Journal article
The information on halo properties contained in spectroscopic observations of late-type galaxies
- Abstract:
- Rotation curves are the key observational manifestation of the dark matter distribution around late-type galaxies. In a halo model context, the precision of constraints on halo parameters is a complex function of properties of the measurements as well as properties of the galaxy itself. Forthcoming surveys will resolve rotation curves to varying degrees of precision, or measure their integrated effect in the HI linewidth. To ascertain the relative significance of the relevant quantities for constraining halo properties, we study the information on halo mass and concentration as quantified by the Kullback–Leibler divergence of the kinematics-informed posterior from the uninformative prior. We calculate this divergence as a function of the different types of spectroscopic observation, properties of the measurement, galaxy properties, and auxiliary observational data on the baryonic components. Using the SPARC (Spitzer Photometry & Accurate Rotation Curves) sample, we find that fits to the full rotation curve exhibit a large variation in information gain between galaxies, ranging from ~1 to ~11 bits. The variation is predominantly caused by the vast differences in the number of data points and the size of velocity uncertainties between the SPARC galaxies. We also study the relative importance of the minimum HI surface density probed and the size of velocity uncertainties on the constraining power on the inner halo density slope, finding the latter to be significantly more important. We spell out the implications of these results for the optimization of galaxy surveys aiming to constrain galaxies’ dark matter distributions, highlighting the need for precise velocity measurements.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 1.4MB, Terms of use)
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- Publisher copy:
- 10.1093/mnras/stad2406
Authors
+ Royal Society
More from this funder
- Funder identifier:
- https://ror.org/03wnrjx87
- Funding agency for:
- Desmond, H
- Grant:
- 211046
- Programme:
- Royal Society University Research Fellowship
+ European Research Council
More from this funder
- Funder identifier:
- https://ror.org/0472cxd90
- Grant:
- 693024
- Publisher:
- Oxford University Press
- Journal:
- Monthly Notices of the Royal Astronomical Society More from this journal
- Volume:
- 525
- Issue:
- 4
- Pages:
- 5066-5079
- Publication date:
- 2023-08-31
- Acceptance date:
- 2023-07-20
- DOI:
- EISSN:
-
1365-2966
- ISSN:
-
0035-8711
- Language:
-
English
- Keywords:
- Pubs id:
-
1546413
- Local pid:
-
pubs:1546413
- Deposit date:
-
2024-04-25
Terms of use
- Copyright holder:
- Yasin et al.
- Copyright date:
- 2023
- Rights statement:
- © The Author(s) 2023. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( https://cr eativecommons.or g/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
- Notes:
- This research was funded in whole or in part by European Research Council (693024). For the purposes of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript (AAM) version arising from this submission.
- Licence:
- CC Attribution (CC BY)
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