相关论文: Quasar winds caught on acceleration and decelerati…

Quasar outflows have been posited as a mechanism to couple super-massive black holes to evolution in their host galaxies. We use multi-epoch spectra from the Hubble Space Telescope and ground-based observatories to study the outflows in…

FeLoBALs are a rare class of quasar outflows with low-ionization broad absorption lines (BALs), large column densities, and potentially large kinetic energies that might be important for `feedback' to galaxy evolution. In order to probe the…

We report the discovery of a Broad Absorption Line (BAL) of \sim 10^4 km s-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as a Mg II BAL. This is the first detection of a BAL, which is…

We present a two-epoch Sloan Digital Sky Survey and Gemini/GMOS+William Herschel Telescope/ISIS variability study of 50 broad absorption line quasars of redshift range 1.9 < z < 4.2, containing 38 Si IV and 59 C IV BALs and spanning…

Recent studies have shown that outflows in at least some broad absorption line (BAL) quasars are extended well beyond the putative dusty torus. Such outflows should be detectable in obscured quasars. We present four WISE selected infrared…

We present the optical-near infrared spectral energy distributions (SED) and near infrared variability properties of 30 low-redshift iron low-ionization Broad Absorption Line quasars (FeLoBALQs) and matched samples of LoBALQs and unabsorbed…

We present combined $\approx 14-37~\rm ks$ Chandra observations of seven $z = 1.6-2.7$ broad absorption line (BAL) quasars selected from the Large Bright Quasar Survey (LBQS). These seven objects are high-ionization BAL (HiBAL) quasars, and…

We report the results of a pilot study of CO$(4-3)$ emission line of three {\it WISE}-selected hyper-luminous, dust-obscured quasars (QSOs) with sensitive ALMA Band 3 observations. These obscured QSOs with $L_{\rm bol}>10^{14}L_\odot$ are…

The blue-shifted broad absorption lines (BAL) or troughs are observed in Active Galactic Nuclei (AGNs) when our line of sight is intercepted by a high speed outflow (wind), likely originating in the accretion disc. The outflow or wind can…

Quasars that exhibit blue-shifted, broad absorption lines (BAL QSOs) are an important probe of black hole feedback on galaxy evolution. Yet the presence of BALs is also a complication for large, spectroscopic surveys that use quasars as…

In this study, we investigated the orientation model of Broad Absorption Line (BAL) quasars using a sample of sources that are common in Sloan Digital Sky Survey (SDSS) Data Release (DR)-16 quasar catalog and Very Large Array (VLA)-Faint…

We present new more sensitive high-resolution radio observations of a compact broad absorption line (BAL) quasar, 1045+352, made with the EVN+MERLIN at 5 GHz. They allowed us to trace the connection between the arcsecond structure and the…

We present a study of molecular gas, traced via CO (3-2) from ALMA data, of four z< 0.2, `radio quiet', type 2 quasars (log [L(bol)/(erg/s)] = 45.3 - 46.2; log [L(1.4 GHz)/(W/Hz)] = 23.7 - 24.3). Targets were selected to have extended radio…

Various unification schemes interpret the complex phenomenology of quasars and luminous active galactic nuclei (AGN) in terms of a simple picture involving a central black hole, an accretion disc and an associated outflow. Here, we continue…

We analyze VLT/UVES observations of the quasar SDSS J024221.87+004912.6. We identify four absorption outflow systems: a CIV BAL at $v\approx -18,000 \text{ km s}^{-1}$, and three narrower low-ionization systems with centroid velocities…

It is been known for more than a decade that BALQSOs (broad absorption line quasars) are highly attenuated in the X-ray regime compared to other quasars, especially in the soft band ($< $ 1 keV). Using X-ray selection techniques we have…

Blue-shifted Broad Absorption Lines (BALs) detected in quasar's spectra are indicative of AGN outflows. We show, using 2D hydrodynamical simulations, that disruption of interstellar clouds by a fast AGN wind can lead to formation of cold,…

We present high-resolution VLT/UVES spectroscopy and a detailed analysis of the unique Broad Absorption-Line system towards the quasar SDSS J165252.67+265001.96. This system exhibits low-ionization metal absorption lines from the ground…

We consider how the profile and multi-year variability properties of a large sample of C IV Broad Absorption Line (BAL) troughs change when BALs from Si IV and/or Al III are present at corresponding velocities, indicating that the…

We report the detection of a Broad Absorption Line (BAL) outflow in the spectrum of Tol 1037-2703 with three main BALs at 36000, 25300 and 22300~\kms outflow velocities. Although the overall flow is dominated by high ionization lines like…