No Arabic abstract
We present Integral Field Spectroscopic (IFS) observations of the nearby ($zsim0.03$) dual Active Galactic Nuclei (AGN) Mrk 739, whose projected nuclear separation is $sim$3.4~kpc, obtained with the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). We find that the galaxy has an extended AGN-ionized emission-line region extending up to $sim 20$ kpc away from the nuclei, while star-forming regions are more centrally concentrated within 2 - 3 kpc. We model the kinematics of the ionized gas surrounding the East nucleus using a circular disk profile, resulting in a peak velocity of $237^{+26}_{-28}$ km s$^{-1}$ at a distance of $sim 1.2$ kpc. The enclosed dynamical mass within 1.2 kpc is $log M(M_{odot})=10.20pm0.06$, $sim$1,000 times larger than the estimated supermassive black hole (SMBH) mass of Mrk 739E. The morphology and dynamics of the system are consistent with an early stage of the collision, where the foreground galaxy (Mrk 739W) is a young star-forming galaxy in an ongoing first passage with its background companion (Mrk 739E). Since the SMBH in Mrk 739W does not show evidence of being rapidly accreting, we claim that the northern spiral arms of Mrk 739W are ionized by the nuclear activity of Mrk 739E.
We present optical and near-IR Integral Field Unit (IFU) and ALMA band 6 observations of the nearby dual Active Galactic Nuclei (AGN) Mrk 463. At a distance of 210 Mpc, and a nuclear separation of $sim$4 kpc, Mrk 463 is an excellent laboratory to study the gas dynamics, star formation processes and supermassive black hole (SMBH) accretion in a late-stage gas-rich major galaxy merger. The IFU observations reveal a complex morphology, including tidal tails, star-forming clumps, and emission line regions. The optical data, which map the full extent of the merger, show evidence for a biconical outflow and material outflowing at $>$600 km s$^{-1}$, both associated with the Mrk 463E nucleus, together with large scale gradients likely related to the ongoing galaxy merger. We further find an emission line region $sim$11 kpc south of Mrk 463E that is consistent with being photoionized by an AGN. Compared to the current AGN luminosity, the energy budget of the cloud implies a luminosity drop in Mrk 463E by a factor 3-20 over the last 40,000 years. The ALMA observations of $^{12}$CO(2-1) and adjacent 1mm continuum reveal the presence of $sim$10$^{9}$M$_odot$ in molecular gas in the system. The molecular gas shows velocity gradients of $sim$800 km/s and $sim$400 km/s around the Mrk 463E and 463W nuclei, respectively. We conclude that in this system the infall of $sim$100s $M_odot$/yr of molecular gas is in rough balance with the removal of ionized gas by a biconical outflow being fueled by a relatively small, $<$0.01% of accretion onto each SMBH.
We present results of our analysis of NuSTAR data of the luminous infrared galaxy Mrk 266, which contains two nuclei, SW and NE, resolved in previous Chandra imaging. Combining with the Chandra data, we intepret the hard X-ray spectrum obtained from a NuSTAR observation as resulting from steeply rising flux from a Compton-thick AGN in the SW nucleus which is very faint in the Chandra band, confirming the previous claim of Mazzarella et al. (2012). This hard X-ray component is dominated by reflection, and its intrinsic 2-10 keV luminosity is likely to be ~1e43 erg/s. Although it is bright in soft X-ray, only moderately absorbed NE nucleus has a 2-10 keV luminosity of 4e41 erg/s, placing it in the low-luminosity AGN class. These results have implications for understanding the detectability and duty cycles of emission from dual AGN in heavily obscured mergers.
There is a supermassive black hole, a gaseous accretion disk and compact star cluster in the center of active galactic nuclei, as known today. So the activity of AGN can be represented as the result of interaction of these three subsystems. In this work we investigate the dynamical interaction of a central star cluster surrounding a supermassive black hole and a central accretion disk. The dissipative force acting on stars in the disk leads to an asymmetry in the phase space distribution of the central star cluster due to the rotating accretion disk. In our work we present some results of Stardisk model, where we see some changes in density and phase space of central star cluster due to influence of rotating gaseous accretion disk.
Radio Active Galactic Nuclei (RAGNs) are mainly found in dense structures (i.e., clusters/groups) at redshifts of z$<$2 and are commonly used to detect protoclusters at higher redshift. Here, we attempt to study the host and environmental properties of two relatively faint ($mathrm L_mathrm{1.4GHz} sim10^{25}$ W Hz$^{-1}$) RAGNs in a known protocluster at z=3.3 in the PCl J0227-0421 field, detected using the latest radio observation obtained as part of the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) Survey. Using new spectroscopic observations obtained from Keck/MOSFIRE as part of the Charting Cluster Construction with the VIMOS Ultra-Deep Survey (VUDS) and ORELSE (C3VO) survey and previous spectroscopic data obtained as part of the VIMOS-VLT Deep Survey (VVDS) and VUDS, we revise the three-dimensional overdensity field around this protocluster. The protocluster is embedded in a large scale overdensity protostructure. This protostructure has an estimated total mass of $sim$2.6$times10^{15} M_odot$ and contains several overdensity peaks. Both RAGNs are hosted by very bright and massive galaxies, while their hosts show extreme differences color, indicating that they have different ages and are in different evolutionary stages. Furthermore, we find that they are not in the most locally dense parts of the protostructure, but are fairly close to the centers of their parent overdensity peaks. We propose a scenario where merging might already have happened in both cases, which lowered the local density of their surrounding area and boosted their stellar mass. This work is the first time that two RAGNs at low luminosity have been found and studied within a high redshift protostructure.
We present the results of a multi-frequency, multi-scale radio polarimetric study with the Very Large Array (VLA) of the Seyfert 1 galaxy and BALQSO, Mrk 231. We detect complex total and polarized intensity features in the source. Overall, the images indicate the presence of a broad, one-sided, curved outflow towards the south which consists of a weakly collimated jet with poloidal inferred magnetic fields, inside a broader magnetized ``wind or ``sheath component with toroidal inferred magnetic fields. The model of a kpc-scale weakly collimated jet/lobe in Mrk 231 is strengthened by its C-shaped morphology, steep spectral index throughout, complexities in the magnetic field structures, and the presence of self-similar structures observed on the 10-parsec-scale in the literature. The ``wind may comprise both nuclear starburst (close to the core) and AGN winds, where the latter maybe the primary contributor. Moving away from the core, the ``wind component may also comprise the outer layers (or ``sheath) of a broadened jet. The inferred value of the (weakly collimated) jet production efficiency, $eta_mathrm{jet}sim$0.01 is consistent with the estimates in the literature. The composite jet and wind outflow in Mrk 231 appears to be low-power and matter-dominated, and oriented at a small angle to our line of sight.