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OBSID:
26251
 Title:
X-ray Properties of High-redshift Close Dual Quasars Discovered by Gaia and HST 
Investigator:
Liu
 Observer:
Liu, Xin
 Phone:
2172658073
 Email:
xinliuxl@illinois.edu
Target Name:
SDSS J074800.54+314647.6
 Sequence Number:
704431
 Instrument:
ACIS-S
 Grating:
NONE
 SI Mode:
TE_006BEB
 Raster Scan:
N
 Annotated DOT:
DEC2721b

Proposal Number:
23700377
 Right Ascension:
117.002
 Declination:
31.7799
 Status:
archived
 Start Date:
2021-12-27 15:20:44
Category:
ACTIVE GALAXIES AND QUASARS
 Type:
GO
 AO Cycle:
23
 Dither Flag:
Y
 Y Offset:
0
 Z Offset:
0
Est. Count Rate:
0.009
 Order-1 Count Rate:

 Exposure Time:
16
 Time Remaining:
16.058
 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
 Dropped Chip Count:
0
 Optional Chips:
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?:
No
 Filter Threshold:

 Filter Range:

 Bias Requested?:
No
 Bias Frequency:

 Bias After?:
No
 Spatial Window?:
No

Abstract:
Dual quasars are expected to be common, yet no <10 kpc case is known in the cosmic noon z~1-3 when quasar activity and star formation peaked. We propose ACIS-S imaging for four Type 1 dual quasars at z~1-3, probing a new parameter space at higher redshift and smaller separations than previous work. We select targets from a new astrometric technique: when two quasars vary stochastically, their combined centroid shifts and is detected by Gaia. HST imaging has uncovered ~0.5"-0.6" double cores ideally matched to Chandra. The proposed observations will confirm the targets as dual quasars and characterize their X-ray properties. The results will empirically constrain the black hole merger rate at the epoch when quasar activity and star formation peaked to inform galaxy and black hole evolution.

psci Run:
172
 Processing Date:
Dec 30 2021
 psci Directory:
/nfs/maaxnew/r3/fd/acis118c/acis118.log
OBSID:
26251
 SIM Mode:
ACIS-S
 OTG Mode:
NONE
 Seq Number:
704431
 Target Name:
SDSS_J074800.54
 AO:
23
Start VCDU:
88513:072
 Start Time (UTC):
361:56260.676
 Stop Time (UTC):
361:72330.214
 Kilosecs:
16.1
 % Frames:
100.0
 # CCDs:
I5
# Frames:
5116
 # Events:
714458
 Events/sec:
44
 PSCI errors:
0
 % drops:
0.0
 Bias Errs:
0
 FP Temp:
-118.5
Parameter Block:
0x006be034
 Window Block:
-
 # Windows:
0
 FEP Mode:
Te3x3
 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:
172

pgf@space.mit.edu Mon Mar 31 10:36:39 EST 2025