ABSTRACT We investigate the correlations between the black hole (BH) mass MBH, the velocity dispersion , the bulge mass MBu, the bulge average spherical density , and its spherical half-mass radius ...rh, constructing a database of 97 galaxies (31 core ellipticals, 17 power-law ellipticals, 30 classical bulges, and 19 pseudobulges) by joining 72 galaxies from the literature to 25 galaxies observed during our recent SINFONI BH survey. For the first time we discuss the full error covariance matrix. We analyze the well-known MBH- and MBH-MBu relations and establish the existence of statistically significant correlations between MBu and rh and anticorrelations between MBu and . We establish five significant bivariate correlations (MBH- - h, MBH- -rh, MBH-MBu- , MBH-MBu- h, MBH-MBu-rh) that predict MBH of 77 core and power-law ellipticals and classical bulges with measured and intrinsic scatter as small as dex and dex, respectively, or 0.26 dex when the subsample of 45 galaxies defined by Kormendy & Ho is considered. In contrast, pseudobulges have systematically lower MBH but approach the predictions of all of the above relations at spherical densities or scale lengths . These findings fit in a scenario of coevolution of BH and classical-bulge masses, where core ellipticals are the product of dry mergers of power-law bulges and power-law ellipticals and bulges the result of (early) gas-rich mergers and of disk galaxies. In contrast, the (secular) growth of BHs is decoupled from the growth of their pseudobulge hosts, except when (gas) densities are high enough to trigger the feedback mechanism responsible for the existence of the correlations between MBH and galaxy structural parameters.
Abstract
Low-luminosity active galactic nuclei, i.e.
$L_{\rm b{\rm ol}}$
/L
edd ∼ 10−6–10−3, constitute the bulk population of active galactic nuclei (AGNs). Powerful jets, common in these objects, ...are a crucial source of feedback energy-driving mass outflows into the host galaxy and the intergalactic medium. This paper reports the first direct measurement of powerful mass outflows traced by the forbidden high-ionization gas in the low-luminosity AGN NGC 1386 at scales of a few parsecs from the central engine. The high-angular resolution of the data allows us to directly measure the location, morphology and kinematic of the outflow. This has the form of two symmetrical expanding hot gas shells moving in opposite directions along the line of sight. The co-spatiality of the gas shells with radio emission seen at the same parsec scales and with X-rays indicates that this is a shock-driven outflow presumably induced by an incipient core jet. With a minimum number of assumptions, we derive a mass outflow rate of 11 M⊙ yr−1, comparable to those of powerful AGN. The result has strong implications in the global accounting of feedback mass and energy driven by a low-luminosity AGN into the medium and the corresponding galaxy evolution.
ABSTRACT Low-luminosity Active Galactic Nuclei (LLAGNs) are characterized for low-radiative efficiency, much less than one percent of their Eddington limit. Nevertheless, their main energy release ...may be mechanical, opposite to powerful AGN classes like Seyfert and Quasars. This work reports on the jet-driven mechanical energy and the corresponding mass outflow deposited by the jet in the central 170 parsecs of the nearby LLAGN ESO 428-G14. The jet kinetic output is traced through the coronal line Si vi λ19641 Å. It is shown that its radial extension, up to hundreds of parsecs, requires a combination of photoionization by the central source and shock excitation as its origin. From the energetics of the ionized gas it is found that the mass outflow rate of the coronal gas is in the range from 3–8 M⊙ yr−1, comparable to those estimated from H i gas at kiloparsec scales in powerful radio galaxies.
We present the first results of an analysis of the properties of the molecular gas in the nuclear regions (r 300 pc) of a sample of six nearby galaxies, based on new high-spatial-resolution ...observations obtained in the K-band with the near-infrared integral field spectrograph SINFONI at the Very Large Telescope. We derive 2D distributions of the warm molecular and ionized gas from the H2, Brγ and He i emission lines present in the spectra of the galaxies. We find a range of morphologies, including bar- and ring-like distributions and either centrally peaked or off-centre emission. The morphologies of the molecular and the ionized gas are not necessarily coincident. The observed emission-line ratios point towards thermal processes as the principal mechanism responsible for the H2 excitation in the nuclear and circumnuclear regions of the galaxies, independently of the presence of an active nucleus. We find that a rescaling of the H2 2.12 μm emission-line luminosity by a factor β 1200 gives a good estimate (within a factor of 2) of the total (cold) molecular gas mass. The galaxies of the sample contain large quantities of molecular gas in their centres, with total masses in the ∼105-108 M range. Nevertheless, these masses correspond to less than 3 per cent of the stellar masses derived for the galaxies in these regions, indicating that the presence of gas should not affect black hole mass estimates based on the dynamical modelling of the stars. The high spatial resolution provided by the SINFONI data allowed us to resolve a circumnuclear ring (with a radius of ∼270 pc) in the galaxy NGC 4536. The measured values of the Brγ equivalent width and the He i/Brγ emission-line ratio suggest that bursts of star formation occurred throughout this ring as recently as 6.5 Myr ago.
We present adaptive optics-assisted J- and K-band integral field spectroscopy of the inner 300 × 300 pc of the Seyfert 2 galaxy NGC 1068. The data were obtained with the Gemini Near-infrared ...Integral-Field Spectrograph integral field unit spectrometer, which provided us with high-spatial and high-spectral resolution sampling. The wavelength range covered by the observations allowed us to study the Ca viii, Si vi, Si vii, Al ix and S ix coronal line (CL) emission, covering ionization potentials up to 328 eV. The observations reveal very rich and complex structures, both in terms of velocity fields and emission-line ratios. The CL emission is elongated along the NE-SW direction, with the stronger emission preferentially localized to the NE of the nucleus. CLs are emitted by gas covering a wide range of velocities, with maximum blueshifts/redshifts of ∼ −1600/1000 km s−1. There is a trend for the gas located on the NE side of the nucleus to be blueshifted while the gas located towards the SW is redshifted. The morphology and the kinematics of the near-infrared CLs are in very good agreement with the ones displayed by low-ionization lines and optical CLs, suggesting a common origin. The line flux distributions, velocity maps, ionization structure (traced by the Si vii/Si vi emission-line ratio) and low-ionization emission-line ratios (i.e. Fe ii/Paβ and Fe ii/P ii) suggest that the radio jet plays an important role in the structure of the CL region of this object, and possibly in its kinematics.
We present an analysis of the H2 emission-line gas kinematics in the inner 4 arcsec radius of six nearby spiral galaxies, based on adaptive optics-assisted integral-field observations obtained in the ...K band with SINFONI/VLT. Four of the six galaxies in our sample display ordered H2 velocity fields, consistent with gas moving in the plane of the galaxy and rotating in the same direction as the stars. However, the gas kinematics is typically far from simple circular motion. We can classify the observed velocity fields into four different types of flows, ordered by increasing complexity: (1) circular motion in a disc (NGC 3351); (2) oval motion in the galaxy plane (NGC 3627 and NGC 4536); (3) streaming motion superimposed on circular rotation (NGC 4501); and (4) disordered streaming motions (NGC 4569 and NGC 4579). The H2 velocity dispersion in the galaxies is usually higher than 50 km s−1 in the inner 1-2 arcsec radii. The four galaxies with ordered kinematics have v/σ < 1 at radii less than 40-80 pc. The radius at which v/σ = 1 is independent of the type of nuclear activity. While the low values of v/σ could be taken as an indication of a thick disc in the innermost regions of the galaxies, other lines of evidence (e.g. H2 morphologies and velocity fields) argue for a thin disc interpretation in the case of NGC 3351 and NGC 4536. We discuss the implications of the high values of velocity dispersion for the dynamics of the gaseous disc and suggest caution when interpreting the velocity dispersion of ionized and warm tracers as being entirely dynamical. Understanding the nature and role of the velocity dispersion in the gas dynamics, together with the full 2D information of the gas, is essential for obtaining accurate black hole masses from gas kinematics.
We report 0.8–4.5 μm SpeX spectroscopy of the narrow-line Seyfert 1 galaxy Mrk 1239. The spectrum is outstanding because the nuclear continuum emission in the near-infrared (NIR) is dominated by a ...strong bump of emission peaking at 2.2 μm, with a strength not reported before in an active galactic nucleus. A comparison of the Mrk 1239 spectrum to that of Ark 564 allowed us to conclude that the continuum is strongly reddened by E(B−V) = 0.54. The excess of emission, confirmed by aperture photometry and additional NIR spectroscopy, follows a simple blackbody curve at T∼ 1200 K. This suggests that we may be observing direct evidence of dust heated to near to the sublimation temperature, likely produced by the putative torus of the unification model. Although other alternatives are also plausible, the lack of star formation, the strong polarization and low extinction derived for the emission lines support the scenario where the hot dust is located between the narrow line region and the broad line region.
Aims.Mrk 1210 is an outstanding Seyfert 2 galaxy because it displays signatures of recent circumnuclear star formation and a high level of X-ray activity, in addition to the classical spectral ...characteristics typical of an AGN. Here we investigate the extinction affecting the nuclear and extended emitting gas, the kinematics of the narrow-line region, and the physical properties and conditions of that gas. Methods.Near-infrared and optical spectra of the nuclear and extended emission region of Mrk 1210 are presented, covering the interval 0.4-2.4 μm. Emission and absorption lines were used to infer, respectively, the geometrical extension of the ionized gas and the contribution of the underlying stellar population to the observed integrated continuum. The emission line profiles were employed to study the kinematics in the NLR. The reddening and physical condition of the gas were investigated by means of flux ratios among permitted and forbidden lines. Results.The NIR nuclear spectrum is dominated by $\ion{H}{i}$ and $\ion{He}{i}$ recombination lines, as well as $\ion{S}{ii}$, $\ion{S}{iii}$, and $\ion{Fe}{ii}$ forbidden lines. Coronal lines of $\ion{S}{viii}$, $\ion{S}{ix}$, $\ion{Si}{vi}$, $\ion{Si}{x}$, and $\ion{Ca}{viii}$, in addition to molecular H2 lines, were also detected. The $^{12}{\rm CO(6{-}3)}$ 1.618 μm overtone bandhead helped to estimate the contribution of the stellar population to the continuum. It was found that $83\pm8\%$ of the H-band continuum has a stellar origin. It improves previous estimates, which claimed that at least 50% of the observed continuum was attributed to the AGN. Analysis of the emission line profiles, both allowed and forbidden, shows a narrower (${\it FWHM} \sim 500$ km s-1) line on top of a broad (${\it FWHM} > 1000$ km s-1) blue-shifted component. This seems to be associated to a nuclear outflow. This hypothesis is supported by 6 cm VLBI observations, which show a radio ejecta extending up to ~30 pc from the nucleus. This result does not require the presence of the hidden BLR claimed to be present in previous NIR observations of this object. Internal extinction, calculated by means of several indicators including $\ion{Fe}{ii}$ flux ratios not previously used before in AGNs, reveals a dusty AGN, while the extended regions are barely affected by dust, if at all. The density and temperature are calculated for the NLR using optical and NIR lines as diagnostic ratios. The results show electronic temperatures from 10 000 K up to 40 000 K and densities between $10^3{-}10^5$ cm-3. The higher temperatures show that shocks, most probably related to the radio outflow, must contribute to the line emission.
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