March 2003



ISPI performance

During the January 2003 engineering night weather permitted us to measure the throughput of ISPI at the telescope, see table. The ISPI throughput is very similar to the throughput of Flamingos at the Kitt Peak 4m. However, these values are slightly less good than our predicted values, as advertised on the ISPI First light announcement. The exposure calculator on the CTIO Infrared Instrument web page has been updated accordingly. The initial estimates were based on the CIRIM performance at the Blanco 4-m telescope.


ISPI performance
based on data taken on Jan. 19, 2003
Band
Background Flux
(electrons/sec)
per pixel		 Integrated Flux
(electrons/sec)
for m=15 star		 point source detection limit
5 sigma in
60 sec *
J 310 4000 19.6
H 1560 5000 18.9
K' 2160 3300 18.3
* Aperture photometry using a three pixel radius


ISPI filters

At the time of writing ISPI is offered with the broad band Y, J, H, Ks and K' filters. The K' filter is on loan from Gemini, until further notice. In the table below are shown all filters already available and already ordered for ISPI. Hopefully all filters ordered will arrive in time to be available for semester 2003B. If you are planning to apply for observing time using any of the filters marked as "ordered", please keep an eye on the ISPI latest news pages, or contact Nicole van der Bliek, Ron Probst, Dara Norman or Bob Blum.


ISPI Filters
Filter Central wavelength
(micron)		 FWHM Comment
J 1.25 Cut-on: 1.170mu
Cut-off: 1.326mu
H 1.635 Cut-on: 1.494mu
Cut-off: 1.775mu
Ks 2.150 Cut-on: 1.985mu
Cut-off: 2.305mu
Y 1.0381 BW 0.1457mu
Continuum, 2.03mu 2.03
ordered, Jan. 2003
He I 2.06
ordered, Jan. 2003
C IV 2.08
ordered, Jan. 2003
H2 2.12
ordered, Jan. 2003
Continuum, 2.14 mu 2.14
ordered, Jan. 2003
Br gamma 2.16
ordered, Jan. 2003
He II 2.19
ordered, Jan. 2003
H2 & continuum 2.25 mu 2.25
ordered, Jan. 2003



March 20, 2003
nvdbliek@ctio.noao.edu