The Hubble Space Telescope Quasar Absorption Line Key Project. 10: Galactic H I 21 centimeter emission toward 143 quasars and active Galactic nuclei

Details The Hubble Space Telescope Quasar Absorption Line Key Project. 10: Galactic H I 21 centimeter emission toward 143 quasars and active Galactic nuclei The Hubble Space Telescope Quasar Absorption Line Key Project. 10: Galactic H I 21 centimeter emission toward 143 quasars and active Galactic nuclei

Mar 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apjs...97....1l&link_type=abstract

Astrophysical Journal Supplement Series (ISSN 0067-0049), vol. 97, no. 1, p. 1-47

Astronomy and Astrophysics

Astronomy

135

Active Galactic Nuclei, Emission Spectra, Hydrogen, Interstellar Extinction, Interstellar Gas, Line Spectra, Quasars, Radio Astronomy, Ultraviolet Absorption, Density (Mass/Volume), Galactic Halos, Hubble Space Telescope, Milky Way Galaxy, Radio Telescopes, Ultraviolet Astronomy, Velocity

Scientific paper

Sensitive H I 21 cm emission line spectra have been measured for the directions to 143 quasars and active galactic nuclei (AGNs) chosen from the observing lists for the Hubble Space Telescope (HST) Quasar Absorption Line Key Project. Narrow-band and wide-band data were obtained with the National Radio Astronomy Observatory (NRAO) 43 m radio telescope for each object. The narrow-band data have a velocity resolution of 1 km/s, extend from -220 to +170 km/s, and are corrected for stray 21 cm radiation. The wide-band data have a resolution of 4 km/s and extend from -1000 to +1000 km/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 absolute value of VLSR greater than 100 km/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.

Affiliated with

Also associated with

No associations

Rating

The Hubble Space Telescope Quasar Absorption Line Key Project. 10: Galactic H I 21 centimeter emission toward 143 quasars and active Galactic nuclei does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Hubble Space Telescope Quasar Absorption Line Key Project. 10: Galactic H I 21 centimeter emission toward 143 quasars and active Galactic nuclei, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Hubble Space Telescope Quasar Absorption Line Key Project. 10: Galactic H I 21 centimeter emission toward 143 quasars and active Galactic nuclei will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-885037