UCL DEPARTMENT OF SPACE AND CLIMATE PHYSICS
MULLARD SPACE SCIENCE LABORATORY
Juno Workshop: Jupiter’s Aurora
Jupiter’s X-rays -- Chandra and XMM-Newton Campaigns
Presenter: William Dunn (w.dunn@ucl.ac.uk)
Investigators: G. R. Gladstone, R. Kraft, C. Jackman, G. Branduardi-Raymont, W. Dunn, J. Nichols, R.
Elsner, L. Ray, T. Kimura, Y. Ezoe
w.dunn@ucl.ac.uk
Summary
1)  Motivations for studying Jupiter’s X-rays
2) X-ray Auroral morphology and features
3) Possible connections between Jupiter’s X-ray Aurora and the Solar Wind
4) Upcoming X-ray campaigns:
a)  Juno approach – Chandra (PI: Kraft and Jackman) & XMM-Newton (PI: Dunn)
b)  Juno polar orbits -- Chandra (PI: Gladstone)
2
w.dunn@ucl.ac.uk
Motivations for Studying Jupiter’s X-ray Aurora
1)  Jupiter’s X-ray Aurora seems to exhibit relationships to the Solar Wind –- general
trends and distinctive order of magnitude brightening during CMEs. This could help to
identify the nature of Jupiter’s relationship to the solar wind.
2)  Provide a partial mapping of downward current regions -- identified through the
spectral lines of precipitating ions.
3)  Information about the drivers and acceleration processes in the main oval and
polar regions -- variation in X-ray emission from 10-100 keV electrons and from MeV ions
3
w.dunn@ucl.ac.uk
Components of X-ray Emission
N
Polar Aurora
Component
Equatorial/Disk
Component
Disk X-rays are from fluoresced and
scattered solar photons – so changes
in solar X-ray flux are reflected in
Jupiter’s disk emission.
4
w.dunn@ucl.ac.uk
Jupiter’s X-ray Morphology
Main Oval
Hard X-ray
•  Big green dots = Hard Xrays (Energies: 2-5 keV)
•  Small green dots = Soft
X-rays (Energies: 0.2-1.5
keV)
Left figure shows a projection
of Jupiter’s North Pole from
Chandra X-ray observations in
2003 (green dots).
These are superposed on a
simultaneous Hubble UV
projection (orange).
Hot Spot
Branduardi-Raymont et al. 2008
5
w.dunn@ucl.ac.uk
Jupiter’s X-ray Morphology
Main Oval
Hard X-ray
Hard X-rays
•  Big green dots
•  Brehmsstrahlung –10s-100s
keV electrons
•  Overlap Main UV oval
•  Significant variation in counts
from observation to
observation, may relate to solar
wind
•  May relate to dawn storms
Branduardi-Raymont et al. 2008
[Branduardi-Raymont et al. 2003, 2004,
2007A, 2008; Dunn et al. 2016]
6
w.dunn@ucl.ac.uk
Jupiter’s X-ray Morphology
Soft X-rays – the Hot Spot
Main Oval
•  Small green dots
•  Hot Spot – poleward of UV oval
– origin beyond middle
magnetosphere.
•  MeV ions Charge Exchange
•  Oxygen (O7+,8+)
•  Sulphur (S7+…16+) and/or Carbon
(C5+,6+) - current spectral
resolution cannot distinguish.
•  S = magnetospheric origin
•  C = solar wind origin
•  O = Either
Hot Spot
Branduardi-Raymont et al. 2008
[Branduardi-Raymontetal.2004,2007A;Elsner
etal.2005;Gladstoneetal.2002]
7
w.dunn@ucl.ac.uk
Jupiter’s X-ray Morphology
Main Oval
The Hot Spot
Rotateswiththeplanet–65-75olaAtude;
160-180olongitude
Quasi-periodicPulsa5ons:
•  45minperioddetectedindisAnct
observaAons
•  12-26minperioddetectedduringCME
•  PeriodabsentinseveralobservaAons
•  SimilarperiodicityinradioandparAcleflux
data(e.g:Macdowalletal1993).
•  CoincidentUVflares(e.g:Elsneretal.2005)
[Branduardi-Raymont et al. 2004; 2007A, 2008;
Gladtstone et al. 2002; Elsner et al. 2005; Dunn et al.
2016]
8
w.dunn@ucl.ac.uk
X-ray Aurora Source
•
•
•
Hot Spot Core (red) maps to near magnetopause
Emission shows a ~50/50 mapping to closed and open field lines
‘Halo’ (blue) maps to several origins
•
Magnetopause mapping implies that Jupiter’s X-ray aurora may provide a diagnostic of
Jupiter-Solar Wind interactions.
S3 Polar Projection
Source
15RJ
30RJ
120RJ
92RJ standoff
Expanded M’sphere
Kimura et al. [2016]
9
w.dunn@ucl.ac.uk
Branduardi-Raymont et al. [2004, 2007A] :
•  Hard and Soft X-ray Emission increased
around the time of the 2003 Halloween
storms.
Counts/sec
Jupiter’s X-ray Solar Wind
Relationship
Kimura et al. 2016 (figure):
•  X-ray emission not correlated to
SW density
•  During generally quieter solar wind
conditions
Counts/sec
•  X-ray emission correlated to SW Velocity
10
a)
Obs1
0.30
0.25
700
0.20
600
Velocity (km/s)
w.dunn@ucl.ac.uk
b) 800
Obs2
Obs1
Obs2
n (cm-3 )
500 Aurora?
What does an 0.15
ICME do to Jupiter’s X-ray
400
0.10
TheMichiganSolarWindpropaga5onModel(upperfigures)predictsthearrivalofanICMEduringanX300
0.05
rayobserva5onin2011.
200
0.00
272
274
276
278
280
282
272
274
276
278
280
282
DoY
DoY
mSWiM Solar Wind Propagation Model
Density Uncertainty
Velocity BT
a)
Obs1
0.30
b) 800
Obs2
0.25
Obs1
Obs2
c)
Obs1
Obs2
0.6
700
0.4
0.15
0.10
600
0.2
BT (nT)
Velocity (km/s)
n (cm-3 )
0.20
500
-0.2
400
0.05
300
0.00
272
200
272
0.0
-0.4
-0.6
274
276
278
280
282
274
276
DoY
b) 800
Obs1
Obs2
278
DoY
c)
700
Obs1
280
282
272
274
276
278
280
282
DoY
Obs2
0.6
600
500
Dunn et al. [2016]
400
0.2
BT (nT)
Velocity (km/s)
0.4
0.0
-0.2
-0.4
11
w.dunn@ucl.ac.uk
What does an ICME do to Jupiter’s X-ray Aurora?
Radio observa5ons show non-Io decametric bursts (lower figure) during the same X-ray observa5on,
mSWiM
Solararrived
Wind Propagation
Model
which suggest an ICME-induced forward
shock
[e.g: Hess
et al. 2012; 2014; Lamy et al. 2012;
GurneWetal2002]
Obs1
a) 0.30
0.25
Obs2
Uncertainty
n (cm-3)
0.20
Frequency (kHz)
10000
STA / Power spectral density (Log V2.Hz-1)
0.15
-15.0
0.10
-15.2
Non-Io/
Io
Non-Io
0.05
1000
0.00
272
274
276
276.2
277.0
276.8
Observation 2
277.2
277.4
-15.6
282
277.6
-15.8
277.8
STB / Power spectral density (Log V2.Hz-1)
Obs1
800
Obs2
-15.0
-15.2
Io
1000
Observation 1
276.0
276.2
Dunn et al. [2016]
Non-Io
700
Velocity (km/s)
Frequency (kHz)
276.6
276.4
b)
10000
280
DoY
Observation 1
276.0
278
-15.4
-15.4
600
-15.6
500
-15.8
Observation 2
400
276.6
276.4
300
276.8
277.0
DOY 2011
277.2
277.4
277.6
277.8
12
Obs1
a) 0.30
Obs1
800
0.25
700
0.20
600
Velocity (km/s)
n (cm-3)
w.dunn@ucl.ac.uk
b)
Obs2
Obs2
What does an ICME do to Jupiter’s X-ray Aurora?
0.15
0.10
500
400
TheMichigansolarwindpropaga5onmodel(upperfigures)predictsthearrivalofanICMEduringanX-ray
observa5onin2011.
b)
a)
c)
Uncertainty
STA / Power spectral density (Log V .Hz )
-15.0
10000
-15.2
Non-Io/
-15.4
Non-Io
1000
Io
-15.6
Radio
observa5ons
show
non-Io
decametric
bursts
(lower
figure)
during
the
same
X-ray
observa5on,
b)
c)
-15.8
which suggest an ICME-induced forward shock arrived [e.g: Hess et al. 2012; 2014; Lamy et al. 2012;
Observation
2
Observation
1
GurneWetal2002]
276.6
277.6
276.4
277.4
276.0
276.2
277.0
277.2
276.8
277.8
0.05
300
0.00
272
274
276
278
280
200
272
282
274
276
DoY
278
280
282
280
282
DoY
mSWiM Solar Wind Propagation Model
Obs1
0.30
Obs2
Obs1
800
Obs2
Obs1
Obs2
700
0.20
600
0.4
0.15
0.10
0.2
2
500
-1
300
0.00
272
200
272
0.0
-0.2
400
0.05
BT (nT)
Velocity (km/s)
n (cm-3)
0.6
0.25
-0.4
Frequency (kHz)
-0.6
274
276
278
280
282
274
276
Obs1
800
278
280
282
272
274
DoY
DoY
Obs1
Obs2
276
278
DoY
Obs2
0.6
0.4
600
0.2
BT (nT)
Velocity (km/s)
700
500
400
10000
Frequency (kHz)
STB / Power spectral density (Log V2.Hz-1)
-15.0
-0.4
300
200
272
0.0
-0.2
-0.6
274
Io
276
Non-Io
278
280
DoY
282
-15.2
272
274
276
278
280
282
DoY
-15.4
1000
c)
-15.6
Obs1
0.6
0.4
0.2
276.0
-0.4
BT (nT)
-15.8
Observation 2
Observation 1
276.2
Dunn0.0et al. [2016]
-0.2
Obs2
276.4
276.6
276.8
277.0
DOY 2011
277.2
277.4
277.6
277.8
13
w.dunn@ucl.ac.uk
X-ray Observations: S3 Polar Projections
ICME Arrival Observation
ICME Recovery Observation
1st Observation !CME Arrival"
Hot Spot Region
180
2nd Observation !CME Recovery"
180
14
14
12
12
10
8
10
8
14
14
6
6
12
12
4
4
10
90
10
270
8
90
270
8
8
6
4
8
6
4
0
New Emission Quadrant:
Dunn et al. [2016] Auroral Enhancement
0
Io Footprint
[Grodent et al. 2008]
L=30 Contour
[Grodent et al.
2008] 14
w.dunn@ucl.ac.uk
ICME Triggers New X-ray Aurora
ICME Arrival Observation
ICME Recovery Observation
1st Observation !CME Arrival"
Hot Spot Region
180
2nd Observation !CME Recovery"
180
14
14
12
12
10
8
10
8
14
14
6
6
12
12
4
4
10
90
10
270
8
90
270
8
8
6
4
8
6
4
0
New Emission Quadrant:
Dunn et al. [2016] Auroral Enhancement
0
Io Footprint
[Grodent et al. 2008]
L=30 Contour
[Grodent et al.
2008] 15
w.dunn@ucl.ac.uk
ICME Triggers New X-ray
Aurora
Splitting the 2 quadrants quantifies the
difference between the two
observations for:
Hot Spot Quadrant
•  ICME Arrival
•  Quieter SW
Upper Figure: Hot Spot Quadrant
(S3 Longitude 90-180o)
Lower Figure: Auroral Enhancement
Quadrant
(S3 Longitude 180-270o)
Auroral Enhancement
New Emission
•  ICME Arrival
•  Quieter SW
Dunn et al. [2016]
16
w.dunn@ucl.ac.uk
X-ray Lightcurves and Radio Bursts
t
dran
a
u
Q
Spot
t
o
H
30
30
Counts
20
per ks
20
First Observation (ICME Arrival): HSQ and AEQ Lightcurves
ICME Arrival
Observation
Sub-Solar Longitude
0
40
10
60 °
120 °
180 °
Hot Spot Quadrant
240 °
Non-Io
0
40
10
Aurora Enhancement
Aurora Enhancement Quadrant
30
30
Hot Spot Q
275.9
276
276.1
276.2
276.3
276.4
Day of Year
Counts
20
per ks
20
10
10
275.9
276
276.1
276.2
276.3
276.4
Day of Year
Second Observation (ICME Recovery): HSQ and AEQ Lightcurves
•
Order of Magnitude ‘Flare’
Enhancement triggered by ICME
Sub-Solar Longitude
40
Quieter
60 °
120Solar
°
180Wind
°
240Observation
°
300 °
0
0
60 °
Hot Spot Quadrant
40
Aurora Enhancement Quadrant
•
•
•
~1.5 hours before the non-Io radio
burst
Heightened Emission throughout
Hot Spot periodicity shifts: ~45 min in
second obs (like Gladstone et al. 2002);
12 and 26 min period during ICME
Dunn et al. [2016]
30
Aurora Enhancement
Quadrant
Hot Spot Q
Counts
20
per ks
40
10
Second Observation (ICME Recovery): HSQ and AEQ Lightcurves
20
Sub-Solar Longitude
0
60 °
120 °
180 °
240 °
300 °
0
Hot Spot Quadrant
Aurora Enhancement Quadrant
60 °
40
10
30
30
277.6
Counts
20
per ks
30
277.7
277.8
Day of Year
277.9
278
17
278.1
20
w.dunn@ucl.ac.uk
Jupiter’s X-ray - Solar Wind Relationship and the Upcoming Observations
Is there a solar wind parameter connected to the X-ray aurora and, if so, how does it link
to the drivers of emission?
•  IMF direction? -- Pulsed Dayside reconnection [Bunce et al. 2004] ?
•  SW Density/Dynamic Pressure? -- Magnetosphere Compression [Dunn et al. 2016] ?
•  SW Velocity? -- Kelvin Helmholtz [Kimura et al. 2016] ?
•  Internally Driven? -- MV Potentials on down FACs [Cravens et al. 2003]
To help identify SW driver -> X-ray obs during Juno approach (PI: Kraft & Jackman;PI: Dunn)
•  May 20: XMM 10 hour Observation
•  May 26: Simultaneous XMM and Chandra 10 hour Observations
•  June 1: Chandra 10 hour Observation
Also simultaneous with HST observations (PI J. Nichols) which helps connect features and
identify global current systems (UV = mostly upward ; X-ray = mostly downward)
18
w.dunn@ucl.ac.uk
Jupiter’s X-ray - Solar Wind Relationship and the Upcoming Observations
•  Ebert et al. 2014 used Ulysses
data from an analogous point in
the solar cycle.
•  More structured
•  ~1 week between compression
and rarefaction.
For X-ray observations:
•  Appropriate separation to
increase chance of alternating SW
conditions
•  Simultaneous with HST
19
19
w.dunn@ucl.ac.uk
XMM- Newton –EPIC and RGS
Chandra – High Resolution Camera
High Spectral Resolution – poor spatial
resolution
High Spatial Resolution – no spectral
resolution
1st Observation !CME Arrival"
2nd Observation !CME Recovery"
180
180
14
14
12
12
10
8
10
8
14
14
6
6
12
12
4
4
10
90
10
270
8
270
8
8
6
4
Branduardi-Raymont et al. 2007A
90
8
6
4
0
0
20
w.dunn@ucl.ac.uk
CXO Campaign During Juno Orbits
Juno presents the unique opportunity to study the X-ray emission from the hot spot, while
traversing the field lines producing it.
-> 80 hour Chandra campaign (PI: Gladstone). Observations during:
Northern Aurora: GRAV orbits 5, 13, 22, & 34
Southern Aurora: MWR orbit 6 and GRAV orbits 11, 20, & 36
This will also help:
•  Identify further connections between UV polar flares and X-rays [E.g: Elsner et al. 2005]
•  Assess the source of the quasi-periodicity
•  Identify hot spot drivers (Dayside reconnection [Bunce et al. 2004] Vs Kelvin Helmholtz
[Kimura et al. 2016] Vs MV Potentials on down FACs [Cravens et al. 2003])
•  Test various mapping models VIPAL, VIP4, Grodent Anomaly….
•  Identify possible X-ray emission from the Galilean moons and Io Plasma Torus.
21
w.dunn@ucl.ac.uk
Conclusions
Juno presents a unique opportunity to probe the sources of Jupiter’s X-ray Aurora:
Science Questions for Approach Campaign (CXO PI: Kraft and Jackman; XMM PI: Dunn)
1.  Which solar wind parameter (if any) is connected with the X-ray aurora?
2.  What is the nature of the X-ray producing Jupiter-Solar wind interaction?
3.  How does X-ray emission connect with UV features (HST) and other wavebands?
Juno instruments ware very important for us to be able to connect SW with X-ray aurora we are very keen to collaborate. We are also keen to collaborate with other EM wavebands.
Science Goals for Polar Orbit Campaign (CXO PI: Gladstone)
1.  Test theories [e.g., Cravens et al. 2003; Bunce et al. 2004] on the source of emissions by
comparing ‘cusp’ measurements with X-ray (Chandra) and UV emissions (Juno UVS).
2.  Identify which conditions produce the ~45 min quasi-periodic X-ray intensity oscillations and
how these correlate with energetic particle fluxes and radio emission.
3.  To constrain mapping models (e.g., VIP4 [Connerney et al., 1998], VIPAL [Hess et al., 2011])
with a high-quality map of X-ray emission topology
4.  Search for X-ray emission from the Galilean moons and Io Plasma Torus (IPT).
22
w.dunn@ucl.ac.uk
Back-Up Slides
23
1 Obs (CME
6
10
8
w.dunn@ucl.ac.uk
14
12
14
180
90
120 ° SSL
st
st Obs
Sub-structure within the Hot Spot?
10
1 Obs1(CME
Arriva
(CME
8
12
14
120 ° SSL
10
180
Vogt Models (2011): balance equatorial magnetic flux with ionospheric magnetic flux
to
90
90
nd
map beyond 30 RJ. st
120 ° SSL
120 ° SSL 8
EmissionFrom:
1 Obs (CME Arrival)
90 120 ° SSL
4
90
4
8
90
6
4
4
12
10 8
0
8
10
180
90RJ
6
150 ° SSL
8
4
12 10
90
ClosedFieldLines
6
4
1
14
12
120RJ
90
10
90
8
90
12
8
12
270
6
8
14
Predicted
10
Open-Closed
Boundary
6
6
14
14
12
14
8
6
4
50RJ
0
6
14
270
14
1
12
Sca8eredSolarPhotons
Sca[eredSolarPhotons
8
14
10
6
Electrons
Electrons
14
10
180
12
8
OxygenIons
OxygenIons
12
14
10 14
Sulphur/CarbonIons
Sulphur/CarbonIons
14
90
12
EmissionFrom:
Dawn
120 ° SSL
10
Obs (CME Reco
8
2
180
2
180
4
14
18
4
12
8
150 ° SSL
15RJ
14
14
Io’sFootprint
0
12
12
10
Dunn et al. [2016]
0
14
10
24
0
0
w.dunn@ucl.ac.uk
Mapping the X-ray Hot Spot Source
Particle Species
Magnetospheric
Local Time
Equatorial Origin
Carbon and/or Sulphur
10:30 – 18:30
60 - 120 RJ and Open Flux
Oxygen
10:30 -- 18:30
80 - 120 RJ and Open Flux
High Energy Electrons
02:00 – 06:00
Middle Magnetosphere
•  Sulphur has a lower ionisation potential than oxygen.
•  So it may be that one region energises sulphur sufficiently for X-ray production, but
does not inject enough energy to do the same for oxygen.
25
8
6
4
w.dunn@ucl.ac.uk
Back-Up Slides – C/S and O separation
0
First Second
Observation:
500!800eV
Observation:
200!500eV
First Observation: 200!500eV
180
180 180
North
14
14
12
North
14
12
10
10
12
10
8
8
14
14
8
14
6
6
12
12
6
12
4
4
10
10
90
27090 90
8
8
270 27090
8
6
4
4
First Observation: 500!800eV
180
8
6
8
4
0
0
0
Second Observation: 500!800eV
North
4
10
8
6
North
180
26
North
w.dunn@ucl.ac.uk
Back-Up Slides – PSDs from 2011 observations
a)
c)
b)
d)
27
w.dunn@ucl.ac.uk
Connecting Wavelengths - UV
Juno UVS alongside HST, Chandra and XMM
observations will help to identify
connections between UV polar flares [e.g:
Bonfond et al. 2011] and X-ray events that
are found in similar locations at similar
times [Elsner et al. 2005].
Providing richer datasets to study the
drivers of features with similar origins.
28
w.dunn@ucl.ac.uk
Connecting Wavebands - Radio
Radio events have been noted to share similar periodicity to the X-ray events [e.g:
Macdowall et al. 1993; Gladstone et al. 2002].
Bursts of Jovian non-Io decametric emission coincident with strong solar activity have also
been found to occur at similar times to significant brightening of the X-ray aurora,
suggesting similar origins. Although the X-ray events were associated with downward
moving ions, while the radio emission is thought to be associated with upward moving
electrons.
29