Zooniverse

Abstract:

We report the discovery of a bright (f (250 μm)>400 mJy), multiply lensed submillimeter galaxy HERMES J105751.1+573027 in Herschel/SPIRE Science Demonstration Phase data from the HerMES project. Interferometric 880 μm Submillimeter Array observations resolve at least four images with a large separation of ∼9″. A high-resolution adaptive optics Kp image with Keck/NIRC2 clearly shows strong lensing arcs. Follow-up spectroscopy gives a redshift of z = 2.9575, and the lensing model gives a total magnification of μ ∼ 11 ± 1. The large image separation allows us to study the multi-wavelength spectral energy distribution (SED) of the lensed source unobscured by the central lensing mass. The far-IR/millimeter-wave SED is well described by a modified blackbody fit with an unusually warm dust temperature, 88 ± 3 K. We derive a lensing-corrected total IR luminosity of (1.43 ± 0.09) × 1013 L⊙, implying a star formation rate of ∼2500 M⊙ yr-1. However, models primarily developed from brighter galaxies selected at longer wavelengths are a poor fit to the full optical-to-millimeter SED. A number of other strongly lensed systems have already been discovered in early Herschel data, and many more are expected as additional data are collected. © 2011. The American Astronomical Society. All rights reserved.

Abstract:

We provide a brief overview of the Galaxy Zoo and Zooniverse projects, including a short discussion of the history of, and motivation for, these projects as well as reviewing the science these innovative internet-based citizen science projects have produced so far. We briefly describe the method of applying en-masse human pattern recognition capabilities to complex data in data-intensive research. We also provide a discussion of the lessons learned from developing and running these community--based projects including thoughts on future applications of this methodology. This review is intended to give the reader a quick and simple introduction to the Zooniverse.

Abstract:

We report initial results from the far-infrared fine structure line observations of a sample of 44 local starbursts, Seyfert galaxies, and infrared luminous galaxies obtained with the PACS spectrometer on board Herschel. We show that the ratio between the far-infrared luminosity and the molecular gas mass, L /M , is a much better proxy for the relative brightness of the far-infrared lines than L alone. Galaxies with high L /M ratios tend to have weaker fine structure lines relative to their far-infrared continuum than galaxies with L /M ≲ 80 L M . A deficit of the [C II] 158 μm line relative to L was previously found with the Infrared Space Observatory, but now we show for the first time that this is a general aspect of all far-infrared fine structure lines, regardless of their origin in the ionized or neutral phase of the interstellar medium. The L /M value where these line deficits start to manifest is similar to the limit that separates between the two modes of star formation recently found in galaxies on the basis of studies of their gas-star formation relations. Our finding that the properties of the interstellar medium are also significantly different in these regimes provides independent support for the different star-forming relations in normal disk galaxies and major merger systems. We use the spectral synthesis code Cloudy to model the emission of the lines. The expected increase of the ionization parameter with L /M can simultaneously explain the line deficits in the [C II], [N II], and [O I] lines. © 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A.