Quasar absorption lines in flat universes with nonzero cosmological constant Lambda are examined and

quasar's broad emission lines. The reddest extent of the broad-line absorption .... lines from the quasar and the low signal-to-noise ...

The optical absorption lines of quasars are examined, and implications of the lines for the physical

These types of lines, called self-absorption systems, have been found in high- redshift quasars and were thought to be produced by material in the quasar ...

Quasar Absorption Lines By J I LL BECHTOLD 1 1 Steward Observatory and the Department of Astronomy lines observed in quasar spectra have given us a detailed picture of the in- tergalactic medium of quasars in the mid- 1960's (Sandage 1965, Gunn & Peterson 1965, Kinman ...

Quasar Absorption Line Systems with the. 2175� Galactic Extinction Bump at z~1.4 ... z=1.3947 towards quasar J1459+0024. The vertical thick blue dash ...

We report on an observation of the broad absorption line (BAL) quasar PG 1115+080 performed with the XMM-Newton observatory. Spectral analysis reveals the second case of a relativistic X-ray-absorbing outflow in a BAL quasar. The first case was revealed i...

Abstract: Quasars variability, distribution, absorption line characteristics, red shift peaks, physical models, cosmological problems, etc ...

Radio continuum spectra are presented for 15 Broad Absorption Line Quasars (BALQs), obtained with the VLA and typically covering four frequencies in the observed range 1.5 to 14.9 GHz. We find the radio spectral shapes of BALQs to be heterogeneous and similar to the shapes found in a general sample of 39 radio quiet ...

Analysis of the spacing between absorption-line systems in quasar spectra and comparison against deep optical survey data for the separation between superclusters of galaxies indicates that the absorption originates in the superclusters. Supported by analogous data on the absorbing gas in the galactic and Magellanic Cloud halos, this ...

Two different interpretations of the phenomenon of broad absorption line (BAL) QSOs are presented and a resolution is suggested. One interpretation is that the BAL clouds cover most of the sky as viewed from the quasar; this implies that BALQSOs are an usual subset of the general class of QSOs. The other interpretation suggests that ...

@ufs.br Considering that quasars evolve into normal galaxies the average ex- pansion velocity of matter in quasars (or galaxies) can be estimated approximately. Such velocity makes us to see the light of quasars slightly on observations of absorption lines of gas clouds seen against background ...

A modified version of the code LINESPEC designed for many purposes is described. Its main goal is to simulate absorption line spectra of the quasars. The spectras are formed due to passing of continuous quasar radiation through distant intervening clouds ...

It was investigated whether the double trough (DT) structure in the mean C IV BAL trough reported by

Broad absorption line (BAL) quasars exhibit broad line aborption in their ultraviolet spectra at outflow velocities up to or even exceeding 0.1c. We compare recently-obtained quasar spectra to those in the Large Bright Quasar Survey (LBQS) to study the variation of BAL ...

We present a very high signal-to-noise ratio composite spectrum created using 657 radio-selected quasars from the FIRST Bright Quasar Survey. The spectrum spans rest-frame wavelengths 900 -- 7500 A. Additionally we present composite spectra formed from subsets of the total data set in order to investigate the spectral dependence on radio loudness and ...

A new attempt is made to identify absorption lines in quasar spectra with H/sub 2/ and CO molecular lines on the basis of actual ultraviolet spectra of the galactic interstellar medium. No molecular lines can be detected in the spectra of 4C 05.34, OQ 172, or 0830+115. In a fourth ...

(QIALs) and spatially intervening absorp- tion lines (SIALs). QIALs are thought to be produced by gas absorbers, which produce lines with b = 10,000�20,000 km s�1, are thought to be at a distance of a few tensSUBARU HIGH-RESOLUTION SPECTROSCOPY OF COMPLEX METAL ABSORPTION LINES OF THE ...

In the spectrum of the quasar PKs 2020--370 (z/sub em/ = 1.050), we find Ca II absorption lines both at near zero redshift and at z/sub abs/ = 0.02865 +- 0.00007. The latter is closely similar to the redshifts of two galaxies in the group Klemola 31, which are nearby on the plane of the sky. This observation adds to the evidence that ...

? A third quasar absorption sample consistent with varying #11; John K. Webb, Michael T. Murphy, Victor V Abstract. We report preliminary results from a third sample of quasar absorption line spectra from the Keck:7. We include a brief discussion of small-scale kinematic structure in ...

Nov 12, 2000 ... These gas clouds leave numerous absorption lines in a distant quasar's spectra, together called the Lyman-alpha forest. ...

Jul 5, 2007 ... Abstract: Quasars variability, distribution, absorption line characteristics, red shift peaks, physical models, cosmological problems, etc ...

Feb 16, 1998 ... Do you truly believe that red-shifts can be utilized as a valid means of ... that have redshifts determined from the absorption lines -- and these ...

Abstract: Quasars variability, distribution, absorption line characteristics, red shift peaks, physical models, cosmological problems, etc ...

... where I have developed a course entitled "Archaeoastronomy and World Cosmology." My research area is actually in quasar absorption line spectroscopy, ...

... where I have developed a course entitled "Archaeoastronomy and World Cosmology." My research area is actually in quasar absorption line spectroscopy, ...

Accordling to the theory of big-bang nucleosynthesis (Yang ... the Lyman a absorption lines in high red-shift quasar spectra. These systems are ...

It is proposed that the infalling (z/sub abs/>z/sub em/) absorption-line systems in the quasar PKS 0119--046 are due to a blueshifting of the broad emission lines with respect to the rest frame of the underlying galaxy in which the quasar is located rather than being due to a real high-velocity infall. The ...

Apr 27, 2009 ... The Sloan Digital Sky Survey (SDSS) Broad Absorption Line (BAL) Quasars Catalog (based on the 3rd SDSS Data Release) contains a total of ...

We present a sample of 68 low-z Mg II low-ionization broad absorption-line (loBAL) quasars. The sample is uniformly selected from the Sloan Digital Sky Survey Data Release 5 according to the following criteria: (1) redshift 0.4 < z <= 0.8, (2) median spectral S/N>7 pixel-1, and (3) Mg II absorption-line width ?vc >= 1600 km ...

Resonance-line formation in QSOs with broad absorption lines is considered. An axisymmetric decelerated-outflow model, with the density of scattering atoms highest in the equatorial plane and lowest toward the poles, can yield line profiles fitting those typified both by PHL 5200 (abrupt changeover from emission to ...

We report the emergence of a high-velocity, broad absorption line outflow in the luminous quasar Ton 34, at zq = 1.928. The outflow is detected through an ultraviolet C IV broad absorption line, in a spectrum obtained in 2006 January by the Sloan Digital Sky Survey. No ...

The quasar PHL 1070 and its surrounding halo of light were observed with the Palomar multichannel spectrophotometer by using circular and annular apertures. The central quasar has a magnitude m/sub v/ = 16.6 and an emission line redshift of z/sub em/ = 0.076 +- 0.002. The halo light has a magnitude m/sub v/ = 19.0 and a possible ...

We have compiled a sample of 14 of the optically brightest radio-quiet quasars (mi <= 17.5 and z >= 1.9) in the Sloan Digital Sky Survey Data Release 5 quasar catalog that have C IV mini-broad absorption lines (mini-BALs) present in their spectra. X-ray data for 12 of the objects were obtained via a Chandra ...

As a direct consequence of the luminosity generated through accretion, quasars can eject energetic outflows at high velocities. These outflows are directly observed in Broad Absorption Line (BAL) quasars through their deep, blue-shifted absorption lines. To date, one of the ...

We discovered Balmer-lines absorption from Halpha to H9 in iron low-ionizaton broad absorption line (FeLoBAL) quasar, SDSS J172341.10+555340.5 by near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) attached to the Subaru telescope. The redshift of the ...

The ''forest'' of absorption lines observed in the spectrum of distant quasars is interpreted in light of the adiabatic (pancake) theory for the origin and evolution of structure in the universe. The hidden mass might reside in neutrino-like particles (perhaps unstable) having a rest mass of about ...

later) VPMS J1342+2840 � an unusual quasar from the variability and proper motion survey H. Meusinger1 the discovery of the highly peculiar, radio-loud quasar VPMS J1342+2840 (z1.3) from the variability and proper structures of broad absorption line (BAL) troughs. The image of the quasar is ...

of sight: the absorption system, a spatially ex� tended emission, and the quasar itself. The velocity separation between the DLA and the quasar is about 500 km s \\Gamma1 , and is similar to the ve� locity offset between the DLA and the emission. The emission itself is traced to about 2 00 away from the quasar, ...

Despite the expenditure of large amounts of telescope time and other resources, most of the fundamental questions concerning quasi-stellar objects (quasars) remain unanswered. A complex phenomenology of radio, infrared, optical, and x-ray properties has accumulated but has not yielded even a satisfactory classification system. The large red shifts (distances) of ...

This program is the continuation of the Q106 program on the study of the OVI phase in galactic halos. We have selected a third quasar, Q0026+1259 (Bowen & Blades, 1997). Two galaxies lie close to the quasar sightline, which could give rise to OVI absorption lines, which FUSE only would be able to detect. ...

1 DARK MATTER STARS GAS NEUTRAL HYDROGEN Tracing the "Cosmic Web" with Diffuse Gas Quasar Absorption Lines �use quasars as bright "beacons" for probing intervening gaseous material �can study both galaxies and diffuse gas that produces no luminosity at any wavelength #12;2 Astrophysics from ...

Infrared and optical spectrophotometric observations of the hydrogen lines in a sample of 16 quasars

We discuss the nature and origin of a rich complex of narrow absorption lines in the quasar J102325.31+514251.0 at redshift 3.447. We measure nine CIV(??1548, 1551) absorption line systems with velocities from -1400 to -6200 kms-1, and full widths at half-minimum ranging from 16 to 350 kms-1. ...

New spectropolarimetry observations of the quasar OI 287, which appears to be the only high-polarization quasar which does not fall into either the category of broad-absorption line QSO or the category of blazars, is presented. The spectropolarimetry, which has a resolution of about 6-8 A, demonstrates that the ...

We report the detection of redshifted neutral atomic hydrogen in absorption toward the quasar 1229--021. The line appears at 1018.231 MHz corresponding to a redshift of z/sub abs/=0.394974; optical absorption lines of Mg II and Mg I have been found previously at this redshift in 1229--021. ...

The discovery of the second quasar with a redshift greater than 4 is reported. This object, which has an r magnitude of 21.0, was detected on a CCD grism survey. The spectrum of the quasar has strong, relatively narrow (but resolved) emission lines; there is a deep absorption trough about 100 A wide on the blue ...

The pattern of Ly-alpha forest absorption lines noted by the present analysis of narrow absorption line spectra of a double quasar is taken as evidence for a quasar that is gravitationally lensed. If the lensing object's z value is of the order of 1.49, then a ...

We have compiled a sample of 14 of the optically brightest radio-quiet quasars ($m_{i}$~$\\le$~17.5 and $z$~$\\ge$~1.9) in the Sloan Digital Sky Survey Data Release 5 quasar catalog that have C IV mini-BALs present in their spectra. X-ray data for 12 of the objects were obtained via a Chandra snapshot survey using ACIS-S, while data for the other two ...

A 12 year-long monitoring of the absorption caused by a z = 0.89 spiral galaxy on the line of sight to the radio-loud gravitationally lensed quasar PKS 1830-211 reveals spectacular changes in the HCO+ and HCN (2-1) line profiles. The depth of the absorption toward the ...

This file contains observations that are part of supplemental time cycle 3 allocation. This allocation is for 25 hours of spacecraft time. The Absorption Line Survey of bright quasars provides a homogeneous data base for studying fundamental questions about the origin and evolution of gaseous systems in the universe. The initial ...

PART 3 consists of replacement targets for objects pulled from the original submission because targets had been previously observed in other programs. The Absorption Line Survey of bright quasars provides a homogeneous data base for studying fundamental questions about the origin and evolution of gaseous systems in the universe. The ...

PART 2 consists of replacement targets for objects pulled from the original submission because targets had been previously observed in other programs. The Absorption Line Survey of bright quasars provides a homogeneous data base for studying fundamental questions about the origin and evolution of gaseous systems in the universe. The ...

The first X-ray spectrum of a high-redshift (z = 2.85) quasar is reported. The Rosat PSPC spectrum of PKS 0438-436, covering 0.3-9 keV in the quasar's rest frame, reveals unexpected absorption of about 1 x 10 exp 22/sq cm, assuming it occurs at the source. Only one other high-luminosity quasar (of greater than ...

... the physics of Polar Broad Absorption Line Quasars, the peculiar X-ray object in RBS 1032, a study of the Narrow-Line Seyfert 1 Galaxy RX J0136.9-3510, ...

The conference presents papers on low-luminosity active galactic nuclei, the narrow line region and associated radio emission in active galactic nuclei, observations of broad emission-line regions, the theory of emission-line regions in active galactic nuclei and the structure and dynamics of the broad line region. ...

We present new results on X-ray properties of radio-loud broad absorption line (BAL) quasars and focus on broadband spectral properties of a high-ionization BAL (HiBAL) compact steep spectrum (CSS) radio-loud quasar 1045+352. This HiBAL quasar has a very complex radio morphology indicating ...

We present new results on X-ray properties of radio-loud broad absorption line (BAL) quasars and focus on broadband spectral properties of a high-ionization BAL (HiBAL) compact steep spectrum (CSS) radio-loud quasar 1045+352. This HiBAL quasar has a very complex radio morphology indicating ...

Recently, convincing evidence was found for extremely large X-ray absorption by column densities greater than 10^23 cm^-2 in broad absorption line quasars. One consequence of this is that any soft X-ray emission from these QSOs would be the scattered light or leaked light from partially covering absorbing material. ...

We report the discovery of a quasar at z=3.050+/-0.003, closely coincident in redshift with the isolated low-opacity feature seen near z =~ 3.056 in the otherwise black portion of the He Ii Gunn-Peterson absorption trough seen toward the z=3.286 background quasar Q0302-003, located 6farcm5 away on the sky. We explore plausible models ...

The main aim of this research program is to determine the ionization equilibrium and abundances in quasar outflows. Especially in the broad absorption line QSO PG 0946+301. We find that the outflow's metalicity is consistent with being solar, while the abundance ratio of phosphorus to other metals is at least ten times solar. These ...

The environments of luminous radio-loud quasars (RLQs) evolve rapidly with redshift: at z=0.6 they are often as rich as Abell class 1 clusters, but at z<0.5 they are never so rich. This rapid, unexplained evolution indicates that the evolution of quasars is tied to their environments. The outstanding feature of quasar evolution is ...

The origin and growth of magnetic fields in galaxies is still something of an enigma. It is generally assumed that seed fields are amplified over time through the dynamo effect, but there are few constraints on the timescale. It was recently demonstrated that field strengths as traced by rotation measures of distant (and hence ancient) quasars are comparable to those seen ...

The velocity field of gas clouds in the envelopes of the nuclei of type 1 Seyfert galaxies and quasars is calculated. Material is assumed to be flowing outward, with the clouds decelerated by the drag of the intercloud gas. A critical cloud size is introduced such that in the L..cap alpha.. line the cloud will have an optical depth tau/sub L/..cap ...

A search has been made for absorption lines of CO molecules in the direction of six high-redshift quasars with strong continuum emission in the millimeter-wave range. The 45-m telescope at the Nobeyama Radio Observatory (NRO) combined with wide-band spectrometers was used to investigate redshifted CO (J = 0-1) ...

We have obtained observational limits on redshifted 21 cm absorption along the line of sight to several of the most highly redshifted quasars. Upper limits on the neutral-hydrogen column density as low as N/sub Hi/< or approx. =1.6 x 10/sup 19/ cm/sup -2/ are found at frequencies (350 MHz--450 MHz) corresponding to known optical ...

High-redshift quasars signal the birth of massive galaxies and the growth of their central super-massive black holes (SMBHs) across cosmic time. The elemental abundances near quasars provide unique constraints on models of SMBH-galaxy evolution and, e.g., on the role of quasars/AGN in regulating star formation and thus shaping the ...

The Quasar Absorption Line Survey of bright sources is an efficient observing program designed to provide a homogeneous data base of absorption features. The data will reveal absorption regions in galaxies, in clusters of galaxies, in voids, in large-scale structures, in Lyman ALPHA clouds, and ...

The Quasar Absorption Line Survey of bright sources is an efficient observing program designed to provide a homogeneous data base of absorption features. The data will reveal absorption regions in galaxies, in clusters of galaxies, in voids, in large-scale structures, in Lyman ALPHA clouds, and ...

We report the discovery of a new gravitationally lensed quasar, SDSS J131339.98+515128.3, at a redshift of 1:875 with an image separation of 1: 0024. The lensing galaxy is clearly detected in visible-light follow-up observations. We also identify three absorption-line doublets in the spectra of the lensed quasar images, from which we ...

High-redshift quasars provide a unique glimpse into the early evolution of massive galaxies. The physical processes that trigger major bursts of star formation in quasar host galaxies (mergers and interactions) probably also funnel gas into the central regions to grow the super-massive black holes (SMBHs) and ignite the luminous quasar ...

The research program supported by this grant now has great momentum. Numerous papers are in progress, and a strong multi-wavelength observing program is rapidly accumulating data on samples of high redshift quasars across the spectrum. ROSAT spectra of quasars continue to yield surprises. Of four z = 3 quasars with X-ray spectra, three ...

We describe a general model for a gaseous galactic corona, and demonstrate that it is in harmony with a variety of observational and theoretical constraints. We then compute the ionization equilibria of H, He, C, N, O, Si, and S atoms in the corona and determine the strengths of resonance absorption lines arising therein. To this end, we obtain approximate ...

There is evidence from radio-loud quasars to suggest that the distribution of the H{beta} broad emission line (BEL) gas is arranged in a predominantly planar orientation, and this result may well also apply to radio-quiet quasars. This would imply that the observed FWHM of the H{beta} BELs is dependent on the orientation of the ...

There is evidence from radio-loud quasars to suggest that the distribution of the H? broad emission line (BEL) gas is arranged in a predominantly planar orientation, and this result may well also apply to radio-quiet quasars. This would imply that the observed FWHM of the H? BELs is dependent on the orientation of the ...

In a statistical study of quasar absorption lines, no evidence is found for large voids in the Ly-alpha forest, contrary to some recent suggestions. The 28 Mpc gap found by Crotts (1987) in the spectrum of Q0420-388 is not statistically significant, and it is possible, from a sample of 18 quasar spectra, to reject ...

By combining the Sloan Digitized Sky Survey Third Data Release quasar list with the VLA FIRST survey, we have identified five objects having both broad absorption lines in their optical spectra and FR-II radio morphologies. We identify an additional example of this class from the FIRST Bright Quasar Survey, ...

The quasar 3C 191 is reexamined in the light of recent rotation measure (RM) observations by Kronberg et al. (1990) and recent He II emission data, and an updated model for the intrinsic formation of the narrow shell of this object is developed. It is argued that the extraordinarily high rotation measure in the jet of this quasar is produced by an ...

The photoionization and heating throughout a quasar emission-line cloud optically thick at the Lyman

A narrow, redshifted absorption line (likely due to Fe XXV or Fe XXVI) super-imposed on the red wing of a broad Fe K line was discovered with the Chandra HETGS in the high luminosity RQ quasar E1821+643 (z=0.297). Although inflow (v/c ~ 0.07-0.11) and/or gravitational redshift can account for the ...

The aim of this project is to identify low-redshift host galaxies of quasar absorption-line systems by selecting galaxies that are seen in projection onto quasar sightlines. To this end, we use the Seventh Data Release of the Sloan Digital Sky Survey to construct a parent sample of 97,489 galaxy/quasar projections ...

Motivated by the detection of a relativistic outflow of highly ionized gas in a previous XMM-Newton observation of the lensed quasar APM08279+5255, we propose four 90ks observations of this object to improve our understanding of the significance of such outflows in regulating black hole growth and in influencing structure formation. The large lensing magnification of about 100 ...

We present a compilation of properties of the 105,783 quasars in the Sloan Digital Sky Survey Data Release 7 (DR7) quasar catalog. In this product, we compile continuum and emission line measurements around the H?, H?, Mg II, and C IV regions, as well as other quantities such as radio properties, and flags indicating broad ...

We present XMM-Newton observations of the broad absorption line (BAL) quasar FBQS J131213.5+231958. The X-ray spectrum of the source can be well described by an absorbed power-law model in which the absorber is either ionized or only partially covers the continuum source. This can explain the apparent lack of ...

HST ultraviolet spectra and ground-based optical spectra of the bright quasar PKS 0405-123 are used to identify two absorption-line systems probably produced by the halos of foreground galaxies. The quasar lies in a rich galaxy field. Loose groups of galaxies are present in the field at mean z1 = 0.1669 and mean z2 = 0.3519. Ly-alpha, ...

It has 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 found ``soft X-ray-loud'' BALQSOs that, by definition, have soft X-ray (0.3 ...

We have detected neutral hydrogen absorption at 21 cm wavelength in the quasar-galaxy pair 3C 268.4/NGC 4138. The absorption spectrum exhibits two features which are separated by 65 and -120 km s/sup -1/, respectively, from the center velocity of 880 km s/sup -1/ of the neutral hydrogen emission profile from NGC 4138. The ...

Observations are sought of two low-redshift quasars which are unusual in two respects: they have extremely narrow broad lines (FWHMs of 420 and 470 km/sec) and unusually weak Balmer lines. They also appear to have exceptionally strong Fe II emission compared with the Balmer lines (but this is entirely because the ...

We have observed a dramatic change in the spectrum of the formerly heavily absorbed 'overlapping-trough' iron low-ionization broad absorption line (FeLoBAL) quasar FBQS J1408+3054. Over a time-span of between 0.6 to 5 rest-frame years, the Mg II trough outflowing at 12 000 km s-1 decreased in equivalent width by a factor of 2 and the ...

Quasars are extremely active nuclei that reside at the centres of galaxies. These nuclei can be factors of 100 more luminous than the entire population of stars of the host galaxies. Along the lines of sight to quasars, intervening gas is revealed in absorption lines. Metal ...

Quasars are extremely active nuclei that reside at the centres of galaxies. These nuclei can be factors of 100 more luminous than the entire population of stars of the host galaxies. Along the lines of sight to quasars, intervening gas is revealed in absorption lines. Metal ...

We present the results of an extension of the FIRST Bright Quasar Survey (FBQS) to the South Galactic cap, and to a fainter optical magnitude limit. Radio source counterparts with SERC R magnitudes brighter than 18.9 which meet the other FBQS criteria are included. We supplement this list with a modest number of additional objects to test our completeness for ...

In the above Letter, two sources on the target list were confused. In particular, the broad absorption line quasar identified as UN J1141-0141 should be designated UN J1141-0143 and possesses different properties than those given in the original Table 1. We provide here a corrected version of Table 1. We note that this source was first ...

We present the discovery of seven quasars at z > 5.7, selected from {approx}2000 deg{sup 2} of multicolor imaging data of the Sloan Digital Sky Survey (SDSS). The new quasars have redshifts z from 5.79 to 6.13. Five are selected as part of a complete flux-limited sample in the SDSS Northern Galactic Cap; two have larger photometric errors and are ...

We present photometric and spectroscopic observations of 15 high-redshift quasars (z{gt}3.6) discovered from {approximately}140 deg{sup 2} of five-color ({ital u}{prime}, {ital g}{prime}, {ital r}{prime}, {ital i}{prime}, and {ital z}{prime}) imaging data taken by the Sloan Digital Sky Survey (SDSS) during its commissioning phase. The quasars are selected ...

We present photometric and spectroscopic observations of 15 high-redshift quasars (z>3.6) discovered from ~140 deg^2 of five-color (u', g', r', i', and z') imaging data taken by the Sloan Digital Sky Survey (SDSS) during its commissioning phase. The quasars are selected by their distinctive colors in SDSS multicolor space. Four of the ...

Accretion disk outflows are an important part of the quasar phenomenon. We report on a high-velocity narrow absorption line (NAL) outflow in the redshift z 2.3 quasar J2123-0050. This outflow is remarkable for having speeds and ionization typical of broad absorption line ...

We propose a 100 ks observation of the high-luminosity, X-ray bright quasar E1821+643 (z=0.297). This source shows a significant redshifted Fe absorption line that can be interpreted either as pure gravitational redshift, or infall of matter onto the black hole. The absorption line is found ...

Hubble Space Telescope Faint Object Spectrograph (HST FOS) observations have shown that the spectrum

We present two ongoing studies of gas phase abundances around high redshift quasars. First, we examine broad emission line (BEL) metallicities for 29 quasars with 2.3 < z < 4.6 and far-infrared (far-IR) luminosities (LFIR) from 1013.4 to ? 1012.2 L&sun;, corresponding to star formation rates (SFRs) of 6740 to ? 1360 ...

We present the first results from a high-resolution spectroscopic survey of 24 quasars to study the nature and origins of the narrow absorption lines (NALs) that form in quasar environments. We present 271 C IV NAL components in 136 C IV systems in 24 quasars at redshifts 1.94 < z < 4.69 ...

We analyze optical-near infrared spectra of a large sample of quasars at high redshift with the aim of investigating both the cosmic reionization history at z ~ 6 and the properties of dust extinction at z > 4. In order to constrain cosmic reionization, we study the transmitted flux in the region blueward the Lya emission line in a sample of 17 ...

The Lyman-? forest is a series of absorption features in the spectra of distant quasars, blue-ward of the Lyman-? emission line. These features arise as the light from the quasar is absorbed by the intervening neutral hydrogen. This gives one-dimensional information about the fluctuations in the neutral hydrogen ...

Weak emission line quasars are a rare and puzzling group of objects. In this paper, we present one more object of this class found in the Sloan Digital Sky Survey (SDSS). The quasar SDSS J094533.99+100950.1, lying at z = 1.66, has practically no CIV emission line, a red continuum very similar to the second steepest ...

A method is presented for estimating the number of accidental redshift systems in quasar absorption-line spectra. The method is based on the use of simulated sets of standard spectral lines in which correlations among the actual line wavelengths of specific ions are neglected. This method is applied to the observed ...

We present a catalog of intervening Mg II quasar absorption-line systems in the redshift interval 0.36 <= z <= 2.28. The catalog was built from Sloan Digital Sky Survey Data Release Four (SDSS DR4) quasar spectra. Currently, the catalog contains ~17, 000 measured Mg II doublets. We also present data on the ~44, 600 ...

The growth of bulges and central black holes in galaxies is one of the key questions of galaxy evolution. Why these co-evolve such that the tight black hole mass, bulge mass correlation is preserved with time is mostly untested though theoretical models suggest that feedback from a central quasar could achieve this by regulating the star formation process. The aim of these ...

The Lyman edge region in the spectra of 11 high-redshift quasars is studied using data designed to detect broadened Lyman edge absorption predicted by thermal models of the 'big blue bump' continuum component, especially thin accretion disks. Three objects have broadened, partial edges near the systemic redshifts, as expected for thermal ...

We perform a systematic study of physical properties and distribution of neutral and ionised gas in the halo of the Milky Way (MW). Beside the large neutral intermediate- and high-velocity cloud (IVC, HVC) complexes there exists a population of partly ionised gaseous structures with low column densities that have a substantial area filling factor. The origin and nature of these structures are ...

The 2l-cm hydrogen line has been detected in absorption at 839.407 MHz in the quasar 3C 286; this corresponds to a redshift of z/sub abs/=0.692154. The narrow velocity dispersion of the line. DELTA /sub v/,=8.2 km s/sup -1/, together with the large inferred column density of neutral hydrogen N/sub H/ ...

We report the results from Chandra and XMM-Newton observations of a sample of 10 type 1 quasars selected to have unusual UV emission-line properties (weak and blueshifted high-ionization lines; strong UV Fe emission) similar to those of PHL 1811, a confirmed intrinsically X-ray weak quasar. These ...

The strong absorption lines in the spectrum of the quasar Q0248 + 4302 are discussed. The absorption has been shown to be produced in a sinuous tidal tail which emanates from the nearby galaxy pair G0248 + 4302A,B. There is a velocity difference of about 260 km/s between the systemic redshift of the interacting ...

We present the discovery of Balmer-line absorption from H? to H9 in an iron low-ionizaton broad absorption line (FeLoBAL) quasar, SDSS J172341.10+555340.5, by near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) attached to the Subaru Telescope. The ...

This is the second paper in a series aimed at finding high-redshift quasars from five-color (u{sup '} g{sup '} r{sup '} i{sup '} z{sup '}) imaging data taken along the Celestial Equator by the Sloan Digital Sky Survey (SDSS) during its commissioning phase. In this paper, we present 22 high-redshift quasars ...

From studies of galaxies in the local Universe we find the masses of the galactic spheroidal component corresponds with the mass of the central supermassive black hole (SMBH). This relation is known as the M(gal) - M(BH) relation, and suggests a close relationship between the formation of the galaxy and the black hole. We study the metallicities near quasars at high redshift ...

Context. Baryonic acoustic oscillations (BAO) and their effects on the matter power spectrum can be studied using the Lyman-? absorption signature of the matter density field along quasar (QSO) lines of sight. A measurement sufficiently accurate to provide useful cosmological constraints requires the observation of ~105 ...

We carried out a Subaru and UKIRT near-infrared imaging survey for H?-emitting galaxies around two pair quasar systems (Q0301-005/Q0302-003 and Q2343+125/Q2344+125) and a triple quasar system (KP 76/KP 77/KP 78). Narrowband near-infrared filters covering the H? emission expected for galaxies at the confirmed C IV absorption redshift ...

Photometric and spectroscopic observations of PC 1158 + 4635, a quasar with a redshift of 4.73, are presented. This object was discovered by the detection of its Ly-alpha emission line in a low-resolution CCD grism survey. The apparent magnitude of the quasar is r = 20.2; its absolute magnitude is similar to that of 3C 273 (for q0 = ...

Approximately 13% of quasars show broad blue-shifted absorption features in their spectra indicative of high velocity outflows. However, the driving mechanism responsible for these outflows remains uncertain. Here we present the results of our search for the ghost of Lyman- ?, a line-locking feature seen in approximately 1-2% of broad ...

The premise of our X-ray observation of the BAL quasar PG1416-129 using Asca was primarily to study the nature of the soft X-ray absorption in this object, and specifically to search for the X-ray signature of the broad absorption lines (BAL) observed in its ultraviolet spectrum. In addition, the unusual and ...

Four faint quasar candidates surrounding the wide quasar pair Tololo 1037-271/1038-272 have been observed with the aim of searching for absorption due to the intervening supercluster proposed to explain the strong correlated absorption seen between z = 1.95 and z = 2.15 in these two objects. A potential positive ...

This paper describes spectra of quasar candidates acquired during the commissioning phase of the Low-Resolution Spectrograph of the Hobby-Eberly Telescope. The objects were identified as possible quasars from multicolor image data from the Sloan Digital Sky Survey. The 10 sources had typical r' magnitudes of 19-20, except for one extremely red ...

The quasar SDSS J133401.39+331534.3 at z = 2.426 is found to be a two-image gravitationally lensed quasar with an image separation of 0farcs833. The object is first identified as a lensed quasar candidate in the Sloan Digital Sky Survey Quasar Lens Search, and then confirmed as a lensed system from follow-up ...

The puzzle posed by the lack of measurable clustering among the Ly..cap alpha.. absorption systems along the lines of sight to quasars is removed if the structure in the universe has evolved according to a nondissipative pancake scenario (proposed elsewhere by fitting simulations to the Local Supercluster). This scenario suggests that ...

In a span of four decades, quasar absorption line spectroscopy has emerged as one of the most efficient methods for probing HI gas and associated metals in a wide range of environments, from redshifts corresponding to the most distant quasars up to the present. The connection between strong MgII ...

From examination of only 4 deg{sup 2} of sky in the NOAO Deep Wide-Field Survey (NDWFS) region, we have identified the first radio-loud quasar at a redshift z > 6. The object, FIRST J1427385+331241, was discovered by matching the FLAMEX IR survey to FIRST survey radio sources with NDWFS counterparts. One candidate z > 6 quasar was found, and ...

The role of mergers in producing galaxies, together with the finding that most large galaxies harbour black holes in their nuclei, implies that binary supermassive black hole systems should be common. Here we report that the quasar SDSS J153636.22+044127.0 is a plausible example of such a system. This quasar shows two broad-line ...

The Sloan Digital Sky Survey has discovered a population of broad absorption line quasars with various extreme properties. Many show absorption from metastable states of Fe II with varying excitations; several objects are almost completely absorbed bluewards of Mg II; at least one shows stronger ...

Spectral differences between lensed quasar image components are common. Since lensing is intrinsically achromatic, these differences are typically explained as the effect of either microlensing, or as light path time delays sampling intrinsic quasar spectral variability. Here we advance a novel third hypothesis: some spectral differences are due to small ...

We study the small population of high-redshift (z em>2.7) quasars detected by the Galaxy Evolution Explorer(GALEX), whose far-UV emission is not extinguished by intervening H I Lyman limit systems. These quasars are of particular importance to detect intergalactic He II absorption along their sight lines. We ...

We report the discovery of two low-luminosity quasars at z~4, both of which show prominent N IV] ?1486 emission. This line is extremely rare in quasar spectra at any redshift; detecting it in two of a sample of 23 objects (i.e., ~9% of the sample) is intriguing and is likely due to the low-luminosity, high-redshift ...

The SDSS-III BOSS Quasar survey will attempt to observe z>2.15 quasars at a density of at least 15 per square degree to yield the first measurement of the Baryon Acoustic Oscillations in the Ly-alpha forest. To help reaching this goal, we have developed a method to identify quasars based on their variability in the u g r i z optical ...

The SDSS-III BOSS Quasar survey will attempt to observe z > 2.15 quasars at a density of at least 15 per square degree to yield the first measurement of the baryon acoustic oscillations in the Ly-? forest. To help reaching this goal, we have developed a method to identify quasars based on their variability in the ugriz optical ...

We have used the Very Large Array (VLA) FIRST survey and the Automated Plate Measuring Facility (APM) catalog of the Palomar Observatory Sky Survey I (POSS-I) plates as the basis for constructing a new radio-selected sample of optically bright quasars. This is the first radio-selected sample that is competitive in size with current optically selected ...

Using a sample of ~30,000 quasars from the 7th Data Release of the Sloan Digital Sky Survey, we explore the range of properties exhibited by high-ionization, broad emission lines, such as C IV ?1549. Specifically, we investigate the anti-correlation between continuum luminosity and emission-line equivalent width (the Baldwin Effect ...

The authors present the discovery of seven quasars at z > 5.7, selected from {approx} 2000 deg{sup 2} of multicolor imaging data of the Sloan Digital Sky Survey (SDSS). The new quasars have redshifts z from 5.79 to 6.13. Five are selected as part of a complete flux-limited sample in the SDSS Northern Galactic Cap; two have larger photometric errors ...

We have detected five (and possibly eight) weak absorption lines in the average of 14 IDS spectra of the quasar 3C 286. These optical lines have a redshift identical to the 21 cm absorption line found by Brown and Roberts at z=692. The observed lines ...

Results of studies with the 305-m telescope at Arecibo at a wavelength of 21 cm of absorption-line clouds in quasars are presented. The results include the detection of 21-cm absorption at a redshift of 1.8 in the redshift system MC3 1331+170, the detection of 21-cm absorption at a redshift of 0.4 in the redshift ...

We report the discovery of a strong Fe K line in the ASCA spectrum of the infrared-luminous galaxy IRAS P09104+4109 at a redshift z = 0.442. It is the most distant Fe K emission line detected so far. The large equivalent width (EW approximately 450 eV) and X-ray continuum spectrum, which has Gamma approximately equal to 2.0 with little ...

Published data on the average metallicities and abundance ratios for absorption-line systems in high-redshift quasars suggest that a dichotomy may exist between the chemical composition of damped Lyman alpha (Lyalpha) systems (interpreted as intervening galaxies in the QSO line of sight) and the z_abs~=z_em ...

We have searched for the 9.7 micrometer silicate feature in four quasar absorption systems at absorption redshifts 0.4 < z < 1.3, using data from the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. These systems were chosen because of hints of their dusty nature from optical/UV spectra of the ...

The report highlights results obtained from the International Ultraviolet Explorer satellite, a project in which the UK was involved. These include the observation of the UV spectra of nearly all primary bodies in the solar system; of a large sample of quasars, including the detection of faint high redshift objects; and of chromospheric effects over a wide range of late-type ...

The SDSS contains the largest set of spectroscopically confirmed broad line quasars ever compiled. Upon its completion, the UKIDSS LAS will provide a near-infrared counterpart to the SDSS, reaching 3 magnitudes deeper than 2MASS over a 4000 square degree area within the SDSS footprint. Combining the SDSS optical and UKIDSS near-infrared data, allows a new ...

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 by N V lines that are strong relative to the Ly? ...

We serendipitiously found that the iron-rich low-ionization broad absorption-line (FeLoBAL) quasar SDSS J 163255.46+420407.7 showed a dramatic change in its spectrum over 3.4 years in the rest frame of the quasar. A simple photoionization model suggests the increase in the nuclear radiation caused these changes. Given the recombination ...

An XMM-Newton deep exposure and variability monitoring of the X-ray bright quasar E1821+643 is proposed. The main aim is to constrain the highly complex iron line profile and its variability: are the very different profiles observed really different, showing iron line fluctuations in both emission and absorption? ...

The absorptive effect of jets on the multi-waveband energy spectrum of the quasar 3C 279 is studied by using a jet model. Based on the timeindependent synchrotron self-Compton (SSC) model, it is assumed that in the jet, the radiant blob is blocked by the preceding cooled blob, thus the emission from the radiation region could be absorbed. This leads to the ...

A Roentgen Satellite (ROSAT) X-ray spectrum of the z = 1.049 'red quasar' 3C 212 has a strong low-energy cutoff. The spectrum can be fitted with a power law (of energy index 1.4(+0.8, -0.6) with low-energy photoelectric absorption in excess of the Galactic value that, if at the redhsift of the quasar, would have a column density of ...

We present the fifth edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog, which is based upon the SDSS Seventh Data Release. The catalog, which contains 105,783 spectroscopically confirmed quasars, represents the conclusion of the SDSS-I and SDSS-II quasar survey. The catalog consists of the SDSS objects that have ...

There are no more than �40 quasars known at redhifts z>5.7 to date. Only three of them are detected in the radio (J0836+0054, z=5.77; J1427+3312, z=6.12; J1429+5447, z=6.21). The highest-redshift quasars are in the forefront of current astrophysical and cosmological research since they provide important constraints on the growth of the earliest ...

We describe the application of non-negative matrix factorization to generate compact reconstructions of quasar spectra from the Sloan Digital Sky Survey (SDSS), with particular reference to broad absorption line quasars (BALQSOs). BAL properties are measured for SiIV?1400, CIV?1550, AlIII?1860 and MgII?2800, ...

We present J1145-0033, a candidate for the most distant (z=2.055) lobe-dominated giant radio quasar, with a projected linear size of 1.34 Mpc. This quasar has both FRII-type radio morphology and broad absorption lines in its optical spectrum. Some physical characteristics (e.g., black hole mass, accretion rate, ...

A search for nitrogen-rich quasars in the Sloan Digital Sky Survey Early Data Release (SDSS EDR) database that are similar to Q0353-383 has yielded 16 candidates, including four with very prominent emission. None of these quasars have emission from both N IV] ?1486 and N III] ?1750 as strong as that seen in Q0353-383. A preliminary search through the EDR ...

Observations with the Swift satellite of X-ray afterglows of more than a hundred gamma-ray bursts (GRBs) with known redshift reveal ubiquitous soft X-ray absorption. The directly measured optical depth ? at a given observed energy is found to be constant on average at redshift z > 2, i.e., lang?(0.5 keV)rang z > 2 = 0.40 � 0.02. Such an asymptotic optical depth is ...

We report the discovery of the faint (V? 21.7) quasar QSO 03027-0010 at z=2.808 in the vicinity of Q 0302-003, one of the few quasars observed with STIS to study intergalactic He II absorption. Together with another newly discovered QSO at z=2.29, there are now 6 QSOs known near the line of sight towards Q ...

Broad absorption lines (BALs) in quasar spectra identify high-velocity outflows that likely exist in all quasars and could play a major role in feedback to galaxy evolution. The variability of BALs can help us understand the structure, evolution and basic physical properties of the outflows. Here we report on our ...

The search for H i absorption in strong compact steep-spectrum sources is a natural way to probe the neutral gas contents in young radio sources. In turn, this may provide information about the evolution of powerful radio sources. The recently improved capabilities of the Westerbork Synthesis Radio Telescope have made it possible to detect a 0.31% (19 mJy) deep neutral atomic ...

29The Messenger 121 � September 2005 Figure 1: Cartoon illustrating a quasar line of sight along which various objects give rise to absorp- tion features seen in the spectrum of the background quasar. The panel presents a typical quasar spectrum, showing the quasar continuum, emission ...

Quasar variability is a long-known but poorly understood phenomenon. The Sloan Digital Sky Survey, while not designed with variability studies in mind, has recently provided a wealth of knowledge on the photometric and spectroscopic variability of quasars. Photometric variability has been studied by comparing imaging data in mulitply-scanned areas, ...

We report results from a 50 ks XMM-Newton observation of the dust-reddened broad-line quasar FTM 0830+3759 (z = 0.413) selected from the Faint Images of the Radio Sky at Twenty cm/Two Micron All Sky Survey red quasar survey. For this active galactic nucleus (AGN), a very short 9 ks Chandra exposure had suggested a feature-rich X-ray ...

We report on the discovery of a high-velocity narrow absorption line outflow in the redshift 2.3 quasar J212329.46 - 005052.9. Five distinct outflow systems are detected with velocity shifts from -9710 to -14 050 km s-1 and C IV ??1548, 1551 linewidths of FWHM ? 62-164 km s-1. This outflow is remarkable for having high speeds and a ...

In recent years, an extremely successful method to study galaxy formation and evolution, has been provided by observation of quasar absorbers. Quasar absorbers are systems intercepting our line-of-sight to a given quasar and thus produce a feature in the quasar spectrum, the so-called ...

We are in the process of searching for intrinsic low velocity-dispersion absorbers in high spectral resolution observations of quasars with HST/STIS. Our goal is to produce a catalog of truly intrinsic absorbers, selected without explicit velocity bias, using the signature of partial coverage (i.e., dilution of absorption troughs) as a selection criterion. ...

Context: While there is growing consensus on the existence of numerous dust-enshrouded red quasars, their discovery and detailed exploration is still an observational challenge. In the course of the near-mid-infrared AGN search combining the 6.7 ?m ISOCAM Parallel Survey and 2MASS we have discovered 24 type-1 quasars about a third of which are too red to ...

We propose spectroscopic observations with COS of eight z~3 QSOs that we found to be bright in the far ultraviolet. Our aim is to study intergalactic absorption caused by the onset of the He II Lyman forest. Several lines of evidence suggest that helium reionization occurred at z~3. Understanding this process is critical for a complete picture of the ...

The detection (at about the 3 sigma level) of an absorption feature at a heliocentric velocity of 1172 km/s in the spectrum of PKS 0241 + 011 is presented. The line of sight to the quasar (z-PKS = 1.4) lies well within the optical and H I boundaries of the barred spiral galaxy NGC 1073 (z-gal = 0.004). Two other continuum sources in ...

We present the first results from the Complete Optical and Radio Absorption Line System (CORALS) survey for Damped Lyman Alpha (DLA) systems based on a radio-selected sample of quasars. We find that the number density and neutral gas content of CORALS DLAs is in good agreement with previous surveys. These results indicate that dust ...

We present results from Chandra and XMM-Newton observations of the low-ionization broad absorption line (LoBAL) quasar H 1413+117 (Cloverleaf quasar). Our spatial and spectral analysis confirm a microlensing event in one of the images. Based on the microlensing interpretation we estimate that the size-scale of the ...

A fundamental astrophysical question is the role of gas in galaxy evolution. Mg II absorption as observed in quasar spectra is found to arise in a broad range of gaseous galactic environments. But the overall relationship between the distribution of Mg II absorbers, their host galaxies, and the larger scale galactic structure is not well known. Lyman-alpha ...

Broad absorption line quasars (BALQSOs) have proven to be elusive soft X-ray sources. Their highly ionized, high column density clouds flow out from the nucleus at 0.1c. On the other hand, the optical/UV emission line spectra of BAL and non-BAL QSOs are quite similar, suggesting similar intrinsic continua. ...

We present six new and two previously published high-resolution spectra of the quasar HS 1603+3820 (zem=2.542) taken over an interval of 4.2 yr (1.2 yr in the quasar rest frame). The observations were made with the High Dispersion Spectrograph on the Subaru telescope and the Medium Resolution Spectrograph on the Hobby-Eberly Telescope. The purpose was to ...

We report on the detection of a zabs= 0.3654 associated absorption-line system in the ultraviolet spectrum of the compact steep-spectrum source (CSS) quasar 3C 48. The absorbing material is blueshifted with respect to the quasar emission-line redshift, zem= 0.3700, suggesting an outflow velocity of ~1000 km s-1. We ...

We present a Spitzer mid-infrared survey of 42 Fanaroff-Riley class II radio galaxies and quasars from the 3CRR catalog at redshift z<1. All of the quasars and 45%+/-12% of the narrow-line radio galaxies have a mid-IR luminosity of ?L?(15 ?m)>8�1043 ergs s-1, indicating strong thermal emission from hot dust in the active ...

We study the characteristics of the ultraviolet continuum of the quasar PKS 0405-123 using the archival HST/FOS spectrum. The spectrum from 1150 to 3300 Angstroms shows a steeply rising continuum in F_? with a strong absorption feature ~ 100 Angstroms wide around the intrinsic Lyman limit of this z=0.574 quasar. The spectrum also shows ...

Twenty-one-cm absorption was detected in the radio spectrum of the quasar PKS 2020-370, at a heliocentric velocity of 8611 + or - 5 km/s. The H I gas is coincident in redshift with previously observed Ca II H and K line absorption (Boksenberg et al. 1980) and is close in velocity to the foreground spiral galaxy ...

We report on Chandra observations of a sample of 11 optically luminous (MB<-28.5) quasars at z=3.96-4.55 selected from the Palomar Digital Sky Survey and the Automatic Plate Measuring Facility Survey. These are among the most luminous z>~4 quasars known and hence represent ideal witnesses of the end of the ``dark age.'' Nine ...

We report the discovery of a new two-image gravitationally lensed quasar, SDSS J024634.11-082536.2 (SDSS J0246-0825). This object was selected as a lensed quasar candidate from the Sloan Digital Sky Survey (SDSS) by the same algorithm that was used to discover other SDSS lensed quasars (e.g., SDSS J0924+0219). Multicolor imaging with ...

We present results from three Suzaku observations of the z = 3.91 gravitationally lensed broad absorption line quasar APM 08279+5255. We detect strong and broad absorption at rest-frame energies of lsim2 keV (low energy) and 7-12 keV (high energy). The detection of these features confirms the results of previous ...

We present results from three Suzaku observations of the z =3.91 gravitationally lensed broad absorption line quasar APM 08279+5255. We detect strong and broad absorption at rest-frame energies of <2 keV (low-energy) and 7-12 keV (high-energy). The detection of these features confirms the results of previous ...

We present the result of second phase of Seoul National University Bright Quasar Survey in Optical (SNUQSO). From this survey, we discovered 173 new bright quasars/Seyferts (0.05quasars have been searched at high Galactic latitude because of the severe stellar contamination ...

Radio spectra of PHL 61 (Takahara et al., 1983) are analyzed in a search for CO radio lines of redshift greater than 1. A possible absorption feature at 39.317 GHz is tentatively attributed to one of two CO lines at z(a) = 1.9318 or 1.8578, or to a pair of CN lines at z(a) = 1.8784. Optical, UV, and radio ...

We report preliminary results of Advanced Satellite for Cosmology and Astrophysics (ASCA) observations of two high-redshift quasars (zeta approximately 3) PKS 0438-436 and PKS 2126-158. We find spectral flattening towards low energies in both sources, first found with Roentgen Satellite (ROSAT) and interpreted as being due to excess X-ray absorption. ...

We report sensitive Chandra X-ray non-detections of two unusual, luminous Iron Low-Ionization Broad Absorption Line Quasars (FeLoBALs). The observations do detect a non-BAL, wide-binary companion quasar to one of the FeLoBAL quasars. We combine X-ray-derived column density lower limits ...

The contribution of cosmological perturbations to the time drift of the cosmological redshift is derived. It is shown that the dominant correction arises from the local acceleration of both the emitter and the observer. The amplitude of this effect is estimated to be of the order of 1% of the drift signal at z=2-4, but can easily be lowered down to 0.1% by using many ...

Active galactic nuclei on the scale of kpc; extended radio emission around kpc-scale radio cores; a search for HI and OH absorption in high redshifted quasars; a 1.4 GHz VLBI survey of active galactic nuclei having narrow emission line profiles; active ga...

The optical spectroscopy of the three quasars Q0118-031 A,B,C is presented. Low dispersion spectra showing the emission lines were obtained for all three objects, and intermediate dispersion spectra were obtained for objects B and C, to search for absorpt...

Topics discussed include the theory of coronal heating mechanisms, absorption lines in the spectra of quasars, abudances in stellar populations and the interstellar medium in galaxies, and the present status of dynamo theory. Also considered are accretion disks in astrophysics, the extragalactic distance scale, compact radio sources, ...

We present broadband HST / WFPC2 images, ground-based H? images, and VLA H I 21 cm emission maps of the nearby galaxy ESO 1327-2041, which is located 38? west of the quasar PKS 1327-206. We find H I 21 cm absorption in the quasar spectrum at czabs = 5250 and 5500 km s-1, the same velocities that metal lines of Na I ...

We study broad absorption line quasars (BALQSOs) because these objects, in particular, probe the high velocity gas ejected by luminous accreting black holes. The variability timescales of BALs can help constrain the size, location, and dynamics of the emitting and absorbing gas near the supermassive black hole. We have obtained ...

We present the results of a detailed many-multiplet analysis performed on a new sample of Mg ii systems observed in high quality quasar spectra obtained using the Very Large Telescope. The weighted mean value of the variation in alpha derived from our analysis over the redshift range 0.4

We present high-resolution optical spectroscopy of several high-redshift BAL (Broad Absorption Line) quasars: 0844+0503, at redshift z=3.3465, which has a known radio counterpart observed by the VLA FIRST survey; 0908+0658, at redshift z=3.0734, with no radio detection recorded in the NASA/IPAC Extragalactic Database (NED); and ...

We present Keck spectropolarimetry of the highly polarized radio-loud quasar 3CR 68.1 ({ital z} = 1.228, {ital V} = 19). The polarization increases from 5{percent} in the red (4000 {Angstrom} rest frame) to greater than 10{percent} in the blue (1900 {Angstrom} rest frame). The broad emission lines are polarized the {ital same} as the continuum, which shows ...

We present high resolution ( ~ 0.15 Angstroms) echelle spectra of the wide QSO pair Tol 1037-2704 (z_em=2.193) and Tol 1038-2712 (z_em=2.331) as well as two neighbouring quasars from the Bohuski and Weedman survey. The components of the Tololo pair are separated by 17.9(') or ~ 4.3 h(-1}_{100) Mpc for q_0 = 0.5, and exhibit a large number of apparently correlated C iv ...

DOES THE FINE STRUCTURE CONSTANT VARY? A THIRD QUASAR ABSORPTION SAMPLE CONSISTENT WITH VARYING of New South Wales, Sydney, NSW 2052, Australia Abstract. We report results from a third sample of quasar structure in quasar absorbing clouds. However, kinematics are unlikely to impact significantly

A large body of recent work points towards feedback processes related to the active accretion of matter onto supermassive black holes in the centers of most massive galaxies as being one of the primary regulatory processes for pc to Mpc scales in the Universe. We seek to close the gap in our knowledge of the physics behind active galactic nuclei (AGN) feedback processes by improving in our ...

Studies of faint, distant galaxies have greatly advanced in recent years. It is now possible to observe hundreds of galaxies out to z=1 and in the range 3 < z < 3.5, yet galaxies in the redshift range 1 < z < 3 remain largely unexplored. Galaxies selected by MgII absorption lines detected in quasar spectra have been ...

We report on 293 quasars with strong N IV] ?1486 or N III] ?1750 emission lines (rest-frame equivalent width >3 �) at 1.7quasars. The comparison between the N-rich ...

Radio spectra near 21 cm wavelength were taken of five close quasar- galaxy pairs. Neutral hydrogen absorption of radiation from the quasar 4C 32.33 (3C 232) has been detected at a velocity (C$delta$lambda/lambda$sub 0$) of 1418 km s$sup -1$. This feature lies 76 km s$sup -1$ away from the velocity of the galaxy NGC 3067 which ...

Quasar outflows may play important role in the evolution of its host galaxy and central black hole, and are most often studied in absorption lines. In this paper, we present a detailed study of multiple outflows in the obscured ultraluminous infrared quasar Q1321+058. The outflows reveal themselves in the complex ...

's spectral energy distribution (SED) and the emission lines it is thought to produce. This is at least belies a strong relation between the two. The emission lines are thought to be similar from objectEmission Lines and the Spectral Energy Distributions of Quasars B. J. Wilkes, P. J. Green, S