Search

We have collected 10025 foreground-background quasar pairs with projected distances $d_p0.15$ Å around foreground quasars, including both the LOS (line-of-sights of foreground quasars) and transverse (TRA, perpendicular to the LOS) absorptions. Both the equivalent width (the correlation coefficient $ρ=-0.915$ and the probability $P < 10^{-4}$ of no correlation) and incident rate ($ρ=-0.964$ and $P < 10^{-6}$) of TRA \Mgii\ absorption lines are obviously anti-correlated with projected distance. The incident rate of TRA \Mgii\ absorption lines is obviously ($>4σ$) greater than that of LOS \Mgii\ absorption lines at projected distances $d_p200$ kpc. The anisotropic radiation from quasars would be the most possible interpretation for the anisotropic absorption around quasars. This could also indicate that the quasar radiation is not obviously impacting the gas halos of quasars at scales $d_p>200$ kpc., 15 pages, Accepted in ApJS

The detection of inflows at the scale of the dusty torus and smaller is crucial for investigating the process of supermassive black hole (SMBH) accretion. However, only a few cases of inflowing gas at small scales have been reported through redshifted broad absorption lines so far. Here we report nine redshifted narrow absorption lines (NALs) of Mg+ions with inflowing speeds of 1071–1979 km s−1, which are likely along the directions close to the axes of accretion disks. The quasars showing inflowing Mg IINALs have, on average, slightly smaller Eddington ratios than the sources with outflowing Mg IINALs. The upper limits on the locations of the detected NALs are at parsec scale, that is, the distance from dusty tori to their central SMBHs. One possible origin of these infalling NALs is from dusty tori. However, these infalling NALs could also be naturally explained by chaotic cold accretion resulting from the nonlinear interaction of active galactic nucleus (AGN) jets with the interstellar medium (ISM), and these cold gaseous blobs may originally precipitate in metal-rich trailing outflows uplifted by AGN jet ejecta. The infalling NALs may therefore provide direct evidence for cold gas precipitation and accretion in AGN feedback processes, and provide direct evidence of inflowing gas along the directions close to quasar jets and at parsec scale. Regardless of whether these infalling NALs are from the dusty tori or the interaction of AGN jets with the ISM, the infalling NALs cannot provide sufficient fuel to power the quasars.

Making use of quasar spectra from LAMOST, in the spectral data around the Mg ii emission lines, research described in this paper has detected 217 Mg ii narrow absorption lines (NALs) with W r λ 2796 ≥ 3 σ w and W r λ 2803 ≥ 2 σ w in a redshift range of 0.4554 ≤ z abs ≤ 2.1110. For quasars observed by both LAMOST and SDSS, we find that 135 Mg ii NALs were obviously observed in the LAMOST spectra, 347 Mg ii NALs were were apparent in the SDSS spectra, and 132 Mg ii NALs were clearly present in both the SDSS and LAMOST spectra. The missed Mg ii NALs are likely ascribed to low signal-to-noise ratios of corresponding spectra. Among the Mg ii NALs obviously observed in SDSS or LAMOST spectra, eight Mg ii NALs were significantly changed with | Δ W r λ 2796 | ≥ 3 σ w in time intervals of Δ MJD/(1 + z em) = 359 – 2819 d.

We investigate the multi-band properties of the GRB 161017A with [Formula: see text], which was detected by Swift and Fermi satellites, and other instruments. The optical and X-ray afterglows were all detected at early times after the prompt emission. The optical light curve shows a very bright onset peak at about 100 s for 13 mag of [Formula: see text]-band, while the X-ray light curve occurs several flares at the beginning. We investigate the origin of X-ray and optical afterglows by analyzing the optical and X-ray data. Considering the smooth onset bump in the early time of the optical band and the erratic pulses for the X-ray lightcurve, we suppose that the early optical afterglow may be produced by the external shock, while the early time of X-ray light curve is dominated by flares. Therefore, GRB optical afterglows with smooth onset bump features at early time are possibly produced by external — forward shock (FS). According to the fireball external-model, the temporal slopes of the onset bumps are determined by both the medium density profile and the electron spectral index. Therefore, the afterglow onset bumps would be an ideal probe to study the properties of the fireball and the circumburst medium. The density profile has a slope of [Formula: see text], which suggests that the circumburst environment of the GRB 161017A would be an intermediate regime that are between the homogeneous interstellar medium (ISM) and wind-type medium. In addition, the optical light curve of the GRB 161017A exhibits a plateau feature and rebrightening after the onset bump, which may be related to the long-acting central engine of GRBs.

Pneumonia caused by Acinetobacter baumannii has become a serious threat to the elderly. However, there are no experimental studies on the relevance between aging and A. baumannii infections. Here, we established an aged pneumonia mouse model by non-invasive intratracheal inoculation with A. baumannii. Higher mortality was observed in aged mice along with increased bacterial burdens and more severe lung injury. Increased inflammatory cell infiltration and enhanced pro-inflammatory cytokines at 24 hours post infection were detected in aged mice than those in young mice. Moreover, infected aged mice had lower myeloperoxidase levels in lungs and less reactive oxygen species-positive neutrophils in bronchoalveolar lavage fluid compared with infected young mice. Reduced efficacy of imipenem/cilastatin against A. baumannii was detected in aged mice. Vaccination of formalin-fixed A. baumannii provided 100% protection in young mice, whereas the efficacy of vaccine was completely diminished in aged mice. In conclusion, aging increased susceptibility to A. baumannii infection and impaired efficacies of antibiotics and vaccine. The aged mice model of A. baumannii pneumonia is a suitable model to study the effects of aging on A. baumannii infection and assess the efficacies of antibiotics and vaccines against A. baumannii for the elderly.

Using the quasars with z_em < 0.9 from the Baryon Oscillation Spectroscopic Survey, we measure the spectral characteristics, including continuum and emission lines, around the Hbeta and Halpha spectral regions, which are lacking in Quasar Data Release 12 (DR12Q). We estimate the virial black hole mass from broad Halpha and/or \hbeta, and infer quasar redshifts from O III5007 emission lines. All the measurements and derived quantities are publicly available. The comparison between O III5007 based redshifts and the visual inspection redshifts included in DR12Q indicates that the visual inspection redshifts are robust. We find that the FWHMs of the broad Halpha are consistent with those of the broad Hbeta, while both the equivalent widths and line luminosities of the broad Halpha are obviously larger than the corresponding quantities of the broad Hbeta. We also find that there is an obviously systematic offset between the Hbeta and Halpha based mass if they are inferred from the empirical relationships in the literature. Using our large quasar sample, we have improved the Hbeta and Halpha based mass estimators by minimizing the difference between the Hbeta- and Halpha-based mass. For the black hole mass estimator (Equation (1)), we find that the coefficients (a,b)=(7.00,0.50) for the Halpha and (a,b)=(6.96,0.50) for the Hbeta are the best choices., 10 pages,12 figures

This paper statistically investigates the properties of C IV and Mg II narrow absorption lines (NALs) to look for velocity cuts that can well constrain quasar-associated NALs. The coverage fraction (f_c) is defined as the ratio between the number of quasars exhibiting at least one detected absorber and the total number of quasars that can be used to detect absorptions with given criteria. We find that, for both C IV and Mg II absorbers, both the number density of absorbers in given velocity intervals (dn/d��) and the f_c show very significant excess at the low-velocity offset from the quasars, relative to the random occurrence that is expected for cosmologically intervening absorbers. These relative excess extensions for Mg II absorptions are not only evidently related to absorption strength but also to quasar luminosity, while they are mainly constrained within 2000 km/s no matter what quasar luminosity and absorption strength are. In addition, we find that the redshift number density (dn/dz) evolution of Mg II absorbers with v_abs 2000 km/s. Turning to C IV absorptions, the relative excess extensions of both dn/d��and f_c are mainly limited within v_abs4000 km/s. We suggest velocity cuts of 4000 km/s and 2000 km/s to define quasar C IV and Mg II associated NALs, respectively., 12 page, 10 figures

We investigate the connections between radio, optical and soft X-ray luminosities with a sample of 538 FSRQs. We find that the radio luminosity is strongly correlated with the optical luminosity, as well as with the soft X-ray luminosity. We also find that the optical luminosity is strongly correlated with the soft X-ray luminosity.

We collect 23 spectral data from literature, which is regarded as a relatively sufficient sample. The evolution index γ was calculated to study the evolution of Ly α line density of Ly α forest. This paper discusses the relationship between the evolution with the redshift in different interval threshold of column density. The results are in accordance with the results of previous research.

Doppler redshifts of a sample of Mg II associated absorbers of SDSS DR7 quasars are analysed. We find that there might be three Gaussian components in the distribution of the Doppler redshift. The first Gaussian component, with the peak being located at z Dopp = − 0.0074, probably arises from absorbers with outflow histories observed in the direction close to jets of quasars. The second Gaussian component, with the peak being located at z Dopp = − 0.0017, possibly arises from absorbers with outflow histories observed in the direction far away from jets of quasars. Whereas, the third Gaussian component, with the peak being located at z Dopp = − 0.0004, might arise from the random motion of absorbers with respect to quasars.

The measurement of the variations of absorption lines over time is a good method to study the physical conditions of absorbers. In this paper, we measure the variations of the line strength of 36 narrow Mg IIλλ2796,2803 associated absorption doublets, which are imprinted on 31 quasar spectra with two observations of the Sloan Digital Sky Survey (SDSS). The timescales of these quasar span 1.1–5.5 years at the quasar rest-frame. On these timescales, we find that these narrow Mg II associated absorption doublets are stable, with no one λ2796 line showing strength variation beyond 2 times error (2σ).

In this paper, we report on two C IV narrow absorption systems emerging from the spectrum of the quasar SDSS J095254.10 +021932.8, which are located at $z_{\rm abs}=2.0053$ and $z_{\rm abs}=1.8011$, respectively. These features have velocity offsets of $\rm \sim 13,800$ and $\rm \sim 34,700~km~s^{-1}$ with respect to the quasar, and show obviously partial coverage to the background emission sources. The two C IV absorption systems are imprinted on the spectrum obtained by the Sloan Digital Sky Survey (SDSS) III on 2011 March 25, which cannot be observed from the spectrum obtained by SDSS-I/II on 2000 December 30. The time interval of the two SDSS observations is 1186.4 d at the quasar rest frame. Because the continuum radiation, broad emission lines and mass accretion rate are stable for the two observations, together with the time interval of observations, we believe that the observed spectral variations are less likely to be caused by the changes in the ionization states of the absorbing gas or by a new outflow, arising from the situation where there was previously no outflow at all. Instead, they probably arise from the motions of multiple streaming gas across the sightline of the quasar.

In this paper, we extend our works of Papers I and II, which are assigned to systematically survey \CIVab\ narrow absorption lines (NALs) with \zabs$\ll$\zem\ on quasar spectra of the Baryon Oscillation Spectroscopic Survey (BOSS), to collect \CIV\ NALs with \zabs$\approx$\zem\ from blue to red wings of \CIVwave\ emission lines. Together with Papers I and II, we have collected a total number of 41,479 \CIV\ NALs with $1.4544\le$\zabs$\le4.9224$ in surveyed spectral region redward of \lya\ until red wing of \CIVwave\ emission line. We find that the stronger \CIV\ NALs tend to be the more saturated absorptions, and associated systems (\zabs$\approx$\zem) seem to have larger absorption strengths when compared to intervening ones (\zabs$\ll$\zem). The redshift density evolution behavior of absorbers (the number of absorbers per redshift path) is similar to the history of the cosmic star formation. When compared to the quasar-frame velocity ($\beta$) distribution of \MgII\ absorbers, the $\beta$ distribution of \CIV\ absorbers is broader at $\beta\approx0$, shows longer extended tail, and exhibits a larger dispersion for environmental absorptions. In addition, for associated \CIV\ absorbers, we find that low-luminosity quasars seem to exhibit smaller $\beta$ and stronger absorptions when compared to high-luminosity quasars., Comment: 11 pages, 12 figures, prublished by MNRAS

In this work, we constructed a sample of 4002 quasars from SDSS DR7 quasar catalogue to calculate the electron density and size of narrow line region. We find that the electron densities are ∼103/cm3, and the sizes are between 27 and 775 pc. We also find that, in the ionization cone, the sizes are tightly correlated with the luminosities of [OIII]λ5007.

In this work, we employ a sample of 185 steep-spectrum radio quasars (SSRQs) to estimate their black hole masses from broad emission lines. Our black hole masses are compared with the virial black hole masses estimated by Shen (2010). We find that there is a large deviation between the two kinds of values if the black hole masses are estimated from broad emission line of CIV. However, both values are in agreement if the black hole masses are estimated from broad emission line of MgII or Hβ.

The quasar absorption lines are crucial to our understanding of the Universe since the absorption lines provide a wealth of information on the gaseous Universe from high redshift to present day. The absorption lines can also allow us to probe the metallicity and ionization state of the gas (Wild et al. 2008). Owing to the advent of large spectroscopic surveys such as the Sloan Digital Sky Survey (SDSS; York et al. 2000), tens of thousands of quasar absorption lines can be identified. However, it is very difficult to identify absorption line systems, especially for the weak absorption line system and the spectrum of low signal-to-noise ratio. In the most previous works, the identification of absorption line systems were mainly completed by two steps: estimating the continuum using the principal component analysis (PCA) and autoidentifying the absorption line systems by computer programs (see, e.g., Lundgren et al. 2009). In this work, we provide our method for identifying the MgII absorption line systems.

We employ a sample of 362 flat-spectrum radio quasars (FSRQs) to calculate their integrated luminosities by integrating the spectral energy distribution (SED) constructed with multi-band (radio, IR, optical, UV and X-ray) data. We compare these luminosities with those estimated from monochromatic luminosities by multiplying them by the conventional bolometric correction factors. Our analysis shows that the integrated luminosities calculated from the SED are much larger than the bolometric luminosities estimated from monochromatic luminosities. Their departing behavior tightly correlates with radio luminosities. The relations between integrated and monochromatic luminosities are explored, which are regarded as empirical relations that might be more suitable to be applied to estimate integrated luminosities of FSRQs from their monochromatic luminosities.

Assuming that the terminated mass is confined within the range of 0.4551–0.5813 M ⊙ when the sun is going to evolve into a white dwarf, the velocity of the sun projecting the shell in the PN stage is much greater than the revolving velocity of the earth-like planet, therefore, we think that the solar mass change is instantaneous.

We assemble 207 variable quasars from the Sloan Digital Sky Survey, all with at least 3 observations, to analyze C IV narrow absorption doublets, and obtain 328 C IV narrow absorption line systems. We find that 19 out of 328 C IV narrow absorption line systems were changed by $\mid\Delta W_r^{\lambda1548}\mid\ge3\sigma_{\Delta W_r^{\lambda1548}}$ on timescales from 15.9 to 1477 days at rest-frame. Among the 19 obviously variable C IV systems, we find that (1) 14 systems have relative velocities $\upsilon_r>0.01c$ and 4 systems have $\upsilon_r>0.1c$, where $c$ is the speed of light; (2) 13 systems are accompanied by other variable C IV systems; (3) 9 systems were changed continuously during multiple observations; and (4) 1 system with $\upsilon_{\rm r}=16~862$ km/s was enhanced by $\Delta W_r^{\lambda1548}=2.7\sigma_{\Delta W_r^{\lambda1548}}$ in 0.67 day at rest-frame. The variations of absorption lines are inversely correlated with the changes in the ionizing continuum. We also find that large variations of C IV narrow absorption lines are difficult to form on a short timescale., Comment: 9 pages, 6figures

We assemble 3524 quasars from Sloan Digital Sky Survey (SDSS) with repeated observations to search for variations of narrow C IV1548,1551 and Mg II2796,2803 absorption doublets in spectral regions shortward of 7000 Ang at the observed frame, which corresponds to time-scales of about 150 ~ 2643 days at quasar rest frame. In these quasar spectra, we detect 3580 C IV absorption systems with z_{abs} = 1.5188 ~ 3.5212, and 1809 Mg II absorption systems with z_{abs} = 0.3948 ~ 1.7167. In term of the absorber velocity (beta) distribution at quasar rest frame, we find a substantial number of C IV absorbers with beta4sigma for lambda2796 lines and >3sigma for lambda2803 lines.

An adaptive control design for a class of stochastic parametric-strict-feedback systems is given. The disturbance considered herein is Wiener noise of unknown covariance, which is represented as a simplified unknown parameter. By using stochastic Lyapunov method and backstepping techniques, an adaptive controller was obtained that guaranteed the global asymptotic stabilization in probability.

In this work, we construct a sample of 1585 radio-loud quasars to measure their black hole masses using broad emission lines. We compare our black hole masses with the virial black hole masses measured by Shen et al. (2010). We find that there is a large deviation between them if our black hole mass is measured from the CIV broad emission line. Whereas, if our black hole mass is measured from broad emission line of Mg II or Hβ, both the values are consistent.

In this work, we explore a sample of 362 flat-spectrum radio quasars (FSRQs) to investigate the jet formation. We find that the fundamental plane for our FSRQs can be expressed as \(L_{\rm 5~GHz}\propto M_{\rm bh}^{-0.19}L_{\rm 2~keV}^{1.08}\). We also find that the 5 GHz luminosities are tightly related to both black hole mass and Eddington ratio, which is established as \(L_{\rm 5~GHz}\propto M_{\rm bh}^{0.67}(L_{\rm bol}/ L_{\rm EDD})^{1.32}\).

In this letter, we present for the first time, the discovery of the disappearance of a narrow Mg II $\lambda\lambda2796,2803$ absorption system from the spectra of quasar SDSS J165501.31+260517.4 ($z_{\rm e}=1.8671$). This absorber is located at $z_{\rm abs} =1.7877$, and has a velocity offset of $8,423\rm ~km~s^{-1}$ with respect to the quasar. According to the velocity offset and the line variability, this narrow Mg II $\lambda\lambda2796,2803$ absorption system is likely intrinsic to the quasar. Since the corresponding UV continuum emission and the absorption lines of another narrow Mg II $\lambda\lambda2796,2803$ absorption system at $z_{\rm abs}=1.8656$ are very stable, we think that the disappearance of the absorption system is unlikely to be caused by the change in ionization of absorption gas. Instead, it likely arises from the motion of the absorption gas across the line of sight.

A large size Bi-2223 HTS magnet coil were manufactured and tested. The HTS coil comprises 45 double pancakes which are grouped into 5 sets. Each set has 9 pancakes connected in series and the 5 sets are connected in parallel to form the coil. The coil has a diameter of 2.1 meters and total turns of 2520. The Ic of the coil is 350 A at 77 K. During and after manufacture of the HTS coil, a series of tests were conducted to examine the performance of the HTS coil. In this paper, the manufacture procedure, parameters of the coil, and test results will be presented.

In some applications, copper wires or tapes are used in parallel with HTS tapes for fabricating magnet coil to enhance its mechanical and electrical stability. The addition of the copper tapes might increase AC loss of the coil. In this work, we investigated the AC loss of HTS coils with strengthening copper tapes. Two HTS coils are fabricated. One is made of HTS tapes only; the other is made of HTS tapes and parallel copper tapes. The HTS tape is G1 Bi-2223/Ag tape with 4.6 mm width and 0.22 mm thickness. The width and thickness of copper tape are 5 mm and 0.1 mm respectively. The inner and outer diameters of the coils are 70 mm and 90mm respectively, with a height is 45 mm. AC loss of the coils was measured by weighting the liquid nitrogen evaporating rate under different AC loads. The experimental data show that the copper tape does not substantially increase the AC loss of the coils.

Gamma-ray bursts (GRBs) are believed to belong to two classes and they are conventionally divided according to their durations. This classification scheme is not satisfied due to the fact that duration distributions of the two classes are heavily overlapped. We collect a new sample (153 sources) of GRBs and investigate the distribution of the logarithmic deviation of the $E_p$ value from the Amati relation. The distribution possesses an obvious bimodality structure and it can be accounted for by the combination of two Gaussian curves. Based on this analysis, we propose to statistically classify GRBs in the well-known $E_{p}$ vs. $E_{iso}$ plane with the logarithmic deviation of the $E_p$ value. This classification scheme divides GRBs into two groups: Amati type bursts and non-Amati type bursts. While Amati type bursts well follow the Amati relation, non-Amati type bursts do not. It shows that most Amati type bursts are long duration bursts and the majority of non-Amati type bursts are short duration bursts. In addition, it reveals that Amati type bursts are generally more energetic than non-Amati type bursts. An advantage of the new classification is that the two kinds of burst are well distinguishable and therefore their members can be identified in certainty.

Quasar J152645.61+193006.7 ($z_{\rm e}=2.5771$) was observed by the Sloan Digital Sky Survey (SDSS) on 2006 May 31, and again on 2011 April 9. The time interval of the SDSS two observations is 497.4 days at the quasar rest frame. From the spectra of this quasar, we detect a phenomenon of disappearance of a narrow $\rm Mg II \lambda\lambda2796,2803$ absorption system with a velocity up to $\rm 166,129 km s^{-1}$ with respect to the quasar. This disappearance event can be caused by changes in the ionization state of absorbing gas or by the bulk motion of the absorbing gas across the quasar sightline. The coverage fraction analysis shows that this absorber partially covers the background emission sources with an effective coverage fraction of $C_{\rm f}=0.40\pm0.06$. The time variation analysis and the coverage fraction analysis imply that this absorber might be intrinsic to the quasar. However, the scenario of a cosmologically separated foreground object located at $z=0.9170$ accounting for the phenomenon cannot be ruled out according to current available data.

The $L_p - E_p$ relation is a well-known relation in gamma-ray bursts. Its implication remains unclear. We propose to investigate the underlying mechanisms of this relation by considering the corresponding kinetic and dynamic mechanisms separately. In this way, one can tell how much the kinetic or dynamic mechanism contributes to the index of the relationship. Our analysis gives rise to several conclusions. (1) The index of the kinetic effect in the $L_p - E_p$ relation can simply be derived from the theory of special relativity, which is generally larger than 2, depending on the situation concerned. (2) The index of the dynamic effect in the relation can be deduced from observation once a model of jets is adopted. According to current GRB data, we find: the dynamic effect alone tends to make an anti-correlation between $L_p$ and $E_p$; in terms of statistics, the dynamic effect is obviously smaller than the kinetic effect; in the situation of jets with moving discrete radio clouds which moves directly towards the observer, the index of the dynamic effect is currently constrained within $(-1.6, -1)$, while in other situations of jets, the constrains are different; both internal and external shocks can account for the current data.

In this work, we analyze the spectra of quasar J125216.58+052737.7 (z em = 1.9035) which was observed by SDSS-I/II on 2003 January 30 and by BOSS on 2011 April 2. Both the continuum and the absorption spectra of this quasar show obvious variations between the two epochs. In the SDSS-I/II spectrum, we detect 8 absorption systems, which are detected at z abs = 1.9098, 1.8948, 1.8841, 1.8770, 1.8732, 1.8635, 1.8154, and 1.7359, respectively, and one absorption system at z abs = 0.9912. Among these absorption systems, two absorption systems at z abs = 1.9098 and 1.7359 and the absorption system are imprinted on the BOSS spectrum as well, and have similar absorption strengths when compared to those measured from the SDSS-I/II spectrum. Three absorption systems at z abs = 1.8948, 1.8841, and 1.8770 are also detected in the BOSS spectrum, while their absorption strengths are much weaker than those measured from the SDSS-I/II spectrum; three systems at z abs = 1.8732, 1.8635, and 1.8154 disappeared from the BOSS spectrum. Based on the variability analysis, the absorption systems that disappeared and weakened are likely to be intrinsic to the quasar. If these intrinsic absorption gases are blown away from the central region of the quasar, with respect to the quasar system, the absorption systems that disappeared would have separation velocities of 3147 kms–1, 4161 km s–1, and 9241 km s–1, while the absorption systems that weakened would have separation velocities of 900 km s–1, 2011 km s–1, and 2751 km s–1. Well-coordinated variations of the six absorption systems that disappeared and weakened, occurring on a timescale of 1026.7 days at the quasar rest frame, can be interpreted as a result of global changes in the ionization state of the absorbing gas.

As the second work in a series of papers aiming to detect absorption systems in the quasar spectra of the Baryon Oscillation Spectroscopic Survey, we continue the analysis of Paper I by expanding the quasar sample to those quasars with zem>2.4. This yields a sample of 21,963 appropriate quasars to search for narrow C IV absorptions with Wr>=0.2A for both lines. There are 9708 quasars with at least one appropriate absorption system imprinted on their spectra. From these spectra, we detect 13,919 narrow Civabsorption systems whose absorption redshifts cover a range of zabs=1.8784 - 4.3704. In this paper and Paper 1, we have selected 37,241 appropriate quasars with median SNR>= 4 and 1.54=0.2A whose absorption redshifts cover a range of zabs=1.4544 - 4.3704. The largest values of Wr are 3.19 A for the \lambda1548 absorption line and 2.93 A for the lambda1551 absorption line, respectively. We find that only a few absorbers show large values of Wr. About 1.1% absorbers of the total absorbers have Wr>=2.0 A.