deletions | additions       diff --git a/begin_table_begin_tabular_c__.tex b/begin_table_begin_tabular_c__.tex  index 5c727ba..2b1c85e 100644  --- a/begin_table_begin_tabular_c__.tex  +++ b/begin_table_begin_tabular_c__.tex 
...
\begin{table}   \begin{tabular}{ c c c c c c c }  asdf & a & 12 & 3 & 4 & 555 & 555 \\   a & d & 55 & we & w & t & we \\   s & a & g & g & asdf & g & a \\   d & 5555 & & 55 & aef & & \\   d & & g & & & & \\   \end{tabular}   \end{table}  \section{Systematic Uncertainties in the Absolute Calibration}  \nobreak  \label{sec:calib_sdss}  The flux calibration of PS1 measurements relies on an iterative process that includes work from T12 and \cite{Schlafly12} \cite{Astier_2006}  and is built on by this work and that of R14. T12 observes several HST Calspec standards \citep{1996AJ....111.1743B} with PS1 and compares the observed magnitudes of these standards to the predicted magnitudes from synthetic photometry. T12 finds the AB offsets so that the observed magnitudes best matches the synthetic photometry, given tight constraints from measurements on the bandpass edges and shapes. Catalogs from the fields that contain the Calspec standards are then included as a basis of the relative calibration performed by \cite{Schlafly12}, which uses repeat PS1 observations of stars and solves simultaneously for the system throughput, the atmospheric transparency, and the large-scale detector flat field (called `ubercal'). In this process, new sky catalogs are created not only for the fields in which the Calspec standards are located, but across the entire observable sky including the Medium Deep fields. standards.  The original observations of Calspec standards by T12 are supplemented by observations of those and other Calspec standards as part of the Pan-STARRs 3Pi survey. In this work, we determine the AB offsets between the observed magnitudes of the entire set of Calspec standards calibrated by ubercal and the synthetic photometry of these standards. This iterative process is thus a more accurate test of the absolute flux calibration of PS1. Once these offsets are found, R14 applies the offsets to the Medium Deep field catalogs, and analyzes further calibration uncertainties that may affect the SN measurements. Zeropoints for the nightly photometry of the supernovae are determined by comparing the photometry of a single image to the photometry from the Medium Deep field catalog at that location. 
...
\subsection{Overview of Calibration Uncertainties}  Uncertainties in the calibration of the various samples comprise the largest systematic uncertainty in our analysis. In Fig.~\ref{fig:cal}, we show a schematic describing the calibration of the various subsamples. The overall systematic uncertainty in the calibration of our combined PS1+lz sample may be expressed as the combination of three uncertainties. The first component encompasses systematic uncertainties in the nightly photometry and how well the filter bandpasses are measured. For the PS1 sample, R14 presents analysis of the systematic uncertainty due to spatial and temporal uncertainties in the nightly photometry. T12 presents the uncertainty in how well the bandpasses are measured (uncertainty of filter edges $<7~\AA$). T12 also analyzes uncertainty in the atmospheric attenuation compensation for the filter zeropoints. edges.  Spatial and temporal variation of the filter bandpasses propagate into our total calibration uncertainty in three ways: how the catalog photometry is determined, how the photometry of the Calspec standards is determined, and how the photometry of the supernovae is determined. We expect that the uncertainty in the nightly zeropoints to be small. We find by comparing Pan-STARRs and SDSS photometry that any variation of the PS1 photometry across the focal plane for colors $0.4  The second major component of the total calibration uncertainty is in determining the flux zeropoints of each filter based on observations of astronomical standards. Since the accuracy of the internal PS1 measurements of the flux zeropoints is not better than $1\%$, the zeropoints are adjusted so that the observed photometry of HST Calspec standards (e.g., AB - HSTCalspec; \citealp{1996AJ....111.1743B}) matches the synthetic photometry of these standards. Analogously, for the low-z sample, this uncertainty encompasses the accuracy of the color transformation of Landolt standards. For PS1, the adjustment of the photometry to agree with the synthetic photometry dominates the uncertainty in the filter measurements by T12. Both uncertainties are included in our analysis.   The third main component of the total calibration uncertainty is the accuracy in the measurements of the standard stars (e.g., HST Calspec or Landolt). This is composed of errors in the color of the standard stars and the absolute flux of the standards. For the PS1 sample and select measurements in the low-z samples, this uncertainty is due to possible errors in measurements of the HST Calspec standards. For most of the low-z sample, this uncertainty is due to color and absolute flux errors from the realization of the Vega\footnote{The absolute flux of Landolt standards is discussed at the end of the section.} magnitude system as implemented in the standard catalogs of Landolt. A common flux scale for the PS1 supernovae and low-z SNe can be achieved by the binding between the Landolt catalog and Calspec standards (\citealp{2007AJ....133..768L}). In a future analysis, we plan to cross-calibrate the Landolt catalog to the PS1 catalog to further improve the flux scales of the different samples. If we limited our analysis to SNe from a single survey, the overall absolute flux calibration would be degenerate with the absolute peak magnitude of SNe. But combining distance moduli of SNe from multiple surveys requires that there is a common absolute flux scale.   R14 presents an error budget for the PS1 photometric system. Here we explain many of these uncertainties, along with uncertainties of the low-z calibration. We also detail the derivation of new zeropoint offsets for the PS1 calibration that are used in R14. The total uncertainty in the recovery of cosmological parameters due to calibration for the PS1+lz sample is given in Table~1. For each uncertainty described, this uncertainty is independently added to each observed magnitude of the SN, and the light curves are refit. Afterwards, cosmological constraints are redetermined.   \begin{figure}[h!]  \centering  \epsscale{\xxScale} % 1.15 for emulateapj  \plotone{FinFigures/absfluxppt.eps}  \caption{A schematic of the calibration of the PS1+lz sample. The calibration of the various subsamples is broken into three parts: `Internal calibration' (filter measurements), `match between Internal and Absolute calibration', and `Absolute calibration'. Arrows show whether in each step there may be an uncertainty due to a color measurement or absolute flux measurement. Directionality of absolute flux arrows show the source of the uncertainty. `C', `L' and `S' represent the HST Calspec, Landolt and Smith standards respectively.}  \label{fig:cal}  \end{figure}  \subsection{Pan-STARRS Absolute Calibration}  The Pan-STARRS AB magnitude system, as described in T12, is based on small ($<0.03$ mag) adjustments to highly accurate measurements of the PS1 system throughput and filter transmissions measured \textit{in situ}. Perturbations to each filter transmission are optimized so that `synthetic' photometry, using measurements of filter transmission throughputs and stellar spectra, agrees with observations of HST Calspec standard stars. To do this, T12 analyzed the PS1 observations of 7 Calspec standards, all observed on the same photometric night. The error in how well the Calspec SEDs are defined on the AB system as well as the offsets between the observed and synthetic Calspec magnitudes represent the two largest errors in the PS1 calibration system. T12 finds that the entire systematic uncertainty from absolute calibration in each filter is $\sim0.017$ mag. We recalculate that value here.  Once the PS1 calibration is defined to be on the AB system, there is an uncertainty from the relative calibration between the fields with Calspec standards to the rest of the sky. To do the relative calibration, \cite{Schlafly12} use repeat PS1 observations of stars. Star catalogs created by this process are used in our supernova pipeline. Internal consistency tests show \cite{Schlafly12} achieve field-to-field relative precision of $<0.01$ mag in \gps,\rps, and \ips~ and $\sim0.01$ mag in \zps~. These errors are included in our overall zeropoint uncertainties, after dividing by $\sqrt{10}$ - the number of fields. While a following discussion will focus on agreement between the absolute calibration of PS1 and SDSS, it is worth mentioning that \cite{Schlafly12} find greater internal inconsistencies at the $\sim0.01$ mag level in the SDSS photometry than in the PS1 photometry.  \begin{figure}[h!]  \centering  \epsscale{\xxScale} % 1.15 for emulateapj  \plotone{FinFigures/focal2.eps}  \caption{(Top panels) The synthetic magnitude differences of Pickles stars, Calspec standards, and a SNIa at different redshifts when the object is observed near the center of the focal plane compared to in an outer annulus. The smooth change in color of the SNIa is due to red shifting a normal SNIa spectrum. Filter functions used in this process are from Tonry et al. 2011. (Bottom panel) Changes in distance found for PS1 SNe when the correct filter function at the focal position is used versus the nominal position.}  \label{fig:ps1_focal}  \end{figure}  \begin{figure}[h!]  \centering  \epsscale{\xxScale} % 1.15 for emulateapj  \plotone{FinFigures/calspec_ps1.eps}  \caption{The magnitude differences in each passband between observed and synthetic PS1 measurements of 12 Calspec standards. The solid line represents synthetic photometry from the PS1 photometry, while the dashed line represents AB offsets (given in Table 2) between the SDSS and PS1 absolute calibration. Standards that are observed by both SDSS and PS1 are shown in red, standards without STIS observed spectra are shown in yellow, and the remaining are shown in black. AB offsets found in this analysis are such that the discrepancies between the observed and synthetic magnitudes are minimized.}  \label{fig:ps1_cal}  \end{figure}  To improve the PS1 absolute calibration, we analyze a larger sample of Calspec standards that have been observed throughout the PS1 survey. In total, there are 12 Calpsec standards that have been observed by PS1 in $gri\zps$~that are not saturated in the observations. These standards were observed so that they avoided the direct center of the focal plane, where there are some unresolved discrepancies as described by R14. We measure the PS1 magnitudes of the observed Calspec standards in the same way as T12. We then apply a zeropoint offset obtained by computing the difference of the magnitudes of stars in the fields with the stars in the full-sky star catalogs set by \cite{Schlafly12}. To avoid a Malmquist bias in the determination of the zeropoint, we empirically determine the magnitude limit at which stars can be used for this comparison. We also remove any observations of Calspec standards where there is greater than a $0.03$ mag difference between the aperture and PSF photometry, as we found this adequately removes any saturated observations. As the Calspec standards observed are so bright, we follow T12 and include a $0.005$ mag uncertainty to account for how some of the standards may be near the saturation limit.  To make full use of the observations of Calspec standards, we must consider how the filter functions change across the focal plane. In Fig.~\ref{fig:ps1_focal}, we show the change in synthetic magnitudes of stars in the Pickles' library \citep{1998PASP..110..863P}, Calspec standards and supernovae for a given color and position on the focal plane. We find the variation in synthetic magnitudes for supernovae and Calspec standards may be significantly larger than the variation of stars in the narrow color range used to define the stellar zeropoints. Therefore, given the measurements of filter functions across the focal plane (measured at $\Delta r=0.15$ deg), we transform the observed magnitudes of the Calspec standards to a uniform system defined at the center of the focal plane. As shown in Fig.~.~\ref{fig:ps1_focal} , this correction for the blue Calspec standards may be as large as 5 mmag. This approach is similar to that of \cite{Betoule2012}.   For each observation of a Calspec standard, we follow Schlafly et al. and assign an observational error of $0.015 + \sigma_{mag-psf}$, which Schlafly et al. finds adequately describes the scatter seen in their star catalogs. To determine the net adjustment needed for each passband, we find the weighted difference of the observed and synthetic magnitudes of the Calspec standards. For this process, we add an additional uncertainty of $0.008$ mag to each difference in order to represent the uncertainty in the ubercal process. In Appendix A, we present the entire set of Calspec standards observed and their synthetic magnitudes in the PS1 system\footnote{PS1 passbands can be found on the ApJ webpage for T12.}, as well as the observed magnitudes. From Figure \ref{fig:ps1_cal}, we find that corrections should be added to the zeropoints of observations in each filter (given by T12 and \citealp{Schlafly12}) such that $\Delta g_{PS1} = -0.008$, $\Delta r_{PS1} = -0.0095$, $\Delta i_{PS1} = -0.004$, $\Delta z_{PS1} = -0.007$. These adjustments represent the weighted difference of the observed and synthetic magnitudes of the Calspec standards. R14 includes these offsets in their light curve fits; we call the new calibration `$\textrm{PS1}_{\textrm{13}}$'. We determine the uncertainties in the mean for all four passbands to be [0.0085,0.0050,0.0060,0.0025] mag. These uncertainties are included in the overall calibration uncertainty table of R14 (T).  T12 finds consistency of $\sim0.01$ mag among their 7 Calspec stars used to define the AB system. For two of the standards, 1740346 and P177D, T12 noticed disagreement at the 0.02 mag level in \ips. T12 explained that this disagreement may be due to the discontinuity at 800 nm where the STIS spectra gives way to NICMOS in the Calspec SEDs. With our larger sample of Calspec standards, we can see that the disagreement T12 noticed is most likely not due to 1740346 and P177D, but rather the three `KF' stars (KF08T3, KF01T5, KF06T2), which are red stars with $r-i\sim0.3$. In the analysis done by T12, the spectra of the KF stars did not include STIS data, which covers the optical spectrum. We find that with an updated STIS spectrum of KF06T2, the synthetic photometry is corrected by $\sim0.02$ mag, in better agreement with observations. While we present the entire set of HST Calspec standards observed, we exclude the two KF stars without STIS measurements from our absolute calibration.  Including the uncertainties described above, R14 finds the combined uncertainty for each filter in quadrature is $\sim 0.012$ mag. Uncertainty in $\gps$ appears to have the largest effect on the cosmological constraints compared to the other passbands. Interestingly, a calibration error in \rps~appears to have a different effect than the other passbands because the change in distance due to peak brightness in this filter cancels out the change in distance due to color (for $>50\%$ of redshift range). The effect on recovered cosmological parameters from $gri\zps$ together (labelled `PS1 ZP +Bandpasses' in Table 1) increase the relative area of the constraints by $40\%$ (SN only).  We also consider the effects of the third component of the total systematic uncertainty in calibration (bottom level of Fig. 1): that of the calibration of the HST Calspec standards to the AB system. T12 states this uncertainty is $0.013$ mag for all filters. We find a more appropriate solution is to take the uncertainty as the inconsistency between the synthetic photometry of the STIS measurement of BD17 and observed photometry from ACS given in \cite{2004AJ....128.3053B}. This error is explained by the STIS flux for BD17 that continuously drops from a multiplicative factor times the flux of $1.005$ at $4000~\AA$~to $0.985$ at $9500~\AA$\footnote{\cite{2004AJ....128.3053B} argue that this error may be partly composed of errors from ACS bandpasses, so our systematic uncertainty here is likely conservative.}. This is similar to the 0.5\% slope uncertainty stated by \cite{BohlinHartig}. Additionally, there is a measurement error in the repeatability of the individual measurements with STIS spectra, on the order of $0.005$ mag \citep{Betoule2012}. The impact of these uncertainties of the Calspec standards is given in Table 1 and increase the relative area by $\sim5\%$. Finally, the absolute flux of the Calspec system itself must be taken into account. This uncertainty will be considered as part of the low-z discussion later in this section (given as `Abs. ZP' in Table~1).   \begin{deluxetable*}{l|ccc|ccc}  \tablecaption{Calibration Systematics  \label{tab:calcheck2}}  \tablehead{  \colhead{Systematic} &  \colhead{$\Delta \Omega_M$} &  \colhead{$\Delta w$ } &  \colhead{Rel. area } &  \colhead{$\Delta \Omega_M$ } &  \colhead{$\Delta w$} &  \colhead{Rel. area} \\  ~ & ~ & SN Only & ~ & ~ & SN+BAO+CMB+$H_0$ & ~   }  \startdata  \input{FinFigures/final_sys1c.txt}  \enddata  \tablecomments{ Individual systematic uncertainties for each of the PS1 passbands as well as the systematic uncertainties for each low-z sample. $\textrm{RelativeArea}$ is the size of the contour that encloses 68.3\% of the probability distribution between $w$ and $\Omega_M$ compared with that of statistical-only uncertainties.}  \end{deluxetable*}  \begin{comment}  \begin{deluxetable}{llllll}  \tablecaption{PS1 Photometric Consistency Checks.  \label{tab:magtest}}  \tablehead{  \colhead{Filter} &  \colhead{SDSS} &  \colhead{$\pm$} &  \colhead{Std} &  \colhead{$\pm$} &  \colhead{N} \\  ~ & [Mag] & [Mag] & [Mag] & [Mag] & ~\\  }  \startdata  \gps & 0.014 & 0.012 & $-$0.004 & 0.007 & 2644\\  \rps & $-$0.019 & 0.010 & $-$0.005 & 0.006 & 3072\\  \ips & 0.008 & 0.011 & 0.008 & 0.009 & 2850\\  \zps & 0.015 & 0.011 & $-$0.009 & 0.007 & 2816\\  \yps & 0.001 & 0.013 & 0.005 & 0.010 & 2150\\  \enddata  \tablecomments{The columns show for each filter, the average difference for the  difference between PS1 \ magnitudes and SDSS magnitudes that have been transformed to be on the PS1~system. The three comparisons show the values obtained by   \end{deluxetable}  \end{comment}  \subsection{Absolute Calibration Agreement Between PS1 and SDSS}  Surveys like SDSS, CSP and SNLS have recently undertaken large, collaborative efforts (\citealp{2012AJ....144...17M}, \citealp{Betoule2012}) to improve the agreement between their respective calibration systems. Here we focus on the consistency of the absolute calibration between PS1/SDSS as the absolute calibration differences between SDSS/SNLS \citep{Betoule2012} and SDSS/CSP \citep{2012AJ....144...17M} have been shown to be less than $1\%$. As SDSS photometry has been defined to be on the AB system, this analysis is an alternate diagnostic to quantify the accuracy of the PS1 photometric system itself.    T12 compares the Pan-STARRS1 magnitudes of stars in the MD09 field with those tabulated by SDSS as part of Stripe 82. They note $\sim0.02$ mag offsets at 3-4$\sigma$ after transforming the SDSS DR8 catalogs into the PS1 system with linear terms in color\footnote{For color transformations: PS1 filter transmissions from T12, SDSS filter transmissions from \cite{2010AJ....139.1628D}~and Pickles star spectra \citep{1998PASP..110..863P}}. T12 conclude that discrepancies are most likely due to errors within the SDSS calibration system.   \begin{figure}[h]  \centering  \epsscale{\xxScale} % 1.15 for emulateapj  \plotone{FinFigures/SDSS_paper.eps}  \caption{Passband magnitude differences between PS1 catalog (T12 catalogs with ubercal zeropoints) and the most up-to-date SDSS S82 Catalog (from \citealp{ivezi_sloan_2007}, \citealp{Betoule2012}) are shown in yellow. In yellow are the synthetic spectrophotometry differences for a set of Pickles \citep{1998PASP..110..863P} stars using the T12 PS1 passbands and \cite{2010AJ....139.1628D} passbands. }  \label{fig:ps1_sdss1}  \end{figure}  For comparisons between SDSS and PS1, we repeat the analysis in T12, now using the most up to date S82 catalogs from \cite{ivezi_sloan_2007} with AB offsets from \cite{Betoule2012}. Discrepancies between these two systems are shown in Fig.~\ref{fig:ps1_sdss1}. The offsets between the calibration zeropoints of PS1 and SDSS are given in Table~\ref{tab:magtest2} and are up to $\sim0.02$ mag in \rps. \cite{Betoule2012} redefines the SDSS AB system using SDSS PT observations of 7 Calspec standards. While T12~explains that the absolute calibration of SDSS DR8 may be biased from using SDSS SEDs, \cite{Betoule2012} uses HST Calspec spectra to define the flux system so there should not be an issue.   \begin{deluxetable}{lcc}  \tablecaption{PS1 Photometric Consistency Checks   \label{tab:magtest2}}  \tablehead{  \colhead{Filter} &  \colhead{From T12} &  \colhead{$\textrm{PS1}_{13}$ +B12} \\  ~ & [Mag] & [Mag] \\  }  \startdata  \gps & \phantom{-}0.014 &\phantom{-} 0.0095 \\  \rps & $-$0.019 & $-$0.017 \\  \ips & \phantom{-}0.008 & -0.015 \\  \zps & \phantom{-}0.015 & \phantom{-}0.016 \\  \enddata  \tablecomments{AB offsets from comparisons of PS1 and color-transformed SDSS and catalogs. The first column shows the offsets obtained in T12, the second column shows comparisons between the $\textrm{PS1}_{13}$ photometry SDSS S82 photometry as released in \cite{Betoule2012}. These offsets are given in the form $m_{\textrm{PS-obs.}}-m_{\textrm{SDSS-obs.}}-(m_{\textrm{PS-syn.}}-m_{\textrm{SDSS-syn.}})$ where $m$ is the magnitude in any given filter.}  \end{deluxetable}  To further probe the inconsistency between the PS1 and SDSS calibration systems, in Appendix A, we compare synthetic and observed magnitudes for the SDSS standards in the same way we did for PS1. In both Fig.~\ref{fig:ps1_cal} and Appendix A, we show how, for PS1 and SDSS, the zeropoints should be shifted into agreement with the color-transformed system of the other. We note that for SDSS, the dispersion of the differences between synthetic and observed photometry is smaller than that for PS1, and likely does not explain the difference in absolute zeropoints. In the comparison of PS1 and SDSS catalogs shown in Fig.~\ref{fig:ps1_sdss1}, the differences have a very small dependence on the color $g-r$ ($<5$ mmag for $g-r < 1.2$, highest in the $z$ band). This result is encouraging that while the absolute zeropoints of the filters are in disagreement, the filter transmission curves appear to be well measured for both systems. Also, the zeropoint discrepancies do not appear to be correlated across filters.   There are three Calspec standards observed by both PS1 and SDSS: P177D, GD71 and GD153. The discrepancies between the PS1 and SDSS observations of these standards are very similar to the overall discrepancies in the calibration of these two systems and do not provide enough leverage to understand the source of the differences. Therefore, more work must be done to understand the disagreement between the PS1 and SDSS calibration. One possible cause may be due to non-linearities with these particular observations of very bright standards, which T12 estimated for the PS1 observations to be up to $\sim0.005$ mag. We conclude that when combining data from the PS1 and SDSS surveys that the AB offsets between the two must be taken into account. We find that the change in $w$ when the PS1 calibration system is chosen to be in agreement with SDSS is $\Delta w = +0.018$ with constraints only from SN measurements, and $\Delta w =-0.006$ when including CMB, BAO and $H_0$ constraints (due to how constraints combine). This difference for the SN-only constraints is the largest variant in our analysis.   \subsection{Nearby Supernova Sample Absolute Calibration}  \nobreak  \label{sec:datasets}  We rely on analysis of past studies, in particular C11 and \cite{2009ApJS..185...32K}, for our understanding of the calibration systematics of low-z surveys. We discuss our additions to the growing low-z sample: the CfA4 survey, a recalibration of the CfA3 survey, and a larger set of CSP SNe. Given the U-Band systematic error discussed in \cite{2009ApJS..185...32K}, we follow the C11 decision to not use rest-frame observations in the U-band.  Each of the newly added nearby samples has photometry on its natural system. For each sample, the absolute calibration is defined by the magnitudes of the fundamental flux standard BD17. For CSP, the magnitudes of BD17 are given in the natural system. For CfA3 and CfA4, we use the linear transformations from the Landolt \citep{1992AJ....104..340L} and Smith \citep{smith02} colors to the natural system to determine the magnitude of BD $17^{\circ} 4708$. These transformations are given in \cite{2009ApJ...700..331H}. The magnitudes of BD17 given in \citet{1992AJ....104..340L} are transformed to calibrate the \emph{BV} bands, and the magnitudes of BD17 given in \citet{smith02} are transformed to calibrate the \emph{r'i'} bands.   We note two peculiarities with the CfA3 and CfA4 samples. To analyze these two samples, we take passbands defined by \citet{cramer12} in which highly precise measurements are obtained of the telescope-plus-detector throughput by direct monochromatic illumination. This method, like that done in T12 is based on \citet{stubbs06}. However, the CfA4 survey must be broken into two separate time periods because it was found that a warming of the CCDs of KeplerCam to remove contamination in May 2011 `produced a dramatic difference' in the response function of the camera \citep{2009ApJ...700.1097H}. This difference is quantified by measurements of the $V$, $V-i'$, $U-B$ and $u'-B$ color coefficients between the Landolt/Smith measurements and the natural system. Therefore, we use a set of transmission functions for before August 2009 and after May 2011, when the system was measured to be consistent, and a separate set of transmission functions between these two dates (Hicken et al. 2012). The second peculiarity is that when analyzing the CfA4 light curves, we found the uncertainties for each observation to be on average roughly $\sqrt {3}$ larger than that of CfA3, a surprising result considering the similarity of the surveys. We discovered this was due to a change in uncertainty accounting in the software pipeline based on the number of image subtractions done for each observation (Hicken, private communication). We have returned the uncertainty propagation method to that used for CfA3, which we believe to be correct.   For our uncertainties in the low-z bandpasses and zeropoints (top level of Fig.~\ref{fig:cal}), we follow the analysis of C11. We use the shifted Bessell bandpasses found empirically by C11 with uncertainties of 12~\AA~(edge locations) for the JRK07 sample and adopt zeropoint uncertainties of $0.015$ mag. For CSP, the uncertainties in the bandpasses are taken from \cite{2010AJ....139..519C} and the uncertainties in the zeropoints for each filter are $0.008$ mag, as given in C11. While more work must be done to better determine this zeropoint uncertainty, this result is consistent with the small discrepancies of $\sim0.01$ mag seen between the CSP and SDSS samples \citep{2012AJ....144...17M}. We take the zeropoint uncertainties for the CfA4 sample given in Hicken et al. 2011 of 0.014, 0.010, 0.012, 0.014, 0.046 mag in $BVr'i'u'$, which are larger than those found by C11 for the CfA3 sample of $0.011,0.007,0.007,0.007$ mag for $BVRr'$. Since the uncertainty of the CfA4 bandpasses measured by Cramer et al. (in prep) has not yet been given, we fix this uncertainty to be that found by T12 for the PS1 passbands (3~\AA), as Cramer et al. and T12 perform very similar measurements to determine the instrument response.  While the absolute flux of the HST Calspec standards is defined by the AB system, the absolute flux of the Landolt standards is not well defined. Although the Landolt measurements are self-consistent, it is not known exactly how the absolute flux was defined. Therefore, there may be discrepancies between the absolute flux of these different sets of standards (see bottom level of Fig.~\ref{fig:cal}). We follow the analysis of \cite{2007AJ....133..768L} of the calibration agreement between the Landolt catalog and HST observations of  Calspecstandards for an uncertainty of $0.006$ mag between the absolute fluxes of the two samples. For the difference between the Smith and AB systems, we take the uncertainty in determining the AB offsets for the SDSS sample of $\sim0.004$ mag \citep{Betoule2012}. We also account for uncertainties in the colors of Landolt measurement of BD17 itself of $\sim0.002$ mag (Regnault et al. 2009). This last uncertainty could be reduced by defining the low-z samples using more standards besides BD17 (a subdwarf star), which will be done in a future work.   \subsection{Further calibration systematics and impact}  While we have discussed the entirety of calibration errors that affect the measurements of the supernova in our sample, we must also propagate how calibration errors affect the SALT2 light curve model that we use to fit distances. To do so, we refit our entire SN sample with 100 variants of the SALT2 model based on the calibration errors of the training sample used to determine the model (Guy10). These variants were provided by the SALT2 team. For the total systematic from the SALT2 calibration error, we sum the covariance matrices over all of the iterations and then divide by the total number of iterations. This impact of this uncertainty is quite large with respect to our other calibration uncertainties as it increases our $w$ versus $\Omega_M$ constraints for the SN-only case by $>15\%$.   The impact on the recovery of cosmological parameters from all of the uncertainties discussed above are presented in Table~1. Uncertainties in the low-z transmission measurements are significant (SN. only relative area $\sim1.07$), though do not have as great an increase on the relative area as the uncertainty in the PS1 transmission throughputs. We present the distance residuals from the best fit cosmology for each low-z survey in Fig.~\ref{fig:lowz_tension}. We refer here to R14 (section 7.2) which details the quality culls on the light curves and reduces the number of light curves significantly. The intrinsic dispersion ($\sigma_{\textrm{int}}$) , RMS and effects on retrieved cosmology from removing a particular subsample are all shown in Table~\ref{tab:lowzrem}. We note that the $\sigma_{\textrm{int}}$ of the PS1 sample ($\sigma_{\textrm{int}}=0.07$) is lower than in other samples, though is closest to the CSP sample. We also note that the CfA4 sample appears to have a larger scatter ($\sigma_{\textrm{int}}=0.22$) than the other samples. The various values of $\sigma_{\textrm{int}}$ may be due to over or under-estimation of calibration uncertainties. Part of this trend may also be due to a low-z Malmquist bias, which will be discussed in a later section. The maximum tension between the low-z subsamples is about $<2\sigma$ from the mean. REF27: There are 23 SNe observed by both CSP and CfA3, and the mean difference in distances for these SNe is $0.026\pm0.03$ mag (CSP-CfA3) with an RMS of 0.16 mag. We only allow a single distance for a given supernova, and choose based on which has better cadence near peak. Following C11, we add different $\sigma_{\textrm{int}}$ values to the photometric uncertainty of the SN distances for our high and low-z samples, though not for the individual low-z subsamples.  \begin{deluxetable*}{lllllll}  \tablecaption{Effects of Removing Low-z Sample on Cosmology  \label{tab:lowzrem}}  \tablehead{  \colhead{Sample:} &  \colhead{$\sigma_{\textrm{int}}$} &  \colhead{$\textrm{RMS}$} &  \colhead{$\Delta \Omega_m$} &  \colhead{$\Delta w$} &  \colhead{$\Delta \Omega_m$} &  \colhead{$\Delta w$} \\  ~&~&~&(SNe only)&(` ')&(SN+H0+CMB+BAO )&(` ')\\  }  \startdata  \input{FinFigures/sint.txt}  \enddata  \tablecomments{For the PS1+lz sample, we show $\Delta \Omega_m$ and $\Delta w$ (SN constraints as well as full SN+H0+CMB+BAO constraints) when we remove one of the subsamples, and keep the rest of the sample intact. We also give the intrinsic dispersion of each subsample and the RMS.}  \end{deluxetable*}  \begin{comment}  \begin{deluxetable}{lll}  \large  \tablecaption{Intrinsic Dispersion for Each Sample  \label{tab:intrinsic}}  \tablehead{  \colhead{Sample} &  \colhead{$\sigma_{\textrm{int}}$$^b$\footnotetext{$^a$ Hello}} &  \colhead{$\textrm{RMS}$$^a$\tablenotetext{$^a$ Hello}} \\  }  \startdata  \input{FinFigures/sint.txt}  \enddata  \tablecomments{This table shows the overall $\sigma_{\textrm{int}}$ value for each sample to be added in quadrature with the individual SN $\sigma_n$ values so that the reduced $\chi^2=1.0$. $\sigma_{\textrm{int}}$ is used here as a single coherent uncertainty, rather than a sum of intrinsic errors of $m_b$,$x_1$ and c. $\sigma_{\textrm{int}}$ is very sensitive to outliers and includes information about residuals and the errors. The Median Absolute Deviation (MAD), shows the median of the absolute value of the best fit residuals, and is given for comparison.}  \end{deluxetable}  \end{comment}  \begin{figure}[h!]  \centering  \epsscale{\xxScale} % 1.15 for emulateapj  \plotone{FinFigures/lowz_panel2.pdf}  \caption{The Hubble Residuals for each supernova sample at low-z. On each panel, the tension between this set and the others is shown.}  \label{fig:lowz_tension}  \end{figure}  %sint.txt