Hisaki & Astro-H:
Temporal variability
Tomoki Kimura (RIKEN,JP),
Hisaki Science team,
R. Kraft (Harvard-Smithsonian Astrophys. Obs),
R. Elsner (NASA),
W. Dunn, G. Branduardi-Raymont (Univ. Coll. London),
R. Gladstone (SwRI), and
Y. Ezoe (Tokyo Metropolitan Univ., JP)
What is Hisaki?
Hisaki satellite
p  An earth-orbiting EUV space telescope dedicated for planets
p  EXCEED instrument continuously monitors EUV emissions
from atmospheres and plasmas around planets
p  Targets : Mercury, Venus, Mars, Jupiter, Saturn, and stars
Specifications
photons
Launch date
14 Sep 2013
Weight
330kg
Size
1m×1m×4m
Orbit
950km×1150km
(LEO) Inclination
31 deg
Nominal mission
life 1 year
Pointing accuracy ±5 arc-sec
(best perform.) EUV
spectrometer
slit
guide
camera
(FOV)
EUV spectrometer
“EXCEED”
Led by JAXA, U Tokyo, and Tohoku U
Instrument
p
EUV spectrometer “EXCEED” (Yoshioka+13)
Wavelength range
60 – 145 nm
Spatial resolution (for Jupiter mode) 17” (~1Rj around opposition)
Field of view
360” (~20Rj)
Spectral resolution (FWHM)
0.4 – 1.0 nm (depends on slit)
Primary mirror
20 cm diameter, F/8
Effective area
~2 cm2 @ 1000 angstrom
dumbbell-shaped slit
p  Jupiter observation
p  dumbbell-shaped slit placed at northern pole
140” 360”
A
B
IPT
aurora
North
20”
Synergetic observations
Hisaki
HST
Chandra X-ray
Observatory
(high-res imaging)
NOAO Gemini
IRTF
Subaru
Hubble Space
Telescope
(high-res imaging)
CXO
XMM
Kitt Peak WIYN
Suzaku
Hisaki (monitoring &
spectroscopy)
Haleakala
U. Tokyo (Chili)
U. Padova
Suzaku (imaging
spectroscopy)
Apache Point
McMath-Pierce
XMM Newton
(imaging
spectroscopy)
Hisaki
launch
14th
Sep
EVLA
Keck
GEMINI
Hisaki-HST campaign Hisaki-X-ray campaignMcMath-Pierce
ALMA
primary
operation
2013
SOFIA
Continuous observation of Jupiter by Hisaki
20th 2014 1st
Nov
Jan
14th
Jan
8th
Apr
21th
Apr
U. California
U. Tokyo (Atacama)
Etc….
Hisaki-HST campaign
Jan 1-16 2014
published papers
Kimura et al. (2015), Geophys. Res. Lett.
Tao et al. (2015), J. Geophys. Res.
Badman et al. (2016), Geophys. Res. Lett.　(Tue)
Hisaki-HST campaign (Kimura+)
Total Power (GW)
p
p
Internally-driven auroral explosions found during solar wind quiet period.
Association with internal processes of magnetosphere like Vasyliunas RX?
Auroral total power
Dynamic pressure of SW (Tao+05)
Kimura+15
Cover image of GRL
JAXA, AGU, and Lancaster U
press releases 25 Mar 2015
7
p
HST found enhancements in all auroral morphologies meaning global
activation of magnetosphere
p a
Morphology of auroral explosion (ＨＳＴ)
8
Correlation with IPT (Tsuchiya & Yoshikawa+)
Photon count
[count/sec]
sensitive to insensitive to
hot electrons hot electrons
6 Plasma torus
64.0-77.0nm 103.8-110.8nm
3
5.5
2.5
5
2
Aurora
Brightness
(relative)
3.5
1.5
1
5
Day of 2014 (1=Jan. 1)
Tsuchiya & Yoshikawa et al. in prep.
6
9
140” 360”
4
North
3
20”
2
Spectral diagnostic (Tao+)
current-voltage relation
estimated from Hisaki EUV
spectrum (Tao+15)
Brightness (Rayleigh)
Last status: large volcanic activity
(Tsuchiya+)
IPT3.5-7.5Rj
S+++
S++
S+
Tsuchiya in prep.
DOY2015
Volcanic activity starts in IPT
Impulsive aurora got frequent
Some are correlated with SW
Hisaki-X-ray campaign
Apr 8-21 2014
published papers
Kimura, T., et al. (2016), J. Geophys. Res.
Source location
p
p
p
CXO High Resolution Camera
‘spot’ region with large
intensity and surrounding
region ‘halo’
Halo is overlapping with the
main oval latitude,
(Spot: red, halo: blue)
Time variability
p
p
EUV aurora enhancement on
day 109-110: solar wind
compression with <48h
accuracy in arrival time
Count rate of spot observed
by CXO is correlated with SW
velocity
red: spot
blue: halo
oxygen band
sulfur/carbon band
Veloc
Dyn.
press
Local time distribution
p
p
p
Polar X-ray source is magnetically mapped the equatorial magnetosphere
using the flux equivalence mapping model [Vogt+11]
Mainly populated in the noon to post dusk sector
Suggestive of association with KH instability and/or m’pause reconnection?
Red: spot
Blue: halo
Sun
Earth
Polar cap
visible time
halo, closed
field line
spot, closed
field line
Synergies with JUNO
2016-17
JUNO-Hisaki-Hitomi
X-ray imaging-spectroscopy
Suzaku Ezoe+10
(Hitomi)
JUNO
EUV spectrum Hisaki Kimura+15
FAST@Earth
ion/ele data
Ergun+98
17
Hisaki & Hitomi (Astro-H)
p
p
EUV spectrometer (EXCEED): continuous long-term monitoring of dynamics
in aurora and IPT
Daily auroral activities can be a proxy for solar wind condition
(Hitomi)
Launched 14 Feb 2016
p
p
Soft X-ray Spectrometer (SXS): highly resolved soft X-ray spectroscopy (7eV
FWHM) corresponding to +/-750km/s particle velocity resolution.
Line shift and width give bulk velocity and temperature of highly charged heavy
ions e.g., O6+ above a few MeV/amu
JUNO
X-ray hot spot
JEDI
• X-ray source ions, e.g., O+n, above X-ray
aurora
• Simultaneously with Astro-H X-ray spect.
JADE
• With JEDI, EUV source electron spectrum
& PAD especially during internally-driven
auroral explosion
• Simultaneously with Hisaki EUV spectrum
UVS
• Temporal & spatial close-up of UV aurora
• Hisaki gives long-term contexts around
JUNO’s close-up
MAG
• Current structure above all auroral
morphologies
JIRAM
WAVES
• Measurement of auroral activities
simultaneously with Hisaki
Jupiter
180
135
Hisaki monitor.
high prior.
Hisaki monitor. Hisaki monitor.
highest prior.
high prior.
Apr-2017
Mar-2017
Feb-2017
Jan-2017
Dec-2016
Nov-2016
Oct-2016
Sep-2016
Aug-2016
Jul-2016
Jun-2016
May-2016
Apr-2016
Mar-2016
Feb-2016
Jan-2016
Dec-2015
Nov-2015
Oct-2015
Sep-2015
Aug-2015
Jul-2015
Jun-2015
0
S-O-T>20deg
Jupiter observable
for Hisaki
45
Astro-H(TBD)
Astro-H(TBD)
90
Sun-Observer-Target angle [degree]
Currently planned schedule
JUNO/JOI
Synergies summary
“Monitor”
“Microscope”
JUNO
p a
•  Auroral dynamics
with source electron
measurements
•  X-ray line spectroscopy
with source ion
measurements
•  X-ray continuum with
source electron
•  Solar wind response
of X-ray aurora
•  Spectral diagnostic
EUV & X-ray aurora
(Hitomi)
“Highest energy”