High-Time Resolution Astrophysics (HTRA) in FP7 Tom Marsh University of Warwick, UK

Outline ●Scientific motivation ●HTRA within OPTICON FP6 ●HTRA & FP7

●Stellar black-holes and neutron stars have innermost orbital periods ~ 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 16 th 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-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 = ”, 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 RXJ (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 UK ATC/Sheffield/Warwick OPTICON JRA3

AApnCCDs & APD arrays ●AApnCCDs (MPI): –alternatives to EMCCDs; >90% QE at 1 micron –columns read out in parallel. –264x 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 ●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 ?