C H A N D R A   S C I E N C E   C E N T E R
O B S E R V A T I O N   C A T A L O G

OBSID:
25766
 Title:
Revealing layers of enhanced magnetic field in ICM via X-ray imaging  
Investigator:
Markevitch
 Observer:
Markevitch, Maxim
 Phone:
301-286-5947
 Email:
maxim.markevitch@nasa.gov
Target Name:
A1068
 Sequence Number:
801971
 Instrument:
ACIS-S
 Grating:
NONE
 SI Mode:
TE_0046EB
 Raster Scan:
N
 Annotated DOT:
MAY0123a

Proposal Number:
23800485
 Right Ascension:
160.186
 Declination:
39.9531
 Status:
archived
 Start Date:
2023-05-07 15:19:08
Category:
CLUSTERS OF GALAXIES
 Type:
GO
 AO Cycle:
23
 Dither Flag:
Y
 Y Offset:
0
 Z Offset:
0
Est. Count Rate:
0.5
 Order-1 Count Rate:

 Exposure Time:
35.5
 Time Remaining:
32.189
 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
 Dropped Chip Count:
0
 Optional Chips:
I2 I3 S1
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?:
Yes
 Filter Threshold:
0.24
 Filter Range:
13
 Bias Requested?:
No
 Bias Frequency:

 Bias After?:
No
 Spatial Window?:
No

Abstract:
The recently discovered low-contrast "channels" in Chandra images of several clusters may represent the first cluster examples of plasma depletion layers (PDL). They are expected to form when the weak and tangled magnetic field in the ICM is stretched and amplified by a gas flow with strong velocity shear (such as at a cold front), squeezing the plasma out and resulting in filamentary X-ray depressions. PDL may become a new and valuable tool for studying the intracluster plasma by allowing us literally to see the structure of the intracluster magnetic field. The survival of such structures would also constrain turbulence. We propose detailed imaging of the cluster A1068, a newly found striking example of this new phenomenon.

psci Run:
143
 Processing Date:
May 15 2023
 psci Directory:
/nfs/maaxnew/r3/fj/acis124b/acis124.log
OBSID:
25766
 SIM Mode:
ACIS-S
 OTG Mode:
NONE
 Seq Number:
801971
 Target Name:
A1068
 AO:
23
Start VCDU:
78349:096
 Start Time (UTC):
127:56548.400
 Stop Time (UTC):
128:02350.106
 Kilosecs:
32.2
 % Frames:
100.0
 # CCDs:
I5
# Frames:
10252
 # Events:
966754
 Events/sec:
30
 PSCI errors:
0
 % drops:
0.0
 Bias Errs:
0
 FP Temp:
-115.5
Parameter Block:
0x0046e034
 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:
143

pgf@space.mit.edu Sat Mar 29 10:37:19 EST 2025