT-Consortium Large Earth Finder (G-CLEF)

Mark Mueller, Daniel Baldwin, Sagi Ben-Ami, Dan Durusky, Ian Evans, Janet Evans, Tom Gauron, Kenneth McCracken, Stuart McMuldroch, Cem Onyuksel, Sang Park, David Plummer, William Podgorski, Andrew Szentgyorgyi, Alan Uomoto

Proceedings Volume 10702, 10702A2 (2018) https://doi.org/10.1117/12.2314038

KEYWORDS: Control systems, Charge-coupled devices, Spectrographs, Thermal modeling, Motion models, Telescopes, Prototyping, Algorithm development, Space telescopes, Temperature metrology

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Proceedings Article | 13 July 2018 Paper

Paper

The opto-mechanical design of the GMT-Consortium Large Earth Finder (G-CLEF)

Mark Mueller, Andrew Szentgyorgyi, Daniel Baldwin, Sagi Ben-Ami, Jamie Budynkiewicz, Moo-Young Chun, Jeffrey Crane, Daniel Durusky, Harland Epps, Ian Evans, Janet Evans, Anna Frebel, Tyson Hare, Andres Jordan, Kang-Min Kim, Mercedes Lopez-Morales, Kenneth McCracken, Stuart McMuldroch, Joseph Miller, Jae Sok Oh, Cem Onyuksel, Chan Park, Sang Park, Charles Paxson, David Plummer, William Podgorski, Alan Uomoto, Young-Sam Yu

Proceedings Volume 10702, 107029U (2018) https://doi.org/10.1117/12.2313582

KEYWORDS: Spectrographs, Telescopes, Space telescopes, Cameras, Mirrors, Optical mounts, Temperature metrology, Electronics, Optomechanical design, Sensors

Read Abstract +

The GMT-Consortium Large Earth Finder (G-CLEF) will be part of the first generation instrumentation suite for the Giant Magellan Telescope (GMT). G-CLEF is a general purpose echelle spectrograph operating in the optical passband with precision radial velocity (PRV) capability. The measurement precision goal of G-CLEF is 10 cm/sec; necessary for the detection of Earth analogues. This goal imposes challenging stability requirements on the optical mounts and spectrograph support structures especially when considering the instrument’s operational environment. G-CLEF’s accuracy will be influenced by changes in temperature and ambient air pressure, vibration, and micro gravity-vector variations caused by normal telescope motions. For these reasons we have chosen to enclose G-CLEF’s spectrograph in a wellinsulated, vibration-isolated vacuum chamber in a gravity invariant location on GMT’s azimuth platform. Additional design constraints posed by the GMT telescope include; a limited space envelope, a thermal leakage ceiling, and a maximum weight allowance. Other factors, such as manufacturability, serviceability, available technology, and budget are also significant design drivers. G-CLEF will complete its Critical Design phase in mid-2018. In this paper, we discuss the design of GCLEF’s optical mounts and support structures including the choice of a low-CTE carbon-fiber optical bench. We discuss the vacuum chamber and vacuum systems. We discuss the design of G-CLEF’s insulated enclosure and thermal control systems which simultaneously maintain the spectrograph at milli-Kelvin level stability and limit thermal leakage into the telescope dome. Also discussed are micro gravity-vector variations caused by normal telescope slewing, their uncorrected influence on image motion, and how they are dealt with in the design. We discuss G-CLEF’s front-end assembly and fiber-feed system as well as other interface, integration and servicing challenges presented by the telescope, enclosure, and neighboring instrumentation. This work has been supported by the GMTO Corporation, a non-profit organization operated on behalf of an international consortium of universities and institutions: Arizona State University, Astronomy Australia Ltd, the Australian National University, the Carnegie Institution for Science, Harvard University, the Korea Astronomy and Space Science Institute, the São Paulo Research Foundation, the Smithsonian Institution, the University of Texas at Austin, Texas AM University, the University of Arizona, and the University of Chicago.

Proceedings Article | 13 July 2018 Paper

Paper

Wide-field multi-object spectroscopy with MANIFEST

Jon Lawrence, Sagi Ben-Ami, David Brown, Rebecca Brown, Scott Case, Timothy Chin, Matthew Colless, Adam Contos, Darren Depoy, Ian Evans, Daniel Faes, Tony Farrell, Peter Gillingham, Michael Goodwin, Sungwook Hong, Narae Hwang, Wong-Seob Jeong, Urs Klauser, Kyler Kuehn, Nuria Lorente, Slavko Mali, Jennifer Marshall, Helen McGregor, Rolf Muller, Rafael Millan-Gabet, Vijay Nichani, Claudia Oliveria, Henrique Ortolan, naveen Pai, Sung-Joon Park, Travis Prochaska, Will Saunders, Luke Schmidt, Aline Souza, Andrew Szentgyorgyi, Lew Waller, Ross Zhelem

Proceedings Volume 10702, 10702A6 (2018) https://doi.org/10.1117/12.2314178

KEYWORDS: Telescopes, Spectrographs, Optical instrument design

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Proceedings Article | 12 July 2018 Paper

Paper

The optical design of the G-CLEF Spectrograph: the first light instrument for the GMT

Sagi Ben-Ami, Jeffrey Crane, Ian Evans, Stuart McMuldroch, Mark Mueller, William Podgorski, Andrew Szentgyorgyi

Proceedings Volume 10702, 107029K (2018) https://doi.org/10.1117/12.2313381

KEYWORDS: Spectrographs, Optical design, Cameras

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Proceedings Article | 11 July 2018 Paper

Paper

Detailed design of the G-CLEF flexure control camera subsystem

Jae Sok Oh, Chan Park, Kang-Min Kim, Moo-Young Chun, Young Sam Yu, Sungho Lee, Jihun Kim, Ueejeong Jeong, Chang-Hee Kim, Andrew Szentgyorgyi, Stuart McMuldroch, William Podgorski, Ian Evans, Mark Mueller, Alan Uomoto, Jeffrey Crane, Tyson Hare

Proceedings Volume 10702, 107028X (2018) https://doi.org/10.1117/12.2311908

KEYWORDS: Optical benches, Collimators, Cameras, Mirrors, Optical filtering, Sensors, Stars, CCD cameras, Space telescopes, Telescopes

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Proceedings Article | 6 July 2018 Presentation + Paper

Presentation + Paper

The preliminary design of the G-CLEF spectrograph instrument device control system

Ian Evans, Daniel Durusky, Janet DePonte Evans, Thomas Gauron, Cem Onyuksel, David Plummer

Proceedings Volume 10707, 107071F (2018) https://doi.org/10.1117/12.2312242

KEYWORDS: Control systems, Control systems design, Spectrographs, Prototyping, Systems modeling

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Proceedings Article | 6 July 2018 Presentation + Paper

Presentation + Paper

The GMT-consortium large earth finder (G-CLEF): an optical echelle spectrograph for the Giant Magellan Telescope (GMT)

Andrew Szentgyorgyi, Daniel Baldwin, Stuart Barnes, Jacob Bean, Sagi Ben-Ami, Patricia Brennan, Jamie Budynkiewicz, Daniel Catropa, Moo-Young Chun, Charlie Conroy, Adam Contos, Jeffrey Crane, Daniel Durusky, Harland Epps, Ian Evans, Janet Evans, Valery Fishman, Anna Frebel, Thomas Gauron, Dani Guzman, Tyson Hare, Bi-Ho Jang, Jeong-Gyun Jang, Andres Jordan, Jihun Kim, Kang-Min Kim, Yunjong Kim, Sungho Lee, Mercedes Lopez-Morales, Claudia Mendes de Oliveira, Kenneth McCracken, Stuart McMuldroch, Joseph Miller, Mark Mueller, Jae Sok Oh, Cem Onyuksel, Byeong-Gon Park, Chan Park, Sung-Joon Park, Charles Paxson, David Phillips, David Plummer, William Podgorski, Adam Rubin, Andreas Seifahrt, Daniel Stark, Joao Steiner, Alan Uomoto, Ronald Walsworth, Young-Sam Yu

Proceedings Volume 10702, 107021R (2018) https://doi.org/10.1117/12.2313539

KEYWORDS: Spectrographs, Cameras, Calibration, Telescopes, Stars, Optical benches, Thorium

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Proceedings Article | 9 August 2016 Paper

Paper

The optical design of the G-CLEF Spectrograph: the first light instrument for the GMT

Sagi Ben-Ami, Harland Epps, Ian Evans, Mark Mueller, William Podgorski, Andrew Szentgyorgyi

Proceedings Volume 9908, 9908A0 (2016) https://doi.org/10.1117/12.2232854

KEYWORDS: Spectrographs, Cameras, Optical fibers, Telescopes, Mirrors, Optical design, Optical components, Sensors, Reflection, Collimators

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Proceedings Article | 9 August 2016 Paper

Paper

The GMT-Consortium Large Earth Finder (G-CLEF): an optical Echelle spectrograph for the Giant Magellan Telescope (GMT)

Andrew Szentgyorgyi, Daniel Baldwin, Stuart Barnes, Jacob Bean, Sagi Ben-Ami, Patricia Brennan, Jamie Budynkiewicz, Moo-Young Chun, Charlie Conroy, Jeffrey Crane, Harland Epps, Ian Evans, Janet Evans, Jeff Foster, Anna Frebel, Thomas Gauron, Dani Guzmán, Tyson Hare, Bi-Ho Jang, Jeong-Gyun Jang, Andres Jordan, Jihun Kim, Kang-Miin Kim, Claudia Mendes Mendes de Oliveira, Mercedes Lopez-Morales, Kenneth McCracken, Stuart McMuldroch, Joseph Miller, Mark Mueller, Jae Sok Oh, Cem Onyuksel, Mark Ordway, Byeong-Gon Park, Chan Park, Sung-Joon Park, Charles Paxson, David Phillips, David Plummer, William Podgorski, Andreas Seifahrt, Daniel Stark, Joao Steiner, Alan Uomoto, Ronald Walsworth, Young-Sam Yu

Proceedings Volume 9908, 990822 (2016) https://doi.org/10.1117/12.2233506

KEYWORDS: Spectrographs, Telescopes, Cameras, Calibration, Lamps, Interfaces, Fiber science, Light sources, Optical design, Mirrors

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Proceedings Article | 9 August 2016 Paper

Paper

The opto-mechanical design of the GMT-Consortium Large Earth Finder (G-CLEF)

Mark Mueller, Andrew Szentgyorgyi, Daniel Baldwin, Jacob Bean, Sagi Ben-Ami, Patricia Brennan, J. Budynkiewicz, Moo-Yung Chun, Jeffrey Crane, Harland Epps, Ian Evans, Janet Evans, Jeff Foster, Anna Frebel, Thomas Gauron, Alex Glenday, Tyson Hare, Bi-Ho Jang, Jeong-Gyun Jang, Andreas Jordan, Jihun Kim, Kang-Min Kim, Claudia Mendes de Oliveira, Mercedes Lopez-Morales, Kenneth McCracken, Stuart McMuldroch, Joseph Miller, Jae Sok Oh, Cem Onyuksel, Mark Ordway, Chan Park, Sung-Joon Park, Charles Paxson, David Phillips, David Plummer, William Podgorski, Andreas Seifahrt, Joao Steiner, Alan Uomoto, Ronald Walsworth, Young-Sam Yu

Proceedings Volume 9908, 9908A2 (2016) https://doi.org/10.1117/12.2233246

KEYWORDS: Spectrographs, Telescopes, Optical mounts, Space telescopes, Cameras, Calibration, Temperature metrology, Control systems, Mirrors, Optical benches

Read Abstract +

The GMT-Consortium Large Earth Finder (G-CLEF) is a fiber-fed, optical echelle spectrograph selected as the first light instrument for the Giant Magellan Telescope (GMT) now under construction at the Las Campanas Observatory in Chile. G-CLEF has been designed to be a general-purpose echelle spectrograph with precision radial velocity (PRV) capability for exoplanet detection. The radial velocity (RV) precision goal of G-CLEF is 10 cm/sec, necessary for detection of Earth-sized exoplanets. This goal imposes challenging stability requirements on the optical mounts and the overall spectrograph support structures especially when considering the instrument’s operational environment. The accuracy of G-CLEF’s PRV measurements will be influenced by minute changes in temperature and ambient air pressure as well as vibrations and micro gravity-vector variations caused by normal telescope slewing. For these reasons we have chosen to enclose G-CLEF’s spectrograph in a well-insulated, vibration isolated vacuum chamber in a gravity invariant location on GMT’s azimuth platform. Additional design constraints posed by the GMT telescope include: a limited space envelope, a thermal emission ceiling, and a maximum weight allowance. Other factors, such as manufacturability, serviceability, available technology and budget are also significant design drivers. All of the above considerations must be managed while ensuring performance requirements are achieved. In this paper, we discuss the design of G-CLEF’s optical mounts and support structures including the choice of a low coefficient of thermal expansion (CTE) carbon-fiber optical bench to minimize the system’s sensitivity to thermal soaks and gradients. We discuss design choices made to the vacuum chamber geared towards minimize the influence of daily ambient pressure variations on image motion during observation. We discuss the design of G-CLEF’s insulated enclosure and thermal control systems which will maintain the spectrograph at milli-Kelvin level stability while simultaneously limiting thermal emissions into the telescope dome. Also discussed are micro gravity-vector variations caused by normal telescope slewing, their uncorrected influence on image motion, and how they are dealt with in the design. Finally, we discuss G-CLEF’s front-end assembly and fiber-feed system as well as other interface challenges presented by the telescope, enclosure and neighboring instrumentation.

Proceedings Article | 9 August 2016 Paper

Paper

Opto-mechanical design of the G-CLEF flexure control camera system

Jae Sok Oh, Chan Park, Jihun Kim, Kang-Min Kim, Moo-Young Chun, Young Sam Yu, Sungho Lee, Jakyoung Nah, Sung-Joon Park, Andrew Szentgyorgyi, Stuart McMuldroch, Timothy Norton, William Podgorski, Ian Evans, Mark Mueller, Alan Uomoto, Jeffrey Crane, Tyson Hare

Proceedings Volume 9908, 99089M (2016) https://doi.org/10.1117/12.2232147

KEYWORDS: Cameras, Mirrors, Telescopes, Sensors, Lenses, Collimators, Space telescopes, CCD cameras, Optical filters, Prisms

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Proceedings Article | 9 August 2016 Paper

Paper

The MANIFEST prototyping design study

Jonathan Lawrence, Sagi Ben-Ami, David Brown, Rebecca Brown, Scott Case, Steve Chapman, Vladimir Churilov, Matthew Colless, Robert Content, Darren Depoy, Ian Evans, Tony Farrell, Michael Goodwin, George Jacoby, Urs Klauser, Kyler Kuehn, Nuria P. Lorente, Slavko Mali, Jennifer Marshall, Rolf Muller, Vijay Nichani, Naveen Pai, Travis Prochaska, Will Saunders, Luke Schmidt, Keith Shortridge, Nicholas Staszak, Andrew Szentgyorgyi, Julia Tims, Minh Vuong, Lewis Waller, Ross Zhelem

Proceedings Volume 9908, 99089O (2016) https://doi.org/10.1117/12.2232412

KEYWORDS: Telescopes, Prototyping, Spectrographs, Optical instrument design, Optical instrument design, Cameras, Interfaces, Connectors, Metrology, Glasses, Galactic astronomy

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Proceedings Article | 8 August 2016 Paper

Paper

Software requirements flow-down and preliminary software design for the G-CLEF spectrograph

Ian Evans, Jamie Budynkiewicz, Janet DePonte Evans, Joseph Miller, Cem Onyuksel, Charles Paxson, David Plummer

Proceedings Volume 9913, 99131Q (2016) https://doi.org/10.1117/12.2232163

KEYWORDS: Spectrographs, Control systems, Software development, Telescopes, Sensors, Systems modeling, Cameras, Calibration, Imaging systems, Algorithm development

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Proceedings Article | 22 July 2016 Paper

Paper

Advanced structural design for precision radial velocity instruments

Dan Baldwin, Andrew Szentgyorgyi, Stuart Barnes, Jacob Bean, Sagi Ben-Ami, Patricia Brennan, Jamie Budynkiewicz, Moo-Young Chun, Charlie Conroy, Jeffrey Crane, Harland Epps, Ian Evans, Janet Evans, Jeff Foster, Anna Frebel, Thomas Gauron, Dani Guzman, Tyson Hare, Bi-Ho Jang, Jeong-Gyun Jang, Andres Jordan, Jihun Kim, Kang-Min Kim, Claudia Mendes de Oliveira, Mercedes Lopez-Morales, Kenneth McCracken, Stuart McMuldroch, Joseph Miller, Mark Mueller, Jae Sok Oh, Mark Ordway, Byeong-Gon Park, Chan Park, Sung-Joon Park, Charles Paxson, David Phillips, David Plummer, William Podgorski, Andreas Seifahrt, Daniel Stark, Joao Steiner, Alan Uomoto, Ronald Walsworth, Young-Sam Yu

Proceedings Volume 9912, 99123I (2016) https://doi.org/10.1117/12.2235250

KEYWORDS: Optical benches, Spectrographs, Optical design, Composites, Telescopes, Structural design, Finite element methods, Thermography, Sensors, Optical components

Read Abstract +

The GMT-Consortium Large Earth Finder (G-CLEF) is an echelle spectrograph with precision radial velocity (PRV) capability that will be a first light instrument for the Giant Magellan Telescope (GMT). G-CLEF has a PRV precision goal of 40 cm/sec (10 cm/s for multiple measurements) to enable detection of Earth-like exoplanets in the habitable zones of sun-like stars¹. This precision is a primary driver of G-CLEF’s structural design. Extreme stability is necessary to minimize image motions at the CCD detectors. Minute changes in temperature, pressure, and acceleration environments cause structural deformations, inducing image motions which degrade PRV precision. The instrument’s structural design will ensure that the PRV goal is achieved under the environments G-CLEF will be subjected to as installed on the GMT azimuth platform, including:

Millikelvin (0.001 °K) thermal soaks and gradients

10 millibar changes in ambient pressure

Changes in acceleration due to instrument tip/tilt and telescope slewing Carbon fiber/cyanate composite was selected for the optical bench structure in order to meet performance goals. Low coefficient of thermal expansion (CTE) and high stiffness-to-weight are key features of the composite optical bench design. Manufacturability and serviceability of the instrument are also drivers of the design.

In this paper, we discuss analyses leading to technical choices made to minimize G-CLEF’s sensitivity to changing environments. Finite element analysis (FEA) and image motion sensitivity studies were conducted to determine PRV performance under operational environments. We discuss the design of the optical bench structure to optimize stiffness-to-weight and minimize deformations due to inertial and pressure effects. We also discuss quasi-kinematic mounting of optical elements and assemblies, and optimization of these to ensure minimal image motion under thermal, pressure, and inertial loads expected during PRV observations.

Proceedings Article | 28 July 2014 Paper

Paper

A novel systems engineering approach to the design of a precision radial velocity spectrograph: the GMT-Consortium Large Earth Finder (G-CLEF)

William Podgorski, Jacob Bean, Henry Bergner, Moo-Young Chun, Jeffrey Crane, Ian Evans, Janet Evans, Gabor Furesz, Dani Guzman, Kang-Min Kim, Kenneth McCracken, Mark Mueller, Timothy Norton, Chan Park, Sang Park, David Plummer, Andrew Szentgyorgyi, Alan Uomoto, In-Soo Yuk

Proceedings Volume 9147, 91478W (2014) https://doi.org/10.1117/12.2056329

KEYWORDS: Spectrographs, Calibration, Telescopes, Error analysis, Velocity measurements, Sensors, Adaptive optics, Cameras, Mirrors, Space telescopes

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Proceedings Article | 28 July 2014 Paper

Paper

A preliminary design for the GMT-Consortium Large Earth Finder (G-CLEF)

Andrew Szentgyorgyi, Stuart Barnes, Jacob Bean, Bruce Bigelow, Antonin Bouchez, Moo-Young Chun, Jeffrey Crane, Harland Epps, Ian Evans, Janet Evans, Anna Frebel, Gabor Furesz, Alex Glenday, Dani Guzman, Tyson Hare, Bi-Ho Jang, Jeong-Gyun Jang, Ueejong Jeong, Andres Jordan, Kang-Min Kim, Jihun Kim, Chih-Hao Li, Mercedes Lopez-Morales, Kenneth McCracken, Brian McLeod, Mark Mueller, Jakyung Nah, Timothy Norton, Heeyoung Oh, Jae Sok Oh, Mark Ordway, Byeong-Gon Park, Chan Park, Sung-Joon Park, David Phillips, David Plummer, William Podgorski, Florian Rodler, Andreas Seifahrt, Kyung-Mo Tak, Alan Uomoto, Marcos Van Dam, Ronald Walsworth, Young Sam Yu, In-Soo Yuk

Proceedings Volume 9147, 914726 (2014) https://doi.org/10.1117/12.2056741

KEYWORDS: Spectrographs, Telescopes, Stars, Mirrors, Calibration, Exoplanets, Adaptive optics, Cameras, Interfaces, Optical design

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Proceedings Article | 28 July 2014 Paper

Paper

The G-CLEF spectrograph optical design

Gábor Fűrész, Harland Epps, Stuart Barnes, William Podgorski, Andrew Szentgyorgyi, Mark Mueller, Daniel Baldwin, Jacob Bean, Henry Bergner, Moo-Young Chun, Jeffrey Crane, Janet Evans, Ian Evans, Jeff Foster, Thomas Gauron, Dani Guzman, Edward Hertz, Andres Jordán, Kang-Min Kim, Kenneth McCracken, Timothy Norton, Mark Ordway, Chan Park, Sang Park, Dave Plummer, Alan Uomoto, In-Soo Yuk

Proceedings Volume 9147, 91479G (2014) https://doi.org/10.1117/12.2057153

KEYWORDS: Mirrors, Spectrographs, Cameras, Collimators, Optical design, Telescopes, Point spread functions, Sensors, Observatories, Spectral resolution

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Proceedings Article | 5 October 2012 Paper

Paper

The GMT-CfA, Carnegie, Catolica, Chicago Large Earth Finder (G-CLEF): a general purpose optical echelle spectrograph for the GMT with precision radial velocity capability

A. Szentgyorgyi, A. Frebel, G. Furesz, E. Hertz, T. Norton, J. Bean, H. Bergner, J. Crane, J. Evans, I. Evans, T. Gauron, A. Jordán, S. Park, A. Uomoto, S. Barnes, W. Davis, M. Eisenhower, H. Epps, D. Guzman, K. McCracken, M. Ordway, D. Plummer, W. Podgorski, D. Weaver

Proceedings Volume 8446, 84461H (2012) https://doi.org/10.1117/12.924957

KEYWORDS: Spectrographs, Cameras, Telescopes, Calibration, Optical design, Interfaces, Molybdenum, Lenses, Charge-coupled devices, Mirrors

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Proceedings Article | 7 October 2011 Paper

Paper

The Extreme Physics Explorer and large area micro-channel plate optics

Michael Garcia, Martin Elvis, Jon Chappell, Laura Brenneman, Daniel Patnaude, Ian Evans, Ricardo Bruni, Suzanne Romaine, Eric Silver, Richard Willingale, George Fraser, T. J. Turner, Brian Ramsey

Proceedings Volume 8147, 81471N (2011) https://doi.org/10.1117/12.894261

KEYWORDS: X-rays, Stars, Particles, Absorption, Physics, X-ray optics, Polarization, Point spread functions, Reflectivity, Glasses

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Proceedings Article | 14 July 2008 Paper

Paper

The software development process at the Chandra X-ray Center

Janet Evans, Ian Evans, Giuseppina Fabbiano

Proceedings Volume 7019, 701917 (2008) https://doi.org/10.1117/12.790524

KEYWORDS: Software development, Space operations, X-rays, Data archive systems, Data analysis, Observatories, Calibration, Databases, Data processing, Data modeling

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Proceedings Article | 12 July 2008 Paper

Paper

Planning and developing the Chandra Source Catalog

Ian Evans, Janet Evans, Guiseppina Fabbiano, Kenny Glotfelty, Michael McCollough, Jonathan McDowell, Francis Primini, Arnold Rots

Proceedings Volume 7016, 70161O (2008) https://doi.org/10.1117/12.790526

KEYWORDS: X-rays, X-ray sources, Databases, X-ray detectors, Algorithm development, Point spread functions, Observatories, X-ray astronomy, Astronomy, Sensors

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Proceedings Article | 30 June 2006 Paper

Paper

The Chandra X-ray Observatory data processing system

Ian Evans, Mark Cresitello-Dittmar, Stephen Doe, Janet Evans, Giuseppina Fabbiano, Gregg Germain, Kenny Glotfelty, David Plummer, Panagoula Zografou

Proceedings Volume 6270, 62701U (2006) https://doi.org/10.1117/12.672641

KEYWORDS: Data processing, Calibration, X-rays, Space operations, Cameras, Sensors, Data archive systems, Observatories, Data analysis, Software development

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Proceedings Article | 30 June 2006 Paper

Paper

The Chandra X-ray Observatory calibration database (CalDB): building, planning, and improving

Dale Graessle, Ian Evans, Kenny Glotfelty, X. Helen He, Janet Evans, Arnold Rots, Giuseppina Fabbiano, Roger Brissenden

Proceedings Volume 6270, 62701X (2006) https://doi.org/10.1117/12.672876

KEYWORDS: Calibration, Sensors, X-rays, Observatories, Databases, Interfaces, Optical filters, Data archive systems, Quantum efficiency, Magnetoencephalography

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Proceedings Article | 29 June 2006 Paper

Paper

The Chandra X-ray Center data system: supporting the mission of the Chandra X-ray Observatory

Janet Evans, Mark Cresitello-Dittmar, Stephen Doe, Ian Evans, Giuseppina Fabbiano, Gregg Germain, Kenny Glotfelty, Diane Hall, David Plummer, Panagoula Zografou

Proceedings Volume 6270, 62700N (2006) https://doi.org/10.1117/12.672660

KEYWORDS: Data archive systems, X-rays, Observatories, Space operations, Data processing, Software development, Databases, Calibration, Data analysis, Data storage

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Proceedings Article | 19 November 1998 Paper

Paper

High-accuracy calibration of the HXDS flow-proportional counter for AXAF at the PTB laboratory at BESSY

Jutta Auerhammer, G. Brandt, Frank Scholze, R. Thornagel, Gerhard Ulm, Bradford Wargelin, Walter McDermott, Timothy Norton, Ian Evans, Edwin Kellogg

Proceedings Volume 3444, (1998) https://doi.org/10.1117/12.331242

KEYWORDS: Sensors, Calibration, Quantum efficiency, Argon, Absorption, X-rays, Radiometry, Energy efficiency, Photodiodes, Synchrotron radiation

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Proceedings Article | 11 July 1997 Paper

Paper

AXAF HXDS germanium solid state detectors

Walter McDermott, Edwin Kellogg, Bradford Wargelin, Ian Evans, S. Vitek, Eugene Tsiang, Daniel Schwartz, Richard Edgar, Stefan Kraft, Frank Scholze, R. Thornagel, Gerhard Ulm, Martin Weisskopf, Stephen O'Dell, Allyn Tennant, Jeffery Kolodziejczak, C. Zirnstein

Proceedings Volume 3113, (1997) https://doi.org/10.1117/12.278888

KEYWORDS: Sensors, Calibration, Crystals, Aluminum, Germanium, Monochromators, Mirrors, Synchrotron radiation, Optical filters, Solid state electronics

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Proceedings Article | 11 July 1997 Paper

Paper

Absolute calibration of the AXAF telescope effective area

Edwin Kellogg, Lester Cohen, Richard Edgar, Ian Evans, Mark Freeman, Terrance Gaetz, Diab Jerius, Walter McDermott, Phillip McKinnon, Stephen Murray, William Podgorski, Daniel Schwartz, Leon Van Speybroeck, Bradford Wargelin, Martin Zombeck, Martin Weisskopf, Ronald Elsner, Stephen O'Dell, Allyn Tennant, Jeffery Kolodziejczak, Gordon Garmire, John Nousek, Stefan Kraft, Frank Scholze, R. Thornagel, Gerhard Ulm, Kathryn Flanagan, Daniel Dewey, Mark Bautz, Scott Texter, Jonathan Arenberg, R. Carlson

Proceedings Volume 3113, (1997) https://doi.org/10.1117/12.278885

KEYWORDS: Calibration, Sensors, X-rays, Quantum efficiency, Data modeling, X-ray sources, Error analysis, Telescopes, Mirrors, X-ray telescopes

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The prelaunch calibration of AXAF encompasses many aspects of the telescope. In principle, all that is needed is the complete point response function. This is, however, a function of energy, off-axis angle of the source, and operating mode of the facility. No single measurement would yield the entire result. Also, any calibration made prior to launch will be affected by changes in conditions after launch, such as the change from one g to zero g. The reflectivity of the mirror and perhaps even the detectors can change as well, for example by addition or removal of small amounts of material deposited on their surfaces. In this paper, we give a broad view of the issues in performing such a calibration, and discuss how they are being addressed in prelaunch preparation of AXAF. As our title indicates, we concentrate here on the total throughput of the observatory. This can be thought of as the integral of the point response function, i.e. the encircled energy, out to the largest practical solid angle for an observation. Since there is no standard x-ray source in the sky whose flux is well known to the approximately 1% accuracy we are trying to achieve, we must do this calibration on the ground. We also must provide a means for monitoring any possible changes in this calibration from prelaunch until on-orbit operation can transfer the calibration to a celestial x-ray source whose emission is stable. In the paper, we analyze the elements of the absolute throughput calibration, which we call the effective area. We review the requirements for calibrations of components or subsystems of the AXAF facility, including the mirror, detectors, and gratings. We show how it is necessary to have an absolute calibrated detection system available during the prelaunch calibrations to measure the flux in the x-ray beam used for calibrating AXAF. We show how it is necessary to calibrate this ground-based detection system at standard man-made x-ray sources, such as electron storage rings. We present the status of all these calibrations, with indications of the measurements remaining to be done, even though the measurements on the AXAF flight optics and detectors will have been completed by the time this paper is presented. We evaluate progress toward the goal of making 1% measurements of the absolute x-ray flux from astrophysical sources, so that comparisons can be made with their emission at other wavelengths, in support of observations such as the Sunyaev-Zeldovitch effect, which can give absolute distance measurements independent of the traditional distance measuring techniques in astronomy.

Proceedings Article | 11 July 1997 Paper

Paper

AXAF calibration: the HXDS flow proportional counters

Bradford Wargelin, Edwin Kellogg, Walter McDermott, Ian Evans, S. Vitek

Proceedings Volume 3113, (1997) https://doi.org/10.1117/12.278887

KEYWORDS: Calibration, Sensors, X-rays, Quantum efficiency, X-ray detectors, Mirrors, Synchrotrons, X-ray sources, Signal processing, Argon

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Proceedings Article | 11 July 1997 Paper

Paper

High-speed imager AXAF calibration microchannel plate detector

Ian Evans, Edwin Kellogg, Walter McDermott, Mark Ordway, J. Rosenberg, Bradford Wargelin

Proceedings Volume 3113, (1997) https://doi.org/10.1117/12.278848

KEYWORDS: Microchannel plates, Calibration, Sensors, Imaging systems, Electronics, X-rays, Quantum efficiency, Ions, X-ray detectors, Spatial resolution

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