The Meskwaki and Anthropologists: Action Anthropology Reconsidered

Review of: "The Meskwaki and Anthropologists: Action Anthropology Reconsidered," by Judith M. Daubenmier

Optical Identification of Cepheids in 19 Host Galaxies of Type Ia Supernovae and NGC 4258 with the Hubble Space Telescope

We present results of an optical search for Cepheid variable stars using the Hubble Space Telescope (HST) in 19 hosts of Type Ia supernovae (SNe Ia) and the maser-host galaxy NGC 4258, conducted as part of the SH0ES project (Supernovae and H0 for the Equation of State of dark energy). The targets include 9 newly imaged SN Ia hosts using a novel strategy based on a long-pass filter that minimizes the number of HST orbits required to detect and accurately determine Cepheid properties. We carried out a homogeneous reduction and analysis of all observations, including new universal variability searches in all SN Ia hosts, that yielded a total of 2200 variables with well-defined selection criteria -- the largest such sample identified outside the Local Group. These objects are used in a companion paper to determine the local value of H0 with a total uncertainty of 2.4%.Comment: ApJ, in press. v2 adds missing co-author to arXiv metadata and text in acknowledgment

The Berkeley Sample of Stripped-Envelope Supernovae

We present the complete sample of stripped-envelope supernova (SN) spectra observed by the Lick Observatory Supernova Search (LOSS) collaboration over the last three decades: 888 spectra of 302 SNe, 652 published here for the first time, with 384 spectra (of 92 SNe) having photometrically-determined phases. After correcting for redshift and Milky Way dust reddening and reevaluating the spectroscopic classifications for each SN, we construct mean spectra of the three major spectral subtypes (Types IIb, Ib, and Ic) binned by phase. We compare measures of line strengths and widths made from this sample to the results of previous efforts, confirming that O I {\lambda}7774 absorption is stronger and found at higher velocity in Type Ic SNe than in Types Ib or IIb SNe in the first 30 days after peak brightness, though the widths of nebular emission lines are consistent across subtypes. We also highlight newly available observations for a few rare subpopulations of interest.Comment: 13 pages; 14 figures; 3 tables. Accepted for publication in MNRA

Hubble Space Telescope and Ground-Based Observations of the Type Iax Supernovae SN 2005hk and SN 2008A

We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n_e >~ 10^9 cm^-3. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected "infrared catastrophe," a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a "complete deflagration" that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.Comment: 20 pages, 15 figure

Improved Standardization of Type II-P Supernovae: Application to an Expanded Sample

In the epoch of precise and accurate cosmology, cross-confirmation using a variety of cosmographic methods is paramount to circumvent systematic uncertainties. Owing to progenitor histories and explosion physics differing from those of Type Ia SNe (SNe Ia), Type II-plateau supernovae (SNe II-P) are unlikely to be affected by evolution in the same way. Based on a new analysis of 17 SNe II-P, and on an improved methodology, we find that SNe II-P are good standardizable candles, almost comparable to SNe Ia. We derive a tight Hubble diagram with a dispersion of 10% in distance, using the simple correlation between luminosity and photospheric velocity introduced by Hamuy & Pinto 2002. We show that the descendent method of Nugent et al. 2006 can be further simplified and that the correction for dust extinction has low statistical impact. We find that our SN sample favors, on average, a very steep dust law with total to selective extinction R_V<2. Such an extinction law has been recently inferred for many SNe Ia. Our results indicate that a distance measurement can be obtained with a single spectrum of a SN II-P during the plateau phase combined with sparse photometric measurements.Comment: ApJ accepted version. Minor change

Photospheric-Phase Spectropolarimetry and Nebular-Phase Spectroscopy of the Peculiar Type Ic Supernova 2002ap

The early-time optical spectrum of the Type Ic supernova (SN) 2002ap was characterized by unusually broad features, leading some authors to designate it a "hypernova." We present optical spectropolarimetry of this object 16 and 37 days after the estimated date of explosion. After correcting for interstellar polarization, we find evidence for a high level of intrinsic continuum polarization at both epochs: p >~ 1.3% on day 16 and p >~ 1.0% on day 37. Prominent line polarization is also seen, especially in the trough of the Ca II near-infrared triplet during the second epoch. When interpreted in terms of the oblate, electron-scattering model atmospheres of Hoeflich (1991), our results imply an asymmetry of at least 20% (day 16) and 17% (day 37). The data suggest a fair degree of axisymmetry, although the polarization angle of the dominant polarization axes are different by about 55 deg. between the two epochs, implying a complex morphology for the thinning ejecta. In particular, there exists some spectropolarimetric evidence for a different distribution of Ca relative to iron-group elements. We also present flux spectra of SN 2002ap taken 131 and 140 days after the explosion. The spectra are characterized by a very weak continuum and broad emission lines, indicating that SN 2002ap has entered the nebular phase. The spectral features are substantially similar to those of ``normal'' SNe Ic in the nebular phase, and the emission lines are not significantly broader. However, some of the broad lines are very sharply peaked, and may possess a narrow component (probably unresolved by our spectra, FWHM <~ 400 km/s that is redshifted by ~ 580$ km/s with respect to the systemic velocity of the host galaxy.Comment: Accepted by PASP. A new Appendix giving details of the observations has been added; minor text change

Evaluating active travel and health economic impacts of small streetscape schemes: An exploratory study in London

Abstract Introduction This article proposes a low-cost approach that transport authorities can use to evaluate small-scale active travel interventions, including estimating health economic benefits from uptake of walking and/or cycling. Methods The method combines post-intervention intercept surveys with the re-use of routinely collected count data. While inferior to more robust, longitudinal methods, the approach represents good value use of primary and secondary data at a far lower cost, for interventions unlikely otherwise to be evaluated at all. It makes use of government-supported tools that estimate physical activity health benefits from increased active travel. Findings The article describes an example in which a residential street was closed to through motor traffic, which led to a decline of 90% in motor traffic volume and uplift in pedestrian and cycle counts. This example is exploratory in nature due to sample size (124 respondents). The intercept survey of pedestrians and cyclists found uplift in perceived quality of the local environment across various indicators. Results suggested that around a third of the increase in pedestrian and cycle counts post-scheme represents new journeys, mainly via mode shift, with most of the remaining two-thirds being diverted journeys. This information is used alongside the before-and-after count data to estimate new cycling and walking trips induced by the route improvement. Finally, the article estimates the health economic benefit resulting from increased physical activity, of approximately £500,000 over 20 years. Conclusions The article demonstrates a method for estimating active traveluptake and associated health benefits for smaller schemes. If applied over a number of schemes, the results could then be used to create an evidence base that could be used in assessing possible benefits of future schemes