ABSTRACT
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 $S_K = \sqrt{K V_{\rm rot}^2 + \sigma ^2}$ 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 ($\sigma _{3^{\prime \prime }}$). We find that while SK and $\sigma _{3^{\prime \prime }}$ are in general tightly correlated, the log M∗ − log SK relation has less scatter than the $\log M_* - \log \sigma _{3^{\prime \prime }}$ relation.
ABSTRACT
The Study of H α from Dwarf Emissions (SHαDE) is a high spectral resolution (R = 13 500) H α integral field survey of 69 dwarf galaxies with stellar masses 106 < M⋆ < 109 M⊙. The survey used ...FLAMES on the ESO Very Large Telescope. SHαDE 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 SHαDE, describe the sample properties, outline the data reduction, and analysis processes. We investigate the log M⋆–log S0.5 mass–kinematics scaling relation, which has 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 M⋆ ∼ 108.6 M⊙. Below this limit, the kinematics of galaxies inside one effective radius appears to be dominated by the internal velocity dispersion limit of the H α-emitting gas, giving a bend in the log M⋆–log S0.5 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 log Mh–log S0.5 scaling relation that is free of any bend, has reduced curvature over the whole mass range, and brings galaxies of all masses and morphologies on to the virial relation.
In a flat Universe with a cosmological constant and cold dark matter (the standard ΛCDM model), the total mass of a galaxy largely determines the motions of its stars and gas. Various scaling ...relations between the kinematics and masses of galaxies have long been observed, and characterised through a myriad observations and theoretical models. Traditionally, however, mass–kinematics scaling relations have 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 SK = p KV 2 rot 2 that combines rotation velocity Vrot and velocity dispersion σ, 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 log M? log SK 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 Vrot and by varying the K value in the SK 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.We find that the log M? log SK relation: (1) is linear above limits set by properties of the samples and observations; (2) has slightly different slopes when derived from stellar and gas kinematic measurements; (3) applies to both early-type and late-type galaxies, with smaller scatter than either the Tully-Fisher relation (log M? log Vrot) for late types or the Faber-Jackson relation (log M? log) 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 0.4–0.7, weakly dependent on galaxy type. We also find that while SK and aperture velocity dispersion (e.g. 3 00) are in general tightly correlated, the log M? log SK relation has less scatter than the log M? log σ3 00 relation.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 H from Dwarf Emissions (SHDE), a high spectral resolution (R=13500) H integral field survey of 69 dwarf galaxies with stellar masses in the range 106 109M. We describe the SHαDE survey goals, design, observations and data reduction processes.
The Study of H$\alpha$ from Dwarf Emissions (SH$\alpha$DE) is a high spectral
resolution (R=13500) H$\alpha$ integral field survey of 69 dwarf galaxies with
stellar masses $10^6<M_\star<10^9 ...\,\rm{M_\odot}$. The survey used FLAMES on
the ESO Very Large Telescope. SH$\alpha$DE 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 SH$\alpha$DE,
describe the sample properties, outline the data reduction and analysis
processes. We investigate the $\log{M_{\star}}-\log{S_{0.5}}$ 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 $M_{\star}\sim10^{8.6}\,\rm{M_\odot}$.
Below this limit, the kinematics of galaxies inside one effective radius appear
to be dominated by the internal velocity dispersion limit of the
H$\alpha$-emitting gas, giving a bend in the $\log{M_{\star}}-\log{S_{0.5}}$
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 $\log{M_{h}}-\log{S_{0.5}}$ 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.
The Study of H\(\alpha\) from Dwarf Emissions (SH\(\alpha\)DE) is a high spectral resolution (R=13500) H\(\alpha\) integral field survey of 69 dwarf galaxies with stellar masses \(10^6<M_\star<10^9 ...\,\rm{M_\odot}\). The survey used FLAMES on the ESO Very Large Telescope. SH\(\alpha\)DE 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 SH\(\alpha\)DE, describe the sample properties, outline the data reduction and analysis processes. We investigate the \(\log{M_{\star}}-\log{S_{0.5}}\) 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 \(M_{\star}\sim10^{8.6}\,\rm{M_\odot}\). Below this limit, the kinematics of galaxies inside one effective radius appear to be dominated by the internal velocity dispersion limit of the H\(\alpha\)-emitting gas, giving a bend in the \(\log{M_{\star}}-\log{S_{0.5}}\) 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 \(\log{M_{h}}-\log{S_{0.5}}\) 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.
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 \(S_K = \sqrt{K V_{rot}^2 + \sigma^2}\) that combines rotation velocity \(V_{rot}\) and velocity dispersion \(\sigma\). We show that the \(\log M_* - \log S_K\) 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 (\(\log M_* - \log V_{rot}\)) for late types or the Faber-Jackson relation (\(\log M_* - \log\sigma\)) 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 \(S_K\) to the aperture second moment (the `aperture velocity dispersion') measured from the integrated spectrum within a 3-arcsecond radius aperture (\(\sigma_{3^{\prime\prime}}\)). We find that while \(S_{K}\) and \(\sigma_{3^{\prime\prime}}\) are in general tightly correlated, the \(\log M_* - \log S_K\) relation has less scatter than the \(\log M_* - \log \sigma_{3^{\prime\prime}}\) relation.
We present the second major release of data from the SAMI Galaxy Survey. Data Release Two includes data for 1559 galaxies, about 50% 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_star/M_sun) < 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 standardised 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/R_e, divided in four galaxy mass bins. In the highest stellar mass bin (log (M_star/M_sun)>11), the velocity dispersion strongly increases towards the centre, whereas below log (M_star/M_sun)<10 we find no evidence for a clear increase in the central velocity dispersion. This suggests a transition mass around log (M_star/M_sun) ~10 for galaxies with or without a dispersion-dominated bulge.
Taipan is a multi-object spectroscopic galaxy survey starting in 2017 that will cover 2pi steradians over the southern sky, and obtain optical spectra for about two million galaxies out to z<0.4. ...Taipan will use the newly-refurbished 1.2m 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-deg diameter focal plane, and a purpose-built spectrograph operating from 370 to 870nm with resolving power R>2000. The main scientific goals of Taipan are: (i) to measure the distance scale of the Universe (primarily governed by the local expansion rate, H_0) to 1% precision, and the structure growth rate of structure to 5%; (ii) to make the most extensive map yet constructed of the 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 mass and environment. The final survey, which will be completed within 5 years, will consist of a complete magnitude-limited sample (i<17) of about 1.2x10^6 galaxies, supplemented by an extension to higher redshifts and fainter magnitudes (i<18.1) of a luminous red galaxy sample of about 0.8x10^6 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.
PDF
