38,287 research outputs found
Organizing Ourselves: Drywallers\u27 Strike Holds Lessons for the Future of Labor Organizing
[Excerpt] In October 1991, drywall hanger Jesus Gomez complained to the drywall contractor for whom he worked that his check was short $60 for the week. The contractor refused to pay up the difference — and he felt safe doing so. He\u27d conducted business this way for years and his predatory attitude told him these drywallers, (poor, immigrant, Mexican, often undocumented, and without a union to defend their interests,) were in no position to challenge the status quo. Besides, the economic recession and construction slump provided added insurance against worker discontent.
Unfortunately for drywall contractors, Gomez was more than discontented. He was determined to do something about this state of affairs. Gomez began to speak with other drywallers at their homes and at worksites throughout southern California, slowly fashioning the complaints and frustration into collective strength and a plan of action. When the group became a few hundred strong, an ultimatum was issued to contractors: Either you agree to increases in piece rates and other conditions by June 1, 1992 or we will strike
UV-IR color profiles of the outer regions of 2K nearby SG galaxies
We present our new, spatially-resolved, photometry in FUV and NUV from images
obtained by GALEX, and IRAC1 (3.6 m) photometry obtained by the Spitzer
Space Telescope. We analyzed the surface brightness profiles ,
, , as well as the radial evolution of the
(FUV-NUV), (FUV - [3.6]), and (NUV - [3.6]) colors in the Spitzer Survey of
Stellar Structures in Galaxies (SG) galaxies (d40 Mpc) sample. We
defined the GALEX Blue Sequence (GBS) and GALEX Red Sequence (GBR) from the
(FUV - NUV) versus (NUV - [3.6]) color-color diagram, populated by late-type
star forming galaxies and quiescent early-type galaxies respectively. While
most disk becomes radially bluer for GBS galaxies, and stay constant for GRS
galaxies, a large fraction (50%) of intermediary GALEX Green Valley (GGV)
galaxies' outer disks are becoming redder. An outside-in quenching mechanism
such as environmentally-related mechanisms such as starvation or
ram-pressure-stripping could explain our results.Comment: 3 pages 1 figure, to be published in the Proceedings of IAU Symposium
321, "Formation and evolution of galaxy outskirts", Eds. A. Gil de Paz, J. C.
Lee & J. H. Knapen, Cambridge University Press, Cambridg
Mapping the star formation history of Mrk86: I. Data and models
We have obtained optical (BVR, [OIII]5007 and Halpha), near infrared (JHK)
imaging and long-slit optical spectroscopy for the Blue Compact Dwarf galaxy
Mrk86 (NGC2537). In this paper, the first of two, we present optical-near-
infrared colors and emission-line fluxes for the currently star-forming
regions, intemediate aged starburst and underlying stellar population. We also
describe the evolutionary synthesis models used in Paper II. The R and Halpha
luminosity distributions of the galaxy star-forming regions show maxima at
M_R=-9.5 and L_Halpha=10^37.3 erg s^-1. The underlying stellar population shows
an exponential surface brigthness profile with central value, mu_E,0=21.5 mag
arcsec^-2, and scale, alpha=0.88 kpc, both measured in the R-band image. In the
galaxy outer regions, dominated by this component, no significant color
gradients are observed. Finally, a set of evolutionary synthesis models have
been developed, covering a wide range in metallicity and burst strength.Comment: 21 pages, 14 figures, 2 landscape tables, accepted for publication in
Astronomy & Astrophysics Supplement Series, for higher resolution images see
ftp://cutrex.fis.ucm.es/pub/OUT/gil/PAPERS/aa00_I.ps.g
An Empirical Connection between the UV Color of Early Type Galaxies and the Stellar Initial Mass Function
Using new UV magnitudes for a sample of early-type galaxies, ETGs, with
published stellar mass-to-light ratios, Upsilon_*, we find a correlation
between UV color and Upsilon_* that is tighter than those previously identified
between Upsilon_* and either the central stellar velocity dispersion,
metallicity, or alpha enhancement. The sense of the correlation is that
galaxies with larger Upsilon_* are bluer in the UV. We conjecture that
differences in the lower mass end of the stellar initial mass function, IMF,
are related to the nature of the extreme horizontal branch populations that are
generally responsible for the UV flux in ETGs. If so, then UV color can be used
to identify ETGs with particular IMF properties and to estimate Upsilon_*.Comment: Submitted for publication in ApJ Letter
Palomar/Las Campanas Imaging Atlas of Blue Compact Dwarf Galaxies: II. Surface Photometry and the Properties of the Underlying Stellar Population
We present the results from an analysis of surface photometry of B, R, and
Halpha images of a total of 114 nearby galaxies drawn from the Palomar/Las
Campanas Imaging Atlas of Blue Compact Dwarf galaxies. Surface brightness and
color profiles for the complete sample have been obtained. We determine the
exponential and Sersic profiles that best fit the surface brightness
distribution of the underlying stellar population detected in these galaxies.
We also compute the (B-R) color and total absolute magnitude of the underlying
stellar population and compared them to the integrated properties of the
galaxies in the sample. Our analysis shows that the (B-R) color of the
underlying population is systematically redder than the integrated color,
except in those galaxies where the integrated colors are strongly contaminated
by line and nebular-continuum emission. We also find that galaxies with
relatively red underlying stellar populations (typically (B-R)>~1mag) show
structural properties compatible with those of dwarf elliptical galaxies (i.e.
a smooth light distribution, fainter extrapolated central surface brightness
and larger scale lengths than BCD galaxies with blue underlying stellar
populations). At least ~15% of the galaxies in the sample are compatible with
being dwarf elliptical (dE) galaxies experiencing a burst of star formation.
For the remaining BCD galaxies in the sample we do not find any correlation
between the recent star formation activity and their structural differences
with respect to other types of dwarf galaxies.Comment: 35 pages, 6 figures, accepted for publication in ApJS. Postscript
files of panels f1a-f1o of figure 1 are available online at
http://www.ociw.edu/~agpaz/astro-ph/apjs2004
A 300 GHz "Always-in-Focus" Focusing System for Target Detection
A focusing system for a 300 GHz radar with 5 m target distance and 10 mm diameter spot size resolution is proposed. The focusing system is based on a Gaussian telescope scheme and its main parameters have been de¬signed using Gaussian beam quasi-optical propagation theory with an in-house developed MATLAB® based analysis tool. Then, this approach has been applied to a real focusing system based on two elliptical mirrors in order to reduce the distortion and cross-polar level and a plane mirror to provide scanning capabilities. The over¬all system has been simulated with a full-wave electromag¬netic simulator and its behavior is presented. With this approach, the focusing system always works "in-focus" since the only mirror that is rotated when scanning is the output plane mirror, so the beam is almost not distorted. The design process, although based in the well-known Gaussian beam quasi-optical propagation theory, provides a fast and accurate method and minimizes the overall size of the mirrors. As a consequence, the size of the focusing system is also reduced
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