AXIS Observing Report ~~~~~~~~~~~~~~~~~~~~~ Dates: October 07,08 2000 Instrument: WFC imaging at INT prime focus Observers: Pete Wheatley, Darren Baskill, Aurora Ullan Filters: U g r i Z Ha Nominal exposures: 1200 600 600 1200 1200 3000 Landolt exposures: 120 30 30 60 60 120 Pointing position: WFC pointing offset from XMM target position by delta RA = 2.5 arcmin, delta Dec = + 2 arcmin, corresponding to option 3 of Watson (observing log for July 2000 WFC observing run). These offsets were applied to our target positions before giving them to the telescope. Observing conditions: Moon dominated observing during first two thirds of each night. Hence concentrated on iZ images and increased exposure times. Decided to double exposures as compromise between loss of sensitivity and survey speed. Exposures were reduced to nominal values as sky background dropped. Once moon had set we observed also in the other filters. 07 Oct: patchy cloud early in night. Seeing gradually improved from 1.4" to about 1.0". 08 Oct: no cloud. Seeing around 0.9". Time lost: None Targets observed: (in order of appearance) Target P N Filters(exposures) Comments EG Peg 1 1 i(60,2400) Z(2400) clouds 2 i(2400) Z(2400) HT Cas 2 1 i(2400) Z(2400) clouds G158-100 1 1 i(2400) Z(2400) Mrk 1014 1 1 i(2400) Z(1200) r(60,1200) g(60,900) U(1200) MBM 12 1 1 i(1200) Z(1200) r(600) g(600) U(1200) PSR J0751+18 1 1 i(1200) r(600) HD108 2 2 i(2400) Z(2400) r(600) Ha(60,3000) low gal lat PSR J0218+42 2 2 i(2400) Z(2400) HCG 16 1 2 i(2400) Z(1500) A339 2 2 i(2400) Z(1500) Mkn 3 1 2 i(1200) Z(1200) r(600) g(600) U(1200) P=priority N=night Calibration frames: Biases: We took 5 bias frames at the beginning of night 1 (231702-231706) and then a further 3 bias frames towards the end of night. The WFC is currently suffering from pattern noise and the extra bias frames were to help quantify the effect (possibly related to the mobile phone transmitter on the roof?!). It seems the noise was much lower during our nights than the previous two nights. Biases on night 2 were taken during the night (because the DAS was down in the afternoon and we had to give up the WFC at sunrise). Sky Flats: Night 1 evening: Ux3 Zx4 ix4 rx3 morning: Ux4 Zx2 rx2 gx5 but blank field vignetted Night 2 evening: Ux4 but blank field too far west? moved... ix3 but 3rd i showing some fringing? morning: rx3 ix1 Zx3 Hax4 Standards: We observed WFC-recommended Landolt field at the beginning and end of each night. Those at the beginning of night one probably suffer from clouds. We observed another Landolt field when the clouds cleared. We were unsure how to choose exposure times for the Landolt fields. The WFC-recommended exposures have a large range (because of the range of standards magnitudes in each field). We chose to expose as follows U(120)g(30)r(30)i(60)Z(60)Ha(120) basically following the exposures of Barcons (see report for 30 April 2000). Summary: We observed eleven XMM fields over two nights with the INT WFC, including all seven fields marked as highest priority in list from Watson (6 Oct). The moon reduced efficiency of deep imaging during the first two thirds of each night, but increased exposure times should ensure we still reach useful limiting magnitudes(?). We obtained i band images of all eleven fields, and Z images of all but one. Other filters were used only after moonset. We made r images of five fields and g and U images for three fields. Finally we made one deep Halpha image of our lowest galactic latitude field (HD108 at gl=117.9 gb=1.3). This was made at relatively high airmass (~1.7) because we had to wait for the moon to set. Pete Wheatley 09 October 2000