Speaker
Description
With the upcoming start of Rubin Observatory Legacy Survey of Space and Time
(LSST), we expect to detect hundreds to thousands of strongly lensed supernovae,
which can be used for time-delay cosmography.
As part of the HOLISMOKES program, we focus on developing methods to measure time delays of strongly lensed type II supernovae (SNe II) to determine the Hubble Constant.
In my talk, I will present two methods of retrieving time delays from lensed SN II.
The first one uses spectra with which we can measure the time delay with an uncertainty of <1 day using multiple spectral lines. For this, we also investigated microlensing effects, which can be neglected in the early phases of the type IIP spectra as they are mostly achromatic at that phase.
I will also present our most recent work, using photometric data to determine the
time delays. The SN IIP color curves show a kink structure around 35 days
after the explosion, which is used as an anchor to retrieve a change in color and the temporal shift of color curves between two lensing images. We can retrieve time delays and differential extinction coefficients using this feature.
| Abstract title | Time-delay cosmography with strongly lensed type II supernovae |
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