Download High-Time Resolution Astrophysics (HTRA) in FP7

High-Time Resolution
Astrophysics (HTRA) in FP7
Tom Marsh
University of Warwick, UK
Outline
● Scientific motivation
● HTRA within OPTICON FP6
● HTRA & FP7
Scientific Motivation - I.
● Stellar black-holes and neutron stars have
innermost orbital periods ~ 0.001 seconds
● White dwarfs are eclipsed and pulsate in
~ 0.1 to 200 seconds
● Earth-sized planet transit ingresses &
egresses take ~ 100 seconds
Flares from a black-hole
A 22nd mag black-hole
accretor:
▬ 5-10 sec long, 50%
flares
▬ Unique to black-hole
accretors
▬ Not detected with 60sec photometry on
Gemini
Shahbaz, VLT + ULTRACAM, May 2005
Brighter & faster
Factor 2-3 flares in ~20ms
from a 16th mag black-hole
(Spruit et al & ESO/VLT)
Fast response to X-ray variations
implies optical light is from a jet.
“Pre-cognition” dip unexplained.
(Kanbach et al, 2001, Nature)
Scientific Motivation - II.
● Solar system occultations, e.g. detection of 100m KBOs
● Exo-planet transits, avoiding saturation
● Lucky imaging,
wavefront sensing
Right: 50 msec spikes
caused by layers in the
atmosphere of Titan
during an occultation
(Fitzsimmons et al)
HTRA in a wider context
X-ray light curve
● HTR plays a major role in
radio and X-ray astronomy
● LISA predicted to detect
~10,000 ultra-short period,
faint sources
● LSST, LOFAR, GAIA and
SKA will also discover
many time-variable objects
and transients
Neutron star burst reveals its spin
HTRA & FP6
The following HTRA projects are supported via OPTICON in FP6:
1. EMCCD development for fast imaging
2. EMCCD development for fast spectroscopy
3. AApnCCD development
4. APD array development
EMCCDs
Electron-multiplying CCDs
extend CCDs' range into
the low count regime.
eAvalanche gain section
amplifies before the readout
Lucky Imaging
On modest aperture
telescopes one can select a
small number of “best”
images with no other
correction.
Must image fast with low
noise
Law, MacKay & Baldwin (2005)
Lucky Imaging
0.65”, no selection
0.26”, 10% best
With the right
controller and data
processing, EMCCDs
make this possible
M15
LuckyCam, Law, MacKay,
Baldwin (IOA, Cambridge).
2.5m NOT, La Palma.
Partial support from OPTICON
0.12” separation
binary.
Delta mag = 2.5
0.65”, no selection
Fast Spectroscopy
The gain for
spectroscopy is
primarily one of
reduced noise
Simulation: 1 night VLT/FORS on V = 21 ultracompact binary RXJ0806+3127 (P = 321 sec)
with (left) and without (right) readout noise.
Fast Spectroscopy
Aim: to characterise EMCCDs
for astronomical spectroscopy
using hardware/software
available already (ULTRACAM).
1k x 1k chip mounted; first data
when cold taken last week; < 1
e- noise
Test run on ESO 3.6/EFOSC in
December 2006.
UK ATC/Sheffield/Warwick
OPTICON JRA3
AApnCCDs & APD arrays
● AApnCCDs (MPI):
– alternatives to EMCCDs; >90% QE at 1 micron
– columns read out in parallel.
– 264x264 array @ 400 fps, 1.7 e- noise (now)
– avalanche amplification stages to give < 1 e- (future)
● APD arrays (Galway):
– CCDs cannot reach << 1 msec & noise too high for
fast pulsar work
– Developing 10 x 10 APD array
HTRA & FP7
The advent of fast, low-noise CCDs has altered the
landscape of HTRA which can now be divided into:
a) CCDs for > 1 msec
b) APDs, STJs, TESs, GaAs for especially
fast and/or low noise applications
Category (a) has the potential
for upgrading instruments on
existing facilities
EMCCDs for HTRA in FP7
Current EMCCDs are too small to be competitive with
standard detectors, and photon counting mode
requires fast readout even if targets do not vary.
● Need fast controllers which can handle multi-port,
multi-chip detectors.
● Large format devices need to be procured and
tested on sky.
● Software/hardware infrastructure is needed to
handle the high data rates (up to ~100 MB/sec for
a single port)
EMCCD deliverables & costs
● High-speed controller with multi-port capability, able to
run both E2V and Texas Instruments EMCCDs,
integrated with array processor and controlling
software. (IOA Cambridge)
● Specification, procurement and testing of a
spectroscopic format EMCCD to match existing
spectrographs (4k x 2k, split frame, 8 readout ports).
(UK ATC/Sheffield/Warwick)
Total cost: € 2M + (1.1 – 1.6)M for new chip
Interim quote from
e2v who are keen to
develop such a chip
FP7: APDs & pnCCDs
● APDs: fabricate arrays of larger pixels (100 vs 20μ)
to reduce dark count/unit area, increase throughput
and field-of-view. Factor 2 improvement possible.
Timescale: 5 years
● pnCCDs: prototype astronomical camera /
controller / data handling software [placeholder]
Total cost: ~ € 3.5 M
HTRA network
● FP6: developed contacts and spread knowledge
● FP7: continuing need to transfer knowledge on
detector developments, but more emphasis on
strategy
– Development of science drivers
– Enabling HTRA in current & future instrumentation
– Linking up HTRA research across the EM spectrum
Deliverables: International HTRA conference plus proceedings;
workshops on science, detectors and instrumentation
Cost ~ € 200K over 5 years
Industrial & EU dimensions
● EMCCDs have significant impetus from digital
cameras; astronomical applications can push the
limits of these devices and motivate the
development of new products.
● HTRA is strong in Europe which is the home of the
ULTRACAM, OPTIMA and STJ fast photometers.
● HTRA-enabled instruments can promote access as
many EU countries without direct access to 4m+
telescopes have HTRA communities.
Management
● Single manager to report to OPTICON, track
progress and adjust resources
● Management of sub-projects & network
devolved to small number of PIs
● Milestones & timescales defined at the start
● 2 progress reviews + 1 face-to-face meeting
per year (2 in first year).
Cost ~ € 150K over 5 years
Summary
● High time resolution is key to understanding
the most extreme astrophysical environments
● HTR is demanding of detectors, and is
sustained by advances in detector technology
● We propose a package that builds on the lead
Europe has in this area
● Total cost ~ € 7M; cost to FP7 ?