ترغب بنشر مسار تعليمي؟ اضغط هنا

Extended ionized-gas structures in Seyfert 2 galaxy Mrk 78

100   0   0.0 ( 0 )
 نشر من قبل Daria Kozlova
 تاريخ النشر 2019
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

Search for and study of extended emission-line regions (EELRs) related to AGN in early-type galaxies is interesting to probe the history of nuclear ionization activity and also to understand the process of external gas accretion. In this work, we present observations of the EELR in Mrk 78 obtained at the 6-m Russian telescope using the long-slit and 3D spectroscopy methods. We show that ionized-gas clouds at the 12-16 kpc projected distances from the nucleus are ionized by the AGN radiation. Also we have checked if the galaxy appearing in the optical images in the immediate neighbourhood of Mrk 78 near the external clouds is a dwarf companion or a part of a tidal structure. However, the spectrum of this galaxy, SDSS J074240.37+651021.4, obtained at the 6-m telescope corresponds to the distant background galaxy.



قيم البحث

اقرأ أيضاً

We present the results of the analysis of the X-ray spectrum of the Seyfert 2 Mrk 348, observed by Suzaku and XMM-Newton. The overall spectrum of Mrk 348 can be described by a primary power law continuum seen through three layers of absorption, of wh ich one is neutral and two are ionised. Comparing Suzaku (2008) and XMM-Newton (2002) observations we find variability of the X-ray spectral curvature. We suggest that the variability can be explained through the change of column density of both the neutral and one of the ionised absorbers, together with a variation of the ionisation level of the same absorber. We thus confirm one of the main features presented in past works, where intrinsic column density variability up to $sim 10^{23}$~cm$^{-2}$ was observed on time scales of months. We also find that the photon index of the underlying power law continuum ($Gamma sim 1.8$) is in agreement with the previous observations of this Seyfert 2.
We present near-infrared and optical emission-line and stellar kinematics of the Seyfert 2 galaxy Mrk 573 using the Near-Infrared Field Spectrograph (NIFS) at Gemini North and Dual Imaging Spectrograph (DIS) at Apache Point Observatory, respectively. By obtaining full kinematic maps of the infrared ionized and molecular gas and stellar kinematics in a 700 x 2100 pc^2 circumnuclear region of Mrk 573, we find that kinematics within the Narrow-Line Region (NLR) are largely due to a combination of both rotation and in situ acceleration of material originating in the host disk. Combining these observations with large-scale, optical long-slit spectroscopy that traces ionized gas emission out to several kpcs, we find that rotation kinematics dominate the majority of the gas. We find that outflowing gas extends to distances less than 1 kpc, suggesting that outflows in Seyfert galaxies may not be powerful enough to evacuate their entire bulges.
We investigate if the active galactic nucleus (AGN) of Mrk 590, whose supermassive black hole was until recently highly accreting, is turning off due to a lack of central gas to fuel it. We analyse new sub-arcsecond resolution ALMA maps of the $^{12} $CO(3-2) line and 344 GHz continuum emission in Mrk 590. We detect no $^{12}$CO(3-2) emission in the inner 150 pc, constraining the central molecular gas mass to $M({rm H_2}) lesssim 1.6 times 10^5, {M_{odot}}$, no more than a typical giant molecular gas cloud, for a CO luminosity to gas mass conversion factor of $alpha_{rm CO}sim 0.8,{M_{odot},rm (K ,km,s^{-1},pc^{2}})^{-1}$. However, there is still potentially enough gas to fuel the black hole for another $2.6 times 10^5$ years assuming Eddington-limited accretion. We therefore cannot rule out that the AGN may just be experiencing a temporary feeding break, and may turn on again in the near future. We discover a ring-like structure at a radius of $sim 1$ kpc, where a gas clump exhibiting disturbed kinematics and located just $sim 200$ pc west of the AGN, may be refueling the centre. Mrk 590 does not have significantly less gas than other nearby AGN host galaxies at kpc scales, confirming that gas reservoirs at these scales provide no direct indication of on-going AGN activity and accretion rates. Continuum emission detected in the central 150 pc likely originates from warm AGN-heated dust, although contributions from synchrotron and free-free emission cannot be ruled out.
We observed the nuclear region of the galaxy NGC 1365 with the integral field unit of the Gemini Multi Object Spectrograph mounted on the GEMINI-South telescope. The field of view covers $13^{primeprime} times 6^{primeprime}$ ($1173 times 541$ pc$^{2 }$) centered on the nucleus, at a spatial resolution of $52$ pc. The spectral coverage extends from $5600$ AA to $7000$ AA, at a spectral resolution $R=1918$. NGC 1365 hosts a Seyfert 1.8 nucleus, and exhibits a prominent bar extending out to $100^{primeprime}$ (9 kpc) from the nucleus. The field of view lies within the inner Lindblad resonance. Within this region, we found that the kinematics of the ionized gas (as traced by [OI], [NII], H$alpha$, and [SII]) is consistent with rotation in the large-scale plane of the galaxy. While rotation dominates the kinematics, there is also evidence for a fan-shaped outflow, as found in other studies based on the [OIII] emission lines. Although evidence for gas inflowing along nuclear spirals has been found in a few barred galaxies, we find no obvious signs of such features in the inner kiloparsec of NGC 1365. However, the emission lines exhibit a puzzling asymmetry that could originate from gas which is slower than the gas responsible for the bulk of the narrow-line emission. We speculate that it could be tracing gas which lost angular momentum, and is slowly migrating from the inner Lindblad resonance towards the nucleus of the galaxy.
254 - E. Congiu , M. Berton (1 2017
We present the first results of a radio survey of 79 narrow-line Seyfert 1 (NLS1) carried out with the Karl G. Jansky Very Large Array (JVLA) at 5 GHz in A configuration aimed at studying the radio properties of these sources. We report the detection of extended emission in one object: Mrk 783. This is intriguing, since the radio-loudness parameter R of this object is close to the threshold between radio-quiet and radio-loud active galactic nuclei (AGN). The galaxy is one of the few NLS1 showing such an extended emission at z < 0.1. The radio emission is divided in a compact core component and an extended component, observed on both sides of the nucleus and extending from 14 kpc south-east to 12 kpc north-west. There is no sign of a collimated jet, and the shape of the extended component is similar to those of some Seyfert galaxies. The properties of the emission are compatible with a relic produced by the intermittent activity cycle of the AGN.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا