high-time resolution astrophysics (htra) in fp7
DESCRIPTION
Tom Marsh University of Warwick, UK. High-Time Resolution Astrophysics (HTRA) in FP7. 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 - PowerPoint PPT PresentationTRANSCRIPT
●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
Scientific Motivation - I.
Flares from a black-hole
▬ 5-10 sec long, 50% flares
▬ Unique to black-hole accretors
▬ Not detected with 60-sec photometry on Gemini
Shahbaz, VLT + ULTRACAM, May 2005
A 22nd mag black-hole accretor:
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
●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
X-ray light curve
HTRA & FP6
1. EMCCD development for fast imaging
2. EMCCD development for fast spectroscopy
3. AApnCCD development
4. APD array development
The following HTRA projects are supported via OPTICON in FP6:
EMCCDs
Electron-multiplying CCDs extend CCDs' range into the low count regime.
Avalanche gain section amplifies before the readout
e-
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
With the right controller and data processing, EMCCDs make this possible
0.65”, no selection 0.26”, 10% best
0.12” separation binary. Delta mag = 2.50.65”, no selection
LuckyCam, Law, MacKay, Baldwin (IOA, Cambridge). 2.5m NOT, La Palma.
Partial support from OPTICON
M15
Fast Spectroscopy
The gain for spectroscopy is primarily one of reduced noise
Simulation: 1 night VLT/FORS on V = 21 ultra-compact 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/WarwickOPTICON 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 & FP7The 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
●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)
Current EMCCDs are too small to be competitive with standard detectors, and photon counting mode requires fast readout even if targets do not vary.
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