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:
27932
 Title:
FINDING TYPE IA SUPERNOVA PROGENITORS AMONG THE SYMBIOTIC STARS   
Investigator:
Luna
 Observer:
Luna, Gerardo Juan Manuel
 Phone:
542615916349
 Email:
gjmluna@iafe.uba.ar
Target Name:
Hen 2-374
 Sequence Number:
300549
 Instrument:
ACIS-S
 Grating:
NONE
 SI Mode:
TE_005C6B
 Raster Scan:
N
 Annotated DOT:
JUN2623a

Proposal Number:
20301068
 Right Ascension:
273.879
 Declination:
-21.5897
 Status:
archived
 Start Date:
2023-06-28 08:56:31
Category:
WD BINARIES AND CV
 Type:
CCT
 AO Cycle:
20
 Dither Flag:
Y
 Y Offset:
0
 Z Offset:
0
Est. Count Rate:
0.002
 Order-1 Count Rate:

 Exposure Time:
13.3
 Time Remaining:
12.406
 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:
At least some symbiotic binaries, in which a white dwarf (WD) accretes from the wind of a red-giant companion, end their lives as type Ia supernovae (SNIa). But which ones and how many of them are in our Galaxy? Those symbiotics with the highest accretion rate should be the best candidates. During the last few years, our group has found that X-ray emission can be used to estimate the accretion rate onto the WD, a quantity that has been elusive to observations in other wavelengths. We propose that 300 of these objects, 130 already known as symbiotics and 170 new candidates, be used as Chandra Cool-Attitude targets. Because of its X-ray sensitivity and low X-ray background, Chandra can provide a comprehensive survey of the X-ray properties of symbiotic stars.

Remarks:
N/A

psci Run:
357
 Processing Date:
Jul 25 2023
 psci Directory:
/nfs/maaxnew/r3/fj/acis124e/acis124.log
OBSID:
27932
 SIM Mode:
ACIS-S
 OTG Mode:
NONE
 Seq Number:
300549
 Target Name:
Hen_2-374
 AO:
20
Start VCDU:
83556:032
 Start Time (UTC):
179:33428.037
 Stop Time (UTC):
179:45850.775
 Kilosecs:
12.4
 % Frames:
100.0
 # CCDs:
S3
# Frames:
3955
 # Events:
218217
 Events/sec:
17
 PSCI errors:
0
 % drops:
0.0
 Bias Errs:
0
 FP Temp:
-117.0
Parameter Block:
0x005c6024
 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:
357

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