RHD simulations of outflows in the Ursa Minor dSph Bert - - PowerPoint PPT Presentation

RHD simulations of outflows in the Ursa Minor dSph

Bert Vandenbroucke

bv7@st-andrews.ac.uk

Kenneth Wood (St Andrews) Diego Falceta-Gonçalves, Anderson Caproni, Gustavo Lanfranchi (São Paulo)

Context: the DIG

Vandenbroucke et al. (2018)

SILCC post-processing

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RHD DIG

Vandenbroucke & Wood, in prep. Slide 3 of 13

Ursa Minor dSph

source: Wikipedia

𝑁ℎ ≈ 1.5 × 109 M⊙ 𝑁𝑐 ≈ 3.0 × 108 M⊙ 𝑒 = 60 ± 10 kpc Milky Way satellite

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UMi stellar population

Bellazzini+ (2002) Slide 5 of 13

UMi star formation history

Lanfranchi & Matteucci (2007)

Chemical modelling shows a single episode of star formation early on, Δ𝑢𝑇𝐺 ≈ 3 Gyr Evidence for strong galactic winds that correlate with the SFR or SN rate

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SN rate

Caproni+ (2017) Slide 7 of 13

SN driven outflows

Caproni+ (2017)

SN feedback drives significant

• utflows, but does not completely

remove UMi's gas

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RHD simulations

Vandenbroucke+ (in prep.)

Use the SFH/SN rate to model number and location of UV luminous O/B stars Run self-consistent RHD models including photoionization feedback to test impact of ionizing radiation Pretty much a toy model for galaxy scale RHD

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Photoionization only

Vandenbroucke+ (in prep.)

Radiation causes moderate

• utflows

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SN + radiation

Vandenbroucke+ (in prep.)

SN lead to higher outflow velocities and a more turbulent galaxy structure Effect of SN seems to weaken because

• f photoionization

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Caveat

Single SN SN in photoionized bubble

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Conclusions (?)

• Ursa Minor dSph (UMi) is an interesting toy

galaxy because of its known SF/SN history

• Self-consistent photoionization models for this

galaxy are possible and show (weak) UV- driven outflows

• SN + photoionization is very tricky and needs a

lot more work before we can trust it

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