m67 8:51:11.95 11:54:12.3 Pa=-30
The MOSFIRE guider imaging zero point is presented below. The guider is equipped with a long pass OG750 filter and the long wavelength cutoff is defined by the detector QE. Known I-band standards in the m67 open cluster were used to calibrate the zero point. The ZP is defined to be the magnitude of a 1 ADU detection in 1 second of integration.
The photometry used for calibration comes from Yadav et al. A&A 484, 609. In the table below, the stars used in the measurements are listed along with the flux and sky background measured in the 1s image. The guider image was acquired using a gain setting of 0 => gain= 0.7 e-/ADU.The MOSFIRE guider image used was centered at: 8:51:11.95 11:54:12.3 and had a pa of -30. A finder chart of the field is shown below. The data were acquired during a full moon night.
The average zero point for the stars below was 28.1 I-band mag. The calculation assumed the standard Mauna Kea extinction value of 0.07 mag/airmass (Gemini).
The sensitivity for the guider for a 1 second exposure was calculated. For this calculation, the objects are assumed to be measured in a 1 arcsec aperture, with the sky background measured in an additional 1 arcsec aperture. The pixel scale was assumed to be 0.164 arcsec/pix for this calculation. For a S/N=10, the guider would detect an 18.9 mag object in a 1 second integration.
_RAJ200 _DEJ200 Bmag e_Bmag Vmag e_Vmag Icmag _Icmag
0 ("h:m:s") 0 ("d:m:s") recno Seq (mag) (mag) (mag) (mag) (mag) (mag) Flux sky/pix
----------- ----------- -------- ---- ------ ------ ------ ------ ------ ------ ------ -------
08 51 06.37 +11 54 18.8 1616 1616 20.025 0.094 18.245 0.017 16.116 0.016 76944 785
08 51 08.27 +11 54 19.9 1618 1618 17.342 0.011 16.715 0.008 15.959 0.005 76927 772
08 51 10.67 +11 54 34.2 1634 1634 17.316 0.011 16.319 0.010 15.208 0.006 163328 770
08 51 12.13 +11 54 40.4 1642 1642 16.025 0.005 15.255 0.005 14.419 0.003 321501 777
08 51 12.29 +11 54 23.0 1622 1622 14.788 0.004 14.156 0.002 13.459 0.004 762677 773
08 51 12.92 +11 53 52.3 1567 1567 16.362 0.006 15.529 0.005 14.634 0.000 255776 760
08 51 12.29 +11 53 36.5 1549 1549 17.373 0.011 16.574 0.010 15.723 0.003 95160 758
08 51 10.71 +11 53 26.6 1532 1532 17.637 0.011 16.567 0.006 15.393 0.004 136566 755
08 51 09.26 +11 53 39.5 1552 1552 18.211 0.010 17.004 0.008 15.699 0.001 99259 758
08 51 09.22 +11 53 14.3 1516 1516 18.981 0.012 17.604 0.016 16.062 0.004 74426 758
08 51 12.34 +11 52 55.7 1493 1493 17.629 0.008 16.416 0.014 15.046 0.000 185229 780
08 51 14.69 +11 53 06.4 1509 1509 19.204 0.029 17.948 0.013 16.593 0.001 45780 770
08 51 15.85 +11 54 03.7 1584 1584 16.263 0.002 15.425 0.005 14.517 0.001 299065 768
08 51 13.78 +11 54 13.5 1606 1606 18.994 0.009 18.415 0.035 17.671 0.018 13351 770
08 51 14.11 +11 54 20.7 1620 1620 22.296 0.197 20.443 0.094 18.173 0.118 563.7 768
m67 8:51:11.95 11:54:12.3 Pa=-30
Original data from May 2012 second light with MOSFIRE