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OBSID:
28687
 Title:
A detailed view of the rare large scale sloshing cold front in the outskirts of Abell 85
Investigator:
Walker
 Observer:
Walker, Stephen
 Phone:
3016553628
 Email:
saw0041@uah.edu
Target Name:
A85 North
 Sequence Number:
802144
 Instrument:
ACIS-I
 Grating:
NONE
 SI Mode:
TE_006E6B
 Raster Scan:
N
 Annotated DOT:
OCT0724a

Proposal Number:
25800211
 Right Ascension:
10.4449
 Declination:
-9.1132
 Status:
observed
 Start Date:
2024-10-06 22:52:34
Category:
CLUSTERS OF GALAXIES
 Type:
GO
 AO Cycle:
25
 Dither Flag:
Y
 Y Offset:
0
 Z Offset:
0
Est. Count Rate:
9
 Order-1 Count Rate:

 Exposure Time:
12
 Time Remaining:
11.721
 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:
Large scale sloshing cold fronts reaching out to half the viral radius are extremely rare, and have been observed in only a handful of clusters. We propose a 170ks observation of the 600kpc radius cold front in the outskirts of Abell 85. The existing brief 10ks Chandra observation shows tantalizing suggestions of complex structure, including a feature which may be a giant Kelvin-Helmholtz roll, which only deeper Chandra observations can resolve. These rare systems provide a unique way to test our understanding of how cold fronts are supported against instabilities as they expand outwards, and provide powerful tests of simulations of magnetic draping.

psci Run:
299
 Processing Date:
Oct 19 00:25
 psci Directory:
/nfs/maaxnew/r3/fn/acis128d/acis128.log
OBSID:
28687
 SIM Mode:
ACIS-I
 OTG Mode:
NONE
 Seq Number:
802144
 Target Name:
A85_North
 AO:
25
Start VCDU:
1864:088
 Start Time (UTC):
280:83265.391
 Stop Time (UTC):
281:08600.327
 Kilosecs:
11.7
 % Frames:
100.0
 # CCDs:
I4
# Frames:
3736
 # Events:
149175
 Events/sec:
12
 PSCI errors:
0
 % drops:
0.0
 Bias Errs:
0
 FP Temp:
-111.8
Parameter Block:
0x006e6034
 Window Block:
-
 # Windows:
0
 FEP Mode:
Te5x5
 BEP Mode:
F
 Start Row:
0
 # Rows:
1024
Primary Exposure:
31
 Secondary Exposure:
0
 Duty Cycle:
0
 Summing?:
No
 Bias?:
Yes
 Trickle?:
Yes
 Bias Run:
299

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