Related papers: Quasar Absorption Lines from Radiative Shocks: Imp…
Broad absorption lines (BALs) in quasar spectra identify high velocity outflows that might exist in all quasars and could play a major role in feedback to galaxy evolution. The viability of BAL outflows as a feedback mechanism depends on…
A generic assumption of ionization models of quasar absorption systems is that radiation from local sources is negligible compared with the cosmological background. We test this assumption and find that it is unlikely to hold for absorbers…
We present new results from our study of the X-rayed outflow of the z = 3.91 gravitationally lensed broad absorption line (BAL) quasar APM 08279+5255. These results are based on spectral fits to all the long exposure observations of APM…
Quasar outflows can play a crucial role in the evolution of their host galaxies through various feedback processes. This effect is expected to be particularly important when the universe was only 2-3 billion years old, during the period…
Massive AGN-driven outflows are invoked by AGN-galaxy co-evolutionary models to suppress both star formation and black hole accretion. Massive molecular outflows have recently been revealed in some AGN hosts. However, the physical…
Using the radio observations by FIRST and NVSS, we build a sample of 151 radio variable quasars selected from the Sloan Digital Sky Survey Data Release 3 (SDSS DR3). Six (probably another two) among them are classified as broad absorption…
We present the analysis of two outflows (S1 at --5500 km s$^{-1}$ and S2 at --9700 km s$^{-1}$) seen in recent HST/COS observations of quasar SDSS J0755+2306 (z = 0.854). The outflows are detected as absorption troughs from both…
We present observations of ionized gas outflows in eleven z$ =1.39-2.59$ radio-loud quasar host galaxies. Data was taken with the integral field spectrograph (IFS) OSIRIS and the adaptive optics system at the W.M. Keck Observatory targeting…
High velocity (HV) outflows are an important but poorly understood aspect of quasar/SMBH evolution. Outflows during the luminous accretion phase might play a critical role in "unveiling" young dusty AGN and regulating star formation in the…
Context. Quasar outflows play a significant role in the active galactic nucleus (AGN) feedback, impacting the interstellar medium and potentially influencing galaxy evolution. Characterizing these outflows is essential for understanding…
Associated absorption lines (AALs) in quasar spectra are valuable probes of the gas kinematics and physical conditions in quasar environments. The host galaxies are by definition in an active evolution stage that might involve large-scale…
We report on a variable high-velocity narrow absorption line outflow in the redshift 2.3 quasar J2123-0050. Five distinct outflow systems are detected with velocity shifts from -9710 to -14,050 km/s and CIV 1548,1551 line widths of FWHM =…
We study the origin of the cold molecular clumps in quasar outflows, recently detected in CO and HCN emission. We first describe the physical properties of such radiation-driven outflows and show that a transition from a momentum- to an…
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,…
Quasar feedback models often predict an expanding hot gas bubble which drives a galaxy-scale outflow. In many circumstances this hot gas radiates inefficiently and is therefore difficult to observe directly. We present an indirect method to…
Although now routinely incorporated into hydrodynamic simulations of galaxy evolution, the true importance of the feedback effect of the outflows driven by active galactic nuclei (AGN) remains uncertain from an observational perspective.…
We employ detailed photoionization models to infer the physical conditions of intrinsic narrow absorption line systems found in high resolution spectra of three quasars at z=2.6-3.0. We focus on a family of intrinsic absorbers characterized…
We explore the origin of fast molecular outflows that have been observed in Active Galactic Nuclei (AGN). Previous numerical studies have shown that it is difficult to create such an outflow by accelerating existing molecular clouds in the…
Outflows from active galactic nuclei (AGNs) seem to be common and are thought to be important from a variety of perspectives: as an agent of chemical enhancement of the interstellar and intergalactic media, as an agent of angular momentum…
Background quasars are potentially sensitive probes of galactic outflows provided that one can determine the origin of the absorbing material since both gaseous disks and strong bipolar outflows can contribute to the absorption…