The strange case of a sub - DLA with very little HI
نویسنده
چکیده
We report a deep search for HI 21cm emission from the z = 0.00632 sub-DLA toward PG1216+069 with the Giant Metrewave Radio Telescope. No emission was detected and our 5σ upper limit on the mass of any associated galaxy is MHI . 107 M⊙, nearly 3 orders of magnitude less than M⋆HI. The z ∼ 0.006 absorber is thus the most extreme known deviation from the standard paradigm in which high column density quasar absorption lines arise in the disks of gas-rich galaxies.
منابع مشابه
HI-selected Galaxies As a Probe of Quasar Absorption Systems
We investigate the properties of local HI-selected galaxies detected in blind radio surveys by using semi-analytic galaxy formation models in the hierarchical structure formation scenario. By drawing a detailed comparison between the properties of the HI-selected galaxies and the quasar absorption systems, we investigate a link between the local galaxy population and the quasar absorption syste...
متن کاملDensity Distribution Function at z = 0 from H
We have measured the column density distribution function, f(NHI), at z = 0 using 21-cm Hi emission from galaxies selected from a blind Hi survey. f(NHI) is found to be smaller and flatter at z = 0 than indicated by high-redshift measurements of Damped Lyman-α (DLA) systems, consistent with the predictions of hierarchical galaxy formation. The derived DLA number density per unit redshift, dNDLA...
متن کاملHI 21 cm observations of the PG 1216 + 069 sub - DLy α absorber field at z = 0 . 00632
The Westerbork Synthesis Radio Telescope finds a weak 21cm line emission feature at the coordinates (RA-Dec-velocity) of the sub-Damped Lyman-α ab-sorber observed at z abs = 0.00632 in the spectrum of PG1216+069. The emission feature, WSRT-J121921+0639, lies within 30 ′′ of the quasar sightline, is detected at 99.8% (3σ) confidence level, has M HI between 5 and 15×10 6 M ⊙ , and has velocity sp...
متن کاملAn Empirical Investigation of the Relation between Corporate Sustainability Performance (CSP) and Corporate Value: Evidence from Iran
This study provides an empirical evidence on how Corporate Sustainability Performance (CSP), is reflected in the corporate value. Using a theoretical framework combining Legitimacy theory, Stakeholder theory and Agency theory, a set of hypotheses that relate the corporate value to CSP is examined. For a sample of Iranian firms, 28 components with four dimensions as Community, Environment, Emplo...
متن کاملStatistical Properties of DLAs and sub-DLAs
Quasar absorbers provide a powerful observational tool with which to probe both galaxies and the intergalactic medium up to high redshift. We present a study of the evolution of the column density distribution, f(N, z), and total neutral hydrogen mass in high-column density quasar absorbers using data from a recent high-redshift survey for damped Lyman-α (DLA) and Lyman limit system (LLS) absor...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2004