3 research outputs found

    Spatially Extended Low Ionization Emission Regions (LIERs) at z∌0.9z\sim0.9

    Full text link
    We present spatially resolved emission diagnostics for eight z∌0.9z\sim0.9 galaxies that demonstrate extended low ionization emission-line regions (LIERs) over kpc scales. Eight candidates are selected based on their spatial extent and emission line fluxes from slitless spectroscopic observations with the HST/WFC3 G141 and G800L grisms in the well-studied GOODS survey fields. Five of the candidates (62.5%) are matched to X-ray counterparts in the \textit{Chandra X-Ray Observatory} Deep Fields. We modify the traditional Baldwin-Philips-Terlevich (BPT) emission line diagnostic diagram to use [SII]/(Hα\alpha+[NII]) instead of [NII]/Hα\alpha to overcome the blending of [NII] and Hα\alpha+[NII] in the low resolution slitless grism spectra. We construct emission line ratio maps and place the individual pixels in the modified BPT. The extended LINER-like emission present in all of our candidates, coupled with X-Ray properties consistent with star-forming galaxies and weak [OIII]λ\lambda5007\AA\ detections, is inconsistent with purely nuclear sources (LINERs) driven by active galactic nuclei. While recent ground-based integral field unit spectroscopic surveys have revealed significant evidence for diffuse LINER-like emission in galaxies within the local universe (z∌0.04)(z\sim0.04), this work provides the first evidence for the non-AGN origin of LINER-like emission out to high redshifts.Comment: 11 pages, 1 table, 6 figures, accepted for publication in the Astrophysics Journal (ApJ

    An assessment of the reliability of cut surface characteristics to distinguish between hand-powered reciprocating saw blades in cases of experimental dismemberment

    No full text
    Criminal dismemberment is most commonly committed with a variety of hand‐powered saws. These saws leave characteristic marks upon the bone that can assist in the identification of the weapon utilized. The current study provides frequencies of presentation of ten cut surface characteristics and examines intra‐ and interindividual variation between three hand‐powered reciprocating saws. Pig radii were used as a proxy for human remains. 42 cut surfaces were created with three hand‐powered reciprocating saws by the same researcher. Cut surface characteristics were assessed macroscopically, microscopically and with Scanning Electron Microscope (SEM), as well as photographed with Reflectance Transformation Imaging (RTI). Cut surface polish is the only characteristic that demonstrates consistently significant difference between saws. Five characteristics demonstrate some variation between blades: entrance shaving, breakaway spurs, breakaway notches, pull‐out striae, and tooth hop. Four characteristics demonstrate no difference between blades: cut surface striation shape, cut surface striation regularity, harmonics, and exit chipping. Tooth hop is the most reliable characteristic for differentiating between blades in this study, while pull‐out striae demonstrates high intra‐individual variability and a low frequency of presentation making it unreliable for differentiating between saw blades. Cut surface striations, exit chipping, and breakaway spurs occurred with the highest frequencies and were reliable for determining direction of blade progress and blade stroke, but were not reliable for differentiating between saw blades. Harmonics were absent. Further research is necessary to create large databases of known saw mark examples with known intra‐ and interindividual variability rates and error rates
    corecore