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Priyanka Jalan, Hum Chand & Raghunathan Srianand

Transverse and Longitudinal proximity effect

(Volume 87 - Année 2018 — Actes de colloques — First Belgo-Indian Network for Astronomy & Astrophysics (BINA) workshop - November 2016 - Nainital, India)
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Mots-clés : AGN, astronomie, astrophysique, spectroscopie

Abstract

With close pairs (1.5arcmin) of quasars (QSOs), absorption in the spectra of a background quasar in the vicinity of a foreground quasar can be used to study the environment of the latter quasar at kpc-Mpc scales. For this we used a sample of 205 quasar pairs from the Sloan Digital Sky-Survey Data Release 12 (SDSS DR12) in the redshift range of 2.5 to 3.5 by studying their H I Ly-α absorption. We study the environment of QSOs both in the longitudinal as well as in the transverse direction by carrying out a statistical comparison of the Ly-α absorption lines in the quasar vicinity to that of the absorption lines caused by the inter-galactic medium (IGM). This comparison was done with IGM, matched in absorption redshift and signal-to-noise ratio (SNR) to that of the proximity region. In contrast to the measurements along the line-of-sight, the regions transverse to the quasars exhibit enhanced H I Ly-α absorption. This discrepancy can either be interpreted as due to an anisotropic emission from the quasars or as a consequence of their finite lifetime.

Keywords : AGN, astronomy, astrophysics, spectroscopy

To cite this article

Priyanka Jalan, Hum Chand & Raghunathan Srianand, «Transverse and Longitudinal proximity effect», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 87 - Année 2018, Actes de colloques, First Belgo-Indian Network for Astronomy & Astrophysics (BINA) workshop - November 2016 - Nainital, India, 330 - 333 URL : https://popups.uliege.be/0037-9565/index.php?id=7761.

About: Priyanka Jalan

Aryabhatta Research Institute of observational sciencES (ARIES), Nainital 263002, India, priyanka@aries.res.in

About: Hum Chand

Aryabhatta Research Institute of observational sciencES (ARIES), Nainital 263002, India

About: Raghunathan Srianand

Inter-University Centre for Astronomy and Astrophysics (IUCAA), Post Bag 4, Pune 411007, India