Table · dataset · 2025
PANDISC. I. HI model applied to ALFAFA & SPARC gal.
Listed in IVOA Registry (Virtual Observatory)
Modeling the integrated HI spectra of galaxies has been a difficult task, due to their diverse shapes, but more dynamical information is waiting to be explored in HI line profiles.
Description
Based on simple assumptions, we construct a physically motivated model for the integrated HI spectra: Parameterized Asymmetric Neutral hydrogen Disk Integrated Spectrum Characterization (PANDISC). The model shows great flexibility in reproducing the diverse HI profiles.
We use Monte Carlo Markov Chain for fitting the model to global HI profiles and produce statistically robust quantitative results. Comparing with several samples of HI data available in the literature, we find the model-fitted widths agree with cataloged velocity widths (e.g., W50) down to S/N<~6. While dynamical information can only be extracted reliably from spectra with S/N>8.
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The model is also shown to be useful for applications like the baryonic Tully-Fisher relation (BTFR) and profile-based sample control. By comparing the model parameter vr to vflat, we uncover how the HI width is affected by the structure of the rotation curve, following a trend consistent with the difference in the BTFR slope. We also select a sample of spectra with broad wing-like features suggestive of a population of galaxies with unusual gas dynamics.
The PANDISC model bears both promise and limitations for potential use beyond HI lines. Further application on the whole ALFALFA sample will enable us to perform large-scale ensemble studies of the HI properties and dynamics in nearby galaxies.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/950/163 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2023ApJ...950..163P ui.adsabs.harvard.edu/abs/2023ApJ...950..163P ↗
publication · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/cds.vizier/j/apj/950/163 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Radio
- From keywords
- Astronomy & Astrophysics
Provenance · 1 source records, 8 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/apj/950/163 | 14 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:radio | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| license_text | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |