HI 21cm absoprtion in two low redshift damped Ly-alpha systems

Abstract

We report the discovery of two low redshift HI 21cm absorbers, one at z = 0.2212 towards the z_{em} = 0.630 quasar OI 363 (B0738+313), and the other at z = 0.3127 towards PKS B1127-145 (z_{em} = 1.187). Both were found during a survey of MgII selected systems at redshifts 0.2 < z < 1 using the new UHF-high system at the Westerbork Synthesis Radio Telescope (WSRT). New HST/FOS observations also identify both systems as damped Ly-alpha (DLa) absorbers. By comparing the column density from the DLa line with that from the HI 21cm line, we calculate the spin temperature, and find that T_s is approximately 1000 K for both of these low redshift absorbers. We briefly discuss some implications of this result.

10 pages incl. 4 eps figures, accepted by AJ

Cited by in corpus (51)

• The Global 21 Centimeter Background from High Redshifts
• Discovery of Damped Lyman-Alpha Systems at Redshifts Less Than 1.65 and Results on their Incidence and Cosmological Mass Density
• Reconciling the local galaxy population with damped Ly-alpha cross sections and metal abundances
• Abundance Profiles and Kinematics of Damped Lyman-alpha Absorbing Galaxies at z < 0.65
• Halo Gas and Galaxy Disk Kinematics Derived from Observations and LCDM Simulations of MgII Absorption Selected Galaxies at Intermediate Redshift
• Hubble Space Telescope Observations of Element Abundances in Low-redshift Damped Lyman-alpha Galaxies and Implications for the Global Metallicity-Redshift Relation
• Low-Redshift Damped Lyman Alpha Galaxies Toward the Quasars B2 0827+243, PKS 0952+179, PKS 1127-145, and PKS 1629+120
• The Nature of Damped Ly-alpha Absorbing Galaxies at z<=1--A Photometric Redshift Survey of Damped Ly-alpha Absorbers
• A deep search for 21cm absorption in high redshift damped Lyman-$\alpha$ systems
• Verifying the mass-metallicity relation in damped Lyman-alpha selected galaxies at 0.1<z<3.2
• Chandra Discovery of a 300 kpc X-ray Jet in the GPS Quasar PKS1127-145
• The spin temperature of high-redshift damped Lyman-$\alpha$ systems
• Formation of Sub-galactic Clouds under UV Background Radiation
• Multi-phase Circum-Galactic Medium probed with MUSE and ALMA
• Implications of 21cm observations for damped Ly-$\alpha$ systems
• Galaxy Group at z=0.3 Associated with the Damped Lyman Alpha System Towards Quasar Q1127-145
• A search for HI 21cm absorption in strong MgII absorbers in the redshift desert
• HI 21cm absorption in low z damped lyman-alpha systems
• Detection of Warm and Cold Phases of the Neutral ISM in a Damped Ly-alpha Absorber
• The neutral gas extent of galaxies as derived from weak intervening CaII absorbers
• A complete sample of 21-cm absorbers at z~1.3: Giant Metrewave Radio Telescope Survey Using MgII Systems
• The z=0.0912 and z=0.2212 Damped Lyman Alpha Galaxies Along the Sight-Line Toward the Quasar OI 363
• Spin temperatures and covering factors for HI 21-cm absorption in damped Lyman-alpha systems
• XMM-Newton observations of a sample of gamma-ray loud active galactic nuclei
• 21 cm Absorption Studies with the Square Kilometer Array
• Chandra Detection of X-ray Absorption Associated with a Damped Lyman Alpha System
• HI 21cm absorption at $z\sim 3.39$ towards PKS 0201+113
• A catalogue of damped Lyman alpha absorption systems and radio flux densities of the background quasars
• Variable 21cm absorption at z=0.3127
• HI content, metallicities and spin temperatures of damped and sub-damped Lyman alpha systems in the redshift desert (0.6 < z < 1.7)
• H-alpha Imaging with HST+NICMOS of An Elusive Damped Ly-alpha Cloud at z=0.6
• A GBT Survey for HI 21 cm Absorption in the Disks and Halos of Low-Redshift Galaxies
• Detection of a multi-phase ISM at $z=0.2212$
• Detection of broad 21-cm absorption at z = 0.656 in the complex sight-line towards 3C336
• A successful search for intervening 21 cm HI absorption in galaxies at 0.4 < z <1.0 with the Australian Square Kilometre Array Pathfinder (ASKAP)
• The evolution of neutral hydrogen over the past 11 Gyr via HI 21 cm absorption
• On the detectability of HI 21-cm in MgII absorption system
• Adaptive Optics Imaging of Low-redshift Damped Lyman-alpha Quasar Absorbers
• Metallicity has followed local gravitational potential of galaxies since z=3
• Lost and Found: The Damped Lyman Alpha Absorbers in the QSO OI 363
• Imaging and spectroscopy of galaxies associated with two z~0.7 damped Lyman-alpha absorption systems
• A search for damped Lyman-alpha systems towards radio-loud quasars I: The optical survey
• Chandra ACIS-S Observations of Three Quasars with Low-Redshift Damped Ly-alpha Absorption: Constraints on the Cosmic Neutral-Gas-Phase Metallicity at Redshift z \approx 0.4
• Giant Metrewave Radio Telescope detection of two new HI 21cm absorbers at $z\approx 2$
• A search for HI 21cm absorption towards a radio-selected quasar sample II: a new low spin temperature DLA at high redshift
• Toward a direct measurement of the cosmic acceleration: the first preparation with FAST
• Mitigation of Pulsed Interference to Redshifted HI and OH Observations between 960 and 1215 MHz
• Dust depletion of Ca and Ti in QSO absorption line systems
• Multiple origins for the DLA at $z_{\mathrm{abs}}=0.313$ toward PKS 1127$-$145 indicated by a complex dust depletion pattern of Ca, Ti, and Mn
• Redshift drift effect through the observation of HI 21cm signal with SKA
• Estimating constraints on cosmological parameters via the canonical and the differential redshift drift with SKA HI 21-cm observations