170,897 research outputs found
Spartan Daily, May 8, 2013
Volume 140, Issue 51https://scholarworks.sjsu.edu/spartandaily/1418/thumbnail.jp
The first IRAM/PdBI polarimetric millimeter survey of active galactic nuclei. II. Activity and properties of individual sources
We present an analysis of the linear polarization of six active galactic
nuclei - 0415+379 (3C~111), 0507+179, 0528+134 (OG+134), 0954+658, 1418+546
(OQ+530), and 1637+574 (OS+562). Our targets were monitored from 2007 to 2011
in the observatory-frame frequency range 80-253 GHz, corresponding to a
rest-frame frequency range 88-705 GHz. We find average degrees of polarization
m_L ~ 2-7%; this indicates that the polarization signals are effectively
averaged out by the emitter geometries. We see indication for fairly strong
shocks and/or complex, variable emission region geometries in our sources, with
compression factors 10 deg. An
analysis of correlations between source fluxes and polarization parameter
points out special cases: the presence of (at least) two distinct emission
regions with different levels of polarization (for 0415+379) as well as
emission from a single, predominant component (for 0507+179 and 1418+546).
Regarding the evolution of flux and polarization, we find good agreement
between observations and the signal predicted by "oblique shock in jet"
scenarios in one source (1418+546). We attempt to derive rotation measures for
all sources, leading to actual measurements for two AGN and upper limits for
three sources. We derive values of RM = -39,000 +/- 1,000 (stat) +/- 13,000
(sys) rad/m^2 and RM = 420,000 +/- 10,000 (stat) +/- 110,000 (sys) rad/m^2 for
1418+546 and 1637+574, respectively; these are the highest values reported to
date for AGN. These values indicate magnetic field strengths of the order
~0.0001 G. For 0415+379, 0507+179, and 0954+658 we derive upper limits |RM| <
17,000 rad/m^2. From the relation |RM| ~ nu^a we find a = 1.9 +/- 0.3 for
1418+546, in good agreement with a = 2 as expected for a spherical or conical
outflow.Comment: 23 pages, 8 figures, 4 tables. Accepted by Astronomy and
Astrophysics. Minor language editing, one missing reference (Macquart et al.
2006) adde
The Crescent - March 12, 1940
Volume 51, Number 10https://digitalcommons.georgefox.edu/the_crescent/1418/thumbnail.jp
The Carbon (November 3, 1972)
https://mushare.marian.edu/crbn/1418/thumbnail.jp
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MGRRE_ThinSections_MGRRE_13_124
https://scholarworks.wmich.edu/tsi/1418/thumbnail.jp
Legislative History: An Act To Restrict the Use of Credit Scoring for Insurance Purposes (HP335)(LD 419)
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