Search

Your search keyword '"Spencer, Locke D."' showing total 82 results
Start Over Author "Spencer, Locke D."
82 results on '"Spencer, Locke D."'

1. Fastcc: fast colour corrections for broadband radio telescope data

Author

Peel, Mike W., Genova-Santos, Ricardo, Dickinson, C., Leahy, J. P., López-Caraballo, Carlos, Fernández-Torreiro, M., Rubiño-Martín, J. A., and Spencer, Locke D.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Broadband receiver data need colour corrections applying to correct for the different source spectra across their wide bandwidths. The full integration over a receiver bandpass may be computationally expensive and redundant when repeated many times. Colour corrections can be applied, however, using a simple quadratic fit based on the full integration instead. Here we describe fastcc and interpcc, quick Python and IDL codes that return, respectively, colour correction coefficients for different power-law spectral indices and modified black bodies for various Cosmic Microwave Background related experiments. The codes are publicly available, and can be easily extended to support additional telescopes., Comment: 3 pages, 1 figure. Published in RNAAS

Published
2022
Full Text
View/download PDF

2. CCAT-prime: Optical and cryogenic design of the 850 GHz module for Prime-Cam

Author

Huber, Anthony I., Chapman, Scott C., Sinclair, Adrian K., Spencer, Locke D., Austermann, Jason E., Choi, Steve K., Devina, Jesslyn, Gallardo, Patricio A., Henke, Doug, Huber, Zachary B., Keller, Ben, Li, Yaqiong, Lin, Lawrence T., Niemack, Mike, Rossi, Kayla M., Vavagiakis, Eve M., and Wheeler, Jordan D.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

Prime-Cam is a first-generation instrument for the Cerro Chajnantor Atacama Telescope-prime (CCAT-prime) Facility. The 850$~$GHz module for Prime-Cam will probe the highest frequency of all the instrument modules. We describe the parameter space of the 850$~$GHz optical system between the F$\lambda$ spacing, beam size, pixel sensitivity, and detector count. We present the optimization of an optical design for the 850$~$GHz instrument module for CCAT-prime. We further describe the development of the cryogenic RF chain design to accommodate $>$30 readout lines to read 41,400 kinetic inductance detectors (KIDs) within the cryogenic testbed., Comment: 12 pages, 7 figures

Published
2022

3. The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder I. The Spectral Feature Finder and Catalogue

Author

Hopwood, R., Valtchanov, I., Spencer, Locke D., Scott, J. P., Benson, C. S., Marchili, N., Hladczuk, N., Polehampton, E. T., Lu, N., Makiwa, G., Naylor, D. A., Gom, B. G., Noble, G., and Griffin, M. J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

We provide a detailed description of the Herschel-SPIRE Fourier Transform Spectrometer (FTS) Spectral Feature Finder (FF). The FF is an automated process designed to extract significant spectral features from SPIRE FTS data products. Optimising the number of features found in SPIRE-FTS spectra is challenging. The wide SPIRE-FTS frequency range (447-1568 GHz) leads to many molecular species and atomic fine structure lines falling within the observed bands. As the best spectral resolution of the SPIRE-FTS is ~1.2 GHz, there can be significant line blending, depending on the source type. In order to find, both efficiently and reliably, features in spectra associated with a wide range of sources, the FF iteratively searches for peaks over a number of signal-to-noise ratio (SNR) thresholds. For each threshold, newly identified features are rigorously checked before being added to the fitting model. At the end of each iteration, the FF simultaneously fits the continuum and features found, with the resulting residual spectrum used in the next iteration. The final FF products report the frequency of the features found and the associated SNRs. Line flux determination is not included as part of the FF products, as extracting reliable line flux from SPIRE-FTS data is a complex process that requires careful evaluation and analysis of the spectra on a case-by-case basis. The FF results are 100% complete for features with SNR greater than 10 and 50-70% complete at SNR of 5. The FF code and all FF products are publicly available via the Herschel Science Archive., Comment: 20 pages, 8 figures, 8 tables, final version accepted by MNRAS June 2020

Published
2020
Full Text
View/download PDF

4. The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder III. Line Identification and Off-Axis Spectra

Author

Benson, Chris S., Hladczuk, N., Spencer, Locke D., Robb, A., Scott, J. P., Valtchanov, I., Hopwood, R., and Naylor, David A.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

The ESA Herschel Spectral and Photometric Imaging Receiver (SPIRE) Fourier Transform Spectrometer (FTS) Spectral Feature Finder (FF) project is an automated spectral feature fitting routine developed within the SPIRE instrument team to extract all prominent spectral features from all publicly available SPIRE FTS observations. We present the extension of the FF to include the off-axis detectors of the FTS in sparsely sampled single-pointing observations, the results of which have been ingested into the catalogue. We also present the results from an automated routine for identifications of the atomic/molecular transitions that correspond to the spectral features extracted by the FF. We use a template of 307 atomic fine structure and molecular lines that are commonly found in SPIRE FTS spectra for the cross-match. The routine makes use of information provided by the line identification to search for low signal-to-noise ratio features that have been excluded or missed by the iterative FF. In total, the atomic/molecular transitions of 178,942 lines are identified (corresponding to 83% of the entire FF catalogue), and an additional 33,840 spectral lines associated with missing features from SPIRE FTS observations are added to the FF catalogue., Comment: 15 pages (+2 appendix pages), 14 figures, 7 tables, final version accepted by MNRAS June 2020

Published
2020
Full Text
View/download PDF

5. The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder IV. Neutral Carbon Detection in the SPIRE FTS Spectra

Author

Scott, Jeremy P., Spencer, Locke D., Hopwood, Rosalind, Valtchanov, Ivan, and Naylor, David A.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The SPIRE FTS Spectral Feature Finder (FF), developed within the Herschel Spectral and Photometric Imaging Receiver (SPIRE) Fourier Transform Spectrometer (FTS) instrument team, is an automated spectral feature fitting routine that attempts to find significant features in SPIRE FTS spectra. The $^3$P$_1$ - $^3$P$_0$ and $^3$P$_2$ - $^3$P$_1$ neutral carbon fine structure lines are common features in carbon rich far-infrared astrophysical sources. These features can be difficult to detect using an automated feature detection routine due to their typically low amplitude and line blending. In this paper we describe and validate the FF sub-routine designed to detect the neutral carbon emission observed in SPIRE spectral data., Comment: 8 pages, 9 figures, 2 tables, final version accepted by MNRAS June 2020

Published
2020
Full Text
View/download PDF

6. The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder II. Estimating Radial Velocity of SPIRE Spectral Observation Sources

Author

Scott, Jeremy P., Hladczuk, Natalia, Spencer, Locke D., Valtchanov, Ivan, Benson, Chris S., and Hopwood, Rosalind

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

The Herschel SPIRE FTS Spectral Feature Finder (FF) detects significant spectral features within SPIRE spectra and employs two routines, and external references, to estimate source radial velocity. The first routine is based on the identification of rotational CO emission, the second cross-correlates detected features with a line template containing most of the characteristic lines in typical far infra-red observations. In this paper, we outline and validate these routines, summarise the results as they pertain to the FF, and comment on how external references were incorporated., Comment: 12 pages, 16 figures, 1 table, accepted by MNRAS March 2020

Published
2020
Full Text
View/download PDF

8. Feedback-controlled transition-edge sensor bolometers in a far-infrared double-Fourier interferometer

Author

Spencer, Locke D., Benson, Christopher S., University of Lethbridge. Faculty of Arts and Science, Spencer, Locke D., Benson, Christopher S., and University of Lethbridge. Faculty of Arts and Science

Abstract

The far-infrared Universe provides substantial insights into the formation of stars and planetary systems, the assembly history and evolution of galaxies, the origins of the Universe, and the search for life. Despite its great scientific potential, the far-infrared Universe remains relatively unexplored with the degree of spatial resolution that is available in observations at other wavelengths. Double-Fourier spatial-spectral interferometry provides a promising path to achieve transformative spatial resolution in far-infrared observations. To further study this technique and improve on its technology readiness, we have constructed a far-infrared double-Fourier interferometry testbed that is coupled to a unique detector array of feedback-controlled transition-edge sensor bolometers. To fully understand measurements made with the interferometry testbed and ensure that these are well-calibrated, the detector system must be understood and characterised at a technical level. The detector array itself is a bespoke system with a substantial parameter space that can be optimized for different use-cases which has made this a daunting task. This thesis centres on the experiments I have conducted to characterise, calibrate, and optimise the detector system both in a general sense and in the context of the double-Fourier instrument. Through this investigation of the detector system, I have reduced the spectral noise of the double-Fourier interferometry testbed by 70%. Throughout this work, I review the concepts and theory related to measurements made with Fourier transform spectrometers and double-Fourier interferometers (Chapter 2). Additionally, I discuss transition-edge sensor bolometers and introduce the feedback-controlled bolometer system (Chapter 3). I have included a detailed discussion of my experiments to chracterise the measurement process of the detector array, optimise its noise performance, and tune its response to optical modulation (Chapter 4). I also provide a

Published
2024

14. CCAT-prime: optical and cryogenic design of the 850 GHz module for Prime-Cam

Author

Huber, Anthony I., primary, Chapman, Scott C., additional, Sinclair, Adrian K., additional, Spencer, Locke D., additional, Austermann, Jason E., additional, Choi, Steve K., additional, Devina, Jesslyn, additional, Gallardo, Patricio A., additional, Henke, Doug, additional, Huber, Zachary B., additional, Keller, Ben, additional, Li, Yaqiong, additional, Lin, Lawrence T., additional, Niemack, Mike, additional, Rossi, Kayla M., additional, Vavagiakis, Eve M., additional, and Wheeler, Jordan D., additional

Published
2022
Full Text
View/download PDF

18. Technique for the metrology calibration of a Fourier transform spectrometer

Author

Spencer, Locke D. and Naylor, David A.

Subjects
Spectrometer -- Usage, Fourier transform spectroscopy -- Equipment and supplies, Fourier transform spectroscopy -- Methods, Calibration -- Methods, Astronomy, Physics
Abstract

A method is presented for using a Fourier transform spectrometer (FTS) to calibrate the metrology of a second FTS. This technique is particularly useful when the second FTS is inside a cryostat or otherwise inaccessible. OCIS codes: 120.0120, 120.3930, 120.3940, 120.6200, 300.6300.

Published
2008

19. CCAT-prime: optical and cryogenic design of the 850 GHz module for Prime-Cam

Author

Zmuidzinas, Jonas, Gao, Jian-Rong, Huber, Anthony I., Chapman, Scott C., Sinclair, Adrian K., Spencer, Locke D., Austermann, Jason E., Choi, Steve K., Devina, Jesslyn, Gallardo, Patricio A., Henke, Doug, Huber, Zachary B., Keller, Ben, Li, Yaqiong, Lin, Lawrence T., Niemack, Mike, Rossi, Kayla M., Vavagiakis, Eve M., and Wheeler, Jordan D.

Published
2022
Full Text
View/download PDF

23. Composite material evaluation at cryogenic temperatures for applications in space-based far-infrared astronomical instrumentation

Author

Spencer, Locke D., primary, Veenendaal, Ian T., primary, Naylor, David A., primary, Gunuganti, Sudhakar, primary, Gom, Brad G., primary, Jones, Martyn, primary, Walker, David, primary, Day, Richard, primary, Zobeiry, Navid, primary, Poursartip, Anoush, primary, Christiansen, Adam, primary, Benson, Chris, primary, Sitwell, Geoffrey R. H., primary, and Huber, Anthony, primary

Published
2018
Full Text
View/download PDF

28. Progress in the Critical Assessment for a Far-Infrared Space Interferometer with Double Fourier Modulation (FP7-FISICA)

Author

Savini, G., Ade, P.A.R., Baccichet, Nicola, Bracken, Colm, Dohlen, Kjetil, Donohoe, Anthony, Gom, Brad, Griffin, Matthew J., Holland, Wayne, Iafolla, Valerio, Ivison, Rob, Jones, Martyn, Juanola-Parramon, Roser, Lightfoot, John, Liu, Scige, McMillan, Alison, Murphy, J.Anthony, Naylor, David A., O'Sullivan, Créidhe, Pascale, Enzo, Pezzuto, Stefano, Rakotonimbahy, Eddy, Schito, Daniele, Spencer, Locke D., Spinoglio, Luigi, Swinyard, Bruce, Veenendaal, Ian, Vives, Sebastien, Walker, David, Leisawitz, David T., Shi, Sheng-Cai, Matsuo, Hiroshi, Savini, G., Ade, P.A.R., Baccichet, Nicola, Bracken, Colm, Dohlen, Kjetil, Donohoe, Anthony, Gom, Brad, Griffin, Matthew J., Holland, Wayne, Iafolla, Valerio, Ivison, Rob, Jones, Martyn, Juanola-Parramon, Roser, Lightfoot, John, Liu, Scige, McMillan, Alison, Murphy, J.Anthony, Naylor, David A., O'Sullivan, Créidhe, Pascale, Enzo, Pezzuto, Stefano, Rakotonimbahy, Eddy, Schito, Daniele, Spencer, Locke D., Spinoglio, Luigi, Swinyard, Bruce, Veenendaal, Ian, Vives, Sebastien, Walker, David, Leisawitz, David T., Shi, Sheng-Cai, and Matsuo, Hiroshi

Abstract

The progress and results of the ongoing FP7-FISICA programme to re-asses the scientific goals of a Far-Infrared Space Interfereometer and push the development of some of its key technology elements are reported.

Published
2015

31. In-orbit performance of the Herschel/SPIRE imaging Fourier transform spectrometer: lessons learned

Author

Oschmann, Jacobus M., Jr., Clampin, Mark, Fazio, Giovanni G., MacEwen, Howard A., Naylor, David A., Baluteau, Jean-Paul, Bendo, George J., Benielli, Dominique, Fulton, Trevor, Gom, Brad G., Griffin, Matthew J., Hopwood, Rosalind, Imhof, Peter, Lim, Tanya L., Lu, Nanyao, Makiwa, Gibion, Marchili, Nicola, Orton, Glen S., Papgeorgiou, Andreas, Pearson, Chris, Polehampton, Edward T., Schulz, Bernhard, Spencer, Locke D., Swinyard, Bruce M., Valtchanov, Ivan, van der Wiel, Matthijs, Veenendaal, Ian T., Wu, Ronin, Oschmann, Jacobus M., Jr., Clampin, Mark, Fazio, Giovanni G., MacEwen, Howard A., Naylor, David A., Baluteau, Jean-Paul, Bendo, George J., Benielli, Dominique, Fulton, Trevor, Gom, Brad G., Griffin, Matthew J., Hopwood, Rosalind, Imhof, Peter, Lim, Tanya L., Lu, Nanyao, Makiwa, Gibion, Marchili, Nicola, Orton, Glen S., Papgeorgiou, Andreas, Pearson, Chris, Polehampton, Edward T., Schulz, Bernhard, Spencer, Locke D., Swinyard, Bruce M., Valtchanov, Ivan, van der Wiel, Matthijs, Veenendaal, Ian T., and Wu, Ronin

Abstract

The Spectral and Photometric Imaging Receiver (SPIRE) is one of three scientific instruments on board the European Space Agency's Herschel Space Observatory which ended its operational phase on 29 April 2013. The low to medium resolution spectroscopic capability of SPIRE is provided by an imaging Fourier transform spectrometer (iFTS) of the Mach-Zehnder configuration. With their high throughput, broad spectral coverage, and variable resolution, coupled with their well-defined instrumental line shape and intrinsic wavelength and intensity calibration, iFTS are becoming increasingly common in far-infrared space astronomy missions. The performance of the SPIRE imaging spectrometer will be reviewed and example results presented. The lessons learned from the measured performance of the spectrometer as they apply to future missions will be discussed.

Published
2014

34. In-orbit performance of the Herschel/SPIRE imaging Fourier transform spectrometer: lessons learned

Author

Naylor, David A., additional, Baluteau, Jean-Paul, additional, Bendo, George J., additional, Benielli, Dominique, additional, Fulton, Trevor R., additional, Gom, Brad G., additional, Griffin, Matthew J., additional, Hopwood, Rosalind, additional, Imhof, Peter, additional, Lim, Tanya L., additional, Lu, Nanyao, additional, Makiwa, Gibion, additional, Marchili, Nicola, additional, Orton, Glenn S., additional, Papageorgiou, Andreas, additional, Pearson, Chris, additional, Polehampton, Edward T., additional, Schulz, Bernhard, additional, Spencer, Locke D., additional, Swinyard, Bruce M., additional, Valtchanov, Ivan, additional, van der Wiel, Matthijs H. D., additional, Veenendaal, Ian T., additional, and Wu, Ronin, additional

Published
2014
Full Text
View/download PDF

36. Empirical modelling of the BLASTPol achromatic half-wave plate for precision submillimetre polarimetry

Author

Moncelsi, Lorenzo, primary, Ade, Peter A. R., additional, Angilè, Francesco E., additional, Benton, Steven J., additional, Devlin, Mark J., additional, Fissel, Laura M., additional, Gandilo, Natalie N., additional, Gundersen, Joshua O., additional, Matthews, Tristan G., additional, Netterfield, C. Barth, additional, Novak, Giles, additional, Nutter, David, additional, Pascale, Enzo, additional, Poidevin, Frédérick, additional, Savini, Giorgio, additional, Scott, Douglas, additional, Soler, Juan Diego, additional, Spencer, Locke D., additional, Truch, Matthew D. P., additional, Tucker, Gregory S., additional, and Zhang, Jin, additional

Published
2013
Full Text
View/download PDF

37. In-orbit performance of the Herschel/SPIRE imaging Fourier transform spectrometer

Author

Oschmann, Jacobus M., Clampin, Mark C., MacEwen, Howard A., Naylor, David A., Baluteau, Jean-Paul, Barlow, Mike J., Benielli, Dominique, Ferlet, Marc, Fulton, Trevor R., Griffin, Matthew J., Grundy, Timothy, Imhof, Peter, Jones, Scott, King, Ken, Leeks, Sarah J., Lim, Tanya L., Lu, Nanyao, Makiwa, Gibion, Polehampton, Edward T., Savini, Giorgio, Sidher, Sunil D., Spencer, Locke D., Surace, Christian, Swinyard, Bruce M., Wesson, Roger, Oschmann, Jacobus M., Clampin, Mark C., MacEwen, Howard A., Naylor, David A., Baluteau, Jean-Paul, Barlow, Mike J., Benielli, Dominique, Ferlet, Marc, Fulton, Trevor R., Griffin, Matthew J., Grundy, Timothy, Imhof, Peter, Jones, Scott, King, Ken, Leeks, Sarah J., Lim, Tanya L., Lu, Nanyao, Makiwa, Gibion, Polehampton, Edward T., Savini, Giorgio, Sidher, Sunil D., Spencer, Locke D., Surace, Christian, Swinyard, Bruce M., and Wesson, Roger

Abstract

The Spectral and Photometric Imaging Receiver (SPIRE) is one of three scientific instruments onboard the European Space Agency's Herschel Space Observatory launched on 14 May 2009. The low to medium resolution spectroscopic capability of SPIRE is provided by an imaging Fourier transform spectrometer of the Mach-Zehnder configuration. Results from the in flight performance verification phase of the SPIRE spectrometer are presented and conformance with the instrument design specifications is reviewed.

Published
2010

41. In-orbit Performance of the Imaging Fourier Transform Spectrometer of the Herschel Space Observatory

Author

Naylor, David A., primary, Baluteau, Jean-Paul, additional, Barlow, Mike J., additional, Benielli, Dominique, additional, Ferlet, Marc, additional, Fulton, Trevor R., additional, Griffin, Matthew J., additional, Grundy, Timothy, additional, Imhof, Peter, additional, Jones, Scott, additional, King, Ken, additional, Leeks, Sarah J., additional, Lim, Tanya L., additional, Lu, Nanyao, additional, Makiwa, Gibion, additional, Polehampton, Edward T., additional, Savini, Giorgio, additional, Sidher, Sunil D., additional, Spencer, Locke D., additional, Surace, Christian, additional, Swinyard, Bruce M., additional, and Wesson, Roger, additional

Published
2011
Full Text
View/download PDF

43. In-orbit performance of the Herschel/SPIRE imaging Fourier transform spectrometer

Author

Naylor, David A., primary, Baluteau, Jean-Paul, additional, Barlow, Mike J., additional, Benielli, Dominique, additional, Ferlet, Marc, additional, Fulton, Trevor R., additional, Griffin, Matthew J., additional, Grundy, Timothy, additional, Imhof, Peter, additional, Jones, Scott, additional, King, Ken, additional, Leeks, Sarah J., additional, Lim, Tanya L., additional, Lu, Nanyao, additional, Makiwa, Gibion, additional, Polehampton, Edward T., additional, Savini, Giorgio, additional, Sidher, Sunil D., additional, Spencer, Locke D., additional, Surace, Christian, additional, Swinyard, Bruce M., additional, and Wesson, Roger, additional

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results