Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-07-14
Astronomy and Astrophysics
Astrophysics
10 pages, 9 figures, accepted by MNRAS
Scientific paper
10.1111/j.1365-2966.2009.14514.x
We discuss the total mass and dark halo properties of the Small Magellanic Cloud (SMC) for reasonable $V$-band stellar-to-mass-to-light ratios ($M_{\rm s}/L_{\rm V}$) based on the high-resolution neutral hydrogen (HI) observations of the SMC. We adopt both the Burkert and the NFW profiles for the dark matter halo of the SMC in order to model the radial profile of the observed rotation curve. We show that the mass ($M_{\rm dm}$) and the mean density (${\rho}_{\rm dm}$) of the dark matter halo within the optical radius ($\sim 3$ kpc) of the SMC can be significantly low for $M_{\rm s}/L_{\rm V}=2-4$ reasonable for a galaxy dominated by older stellar populations. For example, the estimated $M_{\rm dm}$ and ${\rho}_{\rm dm}$ are $7.5 \times 10^7 {\rm M}_{\odot}$ and $6.7 \times 10^{-4} {\rm M}_{\odot}$ pc$^{-3}$, respectively, for $M_{\rm s}/L_{\rm V} = 3.8$. The models with lower $M_{\rm s}/L_{\rm V}$ ($<1.0$) can show higher $M_{\rm dm}$ and ${\rho}_{\rm dm}$ yet have difficulties in reproducing the inner rotation curve profile both for the Burkert and the NFW profiles. The Burkert profile with a larger core radius ($>1$ kpc) (thus a low density) and a large mass (${\rm M}_{\rm dm} > 3 \times 10^9 {\rm M}_{\odot}$) can be better fit to the observed slowly rising rotation curve than the NFW one for a reasonable $M_{\rm s}/L_{\rm V} \sim2$. This means that most of the dark halo mass can be initially located outside the optical radius in the SMC and thus that the dark halo would have already lost a significant fraction of its original mass due to the strong tidal interactions with the Galaxy and possibly with the Large Magellanic Cloud (LMC).
Bekki Kenji
Stanimirovic Snezana
No associations
LandOfFree
The total mass and dark halo properties of the Small Magellanic Cloud does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The total mass and dark halo properties of the Small Magellanic Cloud, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The total mass and dark halo properties of the Small Magellanic Cloud will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-442899