X-ray and radio emission from the compact galaxy III ZW 2

Schnopper, H. W.; Delvaille, J. P.; Epstein, A.; Cash, Webster; Charles, P. A.; Bowyer, S.; Hjellming, R. M.; Owen, F. N.; Cotton, W. D.

doi:10.1086/182699

Cited by 25 publications

(20 citation statements)

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“…The two RIQs stand out from this trend: 1635þ119 has a flat radio spectrum, and that of PG 0007þ106 appears to be inverted. Although we do not have simultaneous flux measurements for PG 0007þ106, its spectral shape is confirmed by the observations of Schnopper et al (1978) and Gower & Hutchings (1984).…”

Section: The Nature Of the Riqssupporting

confidence: 53%

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The radio properties of radio-quiet quasars

Kukula

Dunlop

Hughes

et al. 1998

Monthly Notices of the Royal Astronomical Society

125

173

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A B S T R A C TAlthough radio-quiet quasars (RQQs) constitute տ 90 per cent of optically identified quasar samples, their radio properties are only poorly understood. In this paper we present the results of a multi-frequency VLA study of 27 low-redshift RQQs. We detect radio emission from 20 objects, half of which are unresolved (Յ 0:24 arcsec). In cases where significant structure can be resolved, double, triple and linear radio sources on scales of a few kpc are found. The radio emission (typically) has a steep spectrum (a ϳ 0:7, where S ϰ n ¹a ), and high brightness temperatures (T B Ն 10 5 K) are measured in some of the radio components. The RQQs form a natural extension to the radio luminosity-absolute magnitude distribution of nearby Seyfert 1s. We conclude that a significant fraction of the radio emission in RQQs originates in a compact nuclear source directly associated with the quasar. There are no significant differences between the radio properties of RQQs with elliptical hosts and those in disc galaxies within the current sample.

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Section: The Nature Of the Riqssupporting

confidence: 53%

“…The source is known to be variable at both radio and optical wavelengths (e.g. Schnopper et al 1978;Teräsranta et al 1992). A comparison of our 1992 December 1.4-GHz data with the 1991 August map by Miller shows that the flux of the core component has declined from 155.9 to 102.0 mJy over 16 months.…”

Section: Notes On Individual Objectsmentioning

confidence: 99%

The radio properties of radio-quiet quasars

Kukula

Dunlop

Hughes

et al. 1998

Monthly Notices of the Royal Astronomical Society

125

173

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“…-The quasi-simultaneous spectra of III Zw 2 as plotted in Figure 1. The reference S78 refers to Schnopper et al (1978), N79: Neugebauer et al (1979), K88: Kaastra & de Korte (1988). -SED data of PG 1407+265 as plotted in Figures 2 and 3.…”

Section: Discussionmentioning

confidence: 99%

THE CENTRAL ENGINES OF TWO UNUSUAL RADIO-INTERMEDIATE/QUIET ACTIVE GALACTIC NUCLEI: III Zw 2 AND PG 1407+265

Chen¹,

Cao²,

Bai³

2012

ApJ

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We use the accretion disk/corona+jet model to fit the multi-band spectral energy distributions (SEDs) of two unusual radio-intermediate/quiet quasars. It is found that the optical/UV emission of III Zw 2 is probably dominated by the emission from the accretion disk. The X-ray emission should be dominated by the radiation from the jet, while the contribution of the disk corona is negligible. The optical/UV component in the SED of PG 1407+265 can be well modeled as the emission from the accretion disk, while the IR component is attributed to the thermal radiation from the dust torus with an opening angle ∼ 50 • . If the X-ray continuum emission is dominated by the synchrotron emission of the jet, the source should be a "high peak frequency blazar", which obviously deviates the normal blazar sequence. The observed SED can also be fitted quite well by the accretion disk/corona model with the viscosity parameter α = 0.5. The spectrum of the accretion disk/corona in PG 1407+265 satisfies the weak line quasar criterion suggested in Laor & Davis.

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“…Schnopper et al (1978) described the onset of a huge, 4 yr long radio outburst which peaked around 1980. A more detailed radio light curve of this outburst was presented by Aller et al (1985); the source showed a 20-fold increase in radio flux density, rising from about 100 mJy at 8 GHz to over 2 Jy within 4 yr. For comparison, the typical amplitude variability in blazars like 3C 279 is usually not much larger than a factor of 2 or 3.…”

Section: Zw 2 (Pg 0007ϩ106 Mrk 1501mentioning

confidence: 99%

A Major Radio Outburst in III Z[CLC]w[/CLC] 2 with an Extremely Inverted, Millimeter-peaked Spectrum

Falcke¹,

Bower²,

Lobanov³

et al. 1999

The Astrophysical Journal

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III Zw 2 is a spiral galaxy with an optical spectrum and faint extended radio structure typical of a Seyfert galaxy, but also with an extremely variable, blazar-like radio core. We have now discovered a new radio flare in which the source has brightened more than 20-fold within less than 2 yr. A broadband radio spectrum between 1.4 and 666 GHz shows a textbook-like synchrotron spectrum peaking at 43 GHz, with a self-absorbed synchrotron spectral index ϩ2.5 at frequencies below 43 GHz and an optically thin spectral index Ϫ0.75 at frequencies above 43 GHz. The outburst spectrum can be well fitted by two homogenous, spherical components with equipartition sizes of 0.1 and 0.2 pc at 43 and 15 GHz and with magnetic fields of 0.4 and 1 G. VLBA observations at 43 GHz confirm this double structure and these sizes. Timescale arguments suggest that the emitting regions are shocks which are continuously accelerating particles. This could be explained by a frustrated jet scenario with very compact hot spots. Similar millimeter-peaked spectrum sources could have escaped our attention because of their low flux density at typical survey frequencies and their strong variability.

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X-ray and radio emission from the compact galaxy III ZW 2

Cited by 25 publications

References 0 publications

The radio properties of radio-quiet quasars

The radio properties of radio-quiet quasars

THE CENTRAL ENGINES OF TWO UNUSUAL RADIO-INTERMEDIATE/QUIET ACTIVE GALACTIC NUCLEI: III Zw 2 AND PG 1407+265

A Major Radio Outburst in III Z[CLC]w[/CLC] 2 with an Extremely Inverted, Millimeter-peaked Spectrum

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