eprintid: 16856
rev_number: 16
eprint_status: archive
userid: 1163
dir: disk0/00/01/68/56
datestamp: 2014-05-09 06:41:40
lastmod: 2014-07-21 08:10:48
status_changed: 2014-05-09 06:41:40
type: doctoralThesis
metadata_visibility: show
creators_name: Kalinova Dimitrova, Veselina
title: Mass Distributions of Galaxies from
SAURON and CALIFA Stellar Kinematic Maps
subjects: 520
divisions: 130001
adv_faculty: af-13
abstract: The amount and distribution of dark matter in galaxies defines the formation, evolution and
dynamics of these systems. In this thesis we infer the internal mass distributions of 26 E–Sd
galaxies using SAURON and CALIFA two-dimensional stellar kinematic maps. We compare two
modeling approaches – fitting a solution of the axisymmetric Jeans equations and the commonly
applied asymmetric drift correction (ADC). We show that ADC underestimates the enclosed
mass by a factor of ∼3-4 once random motion (velocity dispersion) becomes significant com-
pared to ordered motion (streaming), that is, when the ratio of ordered-over-random motion is
less than about 1.5. Such kinematics indicate that the stellar mass of the galaxy is not confined
to the disk plane, as happens in bulges and thick disks of spiral galaxies, as well as in elliptical
galaxies. Since this is frequently realized in our sample, as well as in the general galaxy population, a full line-of-sight integration as provided by solutions of the axisymmetric Jeans equation
is needed to reliably infer mass distributions in galaxies. We henceforth use the more realistic
Jeans models to estimate the dark matter fraction (fDM), by modeling the total (dynamical) mass-to-light ratio and comparing it with the value derived for stars (baryons) from stellar population models.
We find several trends of dark matter fraction with global galaxy properties. Ellipticals (E) and
late-type spiral (Scd–Sd) galaxies are the most dark matter-dominated objects, while lenticular
(S0) and early-type spirals (Sa–Sb) have significantly smaller dark matter fractions. On average,
fDM increases both at highest and lowest galaxy (stellar) masses, and is smaller at intermediate
masses. Further, it is also anticorrelated with the ratio of ordered-over-random motion, that is
dispersion-dominated galaxies show a higher dark matter fraction. Finally, we investigate the
maximum circular velocities and qualitative shape of rotation curves as a function of galaxy
morphological type along the Hubble sequence. Peaked rotation curves are found in early-type
galaxies, while slowly rising rotation curves are typical for late-type spirals. This confirms predictions of recent simulations of galaxy evolution with local photoionization feedback. More
generally, our results for dark matter content and dynamics provide empirical constraints on
current and future theoretical models of galaxy evolution across a wide range of galaxy morphological types and masses, and thereby will help us to understand the relevant physical processes.
date: 2014
id_scheme: DOI
id_number: 10.11588/heidok.00016856
ppn_swb: 1658698223
own_urn: urn:nbn:de:bsz:16-heidok-168569
date_accepted: 2014-04-30
advisor: HASH(0x556120ac0380)
language: eng
bibsort: KALINOVADIMASSDISTRI2014
full_text_status: public
citation:   Kalinova Dimitrova, Veselina  (2014) Mass Distributions of Galaxies from SAURON and CALIFA Stellar Kinematic Maps.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/16856/1/thesis_kalinova.pdf