Radio Source Angular Sizes on Vlbi Scales: an Application to a Classical Cosmological Test

نویسنده

  • S Frey
چکیده

A novel approach to deene milliarcsecond scale angular sizes of active galactic nuclei using VLBI visibility data is presented. The \angular size{redshift" relation for a sample of nearly 250 AGN is discussed. The analysis is based on 5 GHz VLBI observations made in the VSOP pre-launch survey and various imaging observations of extremely high redshift quasars.

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

Neutral hydrogen absorption at milliarcsecond resolutions : The radio galaxy 3 C 293

Abstract. We present new milliarcsecond resolution observations of the H absorption against the kiloparsec scale inner jet of the radio galaxy 3C 293. Using a combination of observations obtained with global VLBI, MERLIN and the VLA we have imaged the strong and extensive neutral hydrogen absorption against the radio core and jet of this source across a wide range of angular scales. In this pr...

متن کامل

Very Long Baseline Array observations of the Intraday Variable source J 1128 + 592

Context. Short time-scale flux density variations of flat spectrum radio sources are often explained by the scattering of radio waves in the turbulent ionized Interstellar Matter of the Milky Way. One of the most convincing observational arguments in favor of this is the annual modulation of the variability time-scale caused by the Earth orbital motion around the Sun. J1128+5925 is a recently d...

متن کامل

Radio observations of the quasar 3C395 from parsec to kiloparsec scales

We present results from global VLBI, VLBA,MERLIN and VLA observations of the quasar 3C395 at 5.0 GHz, global VLBI and VLBA observations at 8.4 GHz, and VLBI test observations at 22.2 GHz. These combinations allow us to obtain radio images with resolutions ranging from 0.2 to 200 milliarcseconds, which show the continuity of the radio structure of 3C395 from parsec to kiloparsec scales. On parse...

متن کامل

Probing the Active Massive Black Hole Candidate in the Center of Ngc 404 with Vlbi

Recently Nyland et al. (2012) argued that the radio emission observed in the center of the dwarf galaxy NGC 404 originates in a low-luminosity active galactic nucleus (LLAGN) powered by a massive black hole (MBH, M . 10 M⊙). High-resolution radio detections of MBHs are rare. Here we present sensitive, contemporaneous Chandra X-ray, and very long baseline interferometry (VLBI) radio observations...

متن کامل

v 1 5 A ug 1 99 6 Interstellar Broadening of Images in the Gravitational Lens PKS 1830 - 211

The remarkably strong radio gravitational lens PKS 1830-211 consists of a one arcsecond diameter Einstein ring with two bright compact (milliarcsecond) components located on opposite sides of the ring. We have obtained 22 GHz VLBA data on this source to determine the intrinsic angular sizes of the compact components. Previous VLBI observations at lower frequencies indicate that the brightness t...

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 1999