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OBSID:
24291
 Title:
The superfluid properties of dense neutron star cores     
Investigator:
Degenaar
 Observer:
Degenaar, Nathalie
 Phone:
+31 20 525 3994
 Email:
degenaar@uva.nl
Target Name:
hete j1900.1-2455
 Sequence Number:
402202
 Instrument:
ACIS-S
 Grating:
NONE
 SI Mode:
TE_00914B
 Raster Scan:
N
 Annotated DOT:
JUL1221a

Proposal Number:
22400191
 Right Ascension:
285.036
 Declination:
-24.9205
 Status:
archived
 Start Date:
2021-07-15 01:42:01
Category:
BH AND NS BINARIES
 Type:
GO
 AO Cycle:
22
 Dither Flag:
Y
 Y Offset:
0
 Z Offset:
0
Est. Count Rate:
0.0001
 Order-1 Count Rate:

 Exposure Time:
28
 Time Remaining:
28.089
 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:
VF
On-Chip Summing?:
No
 Row Sum:

 Column Sum:

 Frame Time:
Subarray Mode:
NONE
 Starting Row:
0
 Row Count:
1023
 Subarray Frame Time:

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

 Secondary Exp Time:
Event Filter?:
No
 Filter Threshold:

 Filter Range:

 Bias Requested?:
No
 Bias Frequency:

 Bias After?:
No
 Spatial Window?:
No

Abstract:
It is expected that the ultra-dense core of a neutron star is superfluid. While being a key ingredient for understanding many observable properties of neutron stars, including the long-term evolution of their temperature, spin, and magnetic field, we have no detailed information about the core superfluid. We propose a 500 ks Chandra observation of the transient low-mass X-ray binary HETE J1900.1-2455 to obtain such important constraints. Our 2018 Chandra observation revealed that this neutron star is exceptionally cold, despite actively accreting from 2005 to 2015. With a new deep exposure we will accurately measure its temperature and constrain its heat capacity. This, in turn, determines what fraction of the core is superfluid. We will also directly test equation of state models.

psci Run:
162
 Processing Date:
Jul 25 2021
 psci Directory:
/nfs/maaxnew/r3/fb/acis116c/acis116.log
OBSID:
24291
 SIM Mode:
ACIS-S
 OTG Mode:
NONE
 Seq Number:
402202
 Target Name:
hete_j1900.1-24
 AO:
22
Start VCDU:
45613:104
 Start Time (UTC):
196:07123.301
 Stop Time (UTC):
196:35225.367
 Kilosecs:
28.1
 % Frames:
100.0
 # CCDs:
S1
# Frames:
9241
 # Events:
268935
 Events/sec:
9
 PSCI errors:
0
 % drops:
0.0
 Bias Errs:
0
 FP Temp:
-117.8
Parameter Block:
0x00914014
 Window Block:
-
 # Windows:
0
 FEP Mode:
Te5x5
 BEP Mode:
F
 Start Row:
0
 # Rows:
1024
Primary Exposure:
30
 Secondary Exposure:
0
 Duty Cycle:
0
 Summing?:
No
 Bias?:
Yes
 Trickle?:
Yes
 Bias Run:
162

pgf@space.mit.edu Wed Mar 26 10:00:48 EST 2025