High-Time Resolution Astrophysics (HTRA) in FP7

High-Time Resolution Astrophysics (HTRA) in FP7

Tom MarshUniversity of Warwick, UK

Outline

●Scientific motivation

●HTRA within OPTICON FP6

●HTRA & FP7

●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

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 ?