scholarly journals A comparative study of satellite galaxies in Milky Way-like galaxies from HSC, DECaLS, and SDSS

2020 ◽  
Vol 500 (3) ◽  
pp. 3776-3801
Author(s):  
Wenting Wang ◽  
Masahiro Takada ◽  
Xiangchong Li ◽  
Scott G Carlsten ◽  
Ting-Wen Lan ◽  
...  
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Statistical Study ◽  
Satellite System ◽  
Large Scatter ◽  
Local Universe ◽  
Good Representative ◽  
Luminosity Functions ◽  
Satellite Galaxies ◽  
Good Agreement

ABSTRACT We conduct a comprehensive and statistical study of the luminosity functions (LFs) for satellite galaxies, by counting photometric galaxies from HSC, DECaLS, and SDSS around isolated central galaxies (ICGs) and paired galaxies from the SDSS/DR7 spectroscopic sample. Results of different surveys show very good agreement. The satellite LFs can be measured down to MV ∼ −10, and for central primary galaxies as small as 8.5 < log10M*/M⊙ < 9.2 and 9.2 < log10M*/M⊙ < 9.9, which implies there are on average 3–8 satellites with MV < −10 around LMC-mass ICGs. The bright end cutoff of satellite LFs and the satellite abundance are both sensitive to the magnitude gap between the primary and its companions, indicating galaxy systems with larger magnitude gaps are on average hosted by less massive dark matter haloes. By selecting primaries with stellar mass similar to our Milky Way (MW), we discovered that (i) the averaged satellite LFs of ICGs with different magnitude gaps to their companions and of galaxy pairs with different colour or colour combinations all show steeper slopes than the MW satellite LF; (ii) there are on average more satellites with −15 < MV < −10 than those in our MW; (iii) there are on average 1.5 to 2.5 satellites with MV < −16 around ICGs, consistent with our MW; (iv) even after accounting for the large scatter predicted by numerical simulations, the MW satellite LF is uncommon at MV > −12. Hence, the MW and its satellite system are statistically atypical of our sample of MW-mass systems. In consequence, our MW is not a good representative of other MW-mass galaxies. Strong cosmological implications based on only MW satellites await additional discoveries of fainter satellites in extra-galactic systems. Interestingly, the MW satellite LF is typical among other MW-mass systems within 40 Mpc in the local Universe, perhaps implying the Local Volume is an underdense region.

scholarly journals Dark matter–radiation interactions: the structure of Milky Way satellite galaxies

2016 ◽  
Vol 461 (3) ◽  
pp. 2282-2287 ◽  
Author(s):  
J. A. Schewtschenko ◽  
C. M. Baugh ◽  
R. J. Wilkinson ◽  
C. Bœhm ◽  
S. Pascoli ◽  
...  
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Satellite Galaxies

scholarly journals Too big to fail in light of Gaia

2019 ◽  
Vol 490 (1) ◽  
pp. 231-242 ◽  
Author(s):  
Manoj Kaplinghat ◽  
Mauro Valli ◽  
Hai-Bo Yu
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Large Scatter ◽  
Too Big To Fail ◽  
Dwarf Spheroidal Galaxies ◽  
Ursa Minor ◽  
Spheroidal Galaxies

ABSTRACT We point out an anticorrelation between the central dark matter (DM) densities of the bright Milky Way dwarf spheroidal galaxies (dSphs) and their orbital pericenter distances inferred from Gaia data. The dSphs that have not come close to the Milky Way centre (like Fornax, Carina and Sextans) are less dense in DM than those that have come closer (like Draco and Ursa Minor). The same anticorrelation cannot be inferred for the ultrafaint dSphs due to large scatter, while a trend that dSphs with more extended stellar distributions tend to have lower DM densities emerges with ultrafaints. We discuss how these inferences constrain proposed solutions to the Milky Way’s too-big-to-fail problem and provide new clues to decipher the nature of DM.

scholarly journals Dark Matter Constraints from a Unified Analysis of Strong Gravitational Lenses and Milky Way Satellite Galaxies

2021 ◽  
Vol 917 (1) ◽  
pp. 7
Author(s):  
Ethan O. Nadler ◽  
Simon Birrer ◽  
Daniel Gilman ◽  
Risa H. Wechsler ◽  
Xiaolong Du ◽  
...  
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Gravitational Lenses ◽  
Satellite Galaxies

scholarly journals On the Co-orbitation of Satellite Galaxies along the Great Plane of Andromeda: NGC 147, NGC 185, and Expectations from Cosmological Simulations

2021 ◽  
Vol 923 (1) ◽  
pp. 42
Author(s):  
Marcel S. Pawlowski ◽  
Sangmo Tony Sohn
Keyword(s):  
Milky Way ◽  
Detailed Comparison ◽  
Satellite System ◽  
Line Of Sight ◽  
Proper Motions ◽  
Velocity Correlation ◽  
Cosmological Simulations ◽  
Rotating Structure ◽  
Motion Measurements ◽  
Satellite Galaxies

Abstract Half of the satellite galaxies of Andromeda form a narrow plane termed the Great Plane of Andromeda (GPoA), and their line-of-sight velocities display a correlation reminiscent of a rotating structure. Recently reported first proper-motion measurements for the on-plane satellites NGC 147 and NGC 185 indicate that they indeed co-orbit along the GPoA. This provides a novel opportunity to compare the M31 satellite system to ΛCDM expectations. We perform the first detailed comparison of the orbital alignment of two satellite galaxies beyond the Milky Way with several hydrodynamical and dark-matter-only cosmological simulations (Illustris TNG50, TNG100, ELVIS, and PhatELVIS) in the context of the Planes of Satellite Galaxies Problem. In line with previous works, we find that the spatial flattening and line-of-sight velocity correlation are already in substantial tension with ΛCDM, with none of the simulated analogs simultaneously reproducing both parameters. Almost none (3%–4%) of the simulated systems contain two satellites with orbital poles as well aligned with their satellite plane as indicated by the most likely proper motions of NGC 147 and NGC 185. However, within current measurement uncertainties, it is common (≈70%) that the two best-aligned satellites of simulated systems are consistent with the orbital alignment. Yet, the chance that any two simulated on-plane satellites have as well-aligned orbital poles as observed is low (≈4%). We conclude that confirmation of the tight orbital alignment for these two objects via improved measurements, or the discovery of similar alignments for additional GPoA members, holds the potential to further raise the tension with ΛCDM expectations.

scholarly journals Infrared luminosity functions and dust mass functions in the EAGLE simulation

2020 ◽  
Vol 494 (2) ◽  
pp. 2912-2924 ◽  
Author(s):  
Maarten Baes ◽  
Ana Trčka ◽  
Peter Camps ◽  
James Trayford ◽  
Antonios Katsianis ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Mass Density ◽  
Local Universe ◽  
Luminosity Functions ◽  
Simulation Based ◽  
Dust Mass ◽  
Slow Evolution ◽  
Mass Functions ◽  
Luminosity Evolution ◽  
Good Agreement

ABSTRACT We present infrared luminosity functions and dust mass functions for the EAGLE cosmological simulation, based on synthetic multiwavelength observations generated with the SKIRT radiative transfer code. In the local Universe, we reproduce the observed infrared luminosity and dust mass functions very well. Some minor discrepancies are encountered, mainly in the high luminosity regime, where the EAGLE-SKIRT luminosity functions mildly but systematically underestimate the observed ones. The agreement between the EAGLE-SKIRT infrared luminosity functions and the observed ones gradually worsens with increasing lookback time. Fitting modified Schechter functions to the EAGLE-SKIRT luminosity and dust mass functions at different redshifts up to z = 1, we find that the evolution is compatible with pure luminosity/mass evolution. The evolution is relatively mild: within this redshift range, we find an evolution of L⋆,250 ∝ (1 + z)1.68, L⋆,TIR ∝ (1 + z)2.51 and M⋆,dust ∝ (1 + z)0.83 for the characteristic luminosity/mass. For the luminosity/mass density we find ε250 ∝ (1 + z)1.62, εTIR ∝ (1 + z)2.35, and ρdust ∝ (1 + z)0.80, respectively. The mild evolution of the dust mass density is in relatively good agreement with observations, but the slow evolution of the infrared luminosity underestimates the observed luminosity evolution significantly. We argue that these differences can be attributed to increasing limitations in the radiative transfer treatment due to increasingly poorer resolution, combined with a slower than observed evolution of the SFR density in the EAGLE simulation and the lack of AGN emission in our EAGLE-SKIRT post-processing recipe.

scholarly journals The Evolution of Old Stellar Populations in Our Galaxy

2002 ◽  
Vol 187 ◽  
pp. 185-193
Author(s):  
Steven R. Majewski
Keyword(s):  
Star Formation ◽  
Milky Way ◽  
Star Clusters ◽  
Stellar Populations ◽  
Large Scatter ◽  
Chemical Abundance ◽  
The Galaxy ◽  
Satellite Galaxies ◽  
Galactic Stellar Populations

I would like to focus on one aspect regarding the evolution of Galactic stellar populations that is particularly relevant to discussions at this symposium: Where were the sites of early star formation in the Galaxy? The large scatter in abundance ratios for metal poor stars suggests multiple early settings of star formation in the Milky Way. In this and other ways, interpretation of detailed stellar chemical abundance analyses are converging with those of spatial-kinematical analyses of field stars, star clusters and satellite galaxies.

scholarly journals Phat ELVIS: The inevitable effect of the Milky Way’s disc on its dark matter subhaloes

2019 ◽  
Vol 487 (3) ◽  
pp. 4409-4423 ◽  
Author(s):  
Tyler Kelley ◽  
James S Bullock ◽  
Shea Garrison-Kimmel ◽  
Michael Boylan-Kolchin ◽  
Marcel S Pawlowski ◽  
...  
Keyword(s):  
Dark Matter ◽  
High Resolution ◽  
Milky Way ◽  
Milky Way Galaxy ◽  
Central Galaxy ◽  
The Galaxy ◽  
Satellite Galaxies ◽  
Atomic Cooling

ABSTRACT We introduce an extension of the ELVIS project to account for the effects of the Milky Way galaxy on its subhalo population. Our simulation suite, Phat ELVIS, consists of 12 high-resolution cosmological dark matter-only (DMO) zoom simulations of Milky Way-size ΛCDM haloes [Mv = (0.7−2) × 1012 M⊙] along with 12 re-runs with embedded galaxy potentials grown to match the observed Milky Way disc and bulge today. The central galaxy potential destroys subhalos on orbits with small pericentres in every halo, regardless of the ratio of galaxy mass to halo mass. This has several important implications. (1) Most of the Disc runs have no subhaloes larger than Vmax = 4.5 km s−1 within 20 kpc and a significant lack of substructure going back ∼8 Gyr, suggesting that local stream-heating signals from dark substructure will be rare. (2) The pericentre distributions of Milky Way satellites derived from Gaia data are remarkably similar to the pericentre distributions of subhaloes in the Disc runs, while the DMO runs drastically overpredict galaxies with pericentres smaller than 20 kpc. (3) The enhanced destruction produces a tension opposite to that of the classic ‘missing satellites’ problem: in order to account for ultra-faint galaxies known within 30 kpc of the Galaxy, we must populate haloes with Vpeak ≃ 7 km s−1 (M ≃ 3 × 107 M⊙ at infall), well below the atomic cooling limit of $V_\mathrm{peak}\simeq 16 \,{\rm km} \, {\rm s}^{-1}$ (M ≃ 5 × 108M⊙ at infall). (4) If such tiny haloes do host ultra-faint dwarfs, this implies the existence of ∼1000 satellite galaxies within 300 kpc of the Milky Way.

scholarly journals Addressing γ-ray emissions from dark matter annihilations in 45 Milky Way satellite galaxies and in extragalactic sources with particle dark matter models

2020 ◽  
Vol 500 (4) ◽  
pp. 5589-5602
Author(s):  
Ashadul Halder ◽  
Shibaji Banerjee ◽  
Madhurima Pandey ◽  
Debasish Majumdar
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Dwarf Galaxies ◽  
Upper Bounds ◽  
Density Profiles ◽  
Dark Energy Survey ◽  
Γ Rays ◽  
Γ Ray ◽  
Particle Dark Matter ◽  
Satellite Galaxies

ABSTRACT The mass-to-luminosity ratio of the dwarf satellite galaxies in the Milky Way suggests that these dwarf galaxies may contain substantial dark matter. The dark matter at the dense region such as within or at the vicinity of the centres of these dwarf galaxies may undergo the process of self-annihilation and produce γ-rays as the end product. The satellite borne γ-ray telescope such as Fermi-LAT reported the detection of γ-rays from around 45 Dwarf Spheroidals (dSphs) of Milky Way. In this work, we consider particle dark matter models described in the literature and after studying their phenomenologies, we calculate the γ-ray fluxes from the self-annihilation of the dark matter within the framework of these models in case of each of these 45 dSphs. We then compare the computed results with the observational upper bounds for γ-ray flux reported by Fermi-LAT and Dark Energy Survey for each of the 45 dSphs. The fluxes are calculated by adopting different dark matter density profiles. We then extend similar analysis for the observational upper bounds given by Fermi-LAT for the continuum γ-ray fluxes originating from extragalactic sources.

scholarly journals Precision astrometry, galactic mergers, halo substructure and local dark matter

2007 ◽  
Vol 3 (S248) ◽  
pp. 450-457 ◽  
Author(s):  
S. R. Majewski
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Milky Way ◽  
Satellite System ◽  
Cold Dark Matter Model ◽  
Matter Model ◽  
The Universe ◽  
Dark Matter Model ◽  
Precision Astrometry ◽  
Space Interferometry

AbstractThe concordance Cold Dark Matter model for the formation of structure in the Universe, while remarkably successful at describing observations on large scales, has a number of problems on galactic scales. The Milky Way and its satellite system provide a key laboratory for exploring dark matter (DM) in this regime, but some of the most definitive tests of local DM await microarcsecond astrometry, such as will be delivered by the Space Interferometry Mission (SIM Planetquest). I discuss several tests of Galactic DM enabled by future microarcsecond astrometry.

scholarly journals Galaxies on Sub-Galactic Scales

2012 ◽  
Vol 29 (4) ◽  
pp. 383-394 ◽  
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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