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the most important chemical transitions for quasar absorption line systems at low redshift ( e.g. , @xmath0@xmath11 ) still lay in the ultra - violet spectral range . a limited number of the most uv - bright quasars have been observed with the hubble space telescope ( _ hst_)/ space telescope imaging spectrograph ( stis ) , which has provided a detailed view of absorption systems along the lines of sight . these data are available from the multimission archive at space telescope ( mast ) . however , in order to compile statistics of absorbers or to study particular systems , it is necessary to identify the spectral features . this can be complicated , particularly in the forest region , and when the available spectral coverage is limited . in the course of our studies of the forest and metal - line systems we have studied in detail eight of the highest quality _ spectra , obtained with the e230 m grating . in this paper we present these spectra with a list of @xmath2 absorption features and our suggested line identifications . in particular , metal - line system identifications are necessary in order to remove contaminants from the forest . in a recent paper @xcite , we measured statistics of absorption in the forest at @xmath3 using 74 low resolution _ quasar spectra . as a check , and particularly to assess our ability to separate metal lines from the forest , we also used the available higher resolution e230 m _ hst_/stis spectra . in the present paper , we present the relevant data and line identifications which were used in that paper . we expect that this catalog will facilitate future studies of metal - line absorption systems as well as of the forest . our catalog includes damped absorbers ( dlas ) , lyman limit systems , and forest clouds . the dla and lyman limit systems are expected to have strong absorption @xcite , while the forest clouds may have weak and other low ionization transitions detected ( such as and ) @xcite . some forest clouds have detected and/or , without associated low ionization absorption @xcite . the catalog that we will present will allow for future studies of the various types of absorbers .    in   [ sec : data ] we describe _ quasar spectra and our reduction and continuum fitting procedures . we also outline our line detection and measurement algorithms and line identification strategies . the normalized echelle spectra are presented in   [ sec : results ] , along with a brief description of metal - line systems detected toward each quasar . system plots , showing all detected transitions for each system , are also presented there . in   [ sec : summary ] we present a general summary of the systems presented in this catalog . we selected the eight @xmath4 quasars observed with the _ e230 m grating which had a signal to noise ratio , @xmath5 , over a reasonable fraction of the spectrum . hst_/stis e230 m spectra have a resolution @xmath6 , with two pixels per resolution element . our sample is biased towards quasars that have lyman limit systems , since most of the stis observations were conducted in order to study those particular known systems in detail . several settings are possible covering different wavelength ranges . for seven of the eight quasars in our sample , @xmath7 - @xmath8   is covered . the quasars and the relevant observational details are listed in table [ tab : tab1 ] . specifically , this table lists quasar redshifts , wavelength coverage , @xmath9 per pixel at 2350   and 2750   , primary investigator for the original observation , and proposal i d . the data were reduced using the stis pipeline @xcite . they were combined by simple weighting by exposure time ( as in @xcite ) , rather than by , e.g. , inverse variance methods that are often employed . a bias could be introduced by the latter method , since pixels with smaller counts would be weighted more heavily . this bias is significant only in cases such as these stis spectra , where individual exposures have very small @xmath9 , and is not typically important for reduction of ground - based high resolution echelle spectra . wavelengths were corrected to the heliocentric reference frame . when the same quasar was observed multiple times , there was often a small shift in wavelength between the spectra , due to the intentional shifting of the echelle angle of the instrument . in this case , we chose not to smooth the data by interpolating , but instead chose wavelength bins from one exposure and combined the flux from other exposures into the nearest bin . this results in a slightly decreased effective resolution . continuum fits used the standard iraf sfit task . features were objectively identified by searching for an unresolved line at each pixel ( as employed in @xcite ) , and applying a @xmath10 criterion for detection . however , we found by inspection that some of these formal detections are not likely to be real . in some cases , only 1 pixel had significant absorption , and in other cases it appeared that correlated noise biased the measurement . features that are broad and shallow can be @xmath11 5@xmath12 and yet look unconvincing because they are sensitive to the continuum level . such spurious features , estimated to be 10% of the total number of detections , were eliminated from consideration . we define a feature as all the pixels around a 5@xmath12 detection that have not recover to the continuum after smoothing the spectra using an equation on p.56 of @xcite . this definition means that many features are clearly blends of well separated lines , and hence a feature can have more than one identification , each of which may be secure because they refer to different blended lines . wavelength that we give for a feature is the flux - weighted central value , the mean of the wavelengths where the smoothed flux drops below the continuum , with weighting for the fraction of the photons that are absorbed at each pixel . we attempted to identify all features in each of the quasar spectrum , and the transitions that were identified one or more times are listed with their vacuum wavelengths and oscillator strengths in table  [ tab : tab2 ] . for our line identification we used the following procedure :    1 . examine the spectrum at the expected positions of possible galactic lines , and mark all possible detections . search for the strong resonant doublet transitions : mg0.1emii  @xmath13 , si0.1emiv  @xmath14 , c0.1emiv  @xmath15 , , and o0.1emvi  @xmath16 . in addition to these , we also search for low ionization gas through the combination  @xmath17 and  @xmath18 , which can be used in place of mg0.1emii  @xmath13 when the latter is not covered @xcite . check positions of other transitions that could be detected for systems found through the doublet search , including the lyman series lines . if a system is ambiguous with the doublet alone , and other lyman series lines were used to assess its reality . 4 .   having completed these steps , all features that remain without plausible identifications are considered to be lyman series lines . begin by assuming that the highest order lyman series line is the correct identification and search for all of the stronger ( lower order ) lyman series lines corresponding to the same redshift . if reasonable ratios are found , mark these as possible identifications . otherwise continue assessing the possible identifications of the feature in question until reaching . if no identification , including a identification , is plausible the feature is left unidentified . 7 .   if more than one identification is reasonable ( or if there is likely to be a blend for which more than one system contributes significantly ) , this is noted . figure  1a is a sample of a portion of the normalized spectrum of pg@xmath19 , shown in the printed version . we present all other normalized quasar spectra in figures  1b8d ( see the complete version ) , which are available electronically at http://www.blackwellpublishing.com / products/. similarly , our listings of line identifications are presented electronically in table  [ tab : tab3 ] , with some sample listings appearing in the printed version . in this table , quasars are ordered by right ascension and @xmath10 features by increasing wavelength within a given quasar entry . in table [ tab : tab3 ] we list , for each @xmath10 feature that we did not reject as unconvincing , the observed vacuum wavelength ( @xmath20 ) , the observed frame equivalent width and error ( @xmath21 and @xmath12(@xmath21 ) ) , and the significance level ( @xmath22 ; observed equivalent width/ error in equivalent width ) . it also gives our favored line identification for each feature ( transition and redshift ) along with notes that indicate alternative and/or additional identifications . if the identification can not be confirmed with another line , or is uncertain for some other reason , a `` ? '' is listed after the preferred transition i d . we do not give column densities since there are best done on a system by system basis using velocity plots to ensure that the columns for different ions are representative of the same gas . the following subsections present the eight quasars along with discussion of noteworthy metal - line systems found in their spectra . figure  9 presents an example `` system plot '' for the @xmath23 system toward pg@xmath19 . the transitions detected at @xmath10 for all of the metal - line systems are plotted in velocity space in the electronic versions of figures  964 ( see the complete version ) . the quasar emission redshifts , taken from the nasa / ipac extragalactic database , are listed in the heading of each subsection . this quasar was studied as part of the quasar absorption line key project , using g270h grating of _ hst_/faint object spectrograph ( fos ) , with resolution of @xmath25=1300 . @xcite found possible metal - line systems at @xmath26 , 0.9400 , 0.9676 , 1.0724 , 1.3389 , 1.3426 and 1.3868 . they also found tentative suggestions of metal - line systems at @xmath27 and 1.4952 . is detected in a keck / hires spectrum at @xmath23 , 0.7290 , 1.0480 , 1.3250 and 1.3430 @xcite , and these five systems were modeled ( including constraints from this stis coverage ) by @xcite . @xcite observed this quasar with _ hst_/stis to facilitate a statistical study of the forest . this spectrum covers the forest over almost all of its wavelength coverage , blueward of @xmath28   . the line is covered blueward of @xmath29   , blueward of @xmath30   , and blueward of @xmath31   . there is also limited redshift coverage of higher order lyman series lines . along this line of sight are five absorbers . one of them is a dla , two are strong absorbers , and the other two are multiple - cloud , weak absorbers . three certain , and two possible systems are also detected . the metal - line systems toward this quasar are plotted in figures  918 . the @xmath23 system is a strong absorber . based upon only a low resolution _ hst_/fos spectrum , obtained in spectropolarimetry mode @xcite , it is not clear whether this is a dla or whether it has multiple undamped components @xcite . in the _ hst_/stis spectrum , c0.1emiv  @xmath15 are detected , but both transitions suffer from blending . the  @xmath32 is blended in its blue component with from a system at @xmath33 . an unidentified blend appears on the red wing of  @xmath34 and its blueward component also has a small contribution from  @xmath35 at @xmath36 . @xmath37 is detected , but the blueward member has a blend to its blue , probably with . strong  @xmath38 is detected , as is  @xmath39 . the strong feature redward of  @xmath38 is probably at @xmath40 . in addition to and , and were detected in the keck / hires spectrum @xcite .    the unusual multiple - cloud , weak absorber at @xmath41 is detected only in  @xmath38 and  @xmath42 in the _ hst_/stis spectrum . c0.1emiv  @xmath15 is covered at a high sensitivity , yet it is not detected to a @xmath43 rest - frame equivalent width limit of @xmath44   . this makes it `` deficient '' , possibly indicative of a low level of star formation so that a corona would be weak or absent in its very red , barred spiral galaxy host @xcite . the @xmath36 system was found not to have metal lines detected in the low resolution _ hst_/fos spectrum . the detections of , , , si0.1emiv  @xmath14 in the _ hst_/stis spectrum are consistent with those limits . unfortunately , the stis spectrum does not cover c0.1emiv  @xmath15 , which would provide useful constraints on the system s physical conditions . based upon photoionization modeling @xcite it would appear that there is a significant blend with  @xmath45 , which is most likely . the @xmath46 system is just above the borderline to qualify as a strong absorber . it has six weak components in mg0.1emii  @xmath13 spread over @xmath47   @xcite . there is a partial lyman limit system detected in an _ hst_/fos spectrum @xcite . in the _ hst_/stis spectrum and are detected from the strongest four of these six components . @xmath481207 is also detected over the full velocity range , but it suffers from a blend with galactic  @xmath49 to the blue . there may also be blends redward of this , based upon the photoionization models @xcite , but we were unable to provide identifications besides possible . unfortunately , c0.1emiv @xmath15 , which was detected in the _ hst_/fos spectrum @xcite , is not covered in the stis spectrum . there is a possible weak detection of  @xmath481239 but it can not be confirmed using  @xmath481243 because it is in a noisy part of the spectrum . a strong o0.1emvi  @xmath16 is detected , but  @xmath50 is blended to the red with from the system at @xmath51 , and to the blue with possible . also ,  @xmath52 must have a blend , at least on the red wing of its strong component , since that profile is too strong relative to  @xmath50 at that velocity . this blend could be  @xmath50 from the @xmath51 system . if so , these systems would be `` line - locked '' . we find the evidence for metal lines in the @xmath51 system to be inconclusive . is not detected in the redward portion range of the possible  @xmath53 feature , so not all of that absorption can be at this redshift . two components of  @xmath54 are possible , but they do not align perfectly with the minima of the profile and can not be confirmed in any other way . also , o0.1emvi @xmath16 may be detected . the alignment is reasonably good , though the feature redward of the  @xmath50 component is likely to be  @xmath52 from the system at @xmath46 . the @xmath55 system is also just at the border between strong and multiple - cloud weak absorption . like the @xmath46 system , it has a partial lyman limit break in the _ hst_/fos spectrum @xcite . and are detected in the _ hst_/stis spectrum along with , , , . there is a feature at the expected position of  @xmath56 , which appears to be too strong relative to the other transitions in this system @xcite . we believe this feature could be at @xmath57 . is not covered in the stis spectrum , but strong absorption is detected in the fos spectrum . appears to be detected , but the  @xmath58 transition is blended , probably with at @xmath59 . there is an system , with detected , , and at @xmath60 . another weak , broad doublet at @xmath61 is also detected in and , as well as in . the feature in the  @xmath54 panel , at @xmath62  , is at least partially  @xmath18 at @xmath55 ( as is the stronger feature to its red ) .    at @xmath63 the lyman series is detected down to , which is the last member covered in the _ hst_/stis spectrum . there is a possible doublet at this redshift , but the feature at the position of  @xmath50 transition does not match the profile of that at the position of  @xmath52 .    the system at @xmath33 is another example of associated absorption that appears slightly redward of the quasar emission redshift . it is detected in and . the shows the same components as , but clearly has a blend to the red , probably with . is heavily blended with  @xmath32 from the @xmath23 system . @xmath53 is also detected in three components , though the blueward one is affected by a data defect . this quasar was observed with _ hst_/stis by @xcite in order to study a sub - dla at @xmath65 , for which they also have optical coverage . their study of this system , particularly focused on molecular hydrogen , is published as @xcite . in addition , @xcite and @xcite report on six systems along the line of sight ( at @xmath66 , 1.416 , 1.602 , 1.674 and 1.697 ) , based upon the _ hst_/stis spectrum in conjunction with vlt / uves data . is covered over the entire _ hst_/stis spectrum , up to @xmath67   , and is covered up to @xmath68   . there is more limited coverage of all other lyman series transitions down to the lyman limit of the quasar .    the _ hst_/stis spectrum is dominated by the sub - dla at @xmath65 and its many detected metal and molecular hydrogen transitions . in addition , there is one system , four definite systems , and three possible systems . a couple of these systems are associated . system plots for this quasar are given in figures  1927 . a two component doublet is detected at @xmath69 , which also has and detected . is also probably detected in the redward component , but this ca nt be confirmed because  @xmath70 is blended with an unknown line , probably . the sub - dla at @xmath71 is a very complex system , spanning @xmath72   for absorption in many low ionization transitions . it has many molecular hydrogen lines detected . our identifications for the molecules follow exactly those of @xcite . the saturated region of the sub - dla profile spans @xmath73  . a separate component at @xmath74   is likely also to be , but with no associated metals in the _ hst_/stis spectrum . many neutral species of and are detected in a single , narrow component at @xmath75  , presumably associated with the bulk of the . features at other velocities seen in the neutral transitions panels in figure  20 are not related to this system ( see line identifications in table  [ tab : tab3 ] ) . @xmath76 is blended with at @xmath77 , and can not be measured , and no other strong transitions are covered . many singly ionized transitions are detected for the system , both in the @xmath78   component and at many other velocities to the blue . these match the and from the vlt / uves spectrum @xcite . strong absorption is detected in many components , spanning the full velocity range . si0.1emiv  @xmath14 is detected as well , but there appears to be significant blending with  @xmath79 , because  @xmath80 is much weaker at some velocities . c0.1emiv  @xmath15 is also detected in the vlt / uves spectrum . is covered , but not detected , and o0.1emvi  @xmath16 is not covered . an doublet detected in the _ hst_/stis spectrum at @xmath81 has its @xmath52 member blended to the blue with at @xmath82 . c0.1emiv  @xmath15 is detected at the same redshift in the vlt / uves spectrum @xcite . the corresponding , relatively weak ( unsaturated ) line lies blueward of a larger saturated feature . may also be detected . there is a possible system at @xmath83 , as reported by @xcite , however neither member of the doublet aligns with the and , which are also detected in the stis spectrum . there could be associated with this system , but it is badly blended with a probable line , thus its alignment can not be verified . therefore , there is not convincing evidence for detected metals in this system . the system at @xmath84 is well aligned and is detected in and in the _ hst_/stis spectrum . , and possibly , is detected in the vlt / uves spectrum @xcite . there is a possible system at @xmath85 , though its identity is somewhat uncertain . @xmath52 is blended with a possible line , such that the profiles of the doublet members can not be compared . is not detected at the position , however is detected , with about the same profile shape and equivalent width as the . thus , this could be a fairly typical associated absorber . there is an system at @xmath86 detected in the _ hst_/stis spectrum . @xmath52 is blended to the red with a possible line . is detected , as are higher order lyman series lines , but the latter are blended with other transitions ( see table  [ tab : tab3 ] ) . c0.1emiv  @xmath15 and are detected in the vlt / uves spectrum @xcite . the associated absorber at @xmath87 also has  @xmath53 and probably  @xmath88 detected . @xcite also detected , si0.1emiv @xmath14 , c0.1emiv  @xmath15 , and in their vlt / uves spectrum . the profile is not black , again a signature of associated absorbers . a possible system at @xmath89 can not be confirmed by other features in the _ hst_/stis spectrum . although is covered , it is blended with galactic  @xmath49 . if real , this system would be significantly redshifted relative to the emission redshift of the quasar . this quasar was observed by _ hst_/fos as part of the quasar absorption line key project , but they had difficulty in identifying many of the lines due to uncertain continuum fitting @xcite . they found evidence for an extensive metal - line system separated into subsystems at @xmath91 , 0.9277 and 0.9342 , even at low resolution . @xcite modeled this system based on the _ hst_/fos data , along with keck / hires data @xcite . @xcite refined these models once the _ hst_/stis spectra were available . @xcite observed this quasar with _ hst_/stis to facilitate a detailed study of the systems at @xmath92 . hst_/stis spectrum covers the forest blueward of @xmath93   , but does not cover any higher order lyman series lines . there are only three metal - line systems found in the _ hst_/stis spectrum : the extensive metal - line system at @xmath92 mentioned above , a system , and an associated system . figure  2832 presents system plots for these metal - line systems , detected toward pg@xmath94 . there is a weak doublet at @xmath95 . the  @xmath32 is blended with  @xmath79 from the subsystem at @xmath91 , and also to the red with an unknown blend , probably . the large feature blueward of the  @xmath96 transition is  @xmath79 at @xmath97 . is not detected in the keck / hires spectrum , nor any other low ionization transitions in the _ hst_/stis spectrum . however , the system is confirmed by in the _ hst_/fos spectrum .    the complex metal - line system at @xmath98 is spread over more than @xmath99  . @xcite separated it into three systems at @xmath91 ( system a ) , @xmath98 ( system b ) , and @xmath100 ( system c ) . they suggest that these systems are produced by three different galaxies in a group . system a , at @xmath91 , has detected , , si0.1emiv  @xmath14 , c0.1emiv  @xmath15 , and in the _ hst_/stis spectrum . many other transitions , including o0.1emvi  @xmath16 and lyman series lines , were detected in the _ hst_/fos spectrum . @xmath79 is blended with  @xmath32 from the @xmath95 system . is saturated and covers the entire velocity range between this system and system b.    system b , at @xmath97 , produces a partial lyman limit break in the _ hst_/fos spectrum . it is detected in several transitions of , , , si0.1emiv  @xmath14 , c0.1emiv  @xmath15 , and . galactic  @xmath101 is blended with the red wing of the profile . @xmath42 is blended to the red with an unidentified line , probably . the feature redward of  @xmath70 is  @xmath96 from the @xmath95 system . is self - blended , with the  @xmath96 from system a superimposed on the  @xmath32 from system b.    system c , at @xmath102 is unusual in its high velocity relative to the main system , system b. for this system , which would be considered a single - cloud , weak absorber if isolated from the other systems , is detected in , , , , si0.1emiv  @xmath14 , and c0.1emiv  @xmath15 . @xmath58 is blended with  @xmath103 from system b , but  @xmath103 is not detected in a clean part of the spectrum . again , and various other transitions are detected in the _ hst_/fos spectrum . the system at @xmath104 is almost certainly intrinsic judging by its broad profile and the `` non - black '' line , evidence for partial covering . no other metals are detected besides the . this was also a quasar studied for the quasar absorption line key project @xcite , and a keck / hires spectrum was obtained by @xcite . particular systems , with optical and uv coverage , were studied in @xcite . the @xmath106 , 0.5584 and 0.8954 systems were modeled in detail by @xcite .    this quasar was observed with _ hst_/stis by churchill et al . in order to provide constraints on the physical conditions in absorbers . forest lines appear in _ hst_/stis spectrum quasar spectrum blueward of 2763   , and the forest is covered blueward of 2332   . we find evidence for six metal - line systems : one strong absorber , two weak absorbers , one weak , and two associated absorbers . the system plots for these metal - line systems are shown in figures  3338 . @xcite found a metal - line system at @xmath107 with strong detected . this system corresponds to a strong absorber detected in a keck / hires spectrum @xcite , which also has detected , , and . in the _ hst_/stis spectrum , we also find  @xmath39 ,  @xmath38 , and c0.1emiv  @xmath15 . there is a @xmath43 detection of  @xmath108 at @xmath109  , which coincides with a satellite component of mg0.1emii  @xmath13 in the keck / hires spectrum @xcite .    for the multiple - cloud , weak absorber at @xmath110 , c0.1emiv  @xmath15 was detected in the _ hst_/stis spectrum , but no low ionization transitions were detected , though  @xmath38 , al0.1emiii  @xmath37 , and  @xmath111 were covered .    a possible weak doublet at @xmath112 can not be confirmed , since is not covered in the _ hst_/stis or in the previous _ hst_/fos spectrum . the single - cloud , weak absorber at @xmath113 has detected ,  @xmath54 ,  @xmath79 , and c0.1emiv  @xmath15 . the  @xmath114 is affected by a blend . although there is a detection at the position of  @xmath18 , @xcite note that this may be a blend , since it is difficult to explain the strength of this feature in comparison to the weaker mg0.1emii  @xmath13 lines . the system , at @xmath115 , found by @xcite is confirmed here , showing o0.1emvi  @xmath16 and in the _ hst_/stis spectrum . although a feature is detected at the position of  @xmath58 , also noted by @xcite , this is inconsistent with the lack of detection of  @xmath116 , and so can not be confirmed . @xcite found a strong associated absorber at @xmath117 in their _ hst_/fos spectrum , for which and were also detected . in the higher resolution _ hst_/stis spectrum , we confirm these detections , but do not find any other associated absorption . the relatively weak , as compared to o0.1emvi  @xmath16 is characteristic of a class of associated absorbers @xcite . this quasar was studied by the _ hst _ quasar absorption line key project using g190h and g270h spectra obtained with fos @xcite , who found metal - line systems at @xmath119 , 0.7660 , 0.7732 and 0.8553 . the latter two systems correspond to strong absorbers , modeled by @xcite based on keck / hires data @xcite and the _ hst_/stis spectrum presented here . another system , at @xmath120 , with only c0.1emiv @xmath15 and detected , was discussed in @xcite . @xcite obtained a spectrum of this quasar with _ hst_/stis in order to provide constraints on the physical conditions in the two strong absorbers along the line of sight . hst_/stis spectrum , the forest is only covered up to a wavelength of @xmath121   , and higher order lyman series lines are not covered . we find evidence for two strong and two weak systems in the _ hst_/stis spectra . these systems are shown in figures  3945 . @xmath38 and  @xmath481855 are the only prominent transitions from the possible @xmath119 system that are covered in the _ hst_/stis spectrum . although there is a detection at the position of  @xmath38 , the lack of detected al0.1emiii  @xmath37 and the lack of detection of c0.1emiv  @xmath15 in the fos spectrum leads us to question the reality of this system . thus we prefer an identification of the feature at @xmath122   as . a doublet is found at @xmath123 in the _ hst_/stis spectrum . it is confirmed by a detection in the g190h _ hst_/fos spectrum @xcite . the weak feature at the expected position of  @xmath124 is unlikely to be because of the absence of the stronger  @xmath18 transition in the fos spectrum . there is a very weak possible doublet at @xmath125 in the _ hst_/stis spectrum , however the alignment is not perfect . also , there is no detected in the fos spectrum to a rest frame equivalent width limit of @xmath126   . the absorption system at @xmath120 is confirmed by a detection in the fos spectrum , but there are no additional detections in the _ hst_/stis spectrum . the strong system at @xmath127 has detected  @xmath38 ,  @xmath128 and @xmath124 ,  @xmath42 , si0.1emiv  @xmath14 , and c0.1emiv  @xmath15 in the stis e230 m spectrum . @xmath129 may be detected in the strongest low ionization component , but the spectrum is very noisy in that region .    we can not confirm a system at @xmath130 , which was suggested by @xcite , however we note that we also do not detect c0.1emiv  @xmath15 to a @xmath43 rest frame equivalent width limit of @xmath131   . it is still possible that this system exists , but is collisionally ionized , as proposed by @xcite . the strong system at @xmath132 has detected  @xmath18 ,  @xmath42 , si0.1emiv  @xmath14 , c0.1emiv  @xmath15 , and . kinematically , this system is interesting , with satellite components in low ionization gas ( offset @xmath133   from the main absorption ) having corresponding , broader absorption . this quasar was previously studied through g190h and g270h _ hst_/fos spectra @xcite , but only three metal - line systems were indicated , at @xmath136 , 0.6606 and 1.0022 . the @xmath137 coincides with a strong absorber @xcite , and it was modeled by @xcite . the _ hst_/stis spectrum was obtained in a program ( p.i . churchill ) to facilitate a study of the @xmath137 absorber . this spectrum covers the forest up to a wavelength of @xmath138   , and does not cover any lines . besides galactic absorption , in the _ hst_/stis e230 m spectrum , we detect metal - line absorption from only the system at @xmath139 , which corresponds to a full lyman limit break seen in a _ g160l spectrum @xcite . a system plot is shown in figure  46 . from this system we find  @xmath38 ,  @xmath124 , and c0.1emiv  @xmath15 . is not detected . in fact , the absorption at the velocity of the low ionization absorption is relatively weak , and this system classifies as `` deficient '' @xcite . the strongest absorption is @xmath140   redward of the strongest low ionization component . @xcite note a complex of lines ranging from @xmath141 to @xmath142 . they found no metals associated with this complex in the low resolution _ hst_/fos spectrum . we note that with the stis data , it is possible to set a stronger limit , with a rest frame @xmath43 equivalent width limit @xmath143 . this was one of the _ hst _ qso absorption line key project quasars , and its _ hst_/fos g270 m spectrum was presented in @xcite . in that spectrum , three extensive metal - line systems are present at @xmath146 , 0.9908 and 1.0417 . also , there are possible doublets at @xmath147 , 0.6540 , 0.6790 and 0.7796 , and a possible doublet at @xmath148 . in a keck / hires optical spectrum , strong absorption is detected from the @xmath149 system , and weak absorption from the @xmath150 , 0.9060 and 1.0417 systems @xcite . weak is also detected at @xmath151 in the optical spectrum @xcite . the three single - cloud , weak absorbers at @xmath151 , 0.9056 and 0.6534 were modeled by @xcite , the multiple - cloud , weak absorber at @xmath152 by @xcite , and the strong absorber at @xmath153 by @xcite . two programs contribute different wavelength coverage of this quasar with _ burles ( 1997 , hst proposal i d # 7292 ) observed the quasar in order to measure the primordial d / h ratio . @xcite provided redward coverage in order to conduct a detailed study of the forest . in the _ hst_/stis spectra , is covered up to @xmath154   , up to @xmath155   , and in the small region up to @xmath156   . there is detected absorption from the strong absorber , and from the four weak absorbers mentioned above . there are also several possible systems and a possible system , as well as an interesting `` /-only '' system . there is a possible intrinsic system and an associated system observed toward this quasar as well . we report on these systems here , and shown system plots in figures  4756 . we can only tentatively claim a doublet at @xmath157 . the  @xmath32 and  @xmath96 profiles match reasonably well , but @xmath96 may be a bit too strong at some velocities , and there is no coverage of transitions that could confirm this identification . this could relate to a blend with the  @xmath53 from the @xmath158 system ( see below ) . there is also a probable , narrow doublet at @xmath159 . the  @xmath34 transition is blended with  @xmath32 from the @xmath160 system . if this is real , it is unusual in the weakness of relative to . a weak , narrow doublet may also be detected . the _ hst_/stis spectrum shows weak absorption in several low and intermediate transitions related to the @xmath160 single - cloud , weak absorber . the has two components redward of the dominant low ionization absorption , and is weaker but has similar kinematics . the single - cloud , weak absorber at @xmath161 has detected , , , and absorption , all centered at the same velocity as the . @xmath162 is blended with from a system at @xmath163 , and is apparent as a small depression in the red wing of that feature .    for another single - cloud , weak absorber at @xmath164 , , , , , , , , and are detected in the _ hst_/stis spectrum . the coverage of and is unusual for single - cloud , weak absorbers and is important for considerations of the phase structure of these objects . there is an interesting system detected in the _ hst_/stis spectrum at @xmath165 . most of the common metal transitions have good coverage , but only and are detected . and confirm the reality of this system . the -deficient , strong absorber at @xmath166 has detections in the _ hst_/stis spectrum of the first four lyman series lines , , and a variety of singly to triply ionized transitions , including relatively weak absorption . and are covered , but not detected . the line is detected , but suffers from a blend to the blue with  @xmath167 from the system at @xmath158 . this system is of interest because the higher ionization transitions appear redward of the lower ionization transitions , indicating a density gradient across the system @xcite . the @xmath158 multiple - cloud , weak system has a partial lyman limit break detected in a _ hst_/stis g230 m spectrum . the higher order lyman series lines are detected down to the break in the _ hst_/stis e230 m spectrum , though past  @xmath168 they suffer badly from blending with the lyman series lines from the @xmath166 system . metal lines are detected in , , , , and from each of two subsystems . the low ionization transitions are centered at different velocities than the high ionization transitions . @xmath53 is also detected , but may be blended with the possible doublet at @xmath157 . is detected in a low resolution _ hst_/fos spectrum , but is redward of the _ hst_/stis coverage .    there is a possible absorber at @xmath169 , however its  @xmath50 transition is too strong relative to the  @xmath52 transition . although , , and are detected at this velocity , their relative strengths are also inconsistent , perhaps due to unknown blends .    an doublet is detected from a system at @xmath148 , which is slightly redward of @xmath170 . it is confirmed by a very weak detection , but is badly blended and provides no additional constraint . this is another example of an associated system ( e.g. @xcite ) .      the e230 m observation of this quasar with _ hst_/stis was proposed by burles et al . ( 1997 , hst proposal i d # 7292 ) to facilitate a study of the deuterium to hydrogen ratio in a system at @xmath173 @xcite . hst_/stis g230 m spectrum was also obtained , covering the lyman series for this system @xcite . earlier , this quasar was observed as part of the hst quasar absorption line key project . @xcite found metal - line systems at @xmath174 , 1.0323 and 1.0872 .    in the _ hst_/stis spectrum , is covered up to @xmath175   , up to @xmath176   , and up to @xmath177   . all lyman series lines are covered below @xmath178   . in addition to the @xmath173 system , for which this observation was obtained , we find evidence for four definite and two possible absorbers . these systems are all shown in figures  5764 . the @xmath120 lyman limit system has and detected in the _ hst_/stis spectrum . weak  @xmath42 also appear to be detected , consistent with the weak absorption that @xcite found in a hires / keck spectrum . c0.1emiv  @xmath15 and si0.1emiv  @xmath14 are covered , but not detected . an absorber is found at @xmath179 in the stis spectrum , accompanied by detections of , , and . @xcite also found in a low resolution _ hst_/fos spectrum . another system is detected at @xmath180 in the _ hst_/stis spectrum . and are also detected , confirming this doublet . a stronger absorber is detected at @xmath181 , corresponding to the system found by @xcite . in the _ hst_/stis spectrum the first five lyman series lines are detected , along with , , and o0.1emvi  @xmath16 . there is a feature detected ( just above @xmath10 ) at the position of  @xmath50 for a system at @xmath182 with detected and absorption . the  @xmath52 is not detected , even at @xmath183 , so it is uncertain whether there are detected metals for this system .    the @xmath184 system , with , , , and detected in the _ hst_/stis spectrum , appears to be an absorber , with weak absorption . the doublet can not be confirmed because the  @xmath185 member is blended with at @xmath186 . there is an associated system with @xmath187 , detected in , , and . the profile has a black , saturated region at this redshift . the @xmath187 component has detections in and . there is also a non - black component at @xmath188 . this system detected o0.1emvi  @xmath16 , and resembles many other associated systems . this paper presents a catalog that is useful for investigations of metal - line systems and the forest in eight of the highest s / n - ratio e230 m spectra from the _ hst_/stis archive . we have identified a total of 56 metal - line systems ( with at least one metal line detected ) toward the eight quasars listed in table  [ tab : tab1 ] , as presented in figures  964 . for key transitions , table  [ tab : tab4 ] tabulates in how many of the 56 systems a given transition was covered and in how many it was detected . we must caution that clearly these numbers apply only to this particular dataset and are highly dependent on the detection limits of the spectra , to the exact wavelength coverage , and to biases toward certain kinds of quasars for the sample . in this sample of eight quasars , there may be a preference toward strong low ionization absorbers , since many of them were chosen for a program to study the associated with absorption ( see table  [ tab : tab1 ] ) .    nonetheless , it is useful to note from table  [ tab : tab4 ] that for about half of the 56 systems we have coverage of the and doublets , and that in those cases these high ionization transitions were detected @xmath189% of the time . intermediate ionization transitions such as  @xmath48977 and  @xmath481207 were also covered about half the time , and were detected in 50%/58% of the sight lines , respectively . @xmath481335 is also covered for about half of the systems , and was detected 56% of the time , while  @xmath481260 was only detected in 36% of the sightlines for which it was covered . we conclude that almost all 1 @xmath1 @xmath0 @xmath1 1.7 metal - line systems have high ionization absorption detected , but that only half have detected low ionization absorption . these numbers are consistent with the findings of @xcite , that half of all absorbers at low redshift have detected low ionization absorption ( sometimes weak ) , and that the other half do not . this is not surprising since the samples used for these studies have considerable overlap . studies of the statistics of the forest can be significantly affected by metal lines in the forest . with our catalog we are able to give an indication of the level of contamination by metal lines in the @xmath190 forest . specifically , we scanned the wavelength regions of our catalog that are in the forest of the quasar , but are redward of the forest . table  [ tab : tab1 ] lists how many lines and how many metal lines were detected in this region for each quasar . it also shows that 9 - 10 of the features detected in the e230 m quasar spectra are actually galactic absorption . we conclude that of the @xmath190 forest lines detected toward each of the quasars ( redward of the forest ) , 20 - 33% of the lines in the forest are actually metal lines . this `` contamination '' is significant enough that it is important to remove it before computing the statistics of the lines , and is clearly itself a complicated function of redshift . we acknowledge support from nasa under grant nag5 - 6399 nng04ge73 g and by the national science foundation under grant ast 04 - 07138 . j. r. m. and r. s. l. were partially funded by the nsf research experience for undergraduates ( reu ) program . dt and dk were supported in part by stsci grants hst - ar-10688 and hst - ar-10288 . sb was supported by the nsf / reu program in the summer of 2005 . 99 bahcall j.  n. , et al . , 1996 , apj , 457 , 19 bahcall j.  n. , et al . , 1993 , apjs , 87 , 1 brown , t. , et  al . 2002 , _ hst _ stis data handbook , version 4.0 , ed . b. mobasher ( baltimore ; stsci ) charlton , j.  c. , ding ,  j. , zonak , s.  g. , churchill , c.  w. , bond , n.  a. , & rigby , j.  r. 2003 , apj , 589 , 311 churchill , c.  w. , mellon , r.  r. , charlton , j.  c. , jannuzi , b.  t. , kirhakos , s. , steidel , c.  c. , & schneider , d.  p. 2000 , apjs , 130 , 91 churchill , c.  w. , rigby , j.  r. , charlton , j.  c. , & vogt , s.  s. 1999 , apjs , 120 , 51 churchill , c.  w. , & vogt , s.  s. 2001 , aj , 122 , 679 ding , j. , charlton , j.  c. , & churchill , c.  w. 2005 , apj , 621 , 615 ding , j. , charlton , j.  c. , churchill , c.  w. , & palma , c. 2003a , apj , 590 , 746 ding j. , charlton j.  c. , bond n.  a. , zonak s.  g. , churchill c.  w. , 2003b , apj , 587 , 551 ganguly r. et al . , 2007 , in preparation jannuzi b.  t. , et al . , 1998 , apjs , 118 , 1 kirkman , d. , tytler , d. , lubin , d. , & charlton , j.  2007 , mnras , 376 , 1227 kirkman , d. , et al .  2001 , apj , 559 , 23 koratkar a. , antonucci r. , goodrich r. , storrs a. , 1998 , apj , 503 , 599 levshakov s.  a. , agafonova i.  i. , reimers d. , baade r. , 2003 , a&a , 404 , 449 masiero , j.  r. , charlton , j.  c. , ding , j. , & churchill , c.  w. 2005 , apj , 623 , 57 milutinovi n. , rigby j.  r. , masiero j.  r. , lynch r.  s. , palma c. , charlton j.  c. , 2006 , apj , 641 , 190 narayanan , a. , charlton , j.  c. , masiero , j.  r. , & lynch , r. , 2005 , apj , 632 , 92 rao , s.  m. , & turnshek , d.  a. , 2000 , apjs , 130 , 1 reimers d. , baade r. , quast r. , levshakov s.  a. , 2003 , a&a , 410 , 785 savage , b.  d. , sembach , k.  r. , tripp , t.  m. , & richter , p. , 2002 , apj , 564 , 631 schneider , d.  p. , et  al . 1993 , apjs , 87 , 45 tripp , t.  m. , savage , b.  d. , & jenkins , e.  b. 2000 , apj , 534 , l1 verner , d.  a. , verner , e.  m. , & ferland , g.  j. 1996 , adndt , 64 , 1 zonak , s. g. , charlton , j. c. , ding , j. & churchill , c. w. 2004 , apj , 606 , 196          + @xmath191 number of systems in which transition is covered , @xmath192 number of systems in which transition is detected , @xmath193 probability that transition is detected at @xmath194 for system in which it is covered .
we have produced a catalog of line identifications and equivalent width measurements for all absorption features in eight ultraviolet echelle quasar spectra . 
 these spectra were selected as having the highest signal - to - noise among the _ 
 hst_/stis spectra obtained with the e230 m grating . 
 we identify 56 metal - line systems toward the eight quasars , and present plots of detected transitions , aligned in velocity - space . 
 we found that about 1/4 - 1/3 of the features in the forest region , redward of the incidence of the forest , are metal lines . 
 high ionization transitions are common . 
 we see both and in 88  90%  of the metal - line systems for which the spectra cover the expected wavelength . 
 is seen in 58% , while low ionization absorption in , , and/or is detected in 50%  of the systems for which they are covered . 
 this catalog will facilitate future studies of the forest and of metal - line systems of various types . 
 [ firstpage ]    intergalactic medium  quasars : absorption lines .