x-raying stellar winds in high mass x-ray binaries...x-raying stellar winds in high mass x-ray...

X-raying stellar winds in high mass X-ray binariesVictoria Grinberg, IAAT Tübingen

with N. Hell, M. Lomaeva, R. Amato, M. Hirsch, I. El Mellah, P. Kretschmar, J. Wilms, M.A. Nowak, K. Pottschmidt, M. Leutenegger, S. Martínez Núñez & the X-Wind collaboration

Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �2

One astronomer’s noise —

Copyright: ESA. Illustration by Martin Kornmesser, ESA/ECF

— is another astronomer’s data


Winds in massive stars

Line-driven winds: • mass loss

• terminal velocity up to 3000 km/s

important for: • star formation • enrichment • evolution of star itself

10−7 − 10−4 M⊙/yr

unstable to velocity perturbations ⟹ rapid growth of perturbation ⟹ strong shocks ⟹ wind clumping

Multiple lines of evidence for wind clumping from single stars, but no way to probe clump structure

El Mellah+ 2018; Sundqvist+ 2017


Big questions

Wind properties: • clumps: structure, size, shape &

occurrence • clumping onset • wind acceleration zone • wind’s response to changes in irradiation

Accretion structure: • accretion & photoinization wake • accretion rate variability • clumpy accretion • disk formation

stellar winds & HMXB review: Martínez-Núñez+ 2017Grin

berg

+ 20

17

➤ mass loss rates in O/B stars ➤ accretion history of HMXBs


Probing the innermost parts of the wind

accretionwake

photoionization

wake

3.02.01.00.0-1.0

2.0

1.5

1.0

0.5

0.0

-0.5

-1.0

-1.5

-2.0

-15.0

-14.5

-14.0

-13.5

-13.0

-12.5

-12.0

-11.5

x

z

logρ[g

cm−3]

φorb = 0 φorb = 0.5

Vela X-1/HD 77581 (B0.5 Ib) Cyg X-1/HDE 226868 (O9.7Iab)

• neutron star • 9d eclipsing orbit • accretion/photoionization

wake

• black hole • 5.6d orbit, orbital inclination

~30° • focussed wind accretion

Grinberg+ 2017 Grinberg+ 2015


Cyg X-1: Orbital variability & dipping

1.5

NH[1022cm

−2]

4

2

010.50-0.5

14

12

10

8

orbital phase φorb

6

Smooth focused wind: Clumpy wind:

Grinberg+ 2015



1.5

NH[1022cm

−2]

4

2

010.50-0.5

14

12

10

8

orbital phase φorb

6

14

10

8

6

4

2

0-0.5

orbital phase φorb

NH[1022cm

−2]

12

1.510.50


Grinberg+ 2015

Does not explain the dips



1.5

NH[1022cm

−2]

4

2

010.50-0.5

14

12

10

8

orbital phase φorb

6

14

10

8

6

4

2

0-0.5

orbital phase φorb

NH[1022cm

−2]

12

1.510.50


Grinberg+ 2015

El Mellah+ in prep.

Does not explain the dips



1.5

NH[1022cm

−2]

4

2

010.50-0.5

14

12

10

8

orbital phase φorb

6

14

10

8

6

4

2

0-0.5

orbital phase φorb

NH[1022cm

−2]

12

1.510.50


orbital phase φorbit

0 0.5 1 1.5N

H−

NH,ISM

[1022cm

−2]

NH[1022cm

−2]

0

1

2

3

4

5

6

-0.5

Grinberg+ 2015 Grinberg+ 2015

Does not explain the dips Explains dips and some of the variability, further studies necessary


Cyg X-1: Clump structure

divided in four absorption stages using color-color diagrams

stronger absorption ⟹ lower ionization stages of Si & S

same Doppler-shift for all lines

Hirsch+ 2019

Observed time [ks]

0.5–10keV

countra

te(c

/s)

3814

50

20

100

10

500

Orbital phase φ

(0.5–1.5

keV)/(3

–10keV)

00.95

0.5

0.2

0.05

0.02

1

0.1

8525

200

0.05

9847

200

50

20

100

10

0.2

0.5

0.2

0.05

0.02

1

0.1

Chandra HETG observations



Nondip

8525

SiXIV

SiXIII

SiXII

SiXI

SiX

SiIX

SiVIII

SiVII

1.5

1

0.5

6.26.46.66.87.07.27.47.6

Weak dip

1.5

1

0.5

Dip

1.5

1

0.5

Strong dip

21.951.91.851.81.751.71.65

1.5

1

0.5

Ratio

Wavelength [A]

Ratio

Ratio

Energy [keV]

Ratio




Hirsch+ 2019






Hirsch+ 2019

non-dip

weak dip

dip

strong dip

⟹ structured clumps with cold cores


Vela X-1: multiphase medium

Dor

oshe

nko+

201

3

+ orbit to orbit variability

Wat

anad

e+ 2

006

Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries

accretionwake

photoionization

wake

�8


Dor

oshe

nko+

201

3

Grin

berg

+ 20

17

+ orbit to orbit variability

Wat

anad

e+ 2

006



SiVIII

SiVII

SiII–VI

7.47.276.86.66.46.26

1000

800

600

200

0

400

Vela X-1 with Chandra-HETG2

1.5

1

0.5

(EBIT) @ LLNLElectron Beam Ion TrapLab measurements with

SiXIV

SiXIIIr

SiXIIIf

SiXII

SiXI

SiX

SiIX

Ratio

Wavelength [A]

ECS[couts/eV

]

highly ionised hot part of the wind vs. colder clumps ⟹ shocks? clump interaction with compact object?

Grin

berg

+ 20

17

10

0

0.5–3 keV

3–10 keV/0.5–3 keV

14121086

4

3

2

1

0

countrate

[cps]

30

20

3–10 keV

hard

ness

hours since MJD 51945

ObsID 1928, ⟹ clearly defined periods of

enhanced hardness

high & low ionization ions present

⟹ hot & cold(er)gas present

Other orbital phase: Amato et al. in prep.


Vela X-1: wind’s reaction to a flare

Flare

Pre-flare Post-flare

Lom

aeva

+ to

be

subm

. pn

-ana

ysis

: Mar

tínez

Núñ

ez+

2014


Vela X-1: wind’s reaction to a flare

1 1.5 2

05

01

00

15

0

Cts

s−

1 k

eV−

1

Energy (keV)

Flare

Pre-flare Post-flare

300s (!!)Lo

mae

va+

to b

e su

bm.

pn-a

nays

is: M

artín

ez N

úñez

+ 20

14

probing short timescales:


Summary

➤ high mass X-ray binaries are unique tools to probe massive star winds & accretion structure

➤ absorption-resolved & time resolved analyses necessary ➤ Athena is going to revolutionize the field

See also poster #228 by Silvia Martínez Núñez!

x-raying stellar winds in high mass x-ray binaries...x-raying stellar winds in high mass x-ray...

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