Related papers: Absorption-line Environments of High-redshift BOSS…
We probe the small-scale absorption line variability using absorption depth based analysis of a sample of 64 ultra-fast outflow (UFO) C IV broad absorption line (BAL) quasars monitored using the Southern African Large Telescope. We confirm…
We present the analysis of the absorption troughs of six outflows observed in quasar SDSS J1130+0411 ($z \approx 3.98$) with radial velocities ranging from $-2400$ to $-15,400$ km s$^{-1}$. These spectra were taken with the Very Large…
The flow of gas into and out of galaxies leaves traces in the circumgalactic medium which can then be studied using absorption lines towards background quasars. We analyse 27 log(N_HI) > 18.0 HI absorbers at z = 0.2 to 1.4 from the…
Determining the distance of quasar absorption outflows from the central source (R) and their kinetic luminosity are crucial for understanding their contribution to active galactic nucleus (AGN) feedback. Here we summarize the results for a…
We conducted a survey of quasar outflows using the VLT/X-shooter spectrograph. When choosing the 14 BAL and mini-BALs comprising this sample, the data did not cover the S IV and S IV* troughs, whose ratio can be used to determine the…
The observation that the extremely broad, blueshifted absorption troughs which characterize broad absorption line quasars (BALQs) occur exclusively in radio-quiet quasars (RQQs) suggests that this class of active galactic nuclei (AGN) may…
We report, for the first time, a synchronized velocity shift of Mg II and Al III broad absorption lines (BALs) in quasar SDSS J134444.33+315007.6 (hereafter J1344+3150). We found this quasar from a sample of 134 Mg II BAL quasars with…
We examine the UV and X-ray properties of 256 radio-quiet SDSS quasars (QSOs) observed in X-rays with Chandra and/or XMM-Newton in order to study the relationship between QSOs with broad CIV absorption lines (BALs; width >2000 km/s) and…
We report on the discovery of a peculiar Broad Absorption Line (BAL) quasar identified in our Gaia-assisted survey of red quasars. The systemic redshift of this quasar was difficult to establish due to the absence of conspicuous emission…
We study the distribution and kinematics of the cool circumgalactic medium (CGM) of emission line galaxies (ELGs) traced by metal absorption lines. Using about 200,000 ELGs from SDSS-IV eBOSS and half a million background quasars from SDSS,…
We present results from a comprehensive study of ultrafast outflows (UFOs) detected in a sample of fourteen quasars, twelve of which are gravitationally lensed, in a redshift range of 1.41-3.91, near the peak of the AGN and star formation…
Outflows in active galactic nuclei (AGNs) are crucial to understand in investigating the co-evolution of supermassive black holes (SMBHs) and their host galaxies since outflows may play an important role as an AGN feedback mechanism. Based…
We present the calculations of steady, spherical gas outflows from galaxies in an effort to understand the effects of the galaxy mass on the flow properties such as the size of the outflow regions, the efficiency of radiative cooling, and…
We present spatially resolved kinematic measurements of AGN-driven outflows in dwarf galaxies in the stellar mass range $\sim6\times10^8 - 9\times10^9 M_\odot$, selected from SDSS DR7,8 and followed up with Keck/LRIS spectroscopy. We find…
We present the first observation of a galaxy (z=0.2) that exhibits metal-line absorption back-illuminated by the galaxy ("down-the-barrel") and transversely by a background quasar at a projected distance of 58 kpc. Both absorption systems,…
Some cosmological hydrodynamical simulations predict that outflows driven by active galactic nuclei (AGN) play a key role in powering the Ly$\alpha$ nebulae observed around high-redshift quasars. In such simulations, AGN feedback seeded as…
The quasar mode of Active Galactic Nuclei (AGN) in the high-redshift Universe is routinely observed in gas-rich galaxies together with large-scale AGN-driven winds. It is crucial to understand how photons emitted by the central AGN source…
We briefly review, at a level appropriate for graduate students and non-specialists, the field of quasar absorption lines (QALs). Emphasis is on the intervening absorbers. We present the anatomy of a quasar spectrum due to various classes…
The various ionization mechanisms at play in active galactic nuclei (AGN) and quasars have been well studied, but relatively little has been done to separately investigate the contributions of these ionization mechanisms within the host…
Absorption line spectroscopy using background quasars can provide strong constraints on galactic outflows. In this paper, we investigate possible scaling relations between outflow properties, namely outflow velocity \Vout, the mass ejection…