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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �3
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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �4
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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �5
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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �6
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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �6
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
14
10
8
6
4
2
0-0.5
orbital phase φorb
NH[1022cm
−2]
12
1.510.50
Smooth focused wind: Clumpy wind:
Grinberg+ 2015
Does not explain the dips
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �6
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
14
10
8
6
4
2
0-0.5
orbital phase φorb
NH[1022cm
−2]
12
1.510.50
Smooth focused wind: Clumpy wind:
Grinberg+ 2015
El Mellah+ in prep.
Does not explain the dips
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �6
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
14
10
8
6
4
2
0-0.5
orbital phase φorb
NH[1022cm
−2]
12
1.510.50
Smooth focused wind: Clumpy wind:
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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �7
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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �7
Cyg X-1: Clump structure
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
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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �7
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
non-dip
weak dip
dip
strong dip
⟹ structured clumps with cold cores
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �8
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
Vela X-1: multiphase medium
Dor
oshe
nko+
201
3
Grin
berg
+ 20
17
+ orbit to orbit variability
Wat
anad
e+ 2
006
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �9
Vela X-1: multiphase medium
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.
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �10
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
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �10
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:
Victoria Grinberg: X-raying stellar winds in high mass X-ray binaries �11
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!