Lisa M. Frattare

The KPNO International Spectroscopic Survey. I. Description of the Survey

The KPNO International Spectroscopic Survey (KISS) is a new objective-prism survey for extragalactic emission-line objects. It combines many of the features of previous slitless spectroscopic surveys that were carried out with Schmidt telescopes using photographic plates with the advantages of modern CCD detectors. It is the first purely digital objective-prism survey, and extends previous photographic surveys to substantially fainter flux limits. In this, the first paper in the series, we give an overview of the survey technique, describe our data processing procedures, and present examples of the types of objects found by KISS. Our first H�-selected survey list detects objects at the rate of 18.1 per square degree, which is 181 times higher than the surface density of the Markarian survey. Since the sample is line-selected, there is an imposed redshift limit of z < � 0.095 due to the filter employed for the objective-prism observations. We evaluate the quality of the observed parameters derived from the survey data, which include accurate astrometry, photometry, redshifts, and line fluxes. Finally, we describe some of the many applications the KISS database will have for addressing specific questions in extragalactic astronomy. Subsequent papers in this series will present our survey lists of emission-line galaxy candidates. Subject headings: galaxies: emission-lines — galaxies: Seyfert — galaxies: starburst — surveys

Hubble Space Telescope Advanced Camera for Surveys Mosaic of the Prototypical Starburst Galaxy M82

ABSTRACT In 2006 March, the Hubble Heritage Team obtained a large, four‐filter (B, V, I, and Hα), 6 point mosaic data set of the prototypical starburst galaxy NGC 3034 (M82) with the Advanced Camera for Surveys on board the Hubble Space Telescope (HST). The resulting color composite Heritage image was released in 2006 April to celebrate HST’s 16th anniversary. Cycle 15 HST proposers were encouraged to submit General Observer and Archival Research proposals to complement and/or analyze this unique data set. Since our M82 mosaics represent a significant investment of expert processing beyond the standard archival products, we also released our drizzle‐combined FITS data as a High‐Level Science Product via the Multimission Archive at STScI in 2006 December. This paper documents the key aspects of the observing program and image processing: calibration, image registration and combination (drizzling), and the rejection of cosmic rays and detector artifacts.

Hubble Space Telescope Observations of the Interacting Galaxies NGC 2207 and IC 2163

Original article can be found at: http://www.journals.uchicago.edu/AJ/--Copyright American Astronomical Society

HST observations of the interacting galaxies NGC 2207 and IC 2163

Original article can be found at: http://www.journals.uchicago.edu/AJ/--Copyright American Astronomical Society

IMAGE-PROCESSING TECHNIQUES FOR THE CREATION OF PRESENTATION-QUALITY ASTRONOMICAL IMAGES

The quality of modern astronomical data and the agility of current image-processing software enable the visualization of data in a way that exceeds the traditional definition of an astronomical image. Two developments in particular have led to a fundamental change in how astronomical images can be assembled. First, the availability of high-quality multiwavelength and narrowband data allow for images that do not correspond to the wavelength sensitivity of the human eye, thereby introducing ambiguity in the usage and interpretation of color. Second, many image-processing software packages now use a layering metaphor that allows for any number of astronomical data sets to be combined into a color image. With this technique, images with as many as eight data sets have been produced. Each data set is intensity-scaled and colorized independently, creating an immense parameter space that can be used to assemble the image. Since such images are intended for data visualization, scaling and color schemes must be chosen that best illustrate the science. A practical guide is presented on how to use the layering metaphor to generate publication-ready astronomical images from as many data sets as desired. A methodology is also given on how to use intensity scaling, color, and composition to create contrasts in an image that highlight the scientific detail. Examples of image creation are discussed.

RADIO CONTINUUM EMISSION AT 1.4 GHz FROM KISS EMISSION-LINE GALAXIES

We have searched the Faint Images of the Radio Sky at Twenty centimeters (FIRST) and the NRAO VLA Sky Survey (NVSS) 1.4 GHz radio surveys for sources that are coincident with emission-line galaxy (ELG) candidates from the KPNO International Spectroscopic Survey (KISS). A total of 207 of the 2157 KISS ELGs (~10%) in the first two Hα-selected survey lists were found to possess radio detections in FIRST, NVSS, or both. Follow-up spectra exist for all of the radio detections, allowing us to determine the activity type (star-forming vs. active nucleus) for the entire sample. We explore the properties of the radio-detected KISS galaxies in order to gain a better insight into the nature of radio-emitting galaxies in the local universe (z < 0.1). No dwarf galaxies were detected, despite the large numbers of low-luminosity galaxies present in KISS, suggesting that lower mass, lower luminosity objects do not possess strong galaxian-scale magnetic fields. Because of the selection technique used for KISS, our radio ELGs represent a quasi–volume-limited sample, which allows us to develop a clearer picture of the radio galaxy population at low redshift. Nearly two-thirds of the KISS radio galaxies are starburst or star-forming galaxies, which is in stark contrast to the results of flux-limited radio surveys, which are dominated by active galactic nuclei (AGNs) and elliptical galaxies (i.e., classical radio galaxies). While there are many AGNs among the KISS radio galaxies, there are no objects with large radio powers in our local volume. We derive a radio luminosity function (RLF) for the KISS ELGs that agrees very well with previous RLFs that adequately sample the lower luminosity radio population.