scholarly journals A comprehensive analysis using 9 dark matter halo models on the spiral galaxy NGC 4321

Author(s):  
Wei Shen Tan ◽  
Zamri Zainal Abidin ◽  
Norsiah Hashim
2006 ◽  
Vol 447 (1) ◽  
pp. 49-62 ◽  
Author(s):  
G. Battaglia ◽  
F. Fraternali ◽  
T. Oosterloo ◽  
R. Sancisi

2019 ◽  
Vol 487 (2) ◽  
pp. 2797-2817 ◽  
Author(s):  
A Elagali ◽  
L Staveley-Smith ◽  
J Rhee ◽  
O I Wong ◽  
A Bosma ◽  
...  

ABSTRACT This paper reports on the atomic hydrogen gas (H i) observations of the spiral galaxy NGC 1566 using the newly commissioned Australian Square Kilometre Array Pathfinder radio telescope. We measure an integrated H i flux density of $180.2$ Jy km s−1 emanating from this galaxy, which translates to an H i mass of $1.94\times 10^{10}\, \mathrm{ M}_{\odot }$ at an assumed distance of $21.3$ Mpc. Our observations show that NGC 1566 has an asymmetric and mildly warped H i disc. The H i-to-stellar mass fraction (M$_{\rm{H\,{{\small I}}}}$/M∗) of NGC 1566 is 0.29, which is high in comparison with galaxies that have the same stellar mass ($10^{10.8}$ M⊙). We also derive the rotation curve of this galaxy to a radius of $50$ kpc and fit different mass models to it. The NFW, Burkert, and pseudo-isothermal dark matter halo profiles fit the observed rotation curve reasonably well and recover dark matter fractions of 0.62, 0.58, and 0.66, respectively. Down to the column density sensitivity of our observations ($N_{\rm{H\,{{\small I}}}}\, =\, 3.7\times 10^{19}$ cm−2), we detect no H i clouds connected to, or in the nearby vicinity of, the H i disc of NGC 1566 nor nearby interacting systems. We conclude that, based on a simple analytic model, ram pressure interactions with the IGM can affect the H i disc of NGC 1566 and is possibly the reason for the asymmetries seen in the H i morphology of NGC 1566.


2020 ◽  
Vol 500 (1) ◽  
pp. 1054-1070
Author(s):  
Luca Ciotti ◽  
Antonio Mancino ◽  
Silvia Pellegrini ◽  
Azadeh Ziaee Lorzad

ABSTRACT Recently, two-component spherical galaxy models have been presented, where the stellar profile is described by a Jaffe law, and the total density by another Jaffe law, or by an r−3 law at large radii. We extend these two families to their ellipsoidal axisymmetric counterparts: the JJe and J3e models. The total and stellar density distributions can have different flattenings and scale lengths, and the dark matter halo is defined by difference. First, the analytical conditions required to have a nowhere negative dark matter halo density are derived. The Jeans equations for the stellar component are then solved analytically, in the limit of small flattenings, also in the presence of a central BH. The azimuthal velocity dispersion anisotropy is described by the Satoh k-decomposition. Finally, we present the analytical formulae for velocity fields near the centre and at large radii, together with the various terms entering the virial theorem. The JJe and J3e models can be useful in a number of theoretical applications, e.g. to explore the role of the various parameters (flattening, relative scale lengths, mass ratios, rotational support) in determining the behaviour of the stellar kinematical fields before performing more time-expensive integrations with specific galaxy models, to test codes of stellar dynamics and in numerical simulations of gas flows in galaxies.


2020 ◽  
Vol 500 (1) ◽  
pp. 310-318
Author(s):  
Roberto De Propris ◽  
Michael J West ◽  
Felipe Andrade-Santos ◽  
Cinthia Ragone-Figueroa ◽  
Elena Rasia ◽  
...  

ABSTRACT We explore the persistence of the alignment of brightest cluster galaxies (BCGs) with their local environment. We find that a significant fraction of BCGs do not coincide with the centroid of the X-ray gas distribution and/or show peculiar velocities (they are not at rest with respect to the cluster mean). Despite this, we find that BCGs are generally aligned with the cluster mass distribution even when they have significant offsets from the X-ray centre and significant peculiar velocities. The large offsets are not consistent with simple theoretical models. To account for these observations BCGs must undergo mergers preferentially along their major axis, the main infall direction. Such BCGs may be oscillating within the cluster potential after having been displaced by mergers or collisions, or the dark matter halo itself may not yet be relaxed.


2012 ◽  
Vol 758 (1) ◽  
pp. L23 ◽  
Author(s):  
Sarah R. Loebman ◽  
Željko Ivezić ◽  
Thomas R. Quinn ◽  
Fabio Governato ◽  
Alyson M. Brooks ◽  
...  

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Marc S. Seigar

We investigate the dark matter halo density profile of M33. We find that the HI rotation curve of M33 is best described by an NFW dark matter halo density profile model, with a halo concentration of and a virial mass of . We go on to use the NFW concentration of M33, along with the values derived for other galaxies (as found in the literature), to show that correlates with both spiral arm pitch angle and supermassive black hole mass.


2005 ◽  
Vol 13 ◽  
pp. 199-199
Author(s):  
Terry Bridges ◽  
Steve Zepf ◽  
Katherine Rhode ◽  
Ken Freeman

AbstractWe have found 56 new globular clusters in M104 from 2dF multi-fiber spectroscopy, doubling the number of confirmed clusters, and extending the spatial coverage to 50 kpc radius. We find no significant rotation in the total sample, or for subsets split by color or radius. However, there are hints that the blue clusters have a higher rotation than the red clusters, and for counter-rotation of clusters at large radius. We find a total mass of M ~ 1 × 1012M⊙ and a (M/L)B =30 out to 50 kpc radius, which is strong evidence for a dark matter halo in M104.


2009 ◽  
Vol 397 (1) ◽  
pp. 299-310 ◽  
Author(s):  
Jorge Moreno ◽  
Carlo Giocoli ◽  
Ravi K. Sheth
Keyword(s):  

1998 ◽  
Vol 59 (2) ◽  
Author(s):  
Edward A. Baltz ◽  
Andrew J. Westphal ◽  
Daniel P. Snowden-Ifft

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