Related papers: Low-Ionization BAL QSOs in Ultraluminous Infrared …
We report the discovery of disappearance of Mg ii, Al iii, C iv, and Si iv broad absorption lines (BALs) at the same velocity, accompanied by a new Civ BAL emerging at a higher velocity, in the quasar J0827+4252 at z = 2.038. This is the…
Narrow absorption line (NAL) outflows are an important yet poorly understood part of the quasar outflow phenomenon. We discuss one particular NAL outflow that has high speeds, time variability, and moderate ionizations like typical BAL…
In this paper we explore an evolutionary Unified scenario involving super massive black hole and starburst with outflow, that seems capable of explaining most of the observational properties of at least part of AGNs. Our suggestion is…
We present a detailed analysis of the Astrophysical Research Consortium 3.5 m telescope spectrum of QSO SDSS J0838+2955. The object shows three broad absorption line (BAL) systems at 22,000, 13,000, and 4900 km s^-1 blueshifted from the…
We present a statistical analysis of the associated, high ionization narrow absorption line (NAL) systems in a sample of 59 QSOs defined from the HST QSO Absorption Line Key Project. We have compiled the QSO luminosities at 2500 A, 5 GHz,…
We study the saturation effect on broad absorption line (BAL) variability through a variation phenomenon, which shows significant variation in Si IV BAL but no, or only small, change in C IV BAL (hereafter Phenomenon I). First, we explore a…
Recent results from the ROSAT All Sky Survey, and from deep ROSAT pointings reveal that broad absorption line quasars (BALQSOs) are weak in the soft X-ray bandpass (with optical-to-X-ray spectral slope alpha_{ox}>1.8) in comparison to QSOs…
We present near-IR, low resolution spectra of eight of the most distant quasars known, with redshifts in the range 4.9<z<6.4. Half of these quasars are characterized by deep, broad and blueshifted absorption features associated with both…
Broad absorption line quasars (BAL QSOs) are objects showing absorption from relativistic outflows, with velocities up to 0.2c. These manifest, in about 15% of quasars, as absorption troughs on the blue side of UV emission lines, such as C…
We study the X-ray and optical properties of 16 Broad Absorption Line (BAL) quasars detected in about 3 degree square region common to the wide synoptic (W-1) component of the Canada-France-HawaiiTelescope Legacy Survey (CFHTLS) and the XMM…
We present the results of a multi-wavelength study of a sample of high-redshift Radio Loud (RL) Broad Absorption Line (BAL) quasars. This way we extend to higher redshift previous studies on the radio properties, and broadband optical…
We have selected a sample of broad absorption line (BAL) quasars which show significant radio variations, indicating the presence of polar BAL outflows. We obtained snapshot XMM observations of four polar BAL QSOs, to check whether strong…
I report the discovery of blueshifted broad absorption line (BAL) troughs in at least six transitions of the Balmer series of hydrogen (Hbeta to H9) and in CaII, MgII and excited FeII in the quasar SDSS J125942.80+121312.6. This is only the…
The variability of quasar radiation provides a powerful probe of the photoionization response of ionized gas, which plays a central role in tracing cosmic evolution and plasma physics under extreme conditions. In this work, we investigate…
We present an observational study of wind acceleration based on four low-ionization broad absorption line (LoBAL) quasars (J0136, J1238, J1259, J1344). J0136 and J1344 (group-1) are radio quiet and show large BAL-velocity shifts as opposed…
We present an observational study of 22 broad absorption line quasars (BAL QSOs) at $3\lesssim z \lesssim5$ based on optical/near-IR spectroscopy, aiming to investigate quasar winds and their effects. The near-IR spectroscopy covers the…
We discover that some of the broad absorption lines (BALs) are actually a complex of narrow absorption lines (NALs). As a pilot study of this type of BAL, we show this discovery through a typical example in this paper. Utilizing 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 the results of EVN+MERLIN VLBI polarization observations of 8 Broad Absorption Line (BAL) quasars at 1.6 GHz, including 4 LoBALs and 4 HiBALs with either steep or flat spectra on VLA scales. Only one steep-spectrum source,…
We study the transient (i.e. emerging or disappearing) C IV broad absorption line (BAL) components in 50 radio detected QSOs using multi-epoch spectra available in Sloan Digital Sky Survey DR10. We report the detectionof 6 BALQSOs having at…