The properties of satellite galaxies in simulations of galaxy formation

ABSTRACT Observations of the cold neutral atomic hydrogen (H i) in and around disc galaxies have revealed that spatial and kinematic asymmetries are common place, and are reflected in the global H i spectra. We use the TNG100 box from the IllustrisTNG suite of cosmological simulations to study the conditions under which these asymmetries may arise in current theoretical galaxy formation models. We find that more than 50 per cent of the sample has at least a 10 per cent difference in integrated flux between the high- and low-velocity half of the spectrum, thus the typical TNG100 galaxy has an H i profile that is not fully symmetric. We find that satellite galaxies are a more asymmetric population than centrals, consistent with observational results. Using halo mass as a proxy for environment, this trend appears to be driven by the satellite population within the virial radius of haloes more massive than 1013 M⊙, typical of medium/large groups. We show that, while the excess of H i asymmetry in group satellites is likely driven by ram pressure, the bulk of the asymmetric H i profiles observed in TNG100 are driven by physical processes able to affect both the central and satellite populations. Our results highlight how asymmetries are not driven solely by environment, and multiple physical processes can produce the same asymmetric shape in global H i spectra.

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On the chemical evolution of the Milky Way

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308027841 ◽

2008 ◽

Vol 4 (S254) ◽

pp. 381-392 ◽

Cited By ~ 1

Author(s):

Nikos Prantzos

Keyword(s):

Chemical Evolution ◽

Galaxy Formation ◽

Milky Way ◽

Chemical Properties ◽

Solar Neighborhood ◽

Satellite Galaxies ◽

Metallicity Distribution

AbstractI discuss three different topics concerning the chemical evolution of the Milky Way (MW). 1) The metallicity distribution of the MW halo; it is shown that this distribution can be analytically derived in the framework of the hierarchical merging scenario for galaxy formation, assuming that the component sub-haloes had chemical properties similar to those of the progenitors of satellite galaxies of the MW. 2) The age-metallicity relationship (AMR) in the solar neighborhood; I argue for caution in deriving from data with important uncertainties (such as the age uncertainties in the Geneva-Copenhagen Survey) a relationship between average metallicity and age: derived relationships are shown to be systematically flatter than the true ones and should not be directly compared to models. 3) The radial mixing of stars in the disk, which may have important effects on various observables (scatter in AMR, extension of the tails of the metallicity distribution, flatenning of disk abundance profiles). Recent SPH + N-body simulations find considerable radial mixing, but only comparison to observations will ultimately determine the extent of that mixing.

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SDSS-IV MaNGA: environmental dependence of gas metallicity gradients in local star-forming galaxies

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2218 ◽

2019 ◽

Vol 489 (1) ◽

pp. 1436-1450 ◽

Cited By ~ 4

Author(s):

Jianhui Lian ◽

Daniel Thomas ◽

Cheng Li ◽

Zheng Zheng ◽

Claudia Maraston ◽

...

Keyword(s):

Star Formation ◽

Galaxy Formation ◽

Cold Dark Matter ◽

Star Forming ◽

Spatially Resolved ◽

The Galaxy ◽

Low Mass ◽

Satellite Galaxies ◽

Galaxy Environment ◽

Gas Accretion

ABSTRACT Within the standard model of hierarchical galaxy formation in a Λ cold dark matter universe, the environment of galaxies is expected to play a key role in driving galaxy formation and evolution. In this paper, we investigate whether and how the gas metallicity and the star formation surface density (ΣSFR) depend on galaxy environment. To this end, we analyse a sample of 1162 local, star-forming galaxies from the galaxy survey Mapping Nearby Galaxies at APO (MaNGA). Generally, both parameters do not show any significant dependence on environment. However, in agreement with previous studies, we find that low-mass satellite galaxies are an exception to this rule. The gas metallicity in these objects increases while their ΣSFR decreases slightly with environmental density. The present analysis of MaNGA data allows us to extend this to spatially resolved properties. Our study reveals that the gas metallicity gradients of low-mass satellites flatten and their ΣSFR gradients steepen with increasing environmental density. By extensively exploring a chemical evolution model, we identify two scenarios that are able to explain this pattern: metal-enriched gas accretion or pristine gas inflow with varying accretion time-scales. The latter scenario better matches the observed ΣSFR gradients, and is therefore our preferred solution. In this model, a shorter gas accretion time-scale at larger radii is required. This suggests that ‘outside–in quenching’ governs the star formation processes of low-mass satellite galaxies in dense environments.

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Bursting and quenching in satellite galaxies

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2916 ◽

2019 ◽

Vol 490 (4) ◽

pp. 5375-5389 ◽

Cited By ~ 2

Author(s):

I Koutsouridou ◽

A Cattaneo

Keyword(s):

Star Formation ◽

Galaxy Formation ◽

Mass Function ◽

Chemical Enrichment ◽

Galactic Winds ◽

Theoretical Predictions ◽

Blue Galaxies ◽

Satellite Galaxies ◽

The Difference ◽

Red Galaxies

ABSTRACT The difference in stellar metallicity between red and blue galaxies with the same mass constrains the time-scale over which red galaxies ceased to form stars. Here we investigate this constraint with the galics 2.0 semi-analytic model of galaxy formation. The advantage of this approach is that the time of pericentric passages for satellite galaxies and the mass-loading factor for galactic winds are not free parameters of the chemical evolution model. The former is determined by the N-body simulation used to construct the merger trees, the latter by the requirement that galics 2.0 should reproduce the stellar mass function of galaxies. When we compare our theoretical predictions with observations, we find that galics 2.0 can reproduce the observed metallicity difference only if quenching is preceded by a burst of star formation, which contributes to the chemical enrichment of the stellar population. Physically, this burst can be explained as tidally induced star formation or as an effect of ram pressure, which not only strips gas from galaxies but also compresses it, accelerating its conversion into stars.

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Ages and metallicities of central and satellite galaxies: implications for galaxy formation and evolution

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2010.17074.x ◽

2010 ◽

Vol 407 (2) ◽

pp. 937-954 ◽

Cited By ~ 81

Author(s):

Anna Pasquali ◽

Anna Gallazzi ◽

Fabio Fontanot ◽

Frank C. Van Den Bosch ◽

Gabriella De Lucia ◽

...

Keyword(s):

Galaxy Formation ◽

Galaxy Formation And Evolution ◽

Formation And Evolution ◽

Satellite Galaxies

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KiDS+GAMA: The weak lensing calibrated stellar-to-halo mass relation of central and satellite galaxies

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038693 ◽

2020 ◽

Vol 642 ◽

pp. A83 ◽

Cited By ~ 1

Author(s):

Andrej Dvornik ◽

Henk Hoekstra ◽

Konrad Kuijken ◽

Angus H. Wright ◽

Marika Asgari ◽

...

Keyword(s):

Galaxy Formation ◽

Stellar Mass ◽

Weak Lensing ◽

Mass Relation ◽

Overlapping Data ◽

The Galaxy ◽

Galaxy Halo ◽

Satellite Galaxies ◽

Mass Assembly ◽

Halo Masses

We simultaneously present constraints on the stellar-to-halo mass relation for central and satellite galaxies through a weak lensing analysis of spectroscopically classified galaxies. Using overlapping data from the fourth data release of the Kilo-Degree Survey (KiDS), and the Galaxy And Mass Assembly survey (GAMA), we find that satellite galaxies are hosted by halo masses that are 0.53 ± 0.39 dex (68% confidence, 3σ detection) smaller than those of central galaxies of the same stellar mass (for a stellar mass of log(M⋆/M⊙) = 10.6). This is consistent with galaxy formation models, whereby infalling satellite galaxies are preferentially stripped of their dark matter. We find consistent results with similar uncertainties when comparing constraints from a standard azimuthally averaged galaxy-galaxy lensing analysis and a two-dimensional likelihood analysis of the full shear field. As the latter approach is somewhat biased due to the lens incompleteness and as it does not provide any improvement to the precision when applied to actual data, we conclude that stacked tangential shear measurements are best-suited for studies of the galaxy-halo connection.

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Galaxies on Sub-Galactic Scales

Publications of the Astronomical Society of Australia ◽

10.1071/as11023 ◽

2012 ◽

Vol 29 (4) ◽

pp. 383-394 ◽

Cited By ~ 2

Author(s):

Helmut Jerjen

Keyword(s):

Dark Matter ◽

Galaxy Formation ◽

Cold Dark Matter ◽

Milky Way ◽

Dwarf Galaxy ◽

Near Field ◽

Sloan Digital Sky Survey ◽

Matter Theory ◽

Satellite Galaxies ◽

Star Formation Histories

AbstractThe Sloan Digital Sky Survey has been immensely successful in detecting new Milky Way satellite galaxies over the past seven years. It was instrumental in finding examples of the least luminous galaxies we know in the Universe, uncovering apparent inconsistencies between cold dark matter theory and dwarf galaxy properties, providing first evidence for a possible lower mass limit for dark matter halos in visible galaxies, and reopening the discussion about the building block scenario for the Milky Way halo. Nonetheless, these results are still drawn only from a relatively small number of galaxies distributed over an area covering about 29% of the sky, which leaves us currently with more questions than answers. The study of these extreme stellar systems is a multi-parameter problem: ages, metallicities, star formation histories, dark matter contents, population fractions and spatial distributions must be determined. Progress in the field is discussed and attention drawn to some of the limitations that currently hamper our ability to fully understand the phenomenon of the ‘ultra-faint dwarf galaxy’. In this context, the Stromlo Milky Way Satellite Survey represents a new initiative to systematically search and scrutinize optically elusive Milky Way satellite galaxies in the Southern hemisphere. In doing so, the program aims at investigating some of the challenging questions in stellar evolution, galaxy formation and near-field cosmology.

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The influence of environment on satellite galaxies in the GAEA semi-analytic model

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2370 ◽

2020 ◽

Vol 498 (3) ◽

pp. 4327-4344 ◽

Cited By ~ 1

Author(s):

Lizhi Xie ◽

Gabriella De Lucia ◽

Michaela Hirschmann ◽

Fabio Fontanot

Keyword(s):

Galaxy Evolution ◽

Galaxy Formation ◽

Analytic Model ◽

Gas Stripping ◽

Hot Gas ◽

Ram Pressure ◽

Low Mass ◽

Quenching Mechanisms ◽

Satellite Galaxies ◽

Cold Gas

ABSTRACT Reproducing the observed quenched fraction of satellite galaxies has been a long-standing issue for galaxy formation models. We modify the treatment of environmental effects in our state-of-the-art GAlaxy Evolution and Assembly (GAEA) semi-analytic model to improve our modelling of satellite galaxies. Specifically, we implement gradual stripping of hot gas, ram-pressure stripping of cold gas, and an updated algorithm to account for angular momentum exchanges between the gaseous and stellar disc components of model galaxies. Our updated model predicts quenched fractions that are in good agreement with local observational measurements for central and satellite galaxies, and their dependencies on stellar mass and halo mass. We also find consistency between model predictions and observational estimates of quenching times for satellite galaxies, H i, H2 fractions of central galaxies, and deficiencies of H i, H2, SFR of galaxies in cluster haloes. In the framework of our updated model, the dominant quenching mechanisms are hot gas stripping for low-mass satellite galaxies, and AGN feedback for massive satellite galaxies. The ram-pressure stripping of cold gas only affects the quenched fraction in massive haloes with Mh > 1013.5 M⊙, but is needed to reproduce the observed H i deficiencies.

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Structure of dark matter haloes of Milky Way satellite galaxies in SIDM universes

Proceedings of the International Astronomical Union ◽

10.1017/s174392131800580x ◽

2018 ◽

Vol 14 (S344) ◽

pp. 498-501

Author(s):

Takashi Okamoto

Keyword(s):

Dark Matter ◽

Cross Section ◽

Galaxy Formation ◽

Luminosity Function ◽

Milky Way ◽

Dwarf Galaxies ◽

Interaction Cross Section ◽

Large Cross Section ◽

Stellar Feedback ◽

Satellite Galaxies

AbstractSelf-interacting dark matter (SIDM) can create sufficiently large cores in dark matter haloes of dwarf galaxies if the self-interaction cross-section is sufficiently large on scales of dwarf galaxies. Such a large cross-section can be realized without changing the densities and shapes of cluster-size haloes by introducing a velocity dependent cross-section. Lowering the central densities of dwarf-size haloes, however, may change the strength of stellar feedback required to reproduce observed properties of dwarf galaxies such as the luminosity function of the Milky Way’s satellite galaxies. We perform simulations of galaxy formation by employing such a velocity dependent self-interaction cross-section to investigate the coupled effect of SIDM and feedback.

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