Hector Galaxy Survey: Data processing, quality control, and early science

Abstract The Hector Galaxy Survey is a new optical integral field spectroscopy (IFS) survey currently using the Anglo-Australian Telescope to observe up to 15 000 galaxies at low redshift ( $z \lt 0.1$ ). The Hector instrument employs 21 optical fibre bundles feeding into two double-beam spectrographs, AAOmega and the new Spector spectrograph, to enable wide-field multi-object IFS observations of galaxies. To efficiently process the survey data, we adopt the data reduction pipeline developed for the SAMI Galaxy Survey, with significant updates to accommodate Hector’s dual-spectrograph system. These enhancements address key differences in spectral resolution and other instrumental characteristics relative to SAMI and are specifically optimised for Hector’s unique configuration. We introduce a two-dimensional arc fitting approach that reduces the root-mean-square (RMS) velocity scatter by a factor of 1.2–3.4 compared to fitting arc lines independently for each fibre. The pipeline also incorporates detailed modelling of chromatic optical distortion in the wide-field corrector, to account for wavelength-dependent spatial shifts across the focal plane. We assess data quality through a series of validation tests, including wavelength solution accuracy (1.2–2.7 km s $^{-1}$ RMS), spectral resolution (FWHM of 1.2–1.4 Å for Spector), throughput characterisation, astrometric precision ( $\lesssim$ 0.03 arcsec median offset), sky subtraction residuals (1–1.6% median continuum residual), and flux calibration stability (4% systematic offset when compared to Legacy Survey fluxes). We demonstrate that Hector delivers high-fidelity, science-ready datasets, supporting robust measurements of galaxy kinematics, stellar populations, and emission-line properties and provide examples. Additionally, we address systematic uncertainties identified during the data processing and propose future improvements to enhance the precision and reliability of upcoming data releases. This work establishes a robust data reduction framework for Hector, delivering high-quality data products that support a broad range of extragalactic studies.

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Journal
Publications of the Astronomical Society of Australia
Published
2025-01-01
DOI
https://doi.org/10.1017/pasa.2025.10106
Primary Topic
Astronomical Observations and Instrumentation
Type
article
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0.00

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article

Hector Galaxy Survey: Data processing, quality control, and early science

Andrei Ristea, Edward N. Taylor, E. S. Cheng, Manoj Mohanan et al.
Publications of the Astronomical Society of Australia
Astronomical Observations and Instrumentation
article

Hector Galaxy Survey: Data processing, quality control, and early science

Andrei Ristea, Edward N. Taylor, E. S. Cheng, Manoj Mohanan, Pablo Corcho-Caballero, Will Saunders, Kyuseok Oh, Mina Pak, J. C. Lee, Ross Zhelem, Jiwon Chung, Joss Bland‐Hawthorn, Sung-Hwan Min, S. J. O’Toole, Henry R. M. Zovaro, Joon Hyeop Lee, Caroline Foster, Rebecca J. Brown, A. H. Wang, Tayyaba Zafar, Hyunjin Jeong, O. Çakır, Peter Gillingham, Kathryn Grasha, Jon Lawrence, Minje Beom, Fred Crous, Thomas Rutherford, M. L. P. Gunawardhana, Jesse van de Sande, Jessica Zheng, Barnaby Norris, S. M. Croom, Helen McGregor, David Brodrick, Yiu‐Wing Mai, M. S. Owers, Matthew Colless, E. A. Houston, Sarah M. Sweet, Julia J. Bryant, Sam P Vaughan, Stefania Barsanti, Sree Oh, Anilkumar Mailvaganam, Priya Das, Gabriella Quattropani, Robert Content, Sujeeporn Tuntipong, G. Bhatia, N. Pai, Lisa M. Stuart, Tony Farrell, T. J. Woodrow, A. Sadman
article en

Abstract

Abstract The Hector Galaxy Survey is a new optical integral field spectroscopy (IFS) survey currently using the Anglo-Australian Telescope to observe up to 15 000 galaxies at low redshift ( $z \lt 0.1$ ). The Hector instrument employs 21 optical fibre bundles feeding into two double-beam spectrographs, AAOmega and the new Spector spectrograph, to enable wide-field multi-object IFS observations of galaxies. To efficiently process the survey data, we adopt the data reduction pipeline developed for the SAMI Galaxy Survey, with significant updates to accommodate Hector’s dual-spectrograph system. These enhancements address key differences in spectral resolution and other instrumental characteristics relative to SAMI and are specifically optimised for Hector’s unique configuration. We introduce a two-dimensional arc fitting approach that reduces the root-mean-square (RMS) velocity scatter by a factor of 1.2–3.4 compared to fitting arc lines independently for each fibre. The pipeline also incorporates detailed modelling of chromatic optical distortion in the wide-field corrector, to account for wavelength-dependent spatial shifts across the focal plane. We assess data quality through a series of validation tests, including wavelength solution accuracy (1.2–2.7 km s $^{-1}$ RMS), spectral resolution (FWHM of 1.2–1.4 Å for Spector), throughput characterisation, astrometric precision ( $\lesssim$ 0.03 arcsec median offset), sky subtraction residuals (1–1.6% median continuum residual), and flux calibration stability (4% systematic offset when compared to Legacy Survey fluxes). We demonstrate that Hector delivers high-fidelity, science-ready datasets, supporting robust measurements of galaxy kinematics, stellar populations, and emission-line properties and provide examples. Additionally, we address systematic uncertainties identified during the data processing and propose future improvements to enhance the precision and reliability of upcoming data releases. This work establishes a robust data reduction framework for Hector, delivering high-quality data products that support a broad range of extragalactic studies.

Publications of the Astronomical Society of AustraliaVol. 42
Australian National University (AU), The University of Sydney (AU), Seoul National University (KR), The University of Queensland (AU), University of Groningen (NL), The University of Western Australia (AU), Yonsei University (KR), Korea Astronomy and Space Science Institute (KR), Australian Astronomical Observatory (AU), Mount Stromlo Observatory (AU), UNSW Sydney (AU), Astronomical Institute of the Slovak Academy of Sciences (SK), ARC Centre of Excellence for All-sky Astrophysics (AU), Swinburne University of Technology (AU), Netherlands Institute for Radio Astronomy (NL), Macquarie University (AU)
Society of Interventional Radiology Foundation, Australian Government, University of Cambridge, University of Oxford, Macquarie University, National Research Foundation, Yonsei University, Korea Astronomy and Space Science Institute, National Research Foundation of Korea, Ministry of Science and ICT, South Korea
Openalex Percentile: Top 70%
Astronomical Observations and Instrumentation
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