| | |
| | |
Stat |
Members: 3643 Articles: 2'487'895 Articles rated: 2609
28 March 2024 |
|
| | | |
|
Article overview
| |
|
Non-Axisymmetric Structure in the Satellite Dwarf Galaxy NGC2976: Implications for its Dark/Bright Mass Distribution and Evolution | O. Valenzuela
; H. Hernández-Toledo
; M. Cano-Díaz
; I. Puerari
; R. Buta
; B. Pichardo
; R. Groess
; | Date: |
25 Oct 2013 | Abstract: | We present the result of an extensive search for non-axisymmetric structures
in the dwarf satellite galaxy of M81: NGC 2976, using multiwavelength archival
observations. The galaxy is known to present kinematic evidence for a
bysimmetric distortion, anyhow the stellar bar presence is controversial, due
to the possible interpretation of NGC 2976 presenting an elliptical disk
triggered by a prolate dark matter halo. We applied diagnostics in order to
detect stellar bars or spiral arms. The m=2 fourier phase has a jump around 60
arcsecs consistent with a central bar and bisymmetric arms. The CO, 3.6 $mu$
surface brightness and the dust lanes are consistent with a gas rich central
bar and possibly with gaseous spiral arms. The kinematic jumps related with the
dust lanes suggest that the bar perturbation in the disk kinematics is
non-negligible and the reported non-circular motions, the central gas excess
and the nuclear X-ray source (AGN/Starburst) might be produced by the central
bar. SPH simulations of disks inside triaxial dark halos suggest that the two
symmetric spots at 130 arcsecs and the narrow arms may be produced by gas at
turning points in an elliptical disk, alternatively the potential ellipticity
can be originated by tidally induced strong stellar bar/arms. We conclude that,
the gas rich bar and spiral arms triggered by tidal stirring, and primordial
halo triaxiality, can explain most of the non-circular motions, mass
redistribution and nuclear activity. Distinguishing between them requires
detailed modeling of environmental effects. An analysis similar to this may
reveal such kind of structures in other nearby dwarf satellite galaxies, and if
confirmed, the same evolutionary scenario will be applicable to them. This
implies biases constraining their dark matter distribution and also making
comparison against theoretical predictions for isolated galaxies. | Source: | arXiv, 1310.7021 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser claudebot
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |