Related papers: A Balmer-line Broad Absorption Line Quasar

We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z=0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z<1.3. However, their rest-frame 2…

We are involved in a program to derive properties of broad absorption line (BAL) winds in quasars using combined UV and X-ray observations. A major obstacle is large uncertainties in the derived BAL column densities because of partial…

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 UV to NIR spectroscopic observations of the quasar J0015+1842 and its proximate molecular absorber at z=2.631. The [OIII] emission line of the quasar is composed of a broad (FWHM~1600 km/s), spatially-unresolved component,…

We report the discovery of the first HeI*\lambda 10830 broad absorption line quasar FBQS J1151+3822. Using new infrared and optical spectra, as well as the SDSS spectrum, we extracted the apparent optical depth profiles as a function of…

We present the detection of a rare case of dramatic strengthening in the UV absorption profiles in the spectrum of the quasar J115122.14+020426.3 between observations ~2.86 years apart in the quasar rest-frame. A 2001 spectrum from the…

The early stage of massive galaxy evolution often involves outflows driven by a starburst or a central quasar plus cold mode accretion (infall), which adds to the mass build-up in the galaxies. To study the nature of these infall and…

We present $\it {ASCA}$ observations of the z=1.98 prototype BALQSO: PHL5200. The source was detected in both SIS and GIS. A power-law spectrum ($\alpha_E = 0.6^{+0.9}_{-0.6}$) with large intrinsic absorption (N$_H = 1.3^{+2.3}_{-1.1}…

We present here a detailed analysis of an unusual absorption line system in the quasar SDSS J122826.79+100532.2. The absorption lines in the system have a common redshifted velocity structure starting from $v\sim0$ and extending to…

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 discovery of excess broad band absorption near 2250 A (EBBA) in the spectra of seven broad absorption line (BAL) quasars. By comparing with the statistical results from the control quasar sample, the significance for the…

We analyze HST and ground based spectra of the brightest BALQSO in the UV: PG~0946+301. A detailed study of the absorption troughs as a function of velocity is presented, facilitated by the use of a new algorithm to solve for the optical…

We present NuSTAR hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas…

We analyse high-resolution VLT+UVES spectra of the low-ionization intrinsic absorber observed in the BAL QSO SDSS J001130.56+005550.7. Two narrow absorption systems at velocities -600 km/s and -22000 km/s are detected. The low-velocity…

We investigate the variability of CIV 1549A broad absorption line (BAL) troughs over rest-frame time scales of up to ~7 yr in 14 quasars at redshifts z>2.1. For 9 sources at sufficiently high redshift, we also compare CIV and SiIV 1400A…

The recent discovery by Cantalupo et al. (2014) of the largest (~500 kpc) and luminous Ly-alpha nebula associated with the quasar UM287 (z=2.279) poses a great challenge to our current understanding of the astrophysics of the halos hosting…

HE0141-3932 (zem=1.80) is a bright blue radio-quite quasar which reveals an emission line spectrum with an unusually weak Ly-alpha line. In addition, large redshift differences (Delta z=0.05) are observed between high ionization and low…

Low-ionization broad absorption line (BAL) QSOs present properties that cannot generally be explained by simple orientation effects. We have conducted a deep spectroscopic and imaging study of the host galaxies of the only four BAL QSOs…

Balmer absorption is a rare phenomenon in active galactic nuclei (AGNs). So far, only seven Balmer-absorption AGNs have been reported in literature. We here report the identification of SDSS\,J112611.63+425246 as a new Balmer-absorption AGN…

We study the dramatic decrease in iron absorption strength in the iron low-ionization broad absorption line quasar SDSS J084133.15+200525.8. We report on the continued weakening of absorption in the prototype of this class of variable broad…