J/ApJS/97/1 J/ApJS/97/1 HST Quasar Absorption Line Key Project. X. F J Lockman B D Savage Astrophys. J. Suppl. Ser. 97 1 1995 1995ApJS...97....1L H I data QSOs Radial velocities Redshifts galaxies: active Galaxy: halo ISM: clouds quasars: absorption lines radio lines: ISM Sensitive H I 21cm emission line spectra have been measured for the directions to 143 quasars and AGNs chosen from the observing lists for the HST Quasar Absorption Line Key Project. Narrow-band and wide-band data were obtained with the NRAO 43m radio telescope for each object. The narrow-band data have a velocity resolution of 1km/s, extend from -220 to +170km/s, and are corrected for stray 21cm radiation. The wide-band data have a resolution of 4km/s and extend from -1000 to +1000km/s. The data are important for the interpretation of ultraviolet absorption lines near zero redshift in Key Project spectra. Twenty-two percent of the quasars lie behind Galactic high-velocity H I clouds with |VLSR|>100km/s whose presence can increase the equivalent width of interstellar absorption lines significantly. This paper contains the emission spectra and measures of the H I velocities and column densities along the sight line to each quasar. We discuss how the measurements can be used to estimate the visual and ultraviolet extinction toward each quasar and to predict the approximate strength of the strong ultraviolet resonance lines of neutral gas species in the HST Key Project spectra.

HST

Name Object name --- RAh Right ascension (1950.0) h RAm Right ascension (1950.0) min RAs Right ascension (1950.0) s DE- Declination sign --- DEd Declination deg DEm Declination arcmin DEs Declination arcsec GLON Galactic longitude deg GLAT Galactic latitude deg Vmag V magnitude mag z Redshift --- l_E(B-V) Limit flag on E(B-V) --- E(B-V) B-V colour excess mag V- Observed negative LSR velocity limit of HI emission km/s V+ Observed positive LSR velocity limit of HI emission km/s <V> Average LSR velocity of the HI emission km/s N(HI)i Integrated HI column density assuming the emission to be optically thin 10+19cm-2 N(HI)200 Integrated HI column density assuming a spin temperature of 200K 10+19cm-2 Note Notes number=1 1: Quasar lies on or near an HVC listed in Table 3. 2: Wide-band or narrow-band HI measurements detect gas with |V_LSR_|>100km/s (see V- and V+ above and Table 2). 3: V-emission may extend to -85km/s (UM 341). 4: V+ includes HVC at 111.5km/s (PKS 1101-32). 5: Apparent emission extending to +80km/s probably not real (PKS 1103-00, MC 1104+167, and PKS 1424-11). 6: Apparent emission extending to 90km/s probably not real (B2 1208+32A). 7: Also has HVC at -207 and -198km/s (Mrk 205). 8: Emission wing extending to 50km/s probably not real (T 1542). 9: Emission may extend to 80km/s (PKS1252+11). 10: V- and V+ are averages of two observing sessions (NGC1275). 11: Possible emission to -120km/s (KAZ 102). 12: Because of the large value of T_b_(max), the line core can not be properly corrected for the effects of stray radiation. In Fig.1 we display the uncorrected data in the upper panel and the corrected data in the lower panel (PG 2112+059). 13: Emission may extend to -185km/s (3C 263.0). 14: Stray radiation removal process introduces emission near -90km/s (OJ 287). 15: Stray radiation removal process introduces emission near 60km/s (PG 1402+261). 16: Because of the large value of T_b_(max), the line core can not be properly corrected for the effects of stray radiation. The uncorrected data which are displayed in Fig.1 are reliable in the core but unreliable in the faint wings. The corrected data were used to derive V- and V+ (3C 120). 17: Site line intersects a molecular cloud. E(B-V) from H I is therefore a lower limit (3C 454.3). 18: Because of a telescope pointing error, the position actually observed (RA=11h19m10s9 and DE=12deg10'42") differs by approximately 10' from the correct position. --- James Marcout, Patricia Bauer CDS 1997Mar27 UNKNOWN UNKNOWN Prepared via OCR at CDS. J_ApJS_97_1.xml