The starburst ring around the Seyfert nucleus in NGC 7469

Wilson, A. S.; Helfer, Tamara T.; Haniff, Christopher A.; Ward, M.

doi:10.1086/170630

Cited by 105 publications

(80 citation statements)

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“…The 8.4 GHz map presented by Kukula et al (1995) also shows a point source surrounded by faint emission. Using our flux density and that given by Kukula et al (1995) at 8.4 GHz (obtained in June 1991, we obtain the integrated spectral index α 8.4 GHz 5 GHz = 0.9, similar to the α 15 GHz 5 GHz value determined by Wilson et al (1991). G: Most of the detected emission is from a compact component, though there appears to be an extension toward the north-east.…”

Section: Ngc 7469 (2300+086)supporting

confidence: 80%

“…Y: Our image shows a halo ∼4 kpc in extent around the dominant compact component, which is coincident with the optical nucleus (Clements 1981), similar to the images in Wilson et al (1991). Wilson et al (1991) determine the spectral index to be α 15 GHz 5 GHz ∼ 0.9.…”

Section: Ngc 7469 (2300+086)supporting

confidence: 78%

“…Wilson et al (1991) determine the spectral index to be α 15 GHz 5 GHz ∼ 0.9. The features seen in this source are also seen by Condon et al (1982) and Ulvestad et al (1981) in their lower resolution images.…”

Section: Ngc 7469 (2300+086)mentioning

confidence: 99%

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Milliarcsec-scale radio structure of a matched sample of Seyfert 1 and Seyfert 2 galaxies

Lal

Shastri²,

Gabuzda

2004

A&A

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Abstract.We have obtained mas-scale resolution very long baseline interferometry (VLBI) images of a sample of Seyfert 1 and Seyfert 2 galaxies at 5 GHz (wavelength, λ = 6 cm). The Seyferts of the two types were chosen to be matched in several orientation-independent properties, primarily in order to rigorously test predictions of the unified scheme. We detected all the 15 objects that we observed. In this paper we describe the observations and data reduction procedures, and present the VLBI radio images as well as simultaneous Very Large Array images that we obtained for these 15 Seyferts.

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Section: Ngc 7469 (2300+086)supporting

confidence: 80%

Section: Ngc 7469 (2300+086)supporting

confidence: 78%

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Milliarcsec-scale radio structure of a matched sample of Seyfert 1 and Seyfert 2 galaxies

Lal

Shastri²,

Gabuzda

2004

A&A

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“…For NGC 7469 several tracers (e.g. 5 GHz radio continuum, J, H, K imaging, PAHs, CO (2−1)) were found to be located in a circumnuclear ring/spiral arm system (Wilson et al 1991;Mazzarella et al 1994;Miles et al 1994;Genzel et al 1995;Davies et al 2004). A comparison with the starburst and molecular rings in NGC 1614 shows some prominent similarities.…”

Section: Comparing Ngc 1614 With Galaxies With Nuclear Molecular Ringsmentioning

confidence: 90%

The NGC 1614 interacting galaxy

König

Aalto

Müller

et al. 2013

A&A

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Minor mergers frequently occur between giant and gas-rich low-mass galaxies and can provide significant amounts of interstellar matter to refuel star formation and power active galactic nuclei (AGN) in the giant systems. Major starbursts and/or AGN result when fresh gas is transported and compressed in the central regions of the giant galaxy. This is the situation in the starburst minor merger NGC 1614, whose molecular medium we explore at half-arcsecond angular resolution through our observations of 12 CO (2−1) emission using the Submillimeter Array (SMA). We compare our 12 CO (2−1) maps with optical and Paα, Hubble Space Telescope and high angular resolution radio continuum images to study the relationships between dense molecular gas and the NGC 1614 starburst region. The most intense 12 CO emission occurs in a partial ring with ∼230 pc radius around the center of NGC 1614, with an extension to the northwest into the dust lane that contains diffuse molecular gas. We resolve ten giant molecular associations (GMAs) in the ring, which has an integrated molecular mass of ∼8 × 10 8 M . Our interferometric observations filter out a large part of the 12 CO (1−0) emission mapped at shorter spacings, indicating that most of the molecular gas is diffuse and that GMAs only exist near and within the circumnuclear ring. The molecular ring is uneven with most of the mass on the western side, which also contains GMAs extending into a pronounced tidal dust lane. The spatial and kinematic patterns in our data suggest that the northwest extension of the ring is a cosmic umbilical cord that is feeding molecular gas associated with the dust lane and tidal debris into the nuclear ring, which contains the bulk of the starburst activity. The astrophysical process for producing a ring structure for the final resting place of accreted gas in NGC 1614 is not fully understood, but the presence of numerous GMAs suggests an orbit-crowding or resonance phenomenon. There is some evidence that star formation is progressing radially outward within the ring, indicating that a self-triggering mechanism may also affect star formation processes. The net result of this merger therefore very likely increases the central concentration of stellar mass in the NGC 1614 remnant giant system.

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“…Seyfert galaxies, on the other hand, generally exhibit more compact emission or, in the more radioenergetic cases, linear structures, identifiable as jets and radio lobes (Wilson et al 1991). The use of radio morphology to distinguish the dominant activity within galaxies is well established (Norris et al 1988a;Wilson 1988;Crawford et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Australia Telescope National Facility

The Encyclopedia of Astronomy and Astrophysics

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It was once common to regard Seyfert and starburst galaxies as completely different types of object, but there is growing recognition that these classifications refer to the extremes of a continuous spectrum of galaxy types. In a previous study we investigated a sample of galaxies with ambiguous optical emission-line ratios and concluded from near-infrared spectroscopic observations that the sample consisted of composite galaxies, containing both a starburst and an active galactic nucleus (AGN). We now extend our study using radio synthesis and long-baseline interferometer observations made with the Australia Telescope, together with far-infrared IRAS observations, to discuss the relative contribution of starburst and AGN components to the overall luminosity of the composite galaxies. We find that only a small fraction of the radio emission (< 10%) can be attributed to an AGN, and that the majority of the far-infrared emission (> 90%) is probably due to the starburst component. We also show that an AGN contribution to the optical emission of as little as 10% is sufficient to account for the ambiguous line-ratio diagnostics.

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The starburst ring around the Seyfert nucleus in NGC 7469

Cited by 105 publications

References 0 publications

Milliarcsec-scale radio structure of a matched sample of Seyfert 1 and Seyfert 2 galaxies

Milliarcsec-scale radio structure of a matched sample of Seyfert 1 and Seyfert 2 galaxies

The NGC 1614 interacting galaxy

Australia Telescope National Facility

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