Shape of LOSVDs in barred disks: implications for future IFU surveys
The shape of LOSVDs (line-of-sight velocity distributions) carries important information about the internal dynamics of galaxies. The skewness of LOSVDs represents their asymmetric deviation from a Gaussian profile. Correlations between the skewness parameter ($h_3$) and the mean velocity ($\vm$) of...
| Main Authors: | , , , , , |
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| Format: | Journal article |
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IOP Publishing
2018
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| _version_ | 1826293868437438464 |
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| author | Li, Z Shen, J Bureau, M Zhou, Y Du, M Debattista, V |
| author_facet | Li, Z Shen, J Bureau, M Zhou, Y Du, M Debattista, V |
| author_sort | Li, Z |
| collection | OXFORD |
| description | The shape of LOSVDs (line-of-sight velocity distributions) carries important information about the internal dynamics of galaxies. The skewness of LOSVDs represents their asymmetric deviation from a Gaussian profile. Correlations between the skewness parameter ($h_3$) and the mean velocity ($\vm$) of a Gauss-Hermite series reflect the underlying stellar orbital configurations of different morphological components. Using two self-consistent $N$-body simulations of disk galaxies with different bar strengths, we investigate $h_3-\vm$ correlations at different inclination angles. Similar to previous studies, we find anticorrelations in the disk area, and positive correlations in the bar area when viewed edge-on. However, at intermediate inclinations, the outer parts of bars exhibit anticorrelations, while the core areas dominated by the boxy/peanut-shaped (B/PS) bulges still maintain weak positive correlations. When viewed edge-on, particles in the foreground/background disk (the wing region) in the bar area constitute the main velocity peak, whereas the particles in the bar contribute to the high-velocity tail, generating the $h_3-\vm$ correlation. If we remove the wing particles, the LOSVDs of the particles in the outer part of the bar only exhibit a low-velocity tail, resulting in a negative $h_3-\vm$ correlation, whereas the core areas in the central region still show weakly positive correlations. We discuss implications for IFU observations on bars, and show that the variation of the $h_3-\vm$ correlation in the disk galaxy may be used as a kinematic indicator of the bar and the B/PS bulge. |
| first_indexed | 2024-03-07T03:36:48Z |
| format | Journal article |
| id | oxford-uuid:bc928ccc-2dfb-49d9-a1e2-e70877facd09 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:36:48Z |
| publishDate | 2018 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | oxford-uuid:bc928ccc-2dfb-49d9-a1e2-e70877facd092022-03-27T05:25:17ZShape of LOSVDs in barred disks: implications for future IFU surveysJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bc928ccc-2dfb-49d9-a1e2-e70877facd09Symplectic Elements at OxfordIOP Publishing2018Li, ZShen, JBureau, MZhou, YDu, MDebattista, VThe shape of LOSVDs (line-of-sight velocity distributions) carries important information about the internal dynamics of galaxies. The skewness of LOSVDs represents their asymmetric deviation from a Gaussian profile. Correlations between the skewness parameter ($h_3$) and the mean velocity ($\vm$) of a Gauss-Hermite series reflect the underlying stellar orbital configurations of different morphological components. Using two self-consistent $N$-body simulations of disk galaxies with different bar strengths, we investigate $h_3-\vm$ correlations at different inclination angles. Similar to previous studies, we find anticorrelations in the disk area, and positive correlations in the bar area when viewed edge-on. However, at intermediate inclinations, the outer parts of bars exhibit anticorrelations, while the core areas dominated by the boxy/peanut-shaped (B/PS) bulges still maintain weak positive correlations. When viewed edge-on, particles in the foreground/background disk (the wing region) in the bar area constitute the main velocity peak, whereas the particles in the bar contribute to the high-velocity tail, generating the $h_3-\vm$ correlation. If we remove the wing particles, the LOSVDs of the particles in the outer part of the bar only exhibit a low-velocity tail, resulting in a negative $h_3-\vm$ correlation, whereas the core areas in the central region still show weakly positive correlations. We discuss implications for IFU observations on bars, and show that the variation of the $h_3-\vm$ correlation in the disk galaxy may be used as a kinematic indicator of the bar and the B/PS bulge. |
| spellingShingle | Li, Z Shen, J Bureau, M Zhou, Y Du, M Debattista, V Shape of LOSVDs in barred disks: implications for future IFU surveys |
| title | Shape of LOSVDs in barred disks: implications for future IFU surveys |
| title_full | Shape of LOSVDs in barred disks: implications for future IFU surveys |
| title_fullStr | Shape of LOSVDs in barred disks: implications for future IFU surveys |
| title_full_unstemmed | Shape of LOSVDs in barred disks: implications for future IFU surveys |
| title_short | Shape of LOSVDs in barred disks: implications for future IFU surveys |
| title_sort | shape of losvds in barred disks implications for future ifu surveys |
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