GALAXY CLUSTER GAS MOTIONS AND ASTRO-H: PREDICTIONS AND CHALLENGES FROM SIMULATIONS

John ZuHone, MIT Kavli Institute

withAurora Simionescu (ISAS/JAXA), Eric Miller (MIT),

and Mark Bautz (MIT)

ASTRO-H MISSION

• To be launched early next year

• ~5 eV spectral resolution with ~1’ spatial PSF

VELOCITY BROADENING

6.4 6.5 6.6

0.1

110

norm

aliz

ed c

ount

s s−

1 keV

−1

Energy (keV)

data and folded model

sekiya 6−Jun−2011 12:36

vturb = 0 km/svturb = 100 km/svturb = 300 km/svturb = 1000 km/s

6.7

w

xyz

jk

e

po

Perseus simulated spectrum (wabs＊bapec)

Astro-H cluster white paper, arXiv:1412.1176

He-like Fe line at E0 ≈ 6.7 keV

SLOSHING CORES

FLASH simulations from ZuHone, Markevitch, & Johnson 2010

Gas motions of M ~ 0.3-0.5, several hundred km/s

• Can we detect these sloshing motions with Astro-H?

• If so, what effect will these motions have on the shift and shape of spectral lines?

• Can we use this spectral analysis to tell us something about microphysics?

Z-PROJECTION

Inviscid Viscous

SB T

σμ

SB T

σμ

X-PROJECTION

Inviscid Viscous

SB T

σμ

SB T

σμ

Y-PROJECTION

Inviscid Viscous

SB T

σμ

SB T

σμ

ASTRO-H POINTINGS AND REGIONS

INVISCID: X-PROJECTION

INVISCID: Y-PROJECTION

INVISCID: Z-PROJECTION

INVISCID: Z-PROJECTION

VISCOUS: X-PROJECTION

VISCOUS: Y-PROJECTION

VISCOUS: Z-PROJECTION

VISCOUS: Z-PROJECTION

DIFFERENT VISCOSITY, SAME SHAPE

DIFFERENT MOTIONS, SAME SHAPE (SOMETIMES) σv ~ 200 km/s

σv ~ 200 km/s

SYNTHETIC OBSERVATIONS

ZuHone et al 2014, arXiv:1407.1783

SIMX

http://www.youtube.com/watch?v=fUMq6rmNshc

http://yt-project.org

http://hea-www.harvard.edu/simx/

+ PHOX

http://www.mpa-garching.mpg.de/~kdolag/Phox/(Biffi et al 2012, 2013, MNRAS)

event lists: RA, Dec, E Astro-H event files

0.01

0.1

1

coun

ts su−1

d

2 4 6 8

−0.2

0

0.2

resid

uals

Energy (keV)

0 2 8 17 30 48 68 93 122 154 190

SXI SXS

SYNTHETIC SPECTRA: X-AXISexposure time = 200 ks

SYNTHETIC SPECTRA: Y-AXIS

exposure time = 200 ks

SYNTHETIC SPECTRA: Z-AXISexposure time = 200 ks

FITTING SPECTRA: Y-AXIS

0.01

0.1

0.02

0.05

0.2co

unts

su−1

d

6.2 6.3 6.4 6.5 6.6 6.7

−0.1

0

0.1

resid

uals

Energy (keV)

Single APEC 1T model, w/ thermal broadening

only

exposure time = 200 ks

vbulk = 299 +11 -12 km/s

FITTING SPECTRA: Y-AXIS

Single APEC 1T model, w/ thermal and velocity broadening

exposure time = 200 ks

0.01

0.1

0.02

0.05

0.2co

unts

su−1

d

6.2 6.3 6.4 6.5 6.6 6.7−0.05

0

0.05

resid

uals

Energy (keV)

vbulk = 206 +15 -17 km/sσ = 292 +14 -13 km/s

FITTING SPECTRA: Y-AXIS

Two APEC 1T models, w/ thermal broadening

only

exposure time = 200 ks v1 = 379 +9 -17 km/s

0.01

0.1

0.02

0.05

0.2co

unts

su−1

d

6.2 6.3 6.4 6.5 6.6 6.7−0.05

0

resid

uals

Energy (keV)

v2 = -92 +10 -22 km/s

No BroadeningOne Broadened Component

Two Unbroadened Components

THE UPSHOT• Even in relaxed clusters, we should be able to detect some interesting gas flows with

Astro-H

• But we won’t necessarily be able to tell what those motions are—bulk flows, turbulence? Constraints on viscosity are hence probably limited

• Higher-res imaging may give us some clues to:

• What we’re looking at in the first place (can already do with existing Chandra, XMM-Newton observations)

• Measuring spatial variations in l.o.s. velocity (need Athena, SMART-X, etc.)

• Looking at major mergers next…

COMA CLUSTER SIMULATIONS

ZuHone, Markevitch, & Zhuravleva 2015, in prep.