A 3D hydrodynamic simulation of a black hole outflow in a dwarf spheroidal galaxy

2018 ◽  
Vol 14 (S344) ◽  
pp. 296-300
Author(s):  
Gustavo A. Lanfranchi ◽  
Anderson Caproni ◽  
Roberto Hazenfratz
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Initial Velocity ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Homogeneous Medium ◽  
Intermediate Mass ◽  
Hydrodynamic Simulation ◽  
Dwarf Spheroidal Galaxies ◽  
The Galaxy

AbstractWe present results from a non-cosmological, three-dimensional hydrodynamic simulation of an outflow from an intermediate-mass black hole in Dwarf Spheroidal Galaxies. Assuming an initial baryonic-to-dark-matter ratio derived from the CMB radiation and a cored, static dark matter potential, we evolved the galactic gas distribution over 3 Gyr, taking into account the outflow of a black hole. Our results indicate that in a homogeneous medium the outflow propagates freely in both directions with the same velocity and its capable of removing a fraction of the gas from the galaxy (it depends on the initial conditions of the outflow). When the SNe are taken into account, the effect of the outflow is substantially reduced. It is necessary an initial velocity around 1000 km/s and a density larger than 0.003 particles.cm−3 for the outflow to propagate. In these conditions, the removal of gas from the galaxy is almost negligible at the end of the 3 Gyr of the simulation.

Effects of supernovae feedback and black hole outflows in the evolution of Dwarf Spheroidal Galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 280-282
Author(s):  
Gustavo Amaral Lanfranchi ◽  
Anderson Caproni ◽  
Jennifer F. Soares ◽  
Larissa S. de Oliveira
Keyword(s):  
Black Hole ◽  
Homogeneous Medium ◽  
Massive Black Hole ◽  
Dwarf Spheroidal Galaxies ◽  
Stellar Feedback ◽  
Gas Removal ◽  
The Galaxy ◽  
Main Driver ◽  
Ia Supernovae ◽  
Jet Structure

AbstractThe gas evolution of a typical Dwarf Spheroidal Galaxy is investigated by means of 3D hydrodynamic simulations, taking into account the feedback of type II and Ia supernovae, the outflow of an Intermediate Massive Black Hole (IMBH) and a static cored dark matter potential. When the IMBH’s outflow is simulated in an homogeneous medium a jet structure is created and a small fraction of the gas is pushed away from the galaxy. No jet structure can be seen, however, when the medium is disturbed by supernovae, but gas is still pushed away. In this case, the main driver of the gas removal are the supernovae. The interplay between the stellar feedback and the IMBH’s outflow should be taken into account.

scholarly journals On the formation and stability of fermionic dark matter halos in a cosmological framework

2020 ◽  
Author(s):  
Carlos R Argüelles ◽  
Manuel I Díaz ◽  
Andreas Krut ◽  
Rafael Yunis
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Space Distribution ◽  
Coarse Grained ◽  
Dark Matter Halos ◽  
The Core ◽  
The Galaxy ◽  
Gravitating Systems ◽  
The Given ◽  
First Time

Abstract The formation and stability of collisionless self-gravitating systems is a long standing problem, which dates back to the work of D. Lynden-Bell on violent relaxation, and extends to the issue of virialization of dark matter (DM) halos. An important prediction of such a relaxation process is that spherical equilibrium states can be described by a Fermi-Dirac phase-space distribution, when the extremization of a coarse-grained entropy is reached. In the case of DM fermions, the most general solution develops a degenerate compact core surrounded by a diluted halo. As shown recently, the latter is able to explain the galaxy rotation curves while the DM core can mimic the central black hole. A yet open problem is whether this kind of astrophysical core-halo configurations can form at all, and if they remain stable within cosmological timescales. We assess these issues by performing a thermodynamic stability analysis in the microcanonical ensemble for solutions with given particle number at halo virialization in a cosmological framework. For the first time we demonstrate that the above core-halo DM profiles are stable (i.e. maxima of entropy) and extremely long lived. We find the existence of a critical point at the onset of instability of the core-halo solutions, where the fermion-core collapses towards a supermassive black hole. For particle masses in the keV range, the core-collapse can only occur for Mvir ≳ E9M⊙ starting at zvir ≈ 10 in the given cosmological framework. Our results prove that DM halos with a core-halo morphology are a very plausible outcome within nonlinear stages of structure formation.

scholarly journals Reshaping our understanding on structure formation with the quantum nature of the dark matter

2021 ◽  
Author(s):  
C. R. Argüelles ◽  
E. A. Becerra-Vergara ◽  
A. Krut ◽  
R. Yunis ◽  
J. A. Rueda ◽  
...  
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Structure Formation ◽  
Initial Conditions ◽  
Coarse Grained ◽  
Intermediate Mass ◽  
Open Problems ◽  
Nonlinear Structure ◽  
The Core ◽  
Quantum Nature

We study the nonlinear structure formation in cosmology accounting for the quantum nature of the dark matter (DM) particles in the initial conditions at decoupling, as well as in the relaxation and stability of the DM halos. Different from cosmological N-body simulations, we use a thermodynamic approach for collisionless systems of self-gravitating fermions in general relativity, in which the halos reach the steady state by maximizing a coarse-grained entropy. We show the ability of this approach to provide answers to crucial open problems in cosmology, among others: the mass and nature of the DM particle, the formation and nature of supermassive black holes in the early Universe, the nature of the intermediate mass black holes in small halos, and the core-cusp problem.

scholarly journals Predicted MOND velocity dispersions for a catalog of ultra-diffuse galaxies in group environments

2019 ◽  
Vol 623 ◽  
pp. A36 ◽  
Author(s):  
Oliver Müller ◽  
Benoit Famaey ◽  
Hongsheng Zhao
Keyword(s):  
Dark Matter ◽  
External Field ◽  
Field Effect ◽  
Velocity Dispersion ◽  
A Priori ◽  
Three Dimensional ◽  
The Galaxy ◽  
Lower Limits ◽  
Group Environments

The possibility that ultra-diffuse galaxies are lacking dark matter has recently stimulated interest to check the validity of modified Newton dynamics (MOND) predictions on the scale of such galaxies. It has been shown that the external field effect (EFE) induced by the close-by galaxy can suppress the velocity dispersion of these systems, so that they appear almost dark matter free in the Newtonian context. Here, following up on this, we are making a priori predictions for the velocity dispersion of 22 ultra-diffuse galaxies in the nearby Universe. This sample can be used to test MOND and the EFE with future follow-up measurements. We have constructed a catalog of nearby ultra-diffuse galaxies in galaxy group environments, and set upper and lower limits for the possible velocity dispersion allowed in MOND, taking into account possible variations in the mass-to-light ratio of the dwarf and in the distance to the galaxy group. The prediction for the velocity dispersion is made as a function of the three dimensional separation of the dwarf to its host. In 17 out of 22 cases, the EFE plays a crucial role in the prediction.

scholarly journals POPULATION OF BLACK HOLES IN THE MILKY WAY AND IN THE MAGELLANIC CLOUDS

2013 ◽  
Vol 53 (A) ◽  
pp. 665-670
Author(s):  
Janusz Ziółkowski
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Milky Way ◽  
Stellar Mass ◽  
Magellanic Clouds ◽  
Intermediate Mass ◽  
Different Types ◽  
The Galaxy

In this review, I will briefly discuss the different types of black hole (BH) populations (supermassive, intermediate mass and stellar mass BHs) both in the Galaxy and in the Magellanic Clouds and compare them with each other.

scholarly journals An intermediate-mass black hole of over 500 solar masses in the galaxy ESO 243-49

Nature ◽  
2009 ◽  
Vol 460 (7251) ◽  
pp. 73-75 ◽  
Author(s):  
Sean A. Farrell ◽  
Natalie A. Webb ◽  
Didier Barret ◽  
Olivier Godet ◽  
Joana M. Rodrigues
Keyword(s):  
Black Hole ◽  
Intermediate Mass ◽  
The Galaxy

scholarly journals Numerical Simulation of the Dwarf Companions of Giant Galaxies

2007 ◽  
Vol 3 (S244) ◽  
pp. 226-230
Author(s):  
A. H. Nelson ◽  
P. R. Williams
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Initial Conditions ◽  
Dark Matter Halo ◽  
Initial Population ◽  
Dark Matter Halos ◽  
Disc Galaxy ◽  
Standard Spectrum ◽  
The Galaxy ◽  
Secondary Population

AbstractWe report simulations of the formation of a giant disc galaxy from cosmological initial conditions. Two sets of initial conditions are used, initially smooth density for both gas and stars, representing the Warm dark Matter scenario, and an initially fluctuating density representing the standard spectrum for the Cold dark Matter scenario. For the WDM initial conditions, the galaxy has a population of long lived dwarf satellites at z = 0, with orbits close to a plane coincident with that of the giant galaxy disc. The detailed properties of these dwarfs mimic closely the observed properties of Local Group dwarfs with respect to mass, and kinematics. However they do not have individual dark matter halos, but orbit in the nearly spherical dark matter halo of the giant galaxy. The reason for this is that the initial population of dwarf dark matter haloes, which form during the initial collapse phase, all merge into the halo of the giant galaxy within a few to several Gyears, while the long lived dwarfs form as a secondary population by gravitational collapse of high angular momentum gas in the outer reaches of the giants proto-galactic disc. Due to their late formation and their more distant orbits, they survive until the present epoch as individual dwarf galaxies at radii 20-50kpc from the giants centre. For CDM initial conditions there are many more dwarf satellites at z = 0, some of which form early on as gas condensations in DM sub-halos, and survive with these individual DM halos till z = 0 due to their being sufficiently well bound to avoid merging with the main galaxy. However even in this case some second generation satellites form as initially gas only objects, just as for the smooth initial conditions of WDM.

The gas-loss evolution in dwarf spheroidal galaxies: Supernova feedback and environment effects in the case of the local group galaxy Ursa Minor

2020 ◽  
Vol 15 (S359) ◽  
pp. 117-118
Author(s):  
Anderson Caproni ◽  
Gustavo Amaral Lanfranchi
Keyword(s):  
Three Dimensional ◽  
Hydrodynamic Simulations ◽  
Dwarf Spheroidal Galaxies ◽  
Environment Effects ◽  
Ram Pressure ◽  
The Galaxy ◽  
Ursa Minor ◽  
Gas Loss ◽  
Ia Supernovae ◽  
Supernova Feedback

AbstractIn this work, we performed two distinct non-cosmological, three-dimensional hydrodynamic simulations that evolved the gas component of a galaxy similar to the classical dwarf spheroidal galaxy Ursa Minor. Both simulations take into account types II and Ia supernovae feedback constrained by chemical evolution models, while ram-pressure stripping mechanism is added into one of them considering an intergalactic medium and a galactic velocity that resemble what is observed nowadays for the Ursa Minor galaxy. Our results show no difference in the amount of gas left inside the galaxy until 400 Myr of evolution. Moreover, the ram-pressure wind was stalled and inverted by thermal pressure of the interstellar medium and supernovae feedback during the same interval.

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