Throughput measurements for the CAHA instruments

Below we list the empirical throughput measurements (zeropoints) for all CAHA instruments on which the CAHA Exposure Time Simulator bases its predicted count rates and signal-to-noise.

Optical Imaging (Johnson Filters):

  Instrument    U      B      V      R         I     Date     CCD      Source
  ----------  -----  -----  -----  -----     -----  ------  -------  -----------
  MOSCA 3.5m  23.13  26.27  25.95  26.20(R2) 25.14  990819  SITE#16d  Aguirre
  CAFOS 2.2m  21.41  23.43  23.46  23.80     23.09  000708  SITE#1d   Alises
  CCD 1.23m      -   22.25  22.59  22.64     22.06  010307  SITE#2b   Riffeser/Hoyo


Optical Spectroscopy:

  Instrument            ZEROPOINT         Date        CCD       Source
  ----------        ----------------   -----------  --------   --------
  FOCES 2.2m        22.2 (V-band)        010201     LORAL#11i   Pedraz
  TWIN 3.5m (blue)  25.3 (B-band/T08)    010515     Standard    Pedraz
  TWIN 3.5m (red)   25.8 (R-band/T11)    010515     Standard    Pedraz



NIR Imaging (Johnson Filters):

  Instrument             optics   J      H      K      K'    Ks     Date          Source
  ----------------       ------  -----  -----  -----  ----- -----  ------  ----------------------
  OMEGA-PRIME 3.5m        wf    23.73  23.30    -     23.00 22.82  010211  Guijarro/Sanchez(H,ks)
  OMEGA-CASS  3.5m        hr    23.25  23.17  22.89    -     -     990209      Aceituno     
  ALFA+O-CASS 3.5m        hr    22.46  22.45  22.26    -     -     010701      Aceituno


SKY: The calculations done in the simulator for the optical domain consider the sky brightness at dark-moon taken from Leinert et al. 1995 (A&A Suppl. Ser., 112, 99):

B=22.6, V=21.5, R=20.6, I=18.7 in mag/arcsec2

For the near-IR domain, the sky brightness have been measured using O-prime in February 2001 by Ana Guijarro in J and K'.

J=15.57, K'=12.17 in mag/arcsec2

H=13.6 mag/arcsec2 from MAGIC manual.


NOTE: No empirical zeropoints are available for TWIN, MOSCA spectroscopy, CAFOS spectroscopy, MAGIC, OMEGA-CASS in spectroscopy mode.


Francisco Prada (prada@caha.es)
2001 November 19