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OBSID:
27597
 Title:
DISCOVERING AXIONS WITH X-RAY SEARCHES TOWARDS MAGNETIC WHITE DWARFS  
Investigator:
Safdi
 Observer:
Safdi, Benjamin R.
 Phone:
5136042373
 Email:
brsafdi@berkeley.edu
Target Name:
WD 1859+148
 Sequence Number:
201558
 Instrument:
ACIS-I
 Grating:
NONE
 SI Mode:
TE_00D4EB
 Raster Scan:
N
 Annotated DOT:
DEC0522a

Proposal Number:
24200244
 Right Ascension:
285.386
 Declination:
14.9687
 Status:
archived
 Start Date:
2022-12-10 10:33:10
Category:
STARS AND WD
 Type:
GO
 AO Cycle:
24
 Dither Flag:
Y
 Y Offset:
0
 Z Offset:
0
Est. Count Rate:
0.0001134
 Order-1 Count Rate:

 Exposure Time:
10
 Time Remaining:
10.115
 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:
Axions, which are hypothetical ultra-light particles, are a well-motivated extension to the Standard Model of particle physics. White dwarf (WD) stars may radiate keV-energy axions produced in their stellar cores. This has been studied as a channel by which WDs may cool, with some analyses suggesting that axions can help explain the WD luminosity function. The radiated axions may convert into X-rays in the magnetic fields surrounding magnetic WDs (MWDs). We propose two 40 ks observations of the MWDs WD 1859+148 and PG 0945+246. In the absence of axions we will set the strongest limits to-date on the axion coupling strength and disfavor nearly all of the parameter space for axions predicted by string theory.

psci Run:
255
 Processing Date:
Dec 14 2022
 psci Directory:
/nfs/maaxnew/r3/fh/acis122d/acis122.log
OBSID:
27597
 SIM Mode:
ACIS-I
 OTG Mode:
NONE
 Seq Number:
201558
 Target Name:
WD_1859+148
 AO:
24
Start VCDU:
128401:008
 Start Time (UTC):
344:39278.887
 Stop Time (UTC):
344:49405.479
 Kilosecs:
10.1
 % Frames:
100.0
 # CCDs:
I1
# Frames:
3330
 # Events:
60608
 Events/sec:
5
 PSCI errors:
0
 % drops:
0.0
 Bias Errs:
0
 FP Temp:
-112.0
Parameter Block:
0x00d4e014
 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:
255

pgf@space.mit.edu Thu Apr 3 20:00:53 EST 2025