Chandra Deep Field North ======================== The Chandra Deep Field North is centered on: RA(ICRS) = 12 36 50 Dec(ICRS) = +62 14 00 To deliver user-friendly data products, we have merged 17 CDF-N observations taken during 2000-2002. Note that we excluded three observations (obsid = 580, 966, 967) taken in 1999 with CCD temperature = -110C, because of the problem in the corresponding calibration data. We will regenerate the combined data set including these 3 observations after reliable calibration data are available. CDF-N observations were performed in two different aim points and roll angles. To avoid a source falling in different off-axis angles and different CCDs, we have also merged two data sets seperately. A. 17 CDF-N observations taken during 2000-2002 Total exposure: 1850 ks B. 7 CDF-N observations with aim point (ra, dec) = (12 37 00 +62 13 00) and roll angle = 40 obsid = 2386, 1671, 2344, 3293, 3388, 3408, 3389 Total exposure: 690 ks C. 10 CDF-N observations with aim point (ra, dec) = (12 36 36 +62 14 30) and roll angle = 140 obsid = 957, 2232, 2233, 2423, 2234, 2421, 3409, 3294, 3390, 3391 Total exposure: 1160 ks For data taken in datamode=FAINT, we removed cosmic-ray afterglows using a CIAO tool, acis_detect_afterglow. For data taken in datamode=VFAINT (very faint), we cleaned ACIS background events using a 5x5 pixel event island by setting check_vf_pha=yes in acis_process_events. This step also effectively remove cosmic-ray afterglows. We then refined astrometry based on the matched source positions and reprojected onto a common tangent plane, using a CIAO tool, reproject_aspect. The relative offsets (from obsid 2234) for individual observations are listed below for reference. We then regenerated level 2 event files using CXC pipelines, and merged individual evt2 files, using a CIAO tool, merge_all. The main merged data products are: A. All CDF-N data acismCDFN_ALL_VF_N000_evt2.fits final merged event list for ccdid=0-3 acismCDFN_ALL_VF_N000_expmap.fits final merged exposure map acismCDFN_ALL_VF_N000_full_img2.fits full image in energy=0.5-6 keV acismCDFN_ALL_VF_N000_colorimg.jpg true color image made with 3 energy bands (0.5-1, 1-2, 2-6 keV). These products are tarred up in: CDFNmerge.tar B. roll angle=40 only acismCDFS_SET1_VF_N000_evt2.fits acismCDFS_SET1_VF_N000_expmap.fits acismCDFS_SET1_VF_N000_full_img2.fits acismCDFS_SET1_VF_N000_colorimg.jpg These products are tarred up in: CDFNroll040.tar C. roll angle=140 only acismCDFS_SET2_VF_N000_evt2.fits acismCDFS_SET2_VF_N000_expmap.fits acismCDFS_SET2_VF_N000_full_img2.fits acismCDFS_SET2_VF_N000_colorimg.jpg These products are tarred up in: CDFNroll140.tar We also provide the event list and aspect solution for each obsid so that users may merge a sub-sample as needed. pcad_[obsid]_reproject_asol1.fits aspect solution per observation acism[obsid]N000_reproj_{vf|ag}_evt2.fits Level 2 event list per observation vf for the very faint mode correction with check_vf_pha=yes ag for afterglow removal with acis_detect_afterglow. These products are tarred up in: CDFNbyObsId.tar Please note that the new data sets supersede the old data set linked at: http://cxc.harvard.edu/cda/whatsnew.html#CDFN1 Table 1. Relative positional offsets of individual observations +------+-----------+-----------+-----------+--------------------------+ | | Rotation | X Transl | Y Transl | | |Obsid | Angle deg | in pixels | in pixels | date-obs | +------+-----------+-----------+-----------+--------------------------+ | 957 | -0.023787 | -0.097457 | -0.216781 | Feb 23 2000 | | 2386 | 0.020931 | -0.023528 | 0.855812 | Nov 20 2000 | | 1671 | 0.003000 | 0.074567 | 0.831586 | Nov 21 2000 | | 2344 | 0.006530 | 0.246722 | 0.891108 | Nov 24 2000 | | 2232 | 0.008542 | 0.045954 | -0.168125 | Feb 19 2001 | | 2233 | 0.018630 | -0.162585 | 0.041231 | Feb 22 2001 | | 2423 | -0.019432 | 0.080504 | 0.078210 | Feb 23 2001 | | 2234 | -0.000000 | 0.000000 | 0.000000 | Mar 02 2001 ** reference | | 2421 | 0.006745 | -0.031478 | -0.163606 | Mar 04 2001 | | 3293 | -0.007040 | 0.195266 | 0.870284 | Nov 13 2001 | | 3388 | -0.040640 | -0.001802 | 1.101213 | Nov 16 2001 | | 3408 | 0.004277 | 0.169711 | 0.688793 | Nov 17 2001 | | 3389 | 0.017174 | 0.349922 | 0.605302 | Nov 21 2001 | | 3409 | -0.014773 | 0.115558 | -0.579186 | Feb 12 2002 | | 3294 | 0.003738 | 0.050261 | -0.732207 | Feb 14 2002 | | 3390 | -0.008469 | 0.088183 | -0.594823 | Feb 16 2002 | | 3391 | 0.003806 | 0.208727 | -0.610225 | Feb 22 2002 | +------+-----------+-----------+-----------+--------------------------+ (1 pixel = 0.492 arcsec) Table 2. Dates, exposure times, and roll angles of individual observations +--------+--------------+----------+---------+------------+------------+--------------+ | obsid | date_obs | data mode| exp | ra | dec | roll | +--------+--------------+----------+---------+------------+------------+--------------+ | DATA SET B | | | | 2386 | 2000.11.20 | FAINT | 11.7 | 189.266117 | 62.217594 | 44.499052 | | 1671 | 2000.11.21 | FAINT | 170.3 | 189.266062 | 62.217604 | 44.499416 | | 2344 | 2000.11.24 | FAINT | 94.5 | 189.266070 | 62.217600 | 44.498754 | | 3293 | 2001.11.13 | VFAINT | 164.6 | 189.215465 | 62.217527 | 40.523002 | | 3388 | 2001.11.16 | VFAINT | 52.2 | 189.215459 | 62.217524 | 40.523013 | | 3408 | 2001.11.17 | VFAINT | 69.9 | 189.215469 | 62.217525 | 40.523003 | | 3389 | 2001.11.21 | VFAINT | 127.8 | 189.215231 | 62.217817 | 44.317868 | +--------+--------------+----------+---------+------------+------------+--------------+ | DATA SET C | | | | 957 | 2000.02.23 | FAINT | 60.8 | 189.152183 | 62.244820 | 134.256496 | | 2232 | 2001.02.19 | FAINT | 133.6 | 189.149736 | 62.243410 | 136.808549 | | 2233 | 2001.02.22 | FAINT | 66.3 | 189.148273 | 62.242738 | 138.260242 | | 2423 | 2001.02.23 | FAINT | 70.7 | 189.148270 | 62.242747 | 138.260236 | | 2234 | 2001.03.02 | FAINT | 169.4 | 189.144435 | 62.240797 | 142.263770 | | 2421 | 2001.03.04 | FAINT | 64.0 | 189.143066 | 62.240035 | 143.765023 | | 3409 | 2002.02.12 | VFAINT | 84.5 | 189.153674 | 62.244938 | 133.131409 | | 3294 | 2002.02.14 | VFAINT | 173.9 | 189.153685 | 62.244930 | 133.131395 | | 3390 | 2002.02.16 | VFAINT | 167.8 | 189.153689 | 62.244929 | 133.131391 | | 3391 | 2002.02.22 | VFAINT | 168.4 | 189.153681 | 62.244932 | 133.131396 | +--------+--------------+----------+---------+------------+------------+--------------+