8 research outputs found
Unified kinematic scaling relation in the local Universe using Integral Field Spectroscopy surveys
Mass-kinematics scaling relations have always been highly morphology-specific and the observational methods for the kinematic parameter have been specialised for the scaling relation of interest. Recently, thanks to the observational industrialisation provided by integral field spectroscopy (IFS) and the availability of large IFS galaxy surveys, the possibility of constructing a unified, morphology-independent, galaxy scaling relation has emerged.
In this thesis we study the dynamical scaling relation between galaxy mass (usually stellar mass, M*, but also baryonic and halo mass) and the generalised kinematic parameter S_K = \sqrt{K V_{rot}^2 + \sigma^2} that combines rotation velocity V_[rot} and velocity dispersion \sigma, and has previously shown potential for unifying galaxies of all morphologies in a single scaling relation.
For the construction of this scaling relation, we make use of the data from the Sydney-AAO Multi-object Integral-field-spectroscopy (SAMI) galaxy survey. We investigate the applicability of the M*-S_K scaling relation to galaxies ranging from elliptical galaxies to late-type spiral galaxies. We also investigate the effect of using either the stars or the gas component of galaxies as the kinematic tracer, optimise the combination of V_{rot} and \sigma by varying the K value in the S_K parameter, and compare the kinematic measurements from IFS survey to single-fibre spectroscopy with the intention of applying the findings to large-scale single-fibre surveys.
The linear galaxy scaling relation from SAMI shows a lower limit that may be due either to an intrinsic mass limit or to an instrumental resolution limit. To explore the origin of this apparent linearity limit, we initiated the Study of Ha from Dwarf Emissions (SHaDE), a high spectral resolution (R=13500) Ha integral field survey of 69 dwarf galaxies with stellar masses in the range 10^6<M*<10^9 M_\odot. We describe the SHaDE survey goals, design, observations and data reduction processes. We use SHaDE to extend the study of the M*-S_K scaling relation to include low-mass dwarf galaxies in an attempt to make the scaling relation truly universal. We find that the M*- V_{rot} Tully-Fisher relation is consistent with being linear down to the lowest masses we study. In contrast, the M*- \sigma Faber-Jackson relation appears to have a lower limit due to a floor in the internal velocity dispersion of the Ha-emitting gas of approximately 20\kms. Consequently, the M*- S_{0.5} scaling relation also has a lower limit at around a stellar mass of M*~10^{8.6}M_{\odot}.
One of the motivations for exploring a generalised scaling relation is to develop a powerful tool for measuring galaxy distances and peculiar velocities for cosmological studies, one that is applicable to all the galaxies in large-scale single-fibre spectroscopy surveys and in particular to the planned Taipan galaxy survey. A key step towards that goal is the development of the Taipan Live Data Reduction (TLDR) software. Although delays in commissioning the survey instrument have prevented this potential application of the generalised scaling relation being realised in time for this thesis, we use mock data to validate the functionalities and performance of TLDR and demonstrate its capabilities for measuring redshifts and both absorption-line and emission-line velocity dispersions. We outline the further work that needs to be done to tune TLDR to the as-built survey instrument and future extensions that could improve its performance and accuracy.
A generalised mass-kinematics scaling relation such as that studied in this thesis is a powerful tool. We expect that such scaling relations will soon be in common use for exploring the properties and formation histories of galaxies and for measuring galaxy distances and peculiar velocities in order to measure the mass distribution in the Universe and test the nature of gravity on large scales
SHDE: Survey description and mass-kinematics scaling relations for dwarf galaxies
The Study of H from Dwarf Emissions (SHDE) is a high spectral
resolution (R=13500) H integral field survey of 69 dwarf galaxies with
stellar masses . The survey used FLAMES on
the ESO Very Large Telescope. SHDE is designed to study the kinematics
and stellar populations of dwarf galaxies using consistent methods applied to
massive galaxies and at matching level of detail, connecting these mass ranges
in an unbiased way. In this paper we set out the science goals of SHDE,
describe the sample properties, outline the data reduction and analysis
processes. We investigate the mass-kinematics
scaling relation, which have previously shown potential for combining galaxies
of all morphologies in a single scaling relation. We extend the scaling
relation from massive galaxies to dwarf galaxies, demonstrating this relation
is linear down to a stellar mass of .
Below this limit, the kinematics of galaxies inside one effective radius appear
to be dominated by the internal velocity dispersion limit of the
H-emitting gas, giving a bend in the
relation. Replacing stellar mass with total baryonic mass using gas mass
estimate reduces the severity but does not remove the linearity limit of the
scaling relation. An extrapolation to estimate the galaxies' dark matter halo
masses, yields a scaling relation that is free of
any bend, has reduced curvature over the whole mass range, and brings galaxies
of all masses and morphologies onto the virial relation.Comment: 19 pages, 13 figures, 5 tables; published in MNRA
The SAMI Galaxy Survey: mass-kinematics scaling relations
We use data from the Sydney-AAO Multi-object Integral-field spectroscopy
(SAMI) Galaxy Survey to study the dynamical scaling relation between galaxy
stellar mass and the general kinematic parameter that combines rotation velocity and velocity dispersion
. We show that the relation: (1)~is linear above
limits set by properties of the samples and observations; (2)~has slightly
different slope when derived from stellar or gas kinematic measurements;
(3)~applies to both early-type and late-type galaxies and has smaller scatter
than either the Tully-Fisher relation () for late
types or the Faber-Jackson relation () for early types;
and (4)~has scatter that is only weakly sensitive to the value of , with
minimum scatter for in the range 0.4 and 0.7. We compare to the
aperture second moment (the `aperture velocity dispersion') measured from the
integrated spectrum within a 3-arcsecond radius aperture
(). We find that while and
are in general tightly correlated, the relation has less scatter than the relation.Comment: 14 pages, 8 figures, Accepted 2019 May 22. Received 2019 May 18; in
original form 2019 January
The SAMI Galaxy Survey: The link between angular momentum and optical morphology
We investigate the relationship between stellar and gas specific angular momentum j, stellar massM* and optical morphology for a sample of 488 galaxies extracted from the Sydney-AAO Multi-object Integral field Galaxy Survey.We find that j, measured within one effective radius, monotonically increases with M* and that, for M* > 109.5 M⊙, the scatter in this relation strongly correlates with optical morphology (i.e. visual classification and Sérsic index). These findings confirm that massive galaxies of all types lie on a plane relating mass, angular momentum and stellar-light distribution, and suggest that the large-scale morphology of a galaxy is regulated by its mass and dynamical state. We show that the significant scatter in the M*-j relation is accounted for by the fact that, at fixed stellar mass, the contribution of ordered motions to the dynamical support of galaxies varies by at least a factor of 3. Indeed, the stellar spin parameter (quantified via λR) correlates strongly with Sérsic and concentration indices. This correlation is particularly strong once slow rotators are removed from the sample, showing that late-type galaxies and early-type fast rotators form a continuous class of objects in terms of their kinematic properties
The SAMI Galaxy Survey: mass-kinematics scaling relations
We use data from the Sydney-AAO Multi-object Integral-field spectroscopy (SAMI) Galaxy Survey to study the dynamical scaling relation between galaxy stellar mass M∗ and the general kinematic parameter S_K = \sqrt{K V_rot^2 + σ ^2} that combines rotation velocity Vrot and velocity dispersion σ. We show that the log M∗ - log SK relation: (1) is linear above limits set by properties of the samples and observations; (2) has slightly different slope when derived from stellar or gas kinematic measurements; (3) applies to both early-type and late-type galaxies and has smaller scatter than either the Tully-Fisher relation (log M∗ - log Vrot) for late types or the Faber-Jackson relation (log M∗ - log σ) for early types; and (4) has scatter that is only weakly sensitive to the value of K, with minimum scatter for K in the range 0.4 and 0.7. We compare SK to the aperture second moment (the `aperture velocity dispersion') measured from the integrated spectrum within a 3-arcsecond radius aperture (σ _{3^' ' }}). We find that while SK and σ _{3^' ' }} are in general tightly correlated, the log M∗ - log SK relation has less scatter than the \log M_* - \log σ _{3^' ' }} relation.The SAMI Galaxy
Survey is supported by the Australian Research Council Centre
of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013, the Australian
Research Council Centre of Excellence for All-sky Astrophysics
(CAASTRO), through project number CE110001020, and other
participating institutions. The SAMI Galaxy Survey website is samisurvey.org.
DB is supported by an Australia Government Research Training Program Scholarship and ASTRO 3D. FDE acknowledges
funding through the H2020 ERC Consolidator Grant 683184.
JBH is supported by an ARC Laureate Fellowship that funds
JvdS and an ARC Federation Fellowship that funded the SAMI
prototype. JJB acknowledges support of an Australian Research
Council Future Fellowship (FT180100231). JvdS is funded under
Bland-Hawthorn’s ARC Laureate Fellowship (FL140100278). NS
acknowledges support of a University of Sydney Postdoctoral Research Fellowship. Parts of this research were conducted by ASTRO
3D, through project number CE170100013. LC is the recipient of
an Australian Research Council Future Fellowship (FT180100066)
funded by the Australian Government. SB acknowledges the funding support from the Australian Research Council through a Future
Fellowship (FT140101166). SMC acknowledges the support of an
Australian Research Council Future Fellowship (FT100100457).
BG is the recipient of an Australian Research Council Future Fellowship (FT140101202). MSO acknowledges the funding support
from the Australian Research Council through a Future Fellowship
(FT140100255). Support for AMM is provided by NASA through
Hubble Fellowship grant #HST-HF2-51377 awarded by the Space
Telescope Science Institute, which is operated by the Association
of Universities for Research in Astronomy, Inc., for NASA, under
contract NAS5-26555. SKY acknowledges support from the Korean
National Research Foundation (2017R1A2A1A05001116) and by the Yonsei University Future Leading Research Initiative (2015-
22-0064)
The SAMI Galaxy Survey: Data Release Two with absorption-line physics value-added products
We present the second major release of data from the Sydney – Australian Astronomical
Observatory Multi-Object Integral Field Spectrograph (SAMI) Galaxy Survey. Data Release
Two includes data for 1559 galaxies, about 50 per cent of the full survey. Galaxies included
have a redshift range 0.004 <z< 0.113 and a large stellar mass range 7.5 < log (M/M) <
11.6. The core data for each galaxy consist of two primary spectral cubes covering the blue
and red optical wavelength ranges. For each primary cube, we also provide three spatially
binned spectral cubes and a set of standardized aperture spectra. For each core data product,
we provide a set of value-added data products. This includes all emission line value-added
products from Data Release One, expanded to the larger sample. In addition, we include
stellar kinematic and stellar population value-added products derived from absorption line
measurements. The data are provided online through Australian Astronomical Optics’ Data
Central. We illustrate the potential of this release by presenting the distribution of ∼350 000
stellar velocity dispersion measurements from individual spaxels as a function of R/Re, divided
in four galaxy mass bins. In the highest stellar mass bin [log (M/M) > 11], the velocity
dispersion strongly increases towards the centre, whereas below log (M/M) < 10 we find
no evidence for a clear increase in the central velocity dispersion. This suggests a transition
mass around log (M/M) ∼ 10 for galaxies with or without a dispersion-dominated bulge.NS acknowledges support of a University of Sydney Postdoctoral Research Fellowship. JvdS is funded under Bland-Hawthorn’s
ARC Laureate Fellowship (FL140100278). SMC acknowledges
the support of an Australian Research Council Future Fellowship (FT100100457). BG is the recipient of an Australian Research Council Future Fellowship (FT140101202). MSO acknowledges the funding support from the Australian Research Council
through a Future Fellowship (FT140100255). Support for AMM is
provided by NASA through Hubble Fellowship grant #HST-HF2-
51377 awarded by the Space Telescope Science Institute, which is
operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. CFe gratefully
acknowledges funding provided by the Australian Research Council’s Discovery Projects (grants DP150104329 and DP170100603).
SB acknowledges the funding support from the Australian Research Council through a Future Fellowship (FT140101166). TMB
is supported by an Australian Government Research Training Program Scholarship. MLPG acknowledges the funding received from
the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No
707693
Uvodna riječ
We present the second major release of data from the Sydney - Australian Astronomical Observatory Multi-Object Integral Field Spectrograph (SAMI) Galaxy Survey. Data Release Two includes data for 1559 galaxies, about 50 per cent of the full survey. Galaxies included have a redshift range 0.004 11], the velocity dispersion strongly increases towards the centre, whereas below log (M-*/M-circle dot) < 10 we find no evidence for a clear increase in the central velocity dispersion. This suggests a transition mass around log (M-*/M-circle dot) similar to 10 for galaxies with or without a dispersion-dominated bulge
The taipan galaxy survey:Scientific goals and observing strategy
The Taipan galaxy survey (hereafter simply 'Taipan') is a multi-object spectroscopic survey starting in 2017 that will cover 2π steradians over the southern sky (δ ≲ 10°, |b| ≥ 10°), and obtain optical spectra for about two million galaxies out to z < 0.4. Taipan will use the newly refurbished 1.2-m UK Schmidt Telescope at Siding Spring Observatory with the new TAIPAN instrument, which includes an innovative 'Starbugs' positioning system capable of rapidly and simultaneously deploying up to 150 spectroscopic fibres (and up to 300 with a proposed upgrade) over the 6° diameter focal plane, and a purpose-built spectrograph operating in the range from 370 to 870nm with resolving power R≳;2 000. Themain scientific goals of Taipan are (i) to measure the distance scale of the Universe (primarily governed by the local expansion rate, H0) to 1% precision, and the growth rate of structure to 5%; (ii) to make the most extensive map yet constructed of the total mass distribution and motions in the local Universe, using peculiar velocities based on improved Fundamental Plane distances, which will enable sensitive tests of gravitational physics; and (iii) to deliver a legacy sample of low-redshift galaxies as a unique laboratory for studying galaxy evolution as a function of dark matter halo and stellar mass and environment. The final survey, which will be completed within 5 yrs, will consist of a complete magnitude-limited sample (i ≲ 17) of about 1.2 × 106 galaxies supplemented by an extension to higher redshifts and fainter magnitudes (i ≲ 18.1) of a luminous red galaxy sample of about 0.8 × 106 galaxies. Observations and data processing will be carried out remotely and in a fully automated way, using a purpose-built automated 'virtual observer' software and an automated data reduction pipeline. The Taipan survey is deliberately designed to maximise its legacy value by complementing and enhancing current and planned surveys of the southern sky at wavelengths from the optical to the radio; it will become the primary redshift and optical spectroscopic reference catalogue for the local extragalactic Universe in the southern sky for the coming decade.</p