We present VLA C and D array neutral hydrogen observations of the Seyfert galaxy NCG 3227. The neutral gas is highly disturbed due to the interaction with the nearby elliptical, NGC 3226 and D array observations (with resolution of 40″ and velocity resolution of 40 kms−1) revealed 2 extensive plumes stretching 88 kpc south and 44kpc north of NGC3227. Complex dynamics were observed in the disk, which subsequent C array observations (resolution of 19″ and 20 kms−1) resolved into two components: the galactic disk, which is not significantly disrupted by the interaction and is undergoing predominantly solid body rotation out to a radius of 7 kpc, and an anomalous velocity cloud (with a velocity of 170 kms−1 above systemic) which appears to be associated with the northern plume.

Radio emission from Seyfert nuclei appears to be intimately related to narrow line region (NLR) of ionised gas. Both regions have an extent of a few hundred parsecs corresponding to typically a few arcsec, and are only marginally resolved by ground based observations. HST and adaptive optics are giving optical images of the ionised gas with angular resolutions of order 0.1″. It is essential that high quality radio images are available with similar resolution so that models relating the two regions can be tested. The extended MERLIN is ideally suited for this task. It has angular resolutions of 0.05″ at 5GHz and 0.13″ at 1.5GHz and sensitivities of a few 10s of μJy. In this contribution we shall summarise the results on two objects.

The barred spiral Seyfert galaxy NGC 1365 has been observed in the radio continuum at wavelengths of 2, 6 and 20 cm, using scaled arrays of the VLA, and complete maps have been made in the J = 1–0 and J = 2–1 CO emission lines using the SEST. MEM maps of the 6 and 20 cm emission, as well as a spectral index map, have been produced with a resolution of 2″.3 × 0″.9, and the 2-cm map has a resolution of 0″.25 ×0″.10. The dominant continuum features are a number of unresolved sources with relatively flat non-thermal spectral indices (−0.3 to −0.5), immersed in an incomplete circumnuclear ring, which is superimposed upon a background that extends into the bar along the prominent dust lanes. The ring has angular dimensions of 8″ × 20″, which corresponds to a linear dimension of the order of 1 kpc. There is clear evidence of a jet, about 5″ long, originating at the position of the Seyfert nucleus and extending in a southeastern direction, closely along the minor axis of the galaxy. The jet has a steep non-thermal spectral index (–1.0) and is aligned along the axis of a conical shell of [OIII] emission. The CO molecular gas peaks at the nucleus and is strongly concentrated to the nucleus and bar regions with a certain enhancement along the bar. The total molecular hydrogen gas mass in the observed region is 2 × 1010M⊙, with 6 × 109M⊙ lying within 2.2 kpc of the nucleus. A full presentation of the results will be published in Astronomy and Astrophysics in 1994.

We developed a kinematic jet model for the motion and flux density evolution of the high frequency VLBI jet components C4 and C5 in the quasar 3C345 (Zensus et al. 1994) assuming the conservation of three basic quantities: the Lorentz factor, the angular momentum, and the opening angle of the jet. This model is a simplified description of the helical motion in a conical jet expected from the magnetodynamical model of Camenzind (1986) which is based on a black hole surrounded by a magnetized accretion disc. Our best fit yields Lorentz factors of 5.7 and 5.0 for components C4 and C5, respectively, and an angle between the jet axis and the observer's line of sight of 7.5°. These values are very close to those obtained by Unwin & Wehrle (1992) from component motion further out. An intrinsic bending of the jet axis is necessary to account for the common bent path of all jet components at core separations larger than about 4 mas. We found that differential Doppler boosting alone is not able to explain the flux density variations of component C4. A non-adiabatic expansion model of an inhomogeneous plasma cloud combined with differential Doppler boosting on a helical path fits the flux density evolution (Steffen et al. 1994). We find that the expansion in the decreasing part of the lightcurve is slower than expected from adiabatic expansion.

We have studied a sample of extragalactic jets within the context of a two component model. This model supposes the existence of two flows in the extragalactic jets. An electron-positron fast beam coming from the internal regions of the accretion disk, responsible for the VLBI jet at the parsec scale and for the observed superluminal speeds. A second slow component, responsible for the jet observed at larger scales. The fast beam is destroyed when the parallel magnetic field is smaller than a critical value, BII < Bcrit = 3.2 × 10−3np1/2, where np is the density of the background thermal plasma of the slow component.

The ‘Bloated Stars Scenario’ proposes that AGN broad line emission originates in the winds or envelopes of bloated stars (BS) (see e.g. Kazanas 1989 and references therein). Its main advantage over BLR cloud models is the gravitational confinement of the gas and its major difficulty the large estimated number of BSs and the resulting high collisional and evolutionary mass loss rates (see e.g. Begelman & Sikura 1991). Previous work on this model did not include detailed calculations of the line spectrum, modeled solar neighborhood super giants (SG) and used very simplified stellar distribution functions for the nucleus. Here (Alexander & Netzer, 1993) we calculate the emission line ratios by applying a detailed numerical photoionization code (Rees, Netzer & Ferland, 1989) to the wind and by assuming a detailed nucleus model (Murphy, Cohn & Durisen, 1990). Allowing for the yet unknown effects of the AGN's extreme conditions on stars and stellar evolution, we study a wide range of simplified wind structures rather than confine ourselves to normal SGs. Our model consists of a spherically symmetric outflowing wind that emanates from the surface of the BS (R∗ = 1013 cm, M∗ = 0.8M⊙, M = 10−6M⊙/yr) whose size and edge density are determined by various processes: Comptonization by the central continuum source (calculated self consistently for our Lion = 1046 erg/s model continuum by the photoionization code), tidal disruption by the black hole (Mbh = 8 × 107M⊙) and the limit set by the assumption that the wind's mass ≤ 0.2M⊙. This results in a large range of wind sizes, from 1013 to 1016 cm. We find that the line emission spectrum is mainly determined by the conditions at the edge of the wind rather than by its internal structure. Comptonization results in a very high ionization parameter at the edge which produces an excess of unobserved broad high excitation forbidden lines. The finite mass constraint limits the wind's size, increases the edge density and thus improves the results. Studying power-law wind structures (v(R) = v∗(R/R∗)−α where v∗ is the wind's base velocity at the BS's surface), we find that slow, decelerating, mass-constrained flows (v∗ = 50 m/s, α = 0.5) with high gas densities (108 to 1012 cm−3) are as successful as cloud models in reproducing the overall observed line spectrum. The Mg II λ2798 and N V λ1240 lines are however under-produced in our models. The denser the winds, the more efficient they are as BLR clouds. By calculating the Lα emission from the wind we adjust the number of BSs so as to obtain the BLR's observed EW(Lα). We find that only ∼ 5 × 104 BSs with dense winds (v∗ = 50 m/s, α = 0.5) are required in the inner 1/3 pc (∼ 0.005 of the total stellar population). This small fraction approaches that of SGs in the solar neighborhood. The calculated mass loss from such a small number of BSs is consistent with the observational constraints. We find that the required number of BSs, and consequently their mass loss rate, are a very sensitive functions of the wind's density structure (a ∼ 104 factor between the slow v∗ = 50 m/s, α = 0.5 model and the fast v∗ = 50 km/s, α = −2 model). In particular, high mass loss rules out SG-like BSs (v∗ = 10 km/s, α = 0). We conclude that BSs with dense winds can reproduce the BLR line spectrum and be supported by the stellar population without excessive mass loss and collisional destruction rates. The question whether such hitherto unobserved stars actually exist in the BLR remains open.

There is mounting evidence that type transitions are a common property among Active Galactic Nuclei: the broad lines in, at least, eleven Seyfert galaxies have ocassionaly appeared and subsequently disappeared leading to the reclasification of their nuclei from type 1–1.5 to type 1.8–2 or viceversa.

AGN optical spectra (4000–5000Å) have been obtained with the TV scanner of the 6-m telescope at Special Astrophysical Observatory (N. Arkhiz-North Caucasus) from 1986 to now. Most spectra were obtained with dispersion of 1 Å/channel and with 3–4Å spectral resolution and signal-to-noise ratio S/N=10–25 for individual spectra. NGC 4151, NGC 3516, NGC 5548 and NGC 7469 are the main sources of the programme and are also being used in international AGN watch programmes for diagnosis, estimation of the size and structure of the BLR.

NGC4151:

In 1987 the broad components of the Hβ and Hγ lines decreased strongly (on about 65% as compared with 1986) and fell to a level comparable to that of 1984. In 1988 they increased up approximately to the level of 1986. During the photometrically low state of NGC 4151 satellites of the strong Hβ, Hγ, Hδ and He II4686Å lines were suspected at radial velocities of +9400 km/s and −7500 km/s. The data are could be interprite a two-jet model with jet velocity of 8400–24000 km/s. (Bochkarev et al., 1989). Analysis of the spectra shows that the broad component of HeII λ 4686Å changed its asymmetry over 6 years. Bochkarev et al. (1992), Nazarova et al. (1993) discussed a possible explanation of profile HeII λ 4686Å behavior by involving a precession of cones of ionizing radiation.

NGC5548:

Cross-correction of the optical emission line light curves with the UV continuum light curve reveals that the lines respond to continuum variations with a time delay from 7 days for HeII 4686Å to 18 days for Hβ. Hγ responds more rapidly than the lower order Balmer lines and there is a general trend towards higher amplitude variations in higher-order lines. The time lags for the line variations are consistent with the general pattern of radial ionization stratification of the BLR. During 1988–89 Fe II in blend 4130Å varies with an amplitude of aproximately 20% about the mean, similar the amplitude of the Hβ variations and Balmer continuum.

NGC3516:

Variations of Hβ during 1986–88 were small (20%), the shape of the profile (including the assymetry) did not change, but Hγ - to Hβ ratios of the profile integrated intensities of broad component increased from 0.43 in 1986 to 0.8 in 1988. The 30% variations of continuum on characteristic time scale 10–15 days during the spring of 1988 were not accompanied by any noticeable changes in the line profile (Bochkarev et al., 1990).

Images of the Seyfert 2 galaxy NGC 5929 and its interacting companion NGC 5930 have been obtained with HST's Planetary Camera. This interacting pair is also known as Arp 90. Each galaxy was imaged in the wavelength regions of [O III] λλ 4959, 5007, Hα+[N II] λλ 6548, 6583, and the green and red continua. The nuclei of both galaxies contain emission line gas, enhanced in the images by using the appropriate continuum image to remove the contribution of the continuum light in the on-band images.

We have obtained a longslit spectrum at a position angle (PA) of 84.6° and passing within 0.38 arcsec of the nucleus of NGC 4151, using the FOC f/48 camera on the Hubble Space Telescope. The spectrum shows strong emission lines including [OII] λ 3727 and [OIII] λλ 4959, 5007. By fitting with Gaussian velocity profiles, we resolve the emission lines, within 1 arcsec of the nucleus, into a high and low velocity component. The low velocity component has a total range in radial velocity of 200 km s−1 and appears to be associated with material comprising the knots seen in the FOC, F501N [O III] image of NGC 4151, illustrated in Boksenberg (1993). The much weaker high velocity system has a range of 1000 km s−1, is more smoothly distributed in brightness and shows a peak brightness close to the nucleus. Because the slit did not intersect the nucleus it is possible to determine the PA at which the two velocity systems cross the zero velocity axis. This is at PA −26° for the low velocity system and PA +32° for the high velocity system. These PA values may be subject to a systematic error as the zero velocity is defined by the mean position of the line, in the absence of any external calibration.

Spectroscopic Observations were made to study 42 emission line objects. The analysis of these long slit spectra shows that 15 out of 42 galaxies are blue compact galaxies (BCGs). 21 of them are starforming or HII galaxies and 3 were found to be normal galaxies.

In late 1989 we started a monitoring campaign of the line profile variations of more than 40 Broad-Line Radio Galaxies (BLRG) at Calar Alto Observatory/Spain. BLRG are the most extreme species of AGN regarding line width and structure of their optical emission line profiles showing FWZI up to 35000 km s−1, eg. 3C332 or Arp102B. Quite often the broad emission line profiles are characterized by a double hump structure. The analysis of the broad emission lines provides information about fundamental parameters of the inner part of the AGN like size, structure and kinematics of the line emitting region. In the following we present line profile variations of a BLRG we are studying.

Three active nuclei environments have been observed with the integral field spectrograph TIGER operating in the visible domain : Mkn 34, NGC 5929 and M 51. These three objects exhibit linear radio-sources evocating expulsion of plasmons from the nucleus. Long-slit or Pérot-Fabry observations showed that the gas of the galaxies is interacting with the radio-emitter, and models of this interaction have been proposed. These new observations combines the two spatial dimensions of integral field spectrography (with 0.7″ FWHM) with the rather large spectral domain of classical spectrography.

The Lyα and the C IV line profiles in the spectra of quasars and Seyfert 1 galaxies can be described by a combination of a narrow and a broad component. Over four orders of magnitude in luminosity the profiles of Lyα and C IV lines in the quasar spectra are very similar but a change is observed in the C IV profile in the spectra of Seyfert 1 galaxies which cover a smaller luminosity range. The correlation of the FWHM of Lyα, C IV and Hβ lines suggests that the Lyα and C IV lines are emitted from clouds in a similar kinematic enviornment but part of C IV line may also be emitted from clouds which emit the Hβ line.

Infrared coronal emission lines are providing a new window for observation and analysis of highly ionized gas in Galactic and extragalactic sources such as Seyfert nuclei and classical novae shells. These lines are expected to be primary coolants in colliding galaxies, galaxy cluster cooling flows, cometary-compact HII regions, and supernova remnants. In this poster, we summarize results discussed in detail by Greenhouse et al. 1993, ApJS, 88, 23. We discuss approximately 74 infrared (1 < λ μm < 280) transitions within the ground configurations 2s22pk and 3s23pk (k = 1 to 5) or the first excited configurations 2s2p and 3s3p of highly ionized (χ ≥ 100 eV) O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, and Ni. We present results from detailed balance calculations, critical densities for collisional de-excitation, intrinsic photon rates, branching ratios, and excitation temperatures for the transitions. The temperature and density parameter space for dominant cooling via infrared coronal lines is presented, and the relationship of infrared and optical coronal lines is discussed.

NGC 1365 is a barred Seyfert 1.5 galaxy. Fig 1a is a contour plot of an [OIII]λ5007 image (Jörsäter & Lindblad 1989), showing a plume-like structure pointing towards SE in the direction of the minor axis of the galaxy, which also is the direction of the steepest velocity gradient in [OIII]λ5007. The plume is roughly aligned with a radio feature in the 6 and 20 cm continuum (see Sandqvist et al., this volume). The [OIII]-emission on the NW side is weaker. This plume-like structure is not seen in Hα.

The basic excitation mechanism for the emission lines of Seyfert galaxies is generally believed to be photoionization by radiation emerging from the central power source. In order to deduce the essential physical parameters appropriate to the narrow line region (NLR) on this basis and to overcome some systematic deficiencies of existing photoionization models, we drop the frequent assumption of a constant ionization parameter throughout the NLR and, in particular, allow for a range of densities at fixed radius. We predict all observed emission-lines (ranging from CIV λ1549 in the UV- to [SIII]λ9069 in the NIR spectral region) for the sample of Sy 2 galaxies using the code CLOUDY (Ferland 1993).

We consider multiwavelength observations of Broad Absorption Line (BAL) QSOs which include optical spectrophotometry supplemented by HST-FOS UV spectrophotometry and/or ROSAT-PSPC x-ray observations. For moderate to high redshift objects, increasing the wavelength coverage into the UV permits observation of BALs due to different ions of the same element for several different elements for the first time. By employing appropriate assumptions, ionic column densities as a function of outflow velocity can be derived from these observations, resulting in constraints on the level of ionization and chemical composition of the BAL region (BALR) gas and the photoionization model itself.

Recently Vacca & Conti (1992) have measured the ratio of the luminosity in the broad He II λ4686 emission feature to that in the Hβ emission line in fourteen starburst galaxies. They related these luminosity ratios to the relative numbers of Wolf-Rayet (type WNL) to O-type stars in these galaxies (higher is the ratio L(λ4686)/L(Hβ), higher is NWNL/NO). They found that in general the number ratios are an order of magnitude larger than those expected in region of constant star formation rate. On Fig. 1 the predicted line ratios of our starbursts models (instantaneous burst of star formation at time t = 0; initial mass function dN/dM = CM−2; stellar models from Meynet et al. 1993; conversion formula between the line ratios and the number ratios of WNL to O-type stars given by Vacca & Conti 1992, with η = 1) are compared with the observed values given by these authors. This figure shows that a starburst taking place about 2–3 millions years ago can account for the high observed values of L(λ4686)/L(Hβ). One sees that the effects of the age of the burst (i.e. the time elapsed since the burst) and of the metallicity are quite important. It is the hope that in a next future, it will be possible on the base of this kind of luminosity ratios to disentangle the various effects influencing the WR population resulting from a starburst.

Optical spectra of the galaxies NGC3227, Mkn6, Mkn9, Mkn279, Mkn376 with double-peaked emission lines are presented. The data were obtained with the 1024-pixel TV scanner of the 6-m telescope during the 1984–1991 period. The double-peaked structure of the Hβ line in most galaxies shows changes during this period and only in the galaxy Mkn6 is the double-peaked stucture of Hβ constant. In all the galaxies except Mkn6, the blue peak of line coincides with the rest-wavelength of the line (the opposite occurs in Mkn6).