Répartitions modales urbaines, externalités et instauration de péages: Le cas des externalités de congestion et des " externalités modales croisées "

Moureau, François

doi:10.2307/3502785

Cited by 23 publications

(54 citation statements)

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“…We assume that this is mostly dust emission heated by the nucleus. This is consistent with the 10-20 m nuclear spectrum taken by ISOCAM CVF in a $ 4 00 aperture (Mirabel et al 1999, see their Fig. 2).…”

Section: Cen Asupporting

confidence: 78%

Thermal Emission as a Test for Hidden Nuclei in Nearby Radio Galaxies

Whysong¹,

Antonucci²

2004

ApJ

132

164

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The clear sign of a hidden quasar inside a radio galaxy is the appearance of quasar spectral features in its polarized (scattered) light. However, that observational test requires suitably placed scattering material to act as a mirror, allowing us to see the nuclear light. A rather robust and more general test for a hidden quasar is to look for the predicted high mid-IR luminosity from the nuclear obscuring matter. The nuclear waste heat is detected and well isolated in the nearest narrow-line radio galaxy, Cen A. This confirms other indications that Cen A does contain a modest quasar-like nucleus. However, we show here that M87 does not: at high spatial resolution, the mid-IR nucleus is seen to be very weak and consistent with simple synchrotron emission from the base of the radio jet. This fairly robustly establishes that there are ''real'' narrow-line radio galaxies, without the putative accretion power and with essentially all the luminosity in kinetic form. Next, we show the intriguing morphology of Cygnus A, where all of the mid-IR emission is consistent with reprocessing by the hidden quasar known to exist from spectropolarimetry and other evidence.

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Section: Cen Asupporting

confidence: 78%

Thermal Emission as a Test for Hidden Nuclei in Nearby Radio Galaxies

Whysong¹,

Antonucci²

2004

ApJ

132

164

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“…1). While Mirabel et al (1999) found extended MIR emission from ISO observations, our high-resolution image is not sensitive to such di †use emission on scales much larger than the MANIAC Ðeld of view. Nevertheless, the photometry of the nuclear source is unaffected by this uncertainty because it is measured di †erentia-lly against the background.…”

Section: Centaurus Amentioning

confidence: 95%

N‐Band Imaging of Seyfert Nuclei and the Mid‐Infrared–X‐Ray Correlation

Krabbe¹,

Maiolino²

2001

ApJ

111

118

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We present new mid-infrared (N-band) images of a sample of eight nearby Seyfert galaxies. In all of our targets, we detect a central unresolved source, which in some cases has been identiÐed for the Ðrst time. In particular, we have detected the mid-infrared emission from the active nucleus of NGC 4945, which previously remained undetected at any wavelength but hard X-rays. We also detect circumnuclear extended emission in the Circinus galaxy along its major axis and Ðnd marginal evidence for extended circumnuclear emission in NGC 3281. The high spatial resolution of our data allows us to separate (1A .7) the Ñux of the nuclear point sources from the extended circumnuclear starburst (if present). We complement our sample with literature data for a number of nonactive starburst galaxies and relate the nuclear N-band Ñux to published hard (2È10 keV) X-ray Ñuxes. We Ðnd tight and well-separated correlations between the nuclear N-band Ñux and X-ray Ñux for both Seyfert and starburst nuclei that span over 3 orders of magnitude in luminosity. We demonstrate that these correlations can be used as a powerful classiÐcation tool for galactic nuclei. For example, we Ðnd strong evidence against NGC 1808 currently harboring an active Seyfert nucleus based on its position in the mid-infraredÈX-ray diagram. On the other hand, we conÐrm that NGC 4945 is in fact a Seyfert 2 galaxy.

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“…This emission is probably stellar in origin given the lack of a polycyclic aromatic hydrocarbon feature (Rigopoulou et al 1999) in the ISOPHOT-S spectrum. Rydbeck et al 1993;Mirabel et al 1999;Cyg A: Conway 1999;Whysong & Antonucci 2001;Radomski et al 2001). M87 is intermediate in jet power between Cyg A and Cen A (Owen, Eilek, & Kassim 2000;Chiaberge, Capetti, & Celotti 2001;Wan, Daly, & Guerra 2000;although Reynolds et al 1996b estimate the jet power of M87 to be nearly 2 orders of magnitude lower than do Owen et al 2000).…”

Section: Extended Galactic Emission?mentioning

confidence: 99%

Deep 10 Micron Imaging of M87

Perlman

Sparks

Radomski

et al. 2001

The Astrophysical Journal

110

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We analyze a 10.8 mm image of M87, obtained with the Gemini 8 m telescope ϩ OSCIR. The image has better than 0Љ .5 resolution and represents 7 hr of observing time, making it the deepest high-resolution mid-IR image ever. The core is marginally resolved, and we also detect five optically bright knots in the jet. The spectral energy distributions of these features are entirely consistent with synchrotron radiation; we find little evidence of thermal emission from a dusty torus. Four faint jet regions are below the noise level of these observations. We also find evidence for diffuse galactic emission.

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Répartitions modales urbaines, externalités et instauration de péages: Le cas des externalités de congestion et des " externalités modales croisées "

Cited by 23 publications

References 0 publications

Thermal Emission as a Test for Hidden Nuclei in Nearby Radio Galaxies

Thermal Emission as a Test for Hidden Nuclei in Nearby Radio Galaxies

N‐Band Imaging of Seyfert Nuclei and the Mid‐Infrared–X‐Ray Correlation

Deep 10 Micron Imaging of M87

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