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.

The hydrodynamic evolution of the gas content in the dSph galaxy Ursa Minor induced by the feedback from types Ia and II supernovae

2018 ◽  
Vol 14 (S344) ◽  
pp. 49-52
Author(s):  
Anderson Caproni ◽  
Gustavo A. Lanfranchi ◽  
Gabriel H. Campos Baião ◽  
Grzegorz Kowal ◽  
Diego Falceta-Gonçalves
Keyword(s):  
Local Group ◽  
Dwarf Galaxies ◽  
Three Dimensional ◽  
Gas Content ◽  
Dwarf Spheroidal Galaxies ◽  
Hydrodynamical Simulation ◽  
Hydrodynamic Evolution ◽  
Ursa Minor ◽  
Gas Loss ◽  
Chemical Evolution Model

AbstractDwarf spheroidal galaxies of the Local Group share a similar characteristic nowadays: a low amount of gas in their interiors. In this work, we present results from a three-dimensional hydrodynamical simulation of the gas inside an object with similar characteristics of the Ursa Minor galaxy. We evolved the initial gas distribution over 3 Gyr, considering the effects of the types Ia and II supernovae. The instantaneous supernovae rates were derived from a chemical evolution model applied to spectroscopic data of the Ursa Minor galaxy. Our simulation shows that the amount of gas that is lost varies with time and galactocentric radius. The highest gas-loss rates occurred during the first 600 Myr of evolution. Our results also indicate that types Ia and II supernovae must be essential drivers of the gas loss in Ursa Minor galaxy (and probably in other similar dwarf galaxies).

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 Pushing back the limits: detailed properties of dwarf galaxies in a ΛCDM universe

2018 ◽  
Vol 616 ◽  
pp. A96 ◽  
Author(s):  
Yves Revaz ◽  
Pascale Jablonka
Keyword(s):  
Star Formation ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Mass Scale ◽  
Dwarf Spheroidal Galaxies ◽  
The Galaxy ◽  
Dynamical Simulations ◽  
Ursa Minor ◽  
Stellar Properties ◽  
Star Formation Histories

We present the results of a set of high-resolution chemo-dynamical simulations of dwarf galaxies in a ΛCDM cosmology. Out of an original (3.4 Mpc/h)3 cosmological box, a sample of 27 systems are re-simulated from z = 70 to z = 0 using a zoom-in technique. Gas and stellar properties are confronted to the observations in the greatest details: in addition to the galaxy global properties, we investigated the model galaxy velocity dispersion profiles, half-light radii, star formation histories, stellar metallicity distributions, and [Mg/Fe] abundance ratios. The formation and sustainability of the metallicity gradients and kinematically distinct stellar populations are also tackled. We show how the properties of six Local Group dwarf galaxies, NGC 6622, Andromeda II, Sculptor, Sextans, Ursa Minor and Draco are reproduced, and how they pertain to three main galaxy build-up modes. Our results indicate that the interaction with a massive central galaxy could be needed for a handful of Local Group dwarf spheroidal galaxies only, the vast majority of the systems and their variety of star formation histories arising naturally from a ΛCDM framework. We find that models fitting well the local Group dwarf galaxies are embedded in dark haloes of mass between 5 × 108 to a few 109 M⊙, without any missing satellite problem. We confirm the failure of the abundance matching approach at the mass scale of dwarf galaxies. Some of the observed faint however gas-rich galaxies with residual star formation, such as Leo T and Leo P, remain challenging. They point out the need of a better understanding of the UV-background heating.

scholarly journals The Chemical Abundances of the Halo Clusters of the Galaxy

1978 ◽  
Vol 80 ◽  
pp. 177-182
Author(s):  
R. Canterna ◽  
R. A. Schommer
Keyword(s):  
Globular Clusters ◽  
Broad Band ◽  
Mean Value ◽  
Red Giants ◽  
Galactocentric Distance ◽  
Chemical Abundances ◽  
Dwarf Spheroidal Galaxies ◽  
The Galaxy ◽  
Ursa Minor ◽  
Metal Abundances

Photometric metal abundances of individual red giants in eight extremely distant halo globular clusters and the Draco and Ursa Minor dwarf spheroidal galaxies have been obtained using the Washington broad-band system, C, M, T1, T2(Canterna 1976). Observations were made at the KPNO 2.1-m and CTIO 1.5-m telescopes. In Table I we list for each system the mean value of [Fe/H], the number of stars observed in each system, n, the Galactocentric distance, RGC, the intrinsic color of the giant branch at the level of the horizontal branch (HB), (B-V)o,g, and the fraction of HB stars bluer than the RR Lyrae gap, fB. Sources for unpublished color-magnitude diagram (CMD) data are: Pal 11 (Canterna and Schommer), Pal 12 (Canterna and Harris), and Ursa Minor (Schommer, Olszewski and Kunkel).

scholarly journals THREE-DIMENSIONAL HYDRODYNAMICAL SIMULATIONS OF THE SUPERNOVAE-DRIVEN GAS LOSS IN THE DWARF SPHEROIDAL GALAXY URSA MINOR

2015 ◽  
Vol 805 (2) ◽  
pp. 109 ◽  
Author(s):  
A. Caproni ◽  
G. A. Lanfranchi ◽  
A. Luiz da Silva ◽  
D. Falceta-Gonçalves
Keyword(s):  
Three Dimensional ◽  
Ursa Minor ◽  
Hydrodynamical Simulations ◽  
Gas Loss

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.

scholarly journals The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis

2017 ◽  
Vol 608 ◽  
pp. A89 ◽  
Author(s):  
L. Mashonkina ◽  
P. Jablonka ◽  
T. Sitnova ◽  
Yu. Pakhomov ◽  
P. North
Keyword(s):  
Milky Way ◽  
Dwarf Galaxy ◽  
Chemical Species ◽  
Dwarf Spheroidal Galaxies ◽  
Massive Galaxies ◽  
Type Ia ◽  
Ursa Minor ◽  
R Process ◽  
Ia Supernovae ◽  
Process Elements

We present the non-local thermodynamic equilibrium (NLTE) abundances of up to 10 chemical species in a sample of 59 very metal-poor (VMP, −4 ≤ [Fe/H] ≾−2) stars in seven dwarf spheroidal galaxies (dSphs) and in the Milky Way (MW) halo. Our results are based on high-resolution spectroscopic datasets and homogeneous and accurate atmospheric parameters determined in Paper I. We show that once the NLTE effects are properly taken into account, all massive galaxies in our sample, that is, the MW halo and the classical dSphs Sculptor, Ursa Minor, Sextans, and Fornax, reveal a similar plateau at [α/Fe] ≃ 0.3 for each of the α-process elements: Mg, Ca, and Ti. We put on a firm ground the evidence for a decline in α/Fe with increasing metallicity in the Boötes I ultra-faint dwarf galaxy (UFD), that is most probably due to the ejecta of type Ia supernovae. For Na/Fe, Na/Mg, and Al/Mg, the MW halo and all dSphs reveal indistinguishable trends with metallicity, suggesting that the processes of Na and Al synthesis are identical in all systems, independent of their mass. The dichotomy in the [Sr/Ba] versus [Ba/H] diagram is observed in the classical dSphs, similarly to the MW halo, calling for two different nucleosynthesis channels for Sr. We show that Sr in the massive galaxies is well correlated with Mg suggesting a strong link to massive stars and that its origin is essentially independent of Ba, for most of the [Ba/H] range. Our three UFDs, that is Boötes I, UMa II, and Leo IV, are depleted in Sr and Ba relative to Fe and Mg, with very similar ratios of [Sr/Mg] ≃−1.3 and [Ba/Mg] ≃−1 on the entire range of their Mg abundances. The subsolar Sr/Ba ratios of Boötes I and UMa II indicate a common r-process origin of their neutron-capture elements. Sculptor remains the classical dSph, in which the evidence for inhomogeneous mixing in the early evolution stage, at [Fe/H] <−2, is the strongest.

scholarly journals About the Chemical Evolution of dSphs (and the peculiar Globular Cluster ω Cen)

2008 ◽  
Vol 4 (S255) ◽  
pp. 152-156 ◽  
Author(s):  
Andrea Marcolini ◽  
Annibale D'Ercole
Keyword(s):  
Chemical Evolution ◽  
Globular Cluster ◽  
Stellar System ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Dwarf Spheroidal Galaxies ◽  
Chemical Enrichment ◽  
Type Ia ◽  
Hydrodynamical Simulations ◽  
Ia Supernovae

AbstractWe present three dimensional hydrodynamical simulations aimed at studying the dynamical and chemical evolution of the interstellar medium (ISM) in isolated dwarf spheroidal galaxies (dSphs). This evolution is driven by the explosion of Type II and Type Ia supernovae, whose different contribution on both the dynamics and chemical enrichment is taken into account. Radiative losses are effective in radiating away the huge amount of energy released by SNe explosions, and the dSph is able to retain most of the gas allowing a long period (≥ 2 − 3 Gyr) of star formation, as usually observed in this kind of galaxies. We are able to reproduce the stellar metallicity distribution function (MDF) as well as the peculiar chemical properties of strongly O-depleted stars observed in several dSphs. The model also naturally predicts two different stellar populations, with an anti-correlation between [Fe/H] and velocity dispersion, similarly to what observed in the Sculptor and Fornax dSphs. These results derive from the inhomogeneous pollution of the SNe Ia, a distinctive characteristic of our model. We also applied the model to the peculiar globular cluster (GC) ω Cen in the hypothesis that it is the remnant of a formerly larger stellar system, possibly a dSph.

scholarly journals GAS LOSS BY RAM PRESSURE STRIPPING AND INTERNAL FEEDBACK FROM LOW-MASS MILKY WAY SATELLITES

2016 ◽  
Vol 826 (2) ◽  
pp. 148 ◽  
Author(s):  
Andrew Emerick ◽  
Mordecai-Mark Mac Low ◽  
Jana Grcevich ◽  
Andrea Gatto
Keyword(s):  
Milky Way ◽  
Internal Feedback ◽  
Ram Pressure ◽  
Low Mass ◽  
Gas Loss

scholarly journals Where Does the Galaxy End?

1996 ◽  
Vol 169 ◽  
pp. 669-680
Author(s):  
F.D.A. Hartwick
Keyword(s):  
Spatial Distribution ◽  
Globular Clusters ◽  
Semimajor Axis ◽  
Three Dimensional ◽  
Minor Axis ◽  
Spatial Extension ◽  
The Galaxy ◽  
Nested Hierarchy ◽  
Satellite Galaxies ◽  
Dimensional Surface

The spatial distribution of the outlying satellites of the Galaxy has been determined by fitting a three dimensional surface to the positions of 10 companion galaxies and 13 distant globular clusters. Both groups show a highly flattened distribution whose minor axes are aligned to within ∼ 5°. The combined group of 23 objects shows a triaxial distribution with semimajor axis extending ∼ 400 kpc. The minor axis is inclined at ∼ 76° to the Galactic poles. There is a suggestion of a nested hierarchy consisting of satellite galaxies, globular clusters, and distant halo field stars, in order of decreasing spatial extension.

Sign in / Sign up

Export Citation Format

Share Document