NGST ETC

These are illustrative runs of the NGST exposure time calculator:
http://augusta.stsci.edu/ngst-etc/ngstetc.html for L* galaxies of three
spectral types (Im, Sbc, gE) as a function of redshift. The galaxy size
has been kept constant at 0.5 arcsec diameter - which is clearly
unrealistic at low and high redshifts. but at least the numbers serve as
a rough guide. See the ETC help file for a description of the handling of 
galaxies.

raef, 9 Feb 1999

                                  
          Galaxy type (L*)                                            
          Size (diam)         0.5 arcsec                                        
          SNR       10                                      
          Spec. Res.          100                                     
          Observing band      K                                       
                                                            
z         AB_Im     t_exp_Im  AB_Sbc    t_exp_Sbc AB_gE     t_exp_gE
0.5       19.81     5.8E-01   19.07     2.9E-01   18.6      1.8E-01
1         21.38     2.8E+00   20.71     1.4E+00   20.21     8.6E-01
2         23.15     2.4E+01   22.66     1.3E+01   22.18     7.0E+00
3         24.06     9.4E+01   23.83     6.6E+01   23.47     3.8E+01
4         24.76     2.9E+02   24.78     3.0E+02   24.78     3.0E+02
5         25.56     1.2E+03   25.91     2.1E+03   26.34     4.6E+03
6         26.22     3.7E+03   26.98     1.5E+04   27.56     4.2E+04
8         26.82     1.1E+04   28.16     1.3E+05   30.22     5.6E+06
10        27.23     2.3E+04   28.84     4.4E+05   31.24     3.7E+07