Instruments available on the Liverpool Telescope

1. Instruments available on the Liverpool Telescope http://telescope.livjm.ac.uk Chris Davis, Iain Steele, Mike Bode, Rob Barnsley, Stuart Bates, Neil Clay, Chris Copperwheat, Steve Fraser, Jon Marchant, Chris Mottram, Robert Smith, Mike Tomlinson The Liverpool Telescope offers access to a variety of optical and near-IR imagers, fast photometers, a spectrometer, and an optical polarimeter. Each of these instruments is described below; potential users are encouraged to visit our web pages or contact LT support staff at ltsupport_astronomer@ljmu.ac.uk for further details. IO:O isthe workhorse optical imager on the LT, though IO:THOR may be used if rapid frame readout is important, or RISE if intense monitoring is required over a period of a few hours (e.g. of an occultation, or a binary or planetary transit). IO:I is currently being commissioned (Summer 2013) and may ultimately be used with IO:O to offer simultaneous optical and near-IR imaging. IO:THOR Filter: Single “V+R+I” ~ 520-900 nm Pixel Scale: 0.133 arcsec/pixel Field of View: 2.25 x 2.25 arcmin Frame rate: > 2.55 fps (unbinned) • IO:O • Detector: 4096 x 4112 e2v CCD 231 • Filters: Sloan u’g’r’i’z’; Bessell B,V; • Ha 656.6/663.4/670.5/675.5/682.2 • Pixel size: 15.0 x 15.0 microns • Pixel scale: 0.15 arcsec/pixel • Field of view: 10 x 10 arcmin • Read noise: <8 e- • Binning: 1x1 and 2x2 • Readout time: ~ 12 sec (2x2 bin) IO:I (in preparation) Detector: 2048 x 2048 Hawaii-2RG Filters: Y, J, H Pixel size: 18.0 x 18.0 microns Pixel scale: 0.18 arcsec/pixel Field of view: 6 x 6 arcmin Read noise:19e- (Single CDS) Dark current: 0.001e-/s Readout time:~1s (NDR) RISE Filter: Single "V+R” ~ 510-650 nm Pixel Scale: 0.54 arcsec/pixel Field of view 9.2 x 9.2 arcmin Min exp time:1.5 sec; no readout o/h FRODOSpec is a fibre-fed dual beam spectrometer that is currently used for all optical spectroscopy at the LT. A low-resolution long-slit alternative, SPRAT, is currently under development. The expectation is that this instrument will be a high-throughput complement to FRODOSpec. • FRODOSpec • Low Resolution (Grating) • Blue: 390-570nm; R ~ 2600 • Red: 580-940nm; R ~ 2200 • High Resolution (VPH) • Blue: 390-510nm; R ~ 5500 • Red: 590-800nm; R ~ 5300 • Input: 12x12 lenslets each 0.82 arcsec on-sky • Field-of-view: 9.8 arcsec • Acquisition: imaging with IO:O SDSS 1209+1611 Copperwheat et al. DG Tau Davis et al. Above: FRODOSpec data showing (top) a blue VPH grating spectrum of a subdwarf-B star with strong Balmer absorption lines and (bottom) a red spectrum of a T Tauri star with forbidden emission lines. Above: FRODOSpec optics Below: SkyCam-T image of the Galactic Plane. The ellipse marks the Trifid and Lagoon nebulae RINGO3 offers simultaneous imaging polarimetry in three broad bands. A polaroid rotates in the beam at a frequency of 1 Hz. Eight images are obtained during each rotation; images obtained with the same angle are stacked to build up signal-to-noise. Dichroics positioned downstream of the polaroid are used to direct blue, green and red beams to three separate cameras. RINGO3 Detector: Each camera 512x512 EMCCD Red arm: 760-1000 nm Green arm: 650-750 nm Blue arm: 350-640 nm Pixel scale: 0.49/0.47/0.47 arcsec Field-of-view: 5.1/4.2/4.3 arcmin SkyCam-A, -T and –Z provide wide-field optical imaging of the whole sky (A), a 21o field (T) and a 1o field (Z) with exposures obtained once a minute. Magnitude limits of 6th, 12th and 18th are possible with the three cameras, respectively. Above: plots of the modulation in signal measured at eight polaroid position angles (1-8) for two sources (blue-polarised/red-unpolarised). The green data points show the ratio of the two.