The Optical Spectrum of PKS 1345+12

Grandi, S. A.

doi:10.1086/155374

Cited by 18 publications

(18 citation statements)

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“… The nuclear narrow component is consistent with the narrow component in the extended [O ii ] emission, the only component which can be traced across the entire spatial range. The redshift of the narrow component is consistent with the deep H i 21‐cm absorption observed by Mirabel (1989) and Morganti et al (2003) which is assumed to emanate from the ambient, quiescent ISM in the galaxy. It is also consistent with the redshift of the stellar absorption lines (Grandi 1977). The narrow component is by far the least kinematically disturbed component (FWHM = 340 ± 23 km s −1 ). The narrow component has a small velocity amplitude (Δ vel ≤ 250 km s −1 ) consistent with gravitational motions in low‐ z galaxies (Tadhunter, Fosbury & Quinn 1989).…”

Section: Resultssupporting

confidence: 86%

“…Consistent with its status as a powerful radio source ( P 5 GHz = 10 26 W Hz −1 ; O'Dea 1998 and references therein), the nucleus of PKS 1345+12 emits strong emission lines. However, although classified as an NLRG by Grandi (1977), it has very broad forbidden emission lines with complex structures and strong blue asymmetries.…”

Section: Previous Observations Of Pks 1345+12mentioning

confidence: 99%

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Highly extinguished emission line outflows in the young radio source PKS 1345+12

Holt

Tadhunter

Morganti³

2003

Monthly Notices of the Royal Astronomical Society

166

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We present intermediate resolution, large wavelength coverage spectra for the compact radio source PKS 1345+12 (4C 12.50, z = 0.122) that were taken with the aim of investigating the impact of the nuclear activity on the circumnuclear interstellar medium (ISM). Our spectra show extended line emission up to ∼20 kpc from the nucleus, consistent with the asymmetric halo of diffuse emission observed in optical and infrared images. At the position of the nucleus we observe complex emission line profiles and Gaussian fits to the [O III] emission lines require three components (narrow, intermediate and broad), the broadest of which has width ∼2000 km s −1 (FWHM) and is blueshifted by ∼2000 km s −1 with respect to the halo of the galaxy and H I absorption. We interpret this latter component as material in outflow. We also find evidence for large reddening [0.92 < E(B − V ) < 2.00] and high densities (n e > 4200 cm −3 ) for the most kinematically disturbed component. The corresponding total mass of line-emitting gas in the kinematically disturbed components is M gas < 10 6 M . Not all emission line profiles can be reproduced by the same model: [O I]λλ6300, 6363 and [S II]λλ6716, 6731 require separate, unique models. We argue that PKS 1345+12 is a young radio source with nuclear regions that are enshrouded in a dense cocoon of gas and dust. The radio jets are expanding through this cocoon, sweeping material out of the nuclear regions. Emission originates from three kinematically distinct regions, though gradients (e.g. in density, ionization potential, velocity) must exist across the regions responsible for the emission of the intermediate and broad components. C 2003 RAS 1 H 0 = 75 km s −1 , q 0 = 0.0 assumed throughout, resulting in a scale of 2.37 kpc arcsec −1 at z = 0.122. 2 S ∝ ν −α assumed throughout.

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Section: Resultssupporting

confidence: 86%

Section: Previous Observations Of Pks 1345+12mentioning

confidence: 99%

Highly extinguished emission line outflows in the young radio source PKS 1345+12

Holt

Tadhunter

Morganti³

2003

Monthly Notices of the Royal Astronomical Society

166

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“…Velocity shifts in the BLR lines relative to the forbidden NLR linesÈtaken to be at the systemic host-galaxy redshiftÈare seen for most quasars and are similar to the values we Ðnd for the composite BLR lines relative to [O III] j5007 (see, e.g., Tytler & Fan 1992 ;Laor et al 1995 ;McIntosh et al 1999). The origin of the shifts is not known, but explanations include gas inÑows and outÑows (see, e.g., Gaskell 1982 ;Corbin 1990), attenuation by dust (Grandi 1977 ;Heckman et al 1981), relativistic e †ects (Netzer 1977 ;Corbin 1995Corbin , 1997McIntosh et al 1999), and line emission from physically di †erent locations (see, e.g., Espey et al 1989). The magnitudes of the shifts seem to depend upon the ionization energies (Gaskell 1982 ;Wilkes 1986 ;Espey et al 1989 ;Tytler & Fan 1992 ;McIntosh et al 1999), in the sense that more negative velocities (blueshifts) are seen for higher ionization lines.…”

Section: Discussionsupporting

confidence: 80%

Composite Quasar Spectra from the Sloan Digital Sky Survey

Berk

Richards

Bauer

et al. 2001

The Astronomical Journal

1,579

772

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We have created a variety of composite quasar spectra using a homogeneous data set of over 2200 spectra from the Sloan Digital Sky Survey (SDSS). The quasar sample spans a redshift range of 0.044 ¹ z ¹ 4.789 and an absolute r@ magnitude range of [18.0 to [26.5. The input spectra cover an observed wavelength range of 3800È9200 at a resolution of 1800. The median composite covers a rest-A wavelength range from 800 to 8555 and reaches a peak signal-to-noise ratio of over 300 per 1 A A resolution element in the rest frame. We have identiÐed over 80 emission-line features in the spectrum. Emission-line shifts relative to nominal laboratory wavelengths are seen for many of the ionic species. Peak shifts of the broad permitted and semiforbidden lines are strongly correlated with ionization energy, as previously suggested, but we Ðnd that the narrow forbidden lines are also shifted by amounts that are strongly correlated with ionization energy. The magnitude of the forbidden line shifts is [100 km s~1, compared with shifts of up to 550 km s~1 for some of the permitted and semiforbidden lines. At wavelengths longer than the Lya emission, the continuum of the geometric mean composite is well Ðtted by two power laws, with a break at B5000 The frequency power-law index, is [0.44 from B1300 A. a l , to 5000 and [2.45 redward of B5000 The abrupt change in slope can be accounted for partly by A A. host-galaxy contamination at low redshift. Stellar absorption lines, including higher order Balmer lines, seen in the composites suggest that young or intermediate-age stars make a signiÐcant contribution to the light of the host galaxies. Most of the spectrum is populated by blended emission lines, especially in the range 1500È3500 which can make the estimation of quasar continua highly uncertain unless large A , ranges in wavelength are observed. An electronic table of the median quasar template is available.

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“…It is notable that kinematic disturbed components with high ionization state have been detected in the nuclear regions of several other objects, including the extended radio source Cygnus A (Tadhunter 1991), and the compact radio sources PKS 1549−79 (Tadhunter et al 2001), PKS 1345+12 (Grandi 1977) and 3C 48 (Chatzichristou, Vanderriest & Jaffe 1999). These three latter sources present high‐ionization emission lines that are unusually broad and shifted relative to the low‐ionization emission lines.…”

Section: Discussionmentioning

confidence: 99%

Shocks, illumination cones and intrinsic gas structures in the extreme radio galaxy 3C 265

Solórzano-Iñarrea¹,

Tadhunter²,

Bland-Hawthorn³

2002

Monthly Notices of the Royal Astronomical Society

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We present deep, narrow‐band and continuum images of the powerful high‐redshift radio galaxy 3C 265 (z=0.811), taken with the TAURUS Tunable Filter on the William Herschel Telescope, together with detailed long‐slit spectroscopic observations along the axis defined by the UV/optical emission elongation. The deep images reveal the existence of cones in the ionization structure of 3C 265 within ∼7 arcsec (58 kpc) of the nucleus, where the emission‐line structure is not observed to be closely aligned with the radio axis. This indicates that anisotropic illumination from the central active nucleus dominates on a small scale. In contrast, at larger distances (≳10 arcsec; 80 kpc) from the nucleus, low‐ionization emission gas is closely aligned with the radio axis, suggesting that jet–cloud interactions may become the dominant mechanism in the line‐emitting gas on a larger scale. Moreover, the presence of a high‐velocity cloud at 2.5 arcsec from the nucleus, close to the radio axis, indicates that even close to the nucleus (∼20 kpc) jet‐induced shocks have an important kinematic effect. However, spectroscopic analysis of this region reveals that the ionization state of the high‐velocity gas is similar to or higher than that of the surroundings, which is opposite to what we would expect for a cloud that has been compressed and accelerated by jet‐induced shocks. Our images show that, while on a large scale the low‐ionization emission‐line structures are aligned with the radio axis, on a smaller scale, where AGN‐photoionization dominates, the highest surface‐brightness structure is aligned with the closest companion galaxy (misaligned with the radio axis). This suggest that much of the emission‐line structure reflects the intrinsic gas distribution, rather than the ionization pattern imprinted by the radio jets or by illumination from the central AGN. Overall, our results underline the need for a variety of mechanisms to explain the properties of the extended emission‐line gas in the haloes of radio galaxies.

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The Optical Spectrum of PKS 1345+12

Cited by 18 publications

References 0 publications

Highly extinguished emission line outflows in the young radio source PKS 1345+12

Highly extinguished emission line outflows in the young radio source PKS 1345+12

Composite Quasar Spectra from the Sloan Digital Sky Survey

Shocks, illumination cones and intrinsic gas structures in the extreme radio galaxy 3C 265

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