Milimetre-band variability of the radio-quiet nucleus of NGC 7469

Baldi, Ranieri D.; Behar, E.; Laor, Ari; Horesh, A.

doi:10.1093/mnras/stv2284

Cited by 47 publications

(57 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In terms of luminosity, Laor & Behar (2008) used the PG quasar sample (Schmidt & Green 1983) to demonstrate that LR and LX are correlated and follow the well established LR/LX ∼ 10 −5 correlation observed in coronally active cool stars (Güdel & Benz 1993). In terms of variability, the sole mm-wave monitoring campaign of Baldi et al (2015) indicate the variability parameters of NGC 7469 at 95 GHz are similar to those of NGC 7469 in (non-simultaneous) archival X-ray data, only with much larger uncertainties. However, in order to truly test the connection between the mm-wave and X-ray sources of RQ AGN, simultaneous monitoring is essential.…”

Section: Connection To X-raysmentioning

confidence: 92%

“…In this paper, we report results from a dedicated monitoring campaign of NGC 7469 with the single 30 m dish of the Institut de Radioastronomie Millimetrique (IRAM) at 95 GHz and at 143 GHz, simultaneous with Swift/XRT and Swift/UVOT monitoring that was part of a multiwavelength campaign during the last part of 2015 (Behar et al 2017 was observed with CARMA Baldi et al 2015), and at 350 GHz with ALMA (Izumi et al 2015).…”

Section: Connection To X-raysmentioning

confidence: 99%

See 1 more Smart Citation

Simultaneous Millimetre-wave and X-ray monitoring of the Seyfert galaxy NGC 7469

Behar

Kaspi

Paubert

et al. 2019

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We report on daily monitoring of the Seyfert galaxy NGC 7469, around 95 GHz and 143 GHz, with the IRAM 30 m radio telescope, and with the Swift X-Ray and UV/Optical telescopes, over an overlapping period of 45 days. The source was observed on 36 days with IRAM, and the flux density in both mm bands was on average ∼ 10 mJy, but varied by ±50%, and by up to a factor of 2 between days. The present IRAM variability parameters are consistent with earlier CARMA monitoring, which had only 18 data points. The X-ray light curve of NGC 7469 over the same period spans a factor of 5 in flux with small uncertainties. Similar variability in the mm-band and in the X-rays lends support to the notion of both sources originating in the same physical component of the AGN, likely the accretion disk corona. Simultaneous monitoring in eight UV/optical bands shows much less variability than the mm and X-rays, implying this light originates from a different AGN component, likely the accretion disk itself. We use a tentative 14 day lag of the X-ray light curve with respect to the 95 GHz light curve to speculate on coronal implications. More precise mm-band measurements of a sample of X-ray-variable AGN are needed, preferably also on time scales of less than a day where X-rays vary dramatically, in order to properly test the physical connection between the two bands. Ulvestad et al. 2005) indicate source angular sizes as small as mas, or pc-scales for nearby sources, which can still be consistent with all of the above origins. Since these radio sources could be smaller than our contemporary imaging capability, one needs to revert to spectroscopy and timing in the attempt to characterize their physical origin.

show abstract

Section: Connection To X-raysmentioning

confidence: 92%

Section: Connection To X-raysmentioning

confidence: 99%

Simultaneous Millimetre-wave and X-ray monitoring of the Seyfert galaxy NGC 7469

Behar

Kaspi

Paubert

et al. 2019

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this work we make use of simulated halo catalogues extracted from a set of high resolution N-body simulations (Baldi 2012) of the standard ΛCDM cosmology, performed with the C-GADGET module (Baldi et al 2010). We adopt a model consistent with WMAP7 constraints (Komatsu et al 2011), with σ 8 = 0.809, h 0 = 0.703, Ω λ = 0.7289, Ω M = 0.2711, Ω b = 0.0451, and a power spectrum with an initial scalar amplitude of A s = 2.194 · 10 −9 and a primordial spectral index of n s = 0.96.…”

Section: Simulated Halo Cataloguesmentioning

confidence: 99%

Cosmological exploitation of the size function of cosmic voids identified in the distribution of biased tracers

Contarini

Ronconi

Marulli

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Cosmic voids are large underdense regions that, together with galaxy clusters, filaments and walls, build up the large-scale structure of the Universe. The void size function provides a powerful probe to test the cosmological framework. However, to fully exploit this statistics, the void sample has to be properly cleaned from spurious objects. Furthermore, the bias of the mass tracers used to detect these regions has to be taken into account in the size function model. In our work we test a cleaning algorithm and a new void size function model on a set of simulated dark matter halo catalogues, with different mass and redshift selections, to investigate the statistics of voids identified in a biased mass density field. We then investigate how the density field tracers' bias affects the detected size of voids. The main result of this analysis is a new model of the size function, parameterised in terms of the linear effective bias of the tracers used, which is straightforwardly inferred from the large-scale two-point correlation function. This method is a crucial step in exploiting real surveys. The proposed size function model has been accurately calibrated on halo catalogues, and used to validate the possibility to provide forecasts on the cosmological constraints, namely on the matter density contrast, Ω M , and on the normalisation of the linear matter power spectrum, σ 8 , at different redshifts.

show abstract

“…The Baldi et al 2015 andPronik 1976). On the basis of the dramatic spectral-variability of the optical Notes.…”

Section: Broad Componentmentioning

confidence: 99%

NGC 7469 as seen by MEGARA: new results from high-resolution IFU spectroscopy

Cazzoli

Paz

Márquez

et al. 2020

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present our analysis of high-resolution (R ∼ 20 000) GTC/MEGARA integral-field unit spectroscopic observations, obtained during the commissioning run, in the inner region (12.5 arcsec × 11.3 arcsec) of the active galaxy NGC 7469, at spatial scales of 0.62 arcsec. We explore the kinematics, dynamics, ionisation mechanisms and oxygen abundances of the ionised gas, by modelling the Hα-[N II] emission lines at high signal-to-noise (> 15) with multiple Gaussian components. MEGARA observations reveal, for the first time for NGC 7469, the presence of a very thin (20 pc) ionised gas disc supported by rotation (V/σ = 4.3), embedded in a thicker (222 pc), dynamically hotter (V/σ = 1.3) one. These discs nearly co-rotate with similar peak-to-peak velocities (163 vs. 137 km s −1 ), but with different average velocity dispersion (38 ± 1 vs. 108 ± 4 km s −1 ). The kinematics of both discs could be possibly perturbed by star-forming regions. We interpret the morphology and the kinematics of a third (broader) component (σ > 250 km s −1 ) as suggestive of the presence of non-rotational turbulent motions possibly associated either to an outflow or to the lense. For the narrow component, the [N II]/Hα ratios point to the star-formation as the dominant mechanism of ionisation, being consistent with ionisation from shocks in the case of the intermediate component. All components have roughly solar metallicity. In the nuclear region of NGC 7469, at r ≤ 1.85 arcsec, a very broad (FWHM = 2590 km s −1 ) Hα component is contributing (41 per cent) to the global Hα-[N II] profile, being originated in the (unresolved) broad line region of the Seyfert 1.5 nucleus of NGC 7469.

show abstract

Milimetre-band variability of the radio-quiet nucleus of NGC 7469

Cited by 47 publications

References 46 publications

Simultaneous Millimetre-wave and X-ray monitoring of the Seyfert galaxy NGC 7469

Simultaneous Millimetre-wave and X-ray monitoring of the Seyfert galaxy NGC 7469

Cosmological exploitation of the size function of cosmic voids identified in the distribution of biased tracers

NGC 7469 as seen by MEGARA: new results from high-resolution IFU spectroscopy

Contact Info

Product

Resources

About