Quasar Absorption Lines as a Function of Quasar Orientation Measures

نویسندگان

  • Gordon T. Richards
  • Robert H. Becker
چکیده

We present high resolution radio data at 3.5 and 20 cm from the VLA in the A configuration for 144 quasars with known C IV absorption line properties. Using these measurements, we compare and contrast a number of quasar orientation indicators. These quantities are used to study the velocity distribution of C IV absorption lines as a function of quasar orientation measures. That there is an excess of narrow, highvelocity C IV absorbers in flat-spectrum quasars as compared to steep-spectrum quasars is confirmed. Orientation indicators that are not based upon spectral indices (e.g. RV and the core-to-lobe ratio) do not show the same effect. These seemingly contradictory results may be reconciled if the absorber distribution is not strictly a function of orientation, but rather a function of intrinsic radio properties that may or may not be good orientation indicators. Current address: Department of Astronomy and Astrophysics, The Pennsylvania State University, University

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Estimating the continuum of quasars using the articial neural networks

A lot of absorption lines are in the bluewards of Lyα emission line of quasar which is well-known as Lyαforest. Most of absorption lines in this forest belong to the Lyα absorption of the neutral hydrogen in the inter-galactic medium (IGM). For high redshift quasars and in the continuum with low and medium resolution, there are no many regions without absorption, so that, the quasar continuum i...

متن کامل

Discovery of Newly Formed Broad Absorption Lines in a Radio-Loud Quasar

We report a serendipitous discovery of broad absorption lines that were newly formed in the spectrum of the high-redshift, luminous radio-loud quasar TEX 1726+344, in a time interval of only 12 years. This is the first quasar showing a transition from narrow absorption lines to broad absorption lines. It also becomes one of the few radio-loud broad absorption line quasars. The gas cloud respons...

متن کامل

On the Origin of Very Wide Lyα-Absorption-Lines in Quasar Spectra

We present a new explanation for the very wide absorption features in quasar spectra. In our model, a very wide absorption feature will originate, when the line of sight crosses a bubble wall tangentially. We demonstrate this on the quasar pair (2138-4427), (21394434). Both show two very wide absorption lines in their spectra at the same redshift. The bubble wall model can explain these observa...

متن کامل

The quasar fraction in low–frequency selected complete samples and implications for unified schemes

Low-frequency radio surveys are ideal for selecting orientation-independent samples of extragalactic sources because the sample members are selected by virtue of their isotropic steep-spectrum extended emission. We use the new 7C Redshift Survey along with the brighter 3CRR and 6C samples to investigate the fraction of objects with observed broad emission lines – the ‘quasar fraction’ – as a fu...

متن کامل

CaII absorption lines in the reddened quasar SDSS J 2339 −

We report the detection of strong CaII/MgII absorption lines at the quasar redshift in the narrow line quasar SDSS J2339−0912 (z = 0.6604). The quasar exhibits strong FeII, small Balmer emission line width and a very red B−K s color. Both the optical continuum and broad emission lines are reddened by SMC-like dust of E(B−V)≃1.0 mag, while its near-infrared color (J − K s = 1.60) shows little re...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2001