1. Monitor of All sky X-ray Image (MAXI)
on the International Space Station
JAXA, RIKEN,Osaka Univ., Aoyama Gakuin Univ., Tokyo Inst. of Tech., Nihon Univ.
jaxa.jp
Web :
1. What is MAXI ?
2. X-ray camera on MAXI
All sky X-ray monitor on the Japanese Experiment Module (JEM) Exposed Facility of the International Space Station (ISS)
Scan of all most all over the sky every 90 minutes. No pointing observation.
Launch : 2008 by the Space shuttle
Mission life : at least 2 years
ISS
A concept of slit camera
Field of view of MAXI
Collimators
X-ray source 1
X-ray source 2
Slit
1-d Position
sensitive detector
Forward
FOV
Zenith FOV
Scan
MAXI
Earth
Celestial sphere
ISS motion
JEM
ISS
MAXI has two types of X-ray camera :
Gas Slit Camera (GSC) and Solid-state Slit Camera (SSC)
Both cameras consist of 2 subsets. One has FOV looking zenith direction, and another is forward, in order to compensate non-operational periods (e.g. SAA)
Each subset consists of slits, slat collimators, and 1-dimensional position sensitive X-ray detectors.
Their combination provides a narrow rectangular field of view (FOV) in the sky.
Solid-state Slit Camera (SSC)
Pressurized
Vessel
Gas Slit Camera (GSC)
MAXI
Exposed Facility
3. SCIENCE
X-ray flux of known sources
(taken from Uhuru and HEAO-1 catalog)
＊Galactic sources
＋ AGNs
○ Clusters of galaxies
Sensitivity of Previous
all sky X-ray monitors
～20 mCrab (RXTE AXM)
Detector
Energy Range
Effective Area
Field of View
Energy Resolution
Position Accuracy
Proportional counter
(Xe + CO2 gas)
2 – 30 keV
5350 cm2
1.5 x 160 degree
18 % at Mo-Ka
0.1 degree
X-ray CCD
0.5 – 12 keV
200 cm2
1.5 x 90 degree
150 eV at Mn-Kα
GSC
SSC
X-ray flux (mCrab)
10 mCrab / 1 orbit (96min.)
3 mCrab / 1 day
1 mCrab / 1 week
Sensitivity of MAXI
Distance (light year)
MAXI detects more than 1000 X-ray sources, including many active galactic nuclei (AGNs)
2. 1 Gas Slit Camera (GSC)
proportional counter
A unit of GSC
Day
Cts/sec
Dynamic Catalog of X-ray sources
Long-term variability of AGNs
Alert of X-ray transients
Complete lightcurve of X-ray novae
g-ray bursts and their afterglow
Distribution of distant AGNs (measurement of X-ray BGD)
Survey of emission lines from our Galaxy (with CCD camera)
Discovery of new kinds of X-ray objects
358 mm
236 mm
Be window
(100 mm thick)
A Simulated
Light curve
MCG
Simulated all sky X-ray images, to be obtained with MAXI
Slit and collimator
Three units for forward camera, and three for Zenith.
Wide FOV : 1.5 x 160 degree
Carbon fiber anode (10 mm)
⇒Good position resolution (1mm)
Large Effective Area (5350 cm2)
⇒High Sensitivity (1 mCrab/week)
Slit
Collimator
2 week
1 day
Data flow of MAXI
NASA
MSFC
ISS
50-70% of MAXI date is sent to ground in real time.
All the data will be made accessible through the Internet.
New discoveries (e.g. X-ray novae) are informed through the Internet in 1 minutes
(A picture from the counter side)
NASA Link
2. 2 Solid-state Slit Camera (SSC)
JAXA Link
A unit of SSC
(without slit and collimator)
SSC spectra of emission lines
JAXA
Data relay satellite
MAXI
Al-Ka
1.4876
Ti-Ka
Cl-Ka
V-Ka
Quick follow up observations !!
Zn-Ka
Fe-Ka
6.4038
V-Kb
Ni-Ka
Cl-Kb
2.8156
Fe-Kb
Zn-Kb
9.5720
Ni-Kb
data archive system
update
Comment
light curve
real time
Non-X-ray background data (NXB) is distributed
spectrum
every day
Detector response and NXB are distributed.
all-sky image
exposure corrected
CCD Chip
(Hamamatsu Photonics)
You can obtain above data for major bright objects and any point of X-ray sky
Detail → poster by Namiki et al.
24 mm