Suzaku, Courtesy JAXA

X-ray Imaging Spectrometer (XIS)
Bright Earth Monitoring

Using the Bright Earth Data

This webpage updates an attempt to map the spacial variation of the thickness of the contaminant on the XIS1 filter as it has evolved since launch. This method uses characteristic emission lines of nitrogen, 390 eV, and oxygen, 525 eV, found in the bright earth images.

The work was first summarized here in April 2006. The following updated figures are also available as a single PDF file.

This figure plots the implied contaminant thickness relative to areas outside of a 512 pixel radius. We have assumed a contaminant density of 2.2 gm cm -3. Each line is for a different four week chunk of bright earth data. This is the most recent version of the bottom panel of Figure 3 in the memo cited above.

Updated 2013-01-15
Download the data file

Here is the time dependence of the excess contaminant in the center of XIS1. This is just the leftmost point of each of the curves in the previous figure.

Updated 2013-01-15
Download the data file

The thickness of the contaminant has been determined using the N:O line flux ratios normalized (divided) by the average ratio at r>512 pixels. To do so we have assumed both that the line flux ratio is uniform across the device and that the contamination is due entirely to an azimuthally symmetric layer of carbon with a density of 2.2 gm cm -3.

Here are the normalized line flux ratios for each time bin. This is the most recent version of the top panel of figure 3 of the memo.

Updated 2013-01-15
Download the data file

The following plots show various flux ratios including continuum bands below the nitrogen emission line and above the oxygen emission line (i.e. below the C edge and above the O edge, respectively). This is an attempt to constrain the composition of the contaminant. At this time, the plots are not well understood.

Updated 2013-01-15
Download the data file

The line flux profiles are simply histograms of the distance from the center of of the CCD for each of the two main spectral regions. Because the spectral performance of the device is evolving as well, the spectral regions are determined for each time bin separately. In the original analysis the spectral regions were determined using the widths of the Gaussian peaks, but because some of the fits, especially the later nitrogen fits, are not as good, the boundaries were tweaked by hand.

The following figures are the spectrum and profile of the flux ratios for each of the time bins.

2012-11-06 to 2012-12-01
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 675.253 eV
2012-10-13 to 2012-11-02
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 676.284 eV
2012-09-11 to 2012-10-06
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 671.080 eV
2012-08-06 to 2012-08-27
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 665.568 eV
2012-07-02 to 2012-07-31
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 650.000 eV
2012-05-29 to 2012-06-29
N line measured from 305.000 to 455.000 eV
O line measured from 455.000 to 675.000 eV
2012-04-30 to 2012-05-23
N line measured from 305.000 to 450.000 eV
O line measured from 450.000 to 670.000 eV
2012-03-19 to 2012-04-21
N line measured from 305.000 to 450.000 eV
O line measured from 450.000 to 670.000 eV
2012-01-16 to 2012-03-16
N line measured from 305.000 to 450.000 eV
O line measured from 450.000 to 660.000 eV
2011-12-20 to 2012-01-12
N line measured from 305.000 to 445.000 eV
O line measured from 445.000 to 666.690 eV
2011-11-21 to 2011-12-18
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 650.000 eV
2011-10-24 to 2011-11-19
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 650.000 eV
2011-09-20 to 2011-10-22
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 650.000 eV
2011-08-22 to 2011-09-16
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 650.000 eV
2011-05-05 to 2011-08-07
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 670.000 eV
2011-03-23 to 2011-04-25
N line measured from 300.000 to 447.000 eV
O line measured from 447.000 to 665.000 eV
2011-02-21 to 2011-03-19
N line measured from 305.000 to 450.000 eV
O line measured from 450.000 to 640.000 eV
2011-01-26 to 2011-02-19
N line measured from 320.000 to 450.000 eV
O line measured from 450.000 to 669.432 eV
2010-12-27 to 2011-01-23
N line measured from 320.000 to 450.000 eV
O line measured from 450.000 to 662.703 eV
2010-11-29 to 2010-12-21
N line measured from 320.000 to 450.000 eV
O line measured from 455.000 to 680.000 eV
2010-11-01 to 2010-11-28
N line measured from 320.000 to 455.000 eV
O line measured from 455.000 to 640.000 eV
2010-10-06 to 2010-10-30
N line measured from 320.000 to 445.000 eV
O line measured from 446.515 to 644.373 eV
2010-09-07 to 2010-10-01
N line measured from 305.000 to 455.000 eV
O line measured from 455.000 to 640.369 eV
2010-08-02 to 2010-08-31
N line measured from 310.000 to 455.000 eV
O line measured from 455.000 to 640.000 eV
2010-07-08 to 2010-07-31
N line measured from 305.000 to 460.000 eV
O line measured from 460.000 to 639.947 eV
2010-06-08 to 2010-07-01
N line measured from 305.000 to 460.000 eV
O line measured from 460.000 to 650.000 eV
2010-05-10 to 2010-06-05
N line measured from 320.000 to 455.000 eV
O line measured from 455.000 to 620.000 eV
2010-04-12 to 2010-05-04
N line measured from 310.000 to 460.000 eV
O line measured from 460.000 to 630.000 eV
2010-03-08 to 2010-04-10
N line measured from 310.000 to 450.000 eV
O line measured from 452.922 to 635.391 eV
2009-12-14 to 2010-03-03
N line measured from 310.000 to 450.000 eV
O line measured from 450.000 to 648.056 eV
2009-10-13 to 2009-12-12
N line measured from 310.000 to 455.000 eV
O line measured from 455.000 to 647.496 eV
2009-09-14 to 2009-10-11
N line measured from 315.000 to 455.000 eV
O line measured from 455.000 to 648.648 eV
2009-08-11 to 2009-09-13
N line measured from 310.000 to 460.000 eV
O line measured from 460.000 to 651.492 eV
2009-07-15 to 2009-08-08
N line measured from 315.000 to 460.000 eV
O line measured from 460.000 to 649.071 eV
2009-06-15 to 2009-07-10
N line measured from 315.000 to 455.000 eV
O line measured from 455.000 to 651.262 eV
2009-05-20 to 2009-06-14
N line measured from 310.000 to 455.000 eV
O line measured from 455.000 to 649.452 eV
2009-04-13 to 2009-05-16
N line measured from 305.000 to 450.000 eV
O line measured from 455.000 to 648.541 eV
2009-03-16 to 2009-04-11
N line measured from 295.000 to 440.000 eV
O line measured from 440.000 to 613.665 eV
2009-02-16 to 2009-03-14
N line measured from 300.000 to 435.000 eV
O line measured from 435.000 to 618.484 eV
2009-01-16 to 2009-02-14
N line measured from 300.000 to 440.000 eV
O line measured from 445.000 to 619.973 eV
2008-12-08 to 2009-01-11
N line measured from 295.000 to 440.000 eV
O line measured from 442.000 to 619.752 eV
2008-11-12 to 2008-12-07
N line measured from 300.000 to 435.000 eV
O line measured from 435.419 to 613.469 eV
2008-10-06 to 2008-11-06
N line measured from 300.000 to 440.000 eV
O line measured from 440.000 to 620.273 eV
2008-09-08 to 2008-10-04
N line measured from 300.000 to 435.000 eV
O line measured from 435.946 to 615.901 eV
2008-07-28 to 2008-08-30
N line measured from 300.000 to 430.000 eV
O line measured from 432.981 to 617.441 eV
2008-06-23 to 2008-07-19
N line measured from 300.000 to 440.000 eV
O line measured from 440.000 to 618.178 eV
2008-05-27 to 2008-06-20
N line measured from 300.000 to 435.000 eV
O line measured from 435.000 to 619.977 eV
2008-04-29 to 2008-05-23
N line measured from 300.000 to 435.000 eV
O line measured from 435.610 to 616.628 eV
2008-03-31 to 2008-04-24
N line measured from 300.000 to 438.000 eV
O line measured from 438.778 to 618.721 eV
2008-03-04 to 2008-03-29
N line measured from 300.000 to 438.000 eV
O line measured from 438.223 to 614.804 eV
2008-01-28 to 2008-03-01
N line measured from 295.000 to 440.000 eV
O line measured from 440.000 to 610.938 eV
2007-12-12 to 2008-01-24
N line measured from 295.000 to 445.000 eV
O line measured from 445.000 to 622.493 eV
2007-11-12 to 2007-12-06
N line measured from 300.000 to 440.000 eV
O line measured from 440.097 to 615.831 eV
2007-10-15 to 2007-11-06
N line measured from 300.000 to 440.000 eV
O line measured from 443.135 to 616.544 eV
2007-09-17 to 2007-10-12
N line measured from 300.000 to 440.000 eV
O line measured from 443.435 to 615.283 eV
2007-08-22 to 2007-09-14
N line measured from 300.000 to 440.000 eV
O line measured from 445.000 to 622.304 eV
2007-07-23 to 2007-08-17
N line measured from 300.000 to 440.000 eV
O line measured from 440.844 to 614.765 eV
2007-06-25 to 2007-07-22
N line measured from 300.000 to 450.000 eV
O line measured from 450.000 to 618.169 eV
2007-05-28 to 2007-06-22
N line measured from 300.000 to 440.000 eV
O line measured from 441.694 to 616.849 eV
2007-04-30 to 2007-05-26
N line measured from 295.000 to 440.000 eV
O line measured from 443.556 to 613.196 eV
2007-04-02 to 2007-04-28
N line measured from 295.000 to 440.000 eV
O line measured from 440.840 to 615.761 eV
2007-03-05 to 2007-04-01
N line measured from 295.000 to 440.000 eV
O line measured from 441.652 to 613.673 eV
2007-02-05 to 2007-03-03
N line measured from 295.000 to 440.000 eV
O line measured from 441.089 to 616.740 eV
2007-01-10 to 2007-02-03
N line measured from 295.000 to 440.000 eV
O line measured from 443.951 to 612.630 eV
2006-12-11 to 2007-01-05
N line measured from 295.000 to 441.000 eV
O line measured from 441.292 to 618.026 eV
2006-11-13 to 2006-12-09
N line measured from 295.000 to 445.000 eV
O line measured from 444.701 to 612.640 eV
2006-10-09 to 2006-11-09
N line measured from 295.000 to 443.000 eV
O line measured from 442.798 to 615.787 eV
2006-09-04 to 2006-10-06
N line measured from 295.000 to 446.000 eV
O line measured from 446.000 to 615.004 eV
2006-07-03 to 2006-07-29
N line measured from 290.000 to 440.000 eV
O line measured from 440.000 to 613.717 eV
2006-06-07 to 2006-06-29
N line measured from 295.000 to 441.000 eV
O line measured from 441.000 to 611.688 eV
2006-05-09 to 2006-06-04
N line measured from 295.000 to 443.000 eV
O line measured from 443.000 to 609.088 eV
2006-04-04 to 2006-05-01
N line measured from 290.000 to 442.000 eV
O line measured from 442.000 to 609.604 eV
2006-03-06 to 2006-03-31
N line measured from 290.000 to 445.000 eV
O line measured from 445.000 to 614.837 eV
2006-02-06 to 2006-03-03
N line measured from 295.000 to 440.000 eV
O line measured from 440.000 to 609.782 eV
2006-01-04 to 2006-02-04
N line measured from 290.000 to 445.000 eV
O line measured from 445.000 to 608.965 eV
2005-11-28 to 2005-12-30
N line measured from 290.000 to 443.675 eV
O line measured from 443.675 to 614.042 eV
2005-10-30 to 2005-11-28
N line measured from 290.000 to 450.000 eV
O line measured from 450.000 to 612.111 eV
2005-10-03 to 2005-10-30
N line measured from 290.000 to 450.000 eV
O line measured from 450.000 to 610.857 eV
2005-09-03 to 2005-10-03
N line measured from 287.008 to 450.000 eV
O line measured from 450.000 to 612.370 eV
2005-08-15 to 2005-09-01
N line measured from 282.569 to 450.000 eV
O line measured from 450.000 to 615.932 eV


MKI     
MIT
Last updated: Tue Jan 15 13:17:53 EST 2013
email: milleric@mit.edu