Strategies to identify strongly lensed type Ia supernovae in Rubin LSST
Prajakta Mane
Final year, Integrated BS-MS,
Indian Institute of Science Education and Research (IISER) Mohali, India
Joint SLSC/DESC-SL Telcon
Anupreeta More, Surhud More
Inter-University Centre for Astronomy and Astrophysics (IUCAA), India
April 17, 2024
Time delay cosmography:
accurate time delays, surface mass distribution and redshift of lens
Hubble constant with strong lensing time delays
well-constrained Hubble Constant
Why are SNe Ia a better source for TDC?
well-studied light curves -> more accurate time delay measurements
transient source -> improved constraints on the lens galaxy model
standard candle nature -> help overcome degeneracies
How to find lensed SNe Ia?
DIA: run LSST Stack's difference imaging pipeline to identify multiply imaged SNe
CMA: study outliers in the colour-magnitude space for SNe to identify lensed SNe Ia
SNe light curve simulations
Sky data for DIA
Difference imaging analysis
Template Image
Science Image
Difference Image
Difference imaging analysis
Preliminary results
Template Image
Science Image
Difference Image
Yellow circles of radius 1": injected lensed SNe
Red circles of radius 2": diaSources
Difference imaging analysis
Injected | Detected | % recovery | |
---|---|---|---|
Total | 74k | 51.5k | 70 |
Doubles | 70k | 48.3k | 70 |
Quads | 4.1k | 3.2k | 78 |
g | 310 | 260 | 83 |
r | 5.4k | 4.7k | 86 |
i | 14k | 11k | 80 |
z | 21k | 16k | 76 |
y | 34k | 20k | 58 |
Lens system level analysis:
Is there a diaSource within the radius of 3" from each lens center in each epoch?
Difference imaging analysis
Preliminary results
Recovery fraction variation with injected unresolved magnitude for each band
Lens system level analysis
Difference imaging analysis
Preliminary results
Individual image level analysis:
How many unique diaSources were found corresponding to each lens system?
A single diaSource for entire system: Pipeline could not resolve the system (DUR): ~49k
Two or more diaSources for a system: Pipeline could resolve the system (DR): 1285
Doubles
Quads
vertical dashed line: median seeing
Difference imaging analysis
Preliminary results
Color-magnitude analysis
Quimby et al. 2014
: Unlensed SNIa
: Unlensed core collapse
: Lensed SNIa
: Lensed core collapse
The redder supernovae for given i-band magnitude are more likely to be lensed SNeIa when studied for unresolved photometry on rising phase of light curve.
The black bold curve separates the lensed SNeIa from unlensed both on the rising and the falling edge of light curve for z < 2.4
The criteria hold well for the observed unlensed and lensed SNeIa.
Contamination from unlensed SNe is neglegible.
Contamination from CC SNe
Color-magnitude analysis
Contamination from unlensed SNe is neglegible.
Contamination from CC SNe
Color-magnitude analysis
Primary contaminants are lensed SNe Ib and Ic.
Summary so far...
Ongoing work
Yellow circles of radius 1": injected lensed SNe
Red circles of radius 2": diaSources
Quad system
Difference imaging analysis
Preliminary results
Template Image
Science Image
Difference Image
Quadruply-imaged SN Ia
Max. separation: 2.78"
Total UR magnitude: 18.23
Template Image
Science Image
Difference Image
Yellow circles of radius 1": injected lensed SNe
Red circles of radius 2": diaSources
double system
Difference imaging analysis
Preliminary results
Extra slides
Extra slides
Extra slides
Extra slides
Difference imaging analysis
Resolved fraction with respect to median seeing of each band
Individual image level analysis:
Difference imaging analysis
Resolved fraction with respect to median seeing of each band
some trend
Individual image level analysis
Difference imaging analysis
Resolved fraction with respect to median seeing of each band
no trend
Individual image level analysis
Comaparison of unlensed CC SNe CMDs from low and high redshift
PRJ 501: Recap
Quimby et al. 2014
PRJ 502