Cycle 23 Recommended Targets: Statistics

Statistics for all proposals submitted to the peer review, including the GTO proposals which were competed. This does NOT include GTO time which was uncompeted or Calibration observations. Units for time are given in kiloseconds.

1. Proposals by Type

                                Requested  
Type           #Prop   #Tgts  #TC=Y    ReqTime    w/Prob
--------------------------------------------------------
GO              309     907   117     40085.49  40085.49
LP               28     160     4     15678.20  15678.20
TOO              71     126    41      7998.70   4618.88
TOO/LP            1       2     0       600.00     60.00
VLP               9     208     5     16835.00  16835.00
ARCHIVE          56       0     0      4407.02      0.00
THEORY           43       0     0      3473.40      0.00
                ---    ----   ---    --------- ---------
                517    1403   167     81197.39  77277.57

                 Approved 
#Prop   #Tgts  #TC=Y    AppTime    w/Prob Units
-------------------------------------------------
  91     278    44     10551.70  10551.70  ksec
   5       6     0      2889.00   2889.00  ksec
  34      49    11      3178.50   1448.05  ksec
   1       2     0       600.00     60.00  ksec
   1       1     0      2100.00   2100.00  ksec
  15       0     0      1065.30      0.00  1000 US dollars
   7       0     0       597.00      0.00  1000 US dollars
 ---    ----   ---    --------- ---------
 154     336    55     19319.20  17048.75

Multicycle Proposals

Requested Type #Prop Cycle 23 Cycle 24 Cycle 25 -------------------------------------------------- GO 9 594.60 700.40 447.50 LP 1 150.00 150.00 150.00 TOO 2 430.00 235.00 0.00 ----- --------- --------- --------- 12 1174.60 1085.40 597.50

Approved #Prop Cycle 23 Cycle 24 Cycle 25 ------------------------------------ 5 334.60 440.40 247.50 2 430.00 235.00 0.00 ----- --------- --------- --------- 7 764.60 675.40 247.50

2. Proposals by Subject Category
#Props includes Archive/Theory proposals.

                                                    Requested 
Category                                   #Prop   #Tgts     ReqTime     w/Prob
-------------------------------------------------------------------------------
SOLAR SYSTEM AND EXOPLANETS                    6      19      1116.00   1116.00
STARS AND WD                                  49      64      6148.00   6044.50
WD BINARIES AND CV                             7      11       540.00    442.50
BH AND NS BINARIES                            64     100      5728.00   4565.78
SN, SNR AND ISOLATED NS                       64     121      8753.50   7735.40
GRAVITATIONAL WAVE EVENT                       6       7      1550.00    977.00
NORMAL GALAXIES: DIFFUSE EMISSION             19      13      2515.50   2515.50
NORMAL GALAXIES: X-RAY POPULATIONS            29     244      5039.00   5030.00
ACTIVE GALAXIES AND QUASARS                  170     678     30051.81  29151.56
CLUSTERS OF GALAXIES                          82     116     14596.58  14596.58
EXTRAGALACTIC DIFFUSE EMISSION AND SURVEYS     6       6      2409.00   2409.00
GALACTIC DIFFUSE EMISSION AND SURVEYS         15      24      2750.00   2693.75
                                             ---    ----    --------- ---------
                                             517    1403     81197.39  77277.57

           Approved 
  #Prop   #Tgts    AppTime    w/Prob
  ----------------------------------
    1       1        60.00     60.00
   14      23      1137.00   1137.00
    2       4       105.00     52.50
   26      28      1644.00    857.40
   20      38      1846.50   1582.90
    2       3       840.00    408.00
    9       8       823.50    823.50
    9      19      1019.00   1010.00
   51     178      9067.50   8397.00
   16      31      2381.70   2381.70
    0       0         0.00      0.00
    4       3       395.00    338.75
  ---    ----     --------  --------
  154     336     19319.20  17048.75

Multicycle Proposals

Requested Category #Prop Cycle 23 Cycle 24 Cycle 25 ------------------------------------------------------------------------------ ACTIVE GALAXIES AND QUASARS 2 63.60 69.40 76.50 BH AND NS BINARIES 1 90.00 35.00 0.00 GRAVITATIONAL WAVE EVENT 2 440.00 400.00 0.00 NORMAL GALAXIES: X-RAY POPULATIONS 1 40.00 40.00 40.00 SN, SNR AND ISOLATED NS 1 148.00 148.00 148.00 STARS AND WD 5 393.00 393.00 333.00 ----- --------- --------- --------- 12 1174.60 1085.40 597.50

Approved #Prop Cycle 23 Cycle 24 Cycle 25 ----------------------------------- 2 63.60 69.40 76.50 1 90.00 35.00 0.00 2 440.00 400.00 0.00 1 148.00 148.00 148.00 1 23.00 23.00 23.00 --- --------- --------- --------- 7 764.60 675.40 247.50

3. Targets,Exposure Time by Detector

                                Requested
Detector  Grating    #Tgts      Time    w/Prob
----------------------------------------------
ACIS-I    NONE         189  27591.87  27454.87
ACIS-S    HETG          37   5951.00   5295.80
ACIS-S    NONE        1123  43951.52  40897.90
HRC-I     NONE          32   1719.00   1712.50
HRC-S     LETG          11   1567.00   1499.50
HRC-S     NONE          11    417.00    417.00
                      ---- --------- ---------
                      1403  81197.39  77277.57

            Approved
 #Tgts      Time    w/Prob
--------------------------
    44   5613.20   5476.20
    13   1522.00   1205.00
   267  11466.00   9717.05
     7    374.00    374.00
     4    287.00    219.50
     1     57.00     57.00
  ----  --------  --------
   336  19319.20  17048.75

4. Targets by Exposure Time Range

            Requested
Time            #Tgts
---------------------
   0>=T<2            7
   2>=T<4           88
   4>=T<8          337
   8>=T<16         251
  16>=T<32         240
  32>=T<64         196
  64>=T<128        140
 128>=T<400        113
 400>=T<1000        25
1000>=T<10000        6

5. Proposals by Exposure Time Range

            Requested
Time            #Prop
---------------------
   0>=T<2            0
   2>=T<4            1
   4>=T<8            1
   8>=T<16           9
  16>=T<32          18
  32>=T<64          75
  64>=T<128        121
 128>=T<400        151
 400>=T<1000        33
1000>=T<10000        9

6. Number of Proposals per P.I.

   Requested
#Prop   #P.I.
-------------
  1       306
  2        62
  3        17
  4         6
  6         2

 Approved
     #P.I.
 ---------
     113
      14
       3
       1

7. Proposals by Country

                       Requested
Country         #Prop       Time    w/Prob
------------------------------------------
ARGENTINA         1        60.00     60.00
BELGIUM           2        72.00     72.00
BULGARIA          1       100.00    100.00
CANADA            7      2028.00   2028.00
CHILE             1        91.00     91.00
CHINA             5      1053.80   1053.80
FRANCE            2       260.00    134.00
GERMANY          13      1646.20   1441.80
GREECE            1       100.00    100.00
HONG KONG         1        85.00     85.00
INDIA             7       629.00    621.00
ITALY            39      8114.00   7930.00
JAPAN             9       931.00    847.00
KOREA, SOUTH      2       230.00    230.00
MEXICO            1       100.00    100.00
NETHERLANDS       9      1454.00   1234.40
POLAND            2       110.00    110.00
RUSSIA            1        50.00     50.00
SLOVAKIA          1       105.00    105.00
SPAIN             4       505.00    505.00
SWEDEN            1        60.00     60.00
SWITZERLAND       1       100.00    100.00
TAIWAN            4       425.00    425.00
TURKEY            2       175.00    175.00
UNITED ARAB EMI   1        12.00      2.40
UNITED KINGDOM   12      3097.00   3019.50
USA             387     59604.39  56597.67


Total Foreign   130     21593.00  20679.90

             Approved
    #Prop         Time     w/Prob
    -----------------------------
        1        60.00     60.00
        2        72.00     72.00
        1       100.00    100.00
        2        90.00     90.00

        1        50.00     50.00
        1       150.00     24.00
        5       654.00    560.00


        1        78.00     78.00
       13      2323.00   2178.00
        1        80.00     80.00


        1       180.00     90.00



        1       240.00    240.00





        1        80.00     80.00
      123     15162.20  13346.75


       31      4157.00   3702.00

10.14.2 Tuesday, September 16, 2025
The Chandra X-Ray Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA. Email: cxchelp@cfa.harvard.edu Smithsonian Institution, Copyright © 1998-. All rights reserved.