Dynamics of Disrupting Milky Way Satellite Galaxies and Tidal Streams

2005 ◽  
Author(s):  
S. R. Majewski
Keyword(s):  
Milky Way ◽  
Satellite Galaxies ◽  
Tidal Streams

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 Quantifying tidal stream disruption in a simulated Milky Way

2017 ◽  
Vol 470 (1) ◽  
pp. 522-538 ◽  
Author(s):  
Emily Sandford ◽  
Andreas H. W. Küpper ◽  
Kathryn V. Johnston ◽  
Jürg Diemand
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Galactic Halo ◽  
Mass Range ◽  
Galactic Centre ◽  
High Dimensions ◽  
Density Profiles ◽  
Upper Limits ◽  
Tidal Stream ◽  
Tidal Streams

Abstract Simulations of tidal streams show that close encounters with dark matter subhaloes induce density gaps and distortions in on-sky path along the streams. Accordingly, observing disrupted streams in the Galactic halo would substantiate the hypothesis that dark matter substructure exists there, while in contrast, observing collimated streams with smoothly varying density profiles would place strong upper limits on the number density and mass spectrum of subhaloes. Here, we examine several measures of stellar stream ‘disruption' and their power to distinguish between halo potentials with and without substructure and with different global shapes. We create and evolve a population of 1280 streams on a range of orbits in the Via Lactea II simulation of a Milky Way-like halo, replete with a full mass range of Λcold dark matter subhaloes, and compare it to two control stream populations evolved in smooth spherical and smooth triaxial potentials, respectively. We find that the number of gaps observed in a stellar stream is a poor indicator of the halo potential, but that (i) the thinness of the stream on-sky, (ii) the symmetry of the leading and trailing tails and (iii) the deviation of the tails from a low-order polynomial path on-sky (‘path regularity') distinguish between the three potentials more effectively. We furthermore find that globular cluster streams on low-eccentricity orbits far from the galactic centre (apocentric radius ∼30–80 kpc) are most powerful in distinguishing between the three potentials. If they exist, such streams will shortly be discoverable and mapped in high dimensions with near-future photometric and spectroscopic surveys.

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 THE CONNECTION BETWEEN THE HOST HALO AND THE SATELLITE GALAXIES OF THE MILKY WAY

2016 ◽  
Vol 830 (2) ◽  
pp. 59 ◽  
Author(s):  
Yu Lu ◽  
Andrew Benson ◽  
Yao-Yuan Mao ◽  
Stephanie Tonnesen ◽  
Annika H. G. Peter ◽  
...  
Keyword(s):  
Milky Way ◽  
Satellite Galaxies

scholarly journals Statistical detection of a tidal stream associated with the globular cluster M68 using Gaia data

2019 ◽  
Vol 488 (2) ◽  
pp. 1535-1557 ◽  
Author(s):  
Carles G Palau ◽  
Jordi Miralda-Escudé
Keyword(s):  
Globular Cluster ◽  
Milky Way ◽  
Spectroscopic Studies ◽  
Dark Halo ◽  
General Catalogue ◽  
Tidal Stream ◽  
Statistical Detection ◽  
Tidal Streams ◽  
North Galactic

ABSTRACT A method to search for tidal streams and to fit their orbits based on maximum likelihood is presented and applied to the Gaia data. Tests of the method are performed showing how a simulated stream produced by tidal stripping of a star cluster is recovered when added to a simulation of the Gaia catalogue. The method can be applied to search for streams associated with known progenitors or to do blind searches in a general catalogue. As the first example, we apply the method to the globular cluster M68 and detect its clear tidal stream stretching over the whole North Galactic hemisphere, and passing within 5 kpc of the Sun. This is one of the closest tidal streams to us detected so far, and is highly promising to provide new constraints on the Milky Way gravitational potential, for which we present preliminary fits finding a slightly oblate dark halo consistent with other observations. We identify the M68 tidal stream with the previously discovered Fjörm stream by Ibata et al. The tidal stream is confirmed to contain stars that are consistent with the HR-diagram of M68. We provide a list of 115 stars that are most likely to be stream members, and should be prime targets for follow-up spectroscopic studies.

scholarly journals A QUANTITATIVE EXPLANATION OF THE OBSERVED POPULATION OF MILKY WAY SATELLITE GALAXIES

2009 ◽  
Vol 696 (2) ◽  
pp. 2179-2194 ◽  
Author(s):  
Sergey E. Koposov ◽  
Jaiyul Yoo ◽  
Hans-Walter Rix ◽  
David H. Weinberg ◽  
Andrea V. Macciò ◽  
...  
Keyword(s):  
Milky Way ◽  
Satellite Galaxies ◽  
Quantitative Explanation

scholarly journals SUBSTRUCTURE FORMATION IN TIDAL STREAMS OF GALACTIC MINOR MERGERS

2019 ◽  
Vol 55 (2) ◽  
pp. 273-288
Author(s):  
D. A. Noreña ◽  
J. C. Muñoz-Cuartas ◽  
L. F. Quiroga ◽  
N. Libeskind
Keyword(s):  
Dark Matter ◽  
Dynamical Stability ◽  
Stellar Clusters ◽  
Tidal Stream ◽  
Substructure Formation ◽  
Satellite Galaxies ◽  
Minor Mergers ◽  
Tidal Streams

In this work, we explore the idea that substructures like stellar clusters could be formed from the tidal stream produced in galactic minor mergers. We use N -body and SPH simulations of satellite galaxies interacting with a larger galaxy. We study the distribution of mass in streams to identify overdensity regions in which a substructure could be formed. We find that without gas, no substructure forms as none of the overdensities shows a definite morphology nor dynamical stability. Including gas we find that several clumps appear and prove to be real long standing physical structures (t ≥ 1 Gyr). We analyze the orbits, ages and masses of these structures, finding their correspondence with the halo subsystems. We conclude that it is possible to form cluster-like structures from the material in tidal streams and find evidence in favour of the presence of dark matter in these systems.

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 An SDSS Survey For Resolved Milky Way Satellite Galaxies. I. Detection Limits

2002 ◽  
Vol 123 (2) ◽  
pp. 848-854 ◽  
Author(s):  
Beth Willman ◽  
Julianne Dalcanton ◽  
Željko Ivezić ◽  
Tom Jackson ◽  
Robert Lupton ◽  
...  
Keyword(s):  
Milky Way ◽  
Detection Limits ◽  
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.

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