Pan-STARRS and PS1
Stephen Smartt
Queen’s University Belfast
Contents
•Pan-STARRS and PS1 overview and status
•Challenges ahead
Hardware
Software and computation
Science
The Pan-STARRS project
Panoramic Survey Telescope and Rapid Response System
PI: Nick Kaiser
Camera Lead : John Tonry
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Univ. of Hawaii project : USAF funded, technology demonstrator
– how to survey sky efficiently
Construction of prototype PS1 and 1.4Gigapix camera (GPC1)
Now moving to PS2 and PS4 construction
PS1
• PS1 Director : Ken Chambers
• PS1SC is funding a 3.5 yr science mission with PS1 2009-2012
• PS1 data products release to the consortium – full public release 1yr
after survey finishes
• PS1SC have “long term lease”
Haleakala Observatory, Maui
Pan-STARRS1 & Pan-STARRS4
Pan-STARRS is run by the University of Hawaii partially funded by the US Air
Force
PS1: 1x1.8m telescope on Haleakala
PS1 surveys started May 2009
PS4: 4 x1.8m telescope on Mauna-Kea
Final goal of project
PS1 specs
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1.8m telescope
f/4.4 cass camera
GPC1 =1.4 Gigapix
10µm pixels = 0.26”
Focal Plane = 8 x 8
CCDs
CCD = 8 x 8 cells
Cells : 600x600 pix
Equiv to 60
4800x4800 CCDs
Si area = Sloan x 10
GPC1
Orthogonal Transfer CCDs
Normal guiding (0.73”)
OT tracking (0.50”)
Optical design
OTA Quantum Efficiency
• OTAs demonstrate expected QE (-65ºC)
– 45um thick device is virtually identical to CCID20
– 75um thick device has 50% enhanced QE at 1um
(Megacam)
SDSS and Pan-STARRS
bandpasses
Survey Program Summary
• 3π Survey (grizy, 56%)
– Survey of entire visible sky (from Hawaii)
• Medium Deep Survey (grizy, 25%) = MDS
– 10 GPC1 footprints distributed over sky
– nightly depth set to reach SNIa to z>0.5
• Solar System Sweet Spot Survey (i, 5%)
– 2 rectangles ~500 deg. at opposition region +/- 30 deg.
• Stellar Transit Survey (r, 4%) = STS
– 3 adjacent GPC1 footprint campaign per year
• Deep Survey of M31 (grizy, 2%)
• Calibration Fields (grizy, 2%)
– 20 fields including the MDS and STS fields
Estimated Survey Depths
MDS
3-pi
Filter
Exp.
1 Visit
3 yr
Exp.
1 Visit
1 yr
3 yr
(sec)
(mag)
(mag)
(sec)
(mag)
(mag)
(mag)
g
60
23.2
24.6
3x240
24.8
26.7
27.3
r
38
22.7
24.1
3x240
24.4
26.3
26.9
i
60
22.6
23.9
6x240
24.3
26.3
26.9
z
30
21.5
22.9
6x240
23.7
25.6
26.2
y
30
20.1
21.5
6x240
22.3
24.4
24.8
For 5-sigma point source detection limits
Computational Challenges
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Image Processing Pipeline : IPP
Astrometric and photometric calibration
Keeping up with the data flow
Providing additional capabilities & analysis
Shipping data to PS1SC scientists
Communication and documentation
Long term archiving
IPP Lead : Gene Magnier
IPP Data products
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3GB per image
1-2TB per night
Raw data : 1.8PB over
3.5 yrs
Compute cluster 16
nodes x 5 waves (3
waves installed)
Data Transfer Speeds (tested from Hawaii, Pittsburgh and
Garching)
Rsync Threads
Value
Units
1
0.9 Mbytes/sec
10
7.5 MBytes/sec
Total Data transferrable in 1 day
0.65 TBytes
Initial SDSS comparisons
Key Projects
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ISS - Populations of objects in the Inner Solar System [Jedicke]
OSS - Populations of objects in the Outer Solar System (beyond Jupiter) [Holman]
LMS - Low-Mass Stars, Brown Dwarfs, and Young Stellar Objects [Magnier, Brandner]
STS - Search for Exo-Planets by dedicated Stellar Transit Surveys [Afonso, Henning]
MW - Structure of the Milky Way and Local Group [Bell, Rix]
M31 - Dedicated Deep Survey of M31 [Seitz, Bender]
MSSP - Massive stars and supernova progenitors [Smartt, Bresolin]
CIVET - Cosmology Investigations with Variables & Explosive Transients [Tonry, Riess,
Stubbs]
GAL - Galaxy Properties [Heckman, Meurer]
AGNHZQ - Active Galactic Nuclei and High Redshift Quasars [Chambers, Walter]
CL - Cosmological Lensing [Heavens, Kaiser, Taylor]
LSS - Large Scale Structure [Cole, Phleps, Bender]
The Key Project concept
• Experiences from SDSS collaboration led
partners to suggest different model
• All scientists within the PS1SC institutes have
rights to the data
• “Key Project” status adopted.
• Developed and written (March 08)
• Number of leads in proportion to financial
share of PS1 mission
• Protected (privileged) status
Science Analysis Servers
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MOPS - Moving Object Processing System [Jedicke]
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High Precision Photometry Server [Stubbs]
Photometric Classification Server [Saglia]
Transient Classification Server [Wood-Vasey, Smartt]
Morphological Classification Server [Lucey]
Detection Efficiency Server [Metcalfe]
Galactic Extinction Server [Finkbeiner]
Mock Galaxy Catalogues [Baugh]
PS1 + PS2 ~ 2012
Pan-STARRS 4 – Mauna Kea 2015 (+PS1 & PS2 = PS6 ?)
LASST = PS16 – 4x PS4 around the world
- science on the way
- under consideration by US Decadal Review
Summary
• Main challenges for PS1 now in
computation and software
• Similar issues to other wide-field surveys
(WFC Surveys, SDSS, UKIDSS, VISTA)
• Long term archiving open question
• Transient Science is new (but CSS,
ROTSE, NSF excellent examples)
• PS“n” is on the table for the UK
• Economic benefits – underplayed ?