SN 2010kd: Photometric and Spectroscopic Analysis of a Slow-decaying Superluminous Supernova

This paper presents data and analysis of SN 2010kd, a low-redshift (z = 0.101) H-deficient superluminous supernova (SLSN), based on ultraviolet/optical photometry and optical spectroscopy spanning between curve comparison of SN 2010kd with a subset of well-studied SLSNe I at comparable redshifts indicates that it is a slow-decaying PTF12dam-like SLSN. Analytical light-curve modeling using the Minim code suggests that the bolometric light curve of SN 2010kd favors circumstellar matter phase spectra does not identify broad H or He lines, whereas the photospheric-phase spectra are dominated by O I, O II, C II, C IV, and Si II, in particular the presence of both low- and high-velocity components of O II and Si II lines. The nebular-phase spectra of SN 2010kd are dominated by O I and Ca II emission lines similar to those seen in other SLSNe I. The line velocities in SN 2010kd exhibit flatter evolution curves similar to SN 2015bn but with comparatively higher values. SN 2010kd shows a higher single-zone local thermodynamic equilibrium temperature in comparison to PTF12dam and SN 2015bn, and it has an upper O I ejected mass limit of ∼10 M☉. The host of SN 2010kd is a dwarf galaxy with a high star formation rate (∼0.18 ± 0.04 M☉ yr-1) and extreme emission lines

Cosmological Distance Measurement of 12 Nearby Supernovae IIP with ROTSE-IIIB

We present cosmological analysis of 12 nearby ($z<0.06$) Type IIP supernovae (SNe IIP) observed with the ROTSE-IIIb telescope. To achieve precise photometry, we present a new image differencing technique that is implemented for the first time on the ROTSE SN photometry pipeline. With this method, we find up to a 20\% increase in the detection efficiency and significant reduction in residual RMS scatter of the SN lightcurves when compared to the previous pipeline performance. We use the published optical spectra and broadband photometry of well studied SNe IIP to establish temporal models for ejecta velocity and photospheric temperature evolution for our SNe IIP population. This study yields measurements that are competitive to other methods even when the data are limited to a single epoch during the photospheric phase of SNe IIP. Using the fully reduced ROTSE photometry and optical spectra, we apply these models to the respective photometric epochs for each SN in the ROTSE IIP sample. This facilitates the use of the Expanding Photosphere Method (EPM) to obtain distance estimates to their respective host galaxies. We then perform cosmological parameter fitting using these EPM distances from which we measure the Hubble constant to be $72.9^{+5.7}_{-4.3}~{\rm kms^{-1}~Mpc^{-1}}$, which is consistent with the standard $\Lambda CDM$ model values derived using other independent techniques.Comment: 19 pages, 13 figure

Constraining H0 with ROTSE Low z Supernovae and Baryon Acoustic Oscillations with DESI High z Galaxies and Quasars

Through photometric observations of core collapse supernovae by the ROTSE-III experiment, I examine the ability to use these objects as distance probes to their host galaxies and subsequently determine the expansion of the local universe. For the DESI experiment, I work to develop spectroscopic simulations and a spectroscopic reduction pipeline to be used for data quality assessment. Additionally, I examine the effects of observing conditions on redshift measurements and the ability to extract cosmological parameters

Consumer channeling by health insurers: natural experiments with preferred providers in the Dutch pharmacy market

Consumer channeling is an important element in the insurer-provider bargaining process. Health insurers can influence provider choice by offering insurance contracts with restricted provider networks. Alternatively, they can offer contracts with unrestricted access and use incentives to motivate consumers to visit preferred providers. Little is known, however, about the effectiveness of this alternative strategy of consumer channeling. Using data from two natural experiments in the Dutch pharmacy market, we examine how consumers respond to incentives used by health insurers to influence their choice of provider. We find that consumers are sensitive to rather small incentives and that temporary incentives may sort a long-term effect on provider choice. In addition, we find that both consumer and provider characteristics determine whether consumers are willing to switch to preferred pharmacies. Copyright © 2007 John Wiley & Sons, Ltd.

Channeling Consumers to Preferred Providers and the Impact of Status Quo Bias: Does Type of Provider Matter?

Context. To effectively bargain about the price and quality of health services, health insurers need to successfully channel their enrollees. Little is known about consumer sensitivity to different channeling incentives. In particular, the impact of status quo bias, which is expected to differ between different provider types, can play a large role in insurers' channeling ability. Objective. To examine consumer sensitivity to channeling strategies and to analyze the impact of status quo bias for different provider types. Data Sources/Study Design. With a large-scale discrete choice experiment, we investigate the impact of channeling incentives on choices for pharmacies and general practitioners (GPs). Survey data were obtained among a representative Dutch household panel (n=2,500). Principal Findings. Negative financial incentives have a two to three times larger impact on provider choice than positive ones. Positive financial incentives have a relatively small impact on GP choice, while the impact of qualitative incentives is relatively large. Status quo bias has a large impact on provider choice, which is more prominent in the case of GPs than in the case of pharmacies. Conclusion. The large impact of the status quo bias makes channeling consumers away from their current providers a daunting task, particularly in the case of GP