Wide-Field Slitless Spectroscopy

We are creating methods to enhance studies on transients and SNe Ia. This is the foundational element of our deliverables and includes several components.

• Using linear reconstruction, we can remove self-contamination from the host galaxy.

  • This method can provide contamination-free spectra by inverting the linear system of equations that describes the collection of WFSS images.

  • This method can also be extended by decomposing the host galaxy into separate sub-regions. This will then provide a 3D flux cube for the host galaxy and then subtract its contribution to the 2D WFSS images.

• Subtract local background

  • In cases where multiple spectral orients are not feasible, we can use a local sky subtraction technique with parametric models that interpolate between regions that are near the primary trace.

  • This method requires much less data and is much faster than other methods.

• Extract and model the 1D transient spectra

  • Using the above methods, we are able to remove host-galaxy contribution in the 2D spectroscopic images which allow us to extract the spectrum of the transient.

  • These spectra are used to classify the transient and determine its redshift.

  • We will use a specialized procedure to subtract the galaxy contribution with minimized biases.

• Physically model the host galaxy

  • In cases where local background subtraction is not feasible, we will model the SED of the host and estimate the host-galaxy contribution so that we can extract the SN spectrum.

• Analyze the observed data and validate the simulations and algorithms

  • We will analyze the first-year data and compare that to our simulations. We will then re-calibrate the previous methods with respect to the cycle 1 observations to reduce systematic biases.