Breaking the Degeneracy between Warps and Radial Flows in External Galaxies
Observations of the line-of-sight (LOS) component of emitter velocities in galaxies are valuable for reconstructing their two-dimensional (2D) velocity fields, albeit requiring certain assumptions. A common one is that radial flows can be neglected in the outer regions of galaxies, while their geome...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adc71c |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850106111592497152 |
|---|---|
| author | Francesco Sylos Labini Giordano De Marzo Matteo Straccamore |
| author_facet | Francesco Sylos Labini Giordano De Marzo Matteo Straccamore |
| author_sort | Francesco Sylos Labini |
| collection | DOAJ |
| description | Observations of the line-of-sight (LOS) component of emitter velocities in galaxies are valuable for reconstructing their two-dimensional (2D) velocity fields, albeit requiring certain assumptions. A common one is that radial flows can be neglected in the outer regions of galaxies, while their geometry can be deformed by a warp. A specular approach assumes that galactic disks are flat but allows for the presence of radial flows. This approach enables the reconstruction of 2D velocity maps that encompass both the transversal and radial velocity fields. Through the study of velocity fields in toy disk models, we find that the presence of warps is manifested as a dipolar correlation between the two velocity components obtained by assuming a flat disk. This shows that the analysis of angular velocity anisotropies provides an effective tool for breaking the degeneracy between warps and radial flows. We have applied these findings to the analysis of velocity fields of the galaxies from the THINGS sample and M33. Many of these galaxies exhibit such a dipolar correlation, indicating the presence of warps. However, we have found that the warp alone cannot explain all variations in the velocity field, suggesting that intrinsic perturbations are common. Furthermore, we have observed that the spatial distribution of the LOS velocity dispersion may correlate with both velocity components, providing independent evidence of nontrivial velocity fields. These findings offer a robust approach to reconstructing the velocity fields of galaxies, allowing us to distinguish between the presence of warps and complex velocity structures by assessing their relative amplitude. |
| format | Article |
| id | doaj-art-cea66537149f409b99bd30e29d29d0a5 |
| institution | OA Journals |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-cea66537149f409b99bd30e29d29d0a52025-08-20T02:38:54ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01988112210.3847/1538-4357/adc71cBreaking the Degeneracy between Warps and Radial Flows in External GalaxiesFrancesco Sylos Labini0https://orcid.org/0000-0003-2236-4537Giordano De Marzo1Matteo Straccamore2https://orcid.org/0000-0002-3351-2323Centro Ricerche Enrico Fermi , Via Pansiperna 89a, 00184 Rome, Italy ; sylos@cref.it; Istituto Nazionale Fisica Nucleare , Unità Roma 1, Dipartimento di Fisica, Universitá di Roma “Sapienza,” 00185 Rome, ItalyCentro Ricerche Enrico Fermi , Via Pansiperna 89a, 00184 Rome, Italy ; sylos@cref.it; Dipartimento di Fisica, Sapienza, Universitá di Roma , I-00185, Roma, Italy; Complexity Science Hub Vienna , Josefstaedter Strasse 39, 1080, Vienna, Austria; University of Konstanz , Universitätstraße 10, 78457 Konstanz, GermanyCentro Ricerche Enrico Fermi , Via Pansiperna 89a, 00184 Rome, Italy ; sylos@cref.it; Sony CSL—Rome , Joint Initiative CREF-SONY, Centro Ricerche Enrico Fermi, Via Panisperna 89/A, 00184, Rome, ItalyObservations of the line-of-sight (LOS) component of emitter velocities in galaxies are valuable for reconstructing their two-dimensional (2D) velocity fields, albeit requiring certain assumptions. A common one is that radial flows can be neglected in the outer regions of galaxies, while their geometry can be deformed by a warp. A specular approach assumes that galactic disks are flat but allows for the presence of radial flows. This approach enables the reconstruction of 2D velocity maps that encompass both the transversal and radial velocity fields. Through the study of velocity fields in toy disk models, we find that the presence of warps is manifested as a dipolar correlation between the two velocity components obtained by assuming a flat disk. This shows that the analysis of angular velocity anisotropies provides an effective tool for breaking the degeneracy between warps and radial flows. We have applied these findings to the analysis of velocity fields of the galaxies from the THINGS sample and M33. Many of these galaxies exhibit such a dipolar correlation, indicating the presence of warps. However, we have found that the warp alone cannot explain all variations in the velocity field, suggesting that intrinsic perturbations are common. Furthermore, we have observed that the spatial distribution of the LOS velocity dispersion may correlate with both velocity components, providing independent evidence of nontrivial velocity fields. These findings offer a robust approach to reconstructing the velocity fields of galaxies, allowing us to distinguish between the presence of warps and complex velocity structures by assessing their relative amplitude.https://doi.org/10.3847/1538-4357/adc71cGalaxy kinematicsGalaxy rotationGalaxy rotation curvesGalaxy dynamicsSpiral galaxies |
| spellingShingle | Francesco Sylos Labini Giordano De Marzo Matteo Straccamore Breaking the Degeneracy between Warps and Radial Flows in External Galaxies The Astrophysical Journal Galaxy kinematics Galaxy rotation Galaxy rotation curves Galaxy dynamics Spiral galaxies |
| title | Breaking the Degeneracy between Warps and Radial Flows in External Galaxies |
| title_full | Breaking the Degeneracy between Warps and Radial Flows in External Galaxies |
| title_fullStr | Breaking the Degeneracy between Warps and Radial Flows in External Galaxies |
| title_full_unstemmed | Breaking the Degeneracy between Warps and Radial Flows in External Galaxies |
| title_short | Breaking the Degeneracy between Warps and Radial Flows in External Galaxies |
| title_sort | breaking the degeneracy between warps and radial flows in external galaxies |
| topic | Galaxy kinematics Galaxy rotation Galaxy rotation curves Galaxy dynamics Spiral galaxies |
| url | https://doi.org/10.3847/1538-4357/adc71c |
| work_keys_str_mv | AT francescosyloslabini breakingthedegeneracybetweenwarpsandradialflowsinexternalgalaxies AT giordanodemarzo breakingthedegeneracybetweenwarpsandradialflowsinexternalgalaxies AT matteostraccamore breakingthedegeneracybetweenwarpsandradialflowsinexternalgalaxies |