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OBSID:
26655
 Title:
Monitoring the thermal evolution of the Cas A CCO      
Investigator:
Posselt
 Observer:
Posselt, Bettina
 Phone:
+447943944524
 Email:
posselt@psu.edu
Target Name:
CXOU J232327.8+584842
 Sequence Number:
503415
 Instrument:
ACIS-S
 Grating:
NONE
 SI Mode:
TE_00AD6B
 Raster Scan:
N
 Annotated DOT:
DEC2622a

Proposal Number:
24500364
 Right Ascension:
350.867
 Declination:
58.8118
 Status:
archived
 Start Date:
2022-12-30 03:17:35
Category:
SN, SNR AND ISOLATED NS
 Type:
GO
 AO Cycle:
24
 Dither Flag:
Y
 Y Offset:
-1.3
 Z Offset:
0
Est. Count Rate:
0.065
 Order-1 Count Rate:

 Exposure Time:
30
 Time Remaining:
30.097
 Reqd Start Time:

 Reqd Stop Time:
Period:

 Epoch:

 Start of Period:

 End of Period:

 PS Margin:

 PE Margin:

 Max Segments:
0

ACIS Mode:
TE
 Standard?:
No
 BEP Mode:
F
On-Chip Summing?:
No
 Row Sum:

 Column Sum:

 Frame Time:
Subarray Mode:
CUSTOM
 Starting Row:
385
 Row Count:
256
 Subarray Frame Time:

Duty Cycle?:
No
 Cycle Count:
0
 Primary Exp Time:

 Secondary Exp Time:
Event Filter?:
Yes
 Filter Threshold:
0.24
 Filter Range:
10
 Bias Requested?:
No
 Bias Frequency:

 Bias After?:
No
 Spatial Window?:
No

Abstract:
Previous studies of the young (340 yr) Central Compact Object (CCO) in the Cas A supernova remnant resulted in a reported decrease of the CCO's surface temperature by about 2% in 10 years. However, the actual rate of this exceptional cooling is still uncertain as the most recent data hint at a puzzling difference between cooling trends in early and later years. In order to constrain the cooling rate more accurately, we propose to continue the monitoring of the thermal evolution of this neutron star. The legacy time series of the Cas A CCO provides a crucial checkpoint for theoretical models concerning the properties of the neutron star interior.

psci Run:
337
 Processing Date:
Jan 3 2023
 psci Directory:
/nfs/maaxnew/r3/fh/acis122e/acis122.log
OBSID:
26655
 SIM Mode:
ACIS-S
 OTG Mode:
NONE
 Seq Number:
503415
 Target Name:
CXOU_J232327.8+
 AO:
24
Start VCDU:
49205:032
 Start Time (UTC):
364:12690.980
 Stop Time (UTC):
364:42792.624
 Kilosecs:
30.1
 % Frames:
100.0
 # CCDs:
S2
# Frames:
31988
 # Events:
2952276
 Events/sec:
98
 PSCI errors:
0
 % drops:
0.0
 Bias Errs:
0
 FP Temp:
-118.6
Parameter Block:
0x00ad6014
 Window Block:
-
 # Windows:
0
 FEP Mode:
Te3x3
 BEP Mode:
F
 Start Row:
384
 # Rows:
256
Primary Exposure:
9
 Secondary Exposure:
0
 Duty Cycle:
0
 Summing?:
No
 Bias?:
Yes
 Trickle?:
Yes
 Bias Run:
337

pgf@space.mit.edu Fri Apr 11 21:41:30 EST 2025