P. Fagrelius

Confirmation of a Star Formation Bias in Type Ia Supernova Distances and its Effect on the Measurement of the Hubble Constant

Previously we used the Nearby Supernova Factory sample to show that SNe~Ia having locally star-forming environments are dimmer than SNe~Ia having locally passive environments.Here we use the \constitution\ sample together with host galaxy data from \GALEX\ to independently confirm that result. The effect is seen using both the SALT2 and MLCS2k2 lightcurve fitting and standardization methods, with brightness differences of

UNITY: CONFRONTING SUPERNOVA COSMOLOGY’S STATISTICAL AND SYSTEMATIC UNCERTAINTIES IN A UNIFIED BAYESIAN FRAMEWORK

0.094 \pm 0.037\ \mathrm{mag}

The Extinction Properties of and Distance to the Highly Reddened Type IA Supernova 2012cu

for SALT2 and

Correcting for peculiar velocities of Type Ia Supernovae in clusters of galaxies

0.155 \pm 0.041\ \mathrm{mag}

Understanding type Ia supernovae through their U-band spectra

for MLCS2k2 with

SCALA: In situ calibration for integral field spectrographs

R_V=2.5

Fusion splicing: a novel approach to fiber connections for the Dark Energy Spectroscopic Instrument

. When combined with our previous measurement the effect is

Optical fiber termination method for the Dark Energy Spectroscopic Instrument (DESI)

0.094 \pm 0.025\ \mathrm{mag}

Fiber system design for the Dark Energy Spectroscopic Instrument (DESI)

for SALT2. If the ratio of these local SN~Ia environments changes with redshift or sample selection, this can lead to a bias in cosmological measurements. We explore this issue further, using as an example the direct measurement of

IMPROVING COSMOLOGICAL DISTANCE MEASUREMENTS USING TWIN TYPE IA SUPERNOVAE

H_0