2013A&A...550A..11I


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.08CEST02:13:47

2013A&A...550A..11I - Astronomy and Astrophysics, volume 550A, 11-11 (2013/2-1)

Kinematic imprint of clumpy disk formation on halo objects.

INOUE S.

Abstract (from CDS):

Clumpy disk galaxies in the distant universe, at redshift of z>1, have been observed to host several giant clumps in their disks. They are thought to correspond to early formative stages of disk galaxies. On the other hand, halo objects, such as old globular clusters and halo stars, are likely to consist of the oldest stars in a galaxy (age>10Gyr), clumpy disk formation can thus be presumed to take place in a pre-existing halo system. Giant clumps orbit in the same direction in a premature disk and are so massive that they may be expected to interact gravitationally with halo objects and exercise influence on the kinematic state of the halo. Accordingly, I scrutinize the possibility that the clumps leave a kinematic imprint of the clumpy disk formation on a halo system. I perform a restricted N-body calculation with a toy model to study the kinematic influence on a halo by orbital motions of clumps and the dependence of the results on masses (mass loss), number, and orbital radii of the clumps. I show that halo objects can catch clump motions and acquire disky rotation in a dynamical friction time scale of the clumps, ∼0.5Gyr. The influence of clumps is limited within a region around the disk, while the halo system shows vertical gradients of net rotation velocity and orbital eccentricity. The significance of the kinematic influence strongly depends on the clump masses; the lower limit of postulated clump mass would be ∼5x108 M. The result also depends on whether the clumps are subjected to rapid mass loss or not, which is an open question under debate in recent studies. The existence of such massive clumps is not unrealistic. I therefore suggest that the imprints of past clumpy disk formation could remain in current galactic halos.

Abstract Copyright:

Journal keyword(s): methods: numerical - galaxies: halos - galaxies: spiral - galaxies: evolution

Simbad objects: 7

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Number of rows : 7

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 10903 1
2 NGC 253 SyG 00 47 33.134 -25 17 19.68   8.03   6.94 8.1 ~ 2929 2
3 NGC 524 GiP 01 24 47.707 +09 32 19.65   11.5       ~ 419 1
4 M 33 GiG 01 33 50.904 +30 39 35.79 6.17 6.27 5.72     ~ 5134 1
5 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 14826 1
6 NGC 2683 AGN 08 52 41.345 +33 25 18.48 11.57 10.68 9.79 9.38   ~ 383 1
7 NGC 3115 GiG 10 05 13.978 -07 43 06.89   11   9.37   ~ 926 2

    Equat.    Gal    SGal    Ecl

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2020.07.08-02:13:47

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