scholarly journals Stellar angular momentum distribution linked to galaxy morphology

2020 ◽  
Vol 494 (4) ◽  
pp. 5421-5438
Author(s):  
Sarah M Sweet ◽  
Karl Glazebrook ◽  
Danail Obreschkow ◽  
Deanne B Fisher ◽  
Andreas Burkert ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Galaxy Formation ◽  
Initial Distribution ◽  
Dark Matter Halo ◽  
Spatially Resolved ◽  
Stellar Velocity ◽  
Traditional Component ◽  
Field Area ◽  
Integral Field ◽  
High Quality Sample

ABSTRACT We study the spatially resolved stellar specific angular momentum j* in a high-quality sample of 24 Calar Alto Legacy Integral Field Area galaxies covering a broad range of visual morphology, accounting for stellar velocity and velocity dispersion. The shape of the spaxelwise probability density function of normalized s = j*/j*mean, PDF(s), deviates significantly from the near-universal initial distribution expected of baryons in a dark matter halo and can be explained by the expected baryonic effects in galaxy formation that remove and redistribute angular momentum. Further we find that the observed shape of the PDF(s) correlates significantly with photometric morphology, where late-type galaxies have a PDF(s) that is similar to a normal distribution, whereas early types have a strongly skewed PDF(s) resulting from an excess of low-angular momentum material. Galaxies that are known to host pseudo-bulges (bulge Sérsic index nb < 2.2) tend to have less skewed bulge PDF(s), with skewness (b1rb) ≲ 0.8. The PDF(s) encodes both kinematic and photometric information and appears to be a robust tracer of morphology. Its use is motivated by the desire to move away from traditional component-based classifications which are subject to observer bias, to classification on a galaxy’s fundamental (stellar mass and angular momentum) properties. In future, PDF(s) may also be useful as a kinematic decomposition tool.

scholarly journals The stellar velocity dispersion in nearby spirals: radial profiles and correlations

2019 ◽  
Author(s):  
Keoikantse Moses Mogotsi ◽  
Alessandro B Romeo
Keyword(s):  
Velocity Dispersion ◽  
Spiral Galaxies ◽  
Gravitational Instability ◽  
Stellar Mass ◽  
Radial Profiles ◽  
Stellar Velocity ◽  
The One ◽  
Radial Average ◽  
Field Area ◽  
Integral Field

Abstract The stellar velocity dispersion, σ, is a quantity of crucial importance for spiral galaxies, where it enters fundamental dynamical processes such as gravitational instability and disc heating. Here we analyse a sample of 34 nearby spirals from the Calar Alto Legacy Integral Field Area (CALIFA) spectroscopic survey, deproject the line-of-sight σ to σR and present reliable radial profiles of σR as well as accurate measurements of ⟨σR⟩, the radial average of σR over one effective (half-light) radius. We show that there is a trend for σR to increase with decreasing R, that ⟨σR⟩ correlates with stellar mass (M⋆) and tested correlations with other galaxy properties. The most significant and strongest correlation is the one with M⋆: $\langle \sigma _{R}\rangle \propto M_{\star }^{0.5}$. This tight scaling relation is applicable to spiral galaxies of type Sa–Sd and stellar mass M⋆ ≈ 109.5–1011.5 M⊙. Simple models that relate σR to the stellar surface density and disc scale length roughly reproduce that scaling, but overestimate ⟨σR⟩ significantly.

scholarly journals Galaxy disc scaling relations: A tight linear galaxy–halo connection challenges abundance matching

2019 ◽  
Vol 629 ◽  
pp. A59 ◽  
Author(s):  
Lorenzo Posti ◽  
Antonino Marasco ◽  
Filippo Fraternali ◽  
Benoit Famaey
Keyword(s):  
Angular Momentum ◽  
Galaxy Formation ◽  
Power Law ◽  
Goodness Of Fit ◽  
Dark Matter Halo ◽  
Monotonic Functions ◽  
Stellar Component ◽  
Matching Priors ◽  
Matching Models ◽  
Formation Efficiency

In ΛCDM cosmology, to first order, galaxies form out of the cooling of baryons within the virial radius of their dark matter halo. The fractions of mass and angular momentum retained in the baryonic and stellar components of disc galaxies put strong constraints on our understanding of galaxy formation. In this work, we derive the fraction of angular momentum retained in the stellar component of spirals, fj, the global star formation efficiency fM, and the ratio of the asymptotic circular velocity (Vflat) to the virial velocity fV, and their scatter, by fitting simultaneously the observed stellar mass-velocity (Tully–Fisher), size–mass, and mass–angular momentum (Fall) relations. We compare the goodness of fit of three models: (i) where the logarithm of fj, fM, and fV vary linearly with the logarithm of the observable Vflat; (ii) where these values vary as a double power law; and (iii) where these values also vary as a double power law but with a prior imposed on fM such that it follows the expectations from widely used abundance matching models. We conclude that the scatter in these fractions is particularly small (∼0.07 dex) and that the linear model is by far statistically preferred to that with abundance matching priors. This indicates that the fundamental galaxy formation parameters are small-scatter single-slope monotonic functions of mass, instead of being complicated non-monotonic functions. This incidentally confirms that the most massive spiral galaxies should have turned nearly all the baryons associated with their haloes into stars. We call this the failed feedback problem.

scholarly journals The SAMI–Fornax Dwarfs Survey I: sample, observations, and the specific stellar angular momentum of dwarf elliptical galaxies

2020 ◽  
Vol 497 (2) ◽  
pp. 1571-1582 ◽  
Author(s):  
Nicholas Scott ◽  
F Sara Eftekhari ◽  
Reynier F Peletier ◽  
Julia J Bryant ◽  
Joss Bland-Hawthorn ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Stellar Mass ◽  
Formation Mechanisms ◽  
Early Type ◽  
Spatially Resolved ◽  
Galaxy Type ◽  
Stellar Velocity ◽  
Dwarf Elliptical Galaxies ◽  
Low Mass ◽  
Fornax Cluster

ABSTRACT Dwarf ellipticals are the most common galaxy type in cluster environments; however, the challenges associated with their observation mean that their formation mechanisms are still poorly understood. To address this, we present deep integral field observations of a sample of 31 low-mass (107.5 < M⋆ < 109.5 M⊙) early-type galaxies in the Fornax cluster with the SAMI instrument. For 21 galaxies, our observations are sufficiently deep to construct spatially resolved maps of the stellar velocity and velocity dispersion – for the remaining galaxies, we extract global velocities and dispersions from aperture spectra only. From the kinematic maps, we measure the specific stellar angular momentum λR of the lowest mass dE galaxies to date. Combining our observations with early-type galaxy data from the literature spanning a large range in stellar mass, we find that λR decreases towards lower stellar mass, with a corresponding increase in the proportion of slowly rotating galaxies in this regime. The decrease of λR with mass in our sample dE galaxies is consistent with a similar trend seen in somewhat more massive spiral galaxies from the CALIFA survey. This suggests that the degree of dynamical heating required to produce dEs from low-mass starforming progenitors may be relatively modest and consistent with a broad range of formation mechanisms.

scholarly journals Key dynamical results from the SAMI Galaxy Survey

2019 ◽  
Vol 14 (S353) ◽  
pp. 213-221
Author(s):  
Jesse van de Sande ◽  
Joss Bland-Hawthorn ◽  
Dilyar Barat ◽  
Sarah Brough ◽  
Julia J. Bryant ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Stellar Population ◽  
Stellar Mass ◽  
Two Dimensional ◽  
Physical Processes ◽  
Spatially Resolved ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
Gas Measurements ◽  
Integral Field

AbstractWe present an overview of recent key results from the SAMI Galaxy Survey on the build-up of mass and angular momentum in galaxies across morphology and environment. The SAMI Galaxy survey is a multi-object integral field spectroscopic survey and provides a wealth of spatially-resolved, two-dimensional stellar and gas measurements for galaxies of all morphological types, with high-precision due the stable spectral resolution of the AAOmega spectrograph. The sample size of ~3000 galaxies allows for dividing the sample in bins of stellar mass, environment, and star-formation or morphology, whilst maintaining a statistical significant number of galaxies in each bin. By combining imaging, spatially resolved dynamics, and stellar population measurements, our result demonstrate the power of utilising integral field spectroscopy on a large sample of galaxies to further our understanding of physical processes involved in the build-up of stellar mass and angular momentum in galaxies.

scholarly journals A Photometric and Kinematic Analysis of UDG1137+16: Probing Ultra-Diffuse Galaxy Formation in a Group Environment

2021 ◽  
Author(s):  
Jonah S Gannon ◽  
Bililign T Dullo ◽  
Duncan A Forbes ◽  
R Michael Rich ◽  
Javier Román ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Velocity Dispersion ◽  
Mass Relation ◽  
Stellar Envelope ◽  
Tidal Interaction ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
Stellar Velocity ◽  
Halo Masses ◽  
Integral Field

Abstract The dominant physical formation mechanism(s) for ultra-diffuse galaxies (UDGs) is still poorly understood. Here, we combine new, deep imaging from the Jeanne Rich Telescope with deep integral field spectroscopy from the Keck II telescope to investigate the formation of UDG1137+16. Our new analyses confirm both its environmental association with the low density UGC 6594 group, along with its large size of 3.3 kpc and status as a UDG. The new imaging reveals two distinct stellar components for UDG1137+16, indicating that a central stellar body is surrounded by an outer stellar envelope undergoing tidal interaction. Both the components have approximately similar stellar masses. From our integral field spectroscopy we measure a stellar velocity dispersion within the half-light radius (15 ± 4 km s−1) and find that UDG1137+16 is similar to some other UDGs in that it is likely dark matter dominated. Incorporating literature measurements, we also examine the current state of UDG observational kinematics. Placing these data on the central stellar velocity dispersion – stellar mass relation, we suggest there is little evidence for UDG1137+16 being created through a strong tidal interaction. Finally, we investigate the constraining power current dynamical mass estimates (from stellar and globular cluster velocity dispersions) have on the total halo mass of UDGs. As most are measured within the half-light radius, they are unable to accurately constrain UDG total halo masses.

scholarly journals CALIFA, the Calar Alto Legacy Integral Field Area survey

2012 ◽  
Vol 538 ◽  
pp. A8 ◽  
Author(s):  
S. F. Sánchez ◽  
R. C. Kennicutt ◽  
A. Gil de Paz ◽  
G. van de Ven ◽  
J. M. Vílchez ◽  
...  
Keyword(s):  
Area Survey ◽  
Field Area ◽  
Integral Field ◽  
Calar Alto

scholarly journals Rotation of Galaxy Dark Matter Halos

2006 ◽  
Vol 2 (S235) ◽  
pp. 104-104
Author(s):  
Stéphane Herbert-Fort ◽  
Dennis Zaritsky ◽  
Yeun Jin Kim ◽  
Jeremy Bailin ◽  
James E. Taylor
Keyword(s):  
Dark Matter ◽  
Angular Momentum ◽  
Numerical Simulations ◽  
Galaxy Formation ◽  
Spiral Galaxy ◽  
Observational Studies ◽  
Spiral Galaxies ◽  
Satellite System ◽  
Dark Matter Halos ◽  
The Mean

AbstractThe degree to which outer dark matter halos of spiral galaxies rotate with the disk is sensitive to their accretion history and may be probed with associated satellite galaxies. We use the Steward Observatory Bok telescope to measure the sense of rotation of nearby isolated spirals and combine these data with those of their associated satellites (drawn from SDSS) to directly test predictions from numerical simulations. We aim to constrain models of galaxy formation by measuring the projected component of the halo angular momentum that is aligned with that of spiral galaxy disks, Jz. We find the mean bulk rotation of the ensemble satellite system to be co-rotating with the disk with a velocity of 22 ± 13 km/s, in general agreement with previous observational studies and suggesting that galaxy disks could be formed by halo baryons collapsing by a factor of ≈10. We also find a prograde satellite fraction of 51% and Jz, of the satellite system to be positively correlated with the disk, albeit at low significance (2655 ± 2232 kpc km/s).

scholarly journals A panchromatic spatially resolved study of the inner 500 pc of NGC 1052 – II. Gas excitation and kinematics

2019 ◽  
Vol 489 (4) ◽  
pp. 5653-5668 ◽  
Author(s):  
L G Dahmer-Hahn ◽  
R Riffel ◽  
T V Ricci ◽  
J E Steiner ◽  
T Storchi-Bergmann ◽  
...  
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Elliptical Galaxy ◽  
Field Of View ◽  
Spatially Resolved ◽  
Broad Component ◽  
Single Mechanism ◽  
Line Region ◽  
Nir Emission ◽  
Integral Field

ABSTRACT We map the optical and near-infrared (NIR) emission-line flux distributions and kinematics of the inner 320 × 535 pc2 of the elliptical galaxy NGC 1052. The integral field spectra were obtained with the Gemini Telescope using the GMOS-IFU and NIFS instruments, with angular resolutions of 0.88 and 0.1 arcsec in the optical and NIR, respectively. We detect five kinematic components: (1) and (2) two spatially unresolved components: a broad-line region visible in H α, with a full width at half-maximum (FWHM) of ∼3200 km s−1, and an intermediate broad component seen in the [O iii] λλ4959,5007 doublet; (3) an extended intermediate-width component with 280 km s−1 < FWHM < 450 km s−1 and centroid velocities up to 400 km s−1, which dominates the flux in our data, attributed either to a bipolar outflow related to the jets, rotation in an eccentric disc or to a combination of a disc and large-scale gas bubbles; (4) and (5) two narrow (FWHM < 150 km s−1) components, one visible in [O iii], and another visible in the other emission lines, extending beyond the field of view of our data, which is attributed to large-scale shocks. Our results suggest that the ionization within the observed field of view cannot be explained by a single mechanism, with photoionization being the dominant mechanism in the nucleus with a combination of shocks and photoionization responsible for the extended ionization.

scholarly journals The MAGNUM survey: different gas properties in the outflowing and disc components in nearby active galaxies with MUSE

2019 ◽  
Vol 622 ◽  
pp. A146 ◽  
Author(s):  
M. Mingozzi ◽  
G. Cresci ◽  
G. Venturi ◽  
A. Marconi ◽  
F. Mannucci ◽  
...  
Keyword(s):  
Radiation Field ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
Dust Extinction ◽  
Physical Conditions ◽  
Spatially Resolved ◽  
Line Region ◽  
Central Regions ◽  
Stellar Velocity ◽  
Narrow Line Region

We investigated the interstellar medium (ISM) properties of the disc and outflowing gas in the central regions of nine nearby Seyfert galaxies, all characterised by prominent conical or biconical outflows. These objects are part of the Measuring Active Galactic Nuclei Under MUSE Microscope (MAGNUM) survey, which aims to probe their physical conditions and ionisation mechanism by exploiting the unprecedented sensitivity of the Multi Unit Spectroscopic Explorer (MUSE), combined with its spatial and spectral coverage. Specifically, we studied the different properties of the gas in the disc and in the outflow with spatially and kinematically resolved maps by dividing the strongest emission lines in velocity bins. We associated the core of the lines with the disc, consistent with the stellar velocity, and the redshifted and the blueshifted wings with the outflow. We measured the reddening, density, ionisation parameter, and dominant ionisation source of the emitting gas for both components in each galaxy. We find that the outflowing gas is characterised by higher values of density and ionisation parameter than the disc, which presents a higher dust extinction. Moreover, we distinguish high- and low-ionisation regions across the portion of spatially resolved narrow-line region (NLR) traced by the outflowing gas. The high-ionisation regions characterised by the lowest [N II]/Hα and [S II]/Hα line ratios generally trace the innermost parts along the axis of the emitting cones where the [S III]/[S II] line ratio is enhanced, while the low-ionisation regions follow the cone edges and/or the regions perpendicular to the axis of the outflows, also characterised by a higher [O III] velocity dispersion. A possible scenario to explain these features relies on the presence of two distinct populations of line emitting clouds: one is optically thin to the radiation and is characterised by the highest excitation, while the other is optically thick and is impinged by a filtered, and thus harder, radiation field which generates strong low-excitation lines. The highest values of [N II]/Hα and [S II]/Hα line ratios may be due to shocks and/or a hard filtered radiation field from the active galactic nucleus.

Sign in / Sign up

Export Citation Format

Share Document