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:
29319
 Title:
DEFINING A BONA FIDE SAMPLE OF INTERMEDIATE-MASS BLACK HOLES:X-RAY CONFIRMATION OF OPTICALLY SELECTED AGN CANDIDATES
Investigator:
Chilingarian
 Observer:
Chilingarian, Igor
 Phone:
6174957425
 Email:
igor.chilingarian@cfa.harvard.edu
Target Name:
SDSSJ111551.95-000439.3
 Sequence Number:
705170
 Instrument:
ACIS-S
 Grating:
NONE
 SI Mode:
TE_0057A
 Raster Scan:
N
 Annotated DOT:
MAR1124a

Proposal Number:
20701072
 Right Ascension:
168.966
 Declination:
-0.077578
 Status:
archived
 Start Date:
2024-03-15 18:37:26
Category:
ACTIVE GALAXIES AND QUASARS
 Type:
CCT
 AO Cycle:
20
 Dither Flag:
Y
 Y Offset:
0
 Z Offset:
0
Est. Count Rate:
0.0026
 Order-1 Count Rate:

 Exposure Time:
10
 Time Remaining:
10.443
 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:
X-ray confirmation of a population of intermediate black holes (IMBHs) will allow us to solve one of the long-standing problems in modern astrophysics, the origin of supermassive black holes (SMBHs). Using dedicated analysis of 1 million optical spectra, we identified a sample of 305 IMBH candidates (3x10^4 < Mbh < 2x10^5 Msun), which reside in galaxy centers and appear as active galactic nuclei (AGN). They are evenly distributed across the SDSS DR7 footprint. With XMM- Newton and Chandra DDT observations in 2017 and mining X-ray data archives, we confirmed the AGN nature of ten candidates, thus validating our IMBH search approach. We propose 270 optically selected IMBH candidates as Chandra Cool Attitude Targets, with the aim to increase the number of X-ray confirmed accreting IMBHs by a factor of 10. Even if only 10% of the list gets observed, the sample of known IMBH will double. This will enable detailed statistical studies of the IMBH population and help to constrain the masses of 'seed' black holes in the early Universe.

Remarks:
N/A

psci Run:
14
 Processing Date:
Jul 18 2024
 psci Directory:
/nfs/maaxnew/r3/fm/acis127a/acis127.log
OBSID:
29319
 SIM Mode:
ACIS-S
 OTG Mode:
NONE
 Seq Number:
705170
 Target Name:
SDSSJ111551.95-
 AO:
20
Start VCDU:
116820:064
 Start Time (UTC):
075:68926.508
 Stop Time (UTC):
075:79381.531
 Kilosecs:
10.5
 % Frames:
100.0
 # CCDs:
S2
# Frames:
3438
 # Events:
106618
 Events/sec:
10
 PSCI errors:
0
 % drops:
0.1
 Bias Errs:
0
 FP Temp:
-116.1
Parameter Block:
0x0057b034
 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?:
No
 Trickle?:
Yes
 Bias Run:
12

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