ACIS background

Last change 11 Feb 10

For general info about the ACIS background, please read THE CALIBRATION WEB PAGE. This directory contains experimental ACIS background files and tools to use them (lc_clean, make_acisbg, badpixfilter).
COOKBOOK	- file describing how to use the tools and the background data
data/		- directory with background files, the bad pixel table, 
                  and example PHA files and images
data/psu/	- datasets processed with PSU CTI corrector
data/nocti/	- datasets processed without CTI correction
data/README	- detailed description of the background files
lc_clean_sm	- example parameter files and an SM macro, see COOKBOOK.  
data.tar.gz	- data directory, excluding psu/ and nocti/ subdirs (595 MB)
tools-010409.tar.gz	- the code
README		- this file
To compile lc_clean, make_acisbg and A. Vikhlinin's badpixfilter under Solaris or Linux, download tools-*.tar.gz and see instructions there. You will need the latest CIAO installation and the CFITSIO library (which comes with FTOOLS or CIAO).

Note that there is a CIAO tool reproject_events, which should supersede make_acisbg - trying it may save you the compilation trouble (it's slow but it works).

At the CfA HEAD LAN, the binaries (Solaris), example par files, the SM macro lc_clean_sm, and COOKBOOK can be found in the directory /home/maxim/, and the background event files in /home/maxim/CH/.


2/11/10: added period E blank-sky files for ACIS-S and ACIS-I.
9/6/9: Added recent stowed observations for period E (now 367 ks) and DE (now
       603 ks).
4/1/9: The code is updated to compile with ciao-4.
10/16/8: Stowed dataset now split into D and E periods; added recent stowed
	 observations for E. For FI chips, also include the total file (DE,
	 511 ks), since the FI spectrum does not change.
7/8/7: New gain, t_gain, CTI correction (N0006) applied to C,D datasets
       (this now includes CTI correction for BI chips).
       Also included CTI-uncorrected blank-sky datasets for aciss C,D.
       Longer *stowed* dataset (also processed with N0006 CALDB files).
5/2/7: The code is now in a portable distribution form (thanks to Eric
       Mandel and Alexey Vikhlinin) 
1/30/7: updated code to compile with CIAO-3.4; no longer include binaries.
6/15/6: Longer *stowed* dataset; uses N0005 gain, tgain and CTI files.
12/27/5: Longer *stowed* dataset (CXC CTI correction only).
	 New lc_clean, implementing the band ratio filtering as in
	 astro-ph/0512542. Also, the cleaning algorithm is rewritten to be
	 more economical (throw away fewer boundary bins, etc.)
2/1/5: Longer *stowed* dataset (CXC only; PSU is still old).
       Also, for periods C,D:
       - applied the newest CALDB gain table;
       - applied new badpix_*_041104noedge table that leaves the chip edges in
	 (for consistency with CALDB);
       - some keyword changes for compatibility with CIAO.
       For acisi_D, removed an overlooked bad pixel.
12/12/4: New acisi_D_01236 dataset, now 1.5 Msec long (CXC only, not PSU).
	 For acisi_D files, the new standard CALDB gain and t_gain are applied.
11/4/4: New bad pixel tables badpix_[AB,C,D]_041104 are applied to all
	event files. (They include additional "shadow" columns and vignetted 
	chip edges, and can simply be re-applied to the already-cleaned event
4/17/4: New ACIS-stowed datasets (CXC and PSU): 
	- longer (144 ks);
	- tgain correction includes chip S1 (as in blank-sky files); 
	- all 7 chips are combined into a single file.
11/27/3: 1. Extended the aciss_D dataset (most significantly the 57 subset);
	 2. Completely remade the B datasets:
	    - use different obsid selection,
	    - same OBSIDs for chips acisi_01236, aciss_23678,
	    - lc cleaned using 0.3-12 kev for FI and 2.5-7(6) kev for BI (as
	      for C,D files),
	    - correct for source exclusion holes (as for C,D),
	    - use the latest gain table,
	    - upper pha cutoff 3275 adu (13 kev), same as for C,D,
	    - now include chip S4
	    - now include PSU-corrected versions.
	 3. tgain correction for C,D datasets (not yet in CALDB)
	 4. New gain table for C,D datasets (not yet in CALDB)
	 5. New bad pixel tables (include "dark" columns; not yet in CALDB)
	 6. destreak applied to all FI chips (not just S4)
	 7. All status bits other than the VF bit are set to 0
	 8. Chip coord randomization reduced from 64 pix to 8 pix (to avoid
	    smearing spatial dependence of the contamination)
	 9. A small error in acisi_D exposure corrected
	 10. Dark Moon and CTI-uncorrected C,D datasets removed (dark Moon is 
	     superseded by "stowed" data)
	 11. Minor fits keyword changes
	 12. Numerous COOKBOOK and data/README updates.
8/20/3: Longer ACIS-stowed datasets (CXC and PSU), now tgain-corrected.
1/28/3: CTI-corrected ACIS-stowed datasets (CXC and PSU).
11/14/2: Added aciss_57 (s1,s3 subsets) with PSU correction for periods C,D.
11/10/2: New period D files: extend to 2002; use the same set of observations
	 for all main chips; a subset of aciss data including observations
	 with both s1 and s3 on (aciss_57); VF mode data for aciss. 
	 Period C and D files are processed with the new CXC CTI correction
	 (old uncorrected files are still in data/nocticor). Added period D
	 files processed with PSU CTI corrector. For period D, BI chips are
	 cleaned of flares using 2.5-7 kev band.
10/13/02: Added ACIS-stowed files (particle-only background, from 2002-9-3).
	  Renamed the darkmoon files aciss*, acisi* to acis* for consistency.
7/23/2: New period C files: for ACIS-S, exclude North Polar Spur pointings;
	same observations used for most chips to enable modeling of the soft
	Galactic excess; for BI chips, light curves cleaned in the 2.5-7 kev
	band; for both S and I, correct source exclusion holes (as in D
	files); updated badpix table (adds a few columns for S4); include a
	version processed by PSU 'corrector'. The obsolete *s3_allgrades*,
	*lowe* and *s13* files are removed. 'lc_clean' now has an option 
	ignore_neg_dev=y to ignore (leave in) negative dev. from the mean.
7/12/2: Added dark Moon datasets (particle-only background) from Jul-Sep 2001
2/10/2: Fixed default sky coords in acisi_D_s* files (for those who uses them)
2/8/2: Fixed an error in acisi_D evt files: status bits were garbled.
1/8/2: Set det and sky coords in D event files to their default values.
1/4/2: Added period D (2001) event files; they include VF mode data for
       ACIS-I, and are corrected for "holes" due to source exclusion.
       Updated COOKBOOK; fixed a bug in make_acisbg (which should not have
       affected files other than D).
10/6/01: fixed a bug in lc_clean (sometimes it wrote invalid fits files);
	 added instructions in COOKBOOK on how to update the gain;
	 fixed a typo a header keyword in the aciss_A* files.
9/03/01: added *lowe* evt files including E<0.3 keV (for C i3,s3: see 
6/27/01: fixed a bug in make_acisbg and lc_clean (which could make Linux 
	 binaries refuse to read fits files)
6/15/01: added aciss_C_s13 subset event file (see data/README)
3/28/01: a COOKBOOK update
3/23/01: reformatted all event files to be compatible with dmcopy.
3/22/01: make_acisbg now does not need asp_apply_sim to be run on the aoff1
	 file, and exits with an error message if it was run.
	 lc_clean now accepts gti_file as a name of the fits extension in
	 the event file, no need to extract it into a separate file. 
1/11/01: added aciss_C_s3_*allgrades.fits (not included in data.tar)
1/6/01: included precompiled CIAO-2 libs for Solaris-2.6 and Linux Redhat-6.2,
        also binaries for Linux.
1/1/01: updated Makefile for CIAO-2; code for CIAO-1 is now in separate dir;
	updated COOKBOOK
11/27/00: a minor fix of the aciss_s1_C* evt file (now version 271100)
10/26/00: fixed minor bug in lc_clean
10/20/00: added ACIS-S data files for period C (-120C); please note that
	there have been 2 unannounced versions of these files, 041000 and
	161000, which are superseded by 191000 (see data/README).
	Also new version of lc_clean (now treats time as real rather than
	integer number, so can use small time bins). 
8/30/00: added a merged I0123 data file for period B for convenience.
8/25/00: added ACIS-I data files for period C (-120C);
	 new badpix table (ascii and fits, also fits version of old table).
6/8/00: added example spectra (PHA files) for whole chips S3 and I3 (dir. data)
6/6/00: added some libs and includes for sunos56 (dir. src/lib_inc_sunos56/);
       	added data files *060600* that use the new N0004 gain table;
	added a few keywords to aciss*180400* files for CIAO compatibility.
4/18/00: added several observations to the background files, most notably 
         to acisi_B_i3*. Some additions to COOKBOOK, incl. a section about sky
         coords. Makefile now says what additional g77 option to use (from AV).
3/15/00: original version.

Maxim Markevitch (maxim %