Detection of broad 21-cm absorption at z = 0.656 in the complex sight-line towards 3C336

Abstract

We report the detection of 21-cm absorption at z = 0.656 towards 1622+238 (3C336). The line is very broad with a Full-Width Half Maximum (FWHM) of 235 km/s, giving a velocity integrated optical depth of 2.2 km/s. The centroid of the line is offset from that of the known damped Lyman-alpha absorption (DLA) system by 50 km/s, and if the Lyman-alpha and 21-cm absorption are due to the same gas, we derive a spin temperature of < 60 K, which would be the lowest yet in a DLA. The wide profile, which is over four times wider than that of any other DLA, supports the hypothesis that the hydrogen absorption is occurring either in the disk of a large underluminous spiral or a group of dim unidentified galaxies, associated with the single object which has been optically identified at this redshift.

arXiv comment5 pages, 3 figures, accepted by MNRAS Letters

References in corpus (26)

• The 1000 Brightest HIPASS Galaxies: HI Properties
• Further evidence for a variable fine-structure constant from Keck/HIRES QSO absorption spectra
• The SDSS Damped Lya Survey: Data Release 3
• The Present and Future Mass of the Milky Way Halo
• 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
• The Gaseous Extent of Galaxies and the Origin of \lya Absorption Systems. III. Hubble Space Telescope Imaging of \lya-Absorbing Galaxies at z < 1
• QSO Absorbing Galaxies at z<~1: Deep Imaging and Spectroscopy in the Field of 3C 336
• A deep search for 21cm absorption in high redshift damped Lyman-$\alpha$ systems
• A Dark Hydrogen Cloud in the Virgo Cluster
• Dynamical Mass Estimates for the Halo of M31 from Keck Spectroscopy
• The abundance of dark galaxies
• Implications of 21cm observations for damped Ly-$\alpha$ systems
• A survey for redshifted molecular and atomic absorption lines I
• HI 21cm absoprtion in two low redshift damped Ly-alpha systems
• HI 21cm absorption in low z damped lyman-alpha systems
• Spin temperatures and covering factors for HI 21-cm absorption in damped Lyman-alpha systems
• Probing variations in fundamental constants with radio and optical quasar absorption-line observations
• HI 21cm Absorption at $z\sim 2.347$ towards PKS B0438-436
• HI 21cm absorption at $z\sim 3.39$ towards PKS 0201+113
• The detectability of HI 21-cm absorption in damped Lyman-alpha systems
• A catalogue of damped Lyman alpha absorption systems and radio flux densities of the background quasars
• Two New Low Redshift 21cm Absorbers
• H-alpha Imaging with HST+NICMOS of An Elusive Damped Ly-alpha Cloud at z=0.6
• Detection of 21 Centimeter HI Absorption at z = 0.78 in a Survey of Radio Continuum Sources
• Discovery of Optical Emission in the Hotspots of Three 3CR Quasars: High-Energy Particle Acceleration in Powerful Radio Hotspots

Cited by in corpus (23)

• Fluctuations in 21cm Emission After Reionization
• A survey for redshifted molecular and atomic absorption lines - II. Associated HI, OH and millimetre lines in the z >~ 3 Parkes quarter-Jansky flat-spectrum sample
• A search for HI 21cm absorption in strong MgII absorbers in the redshift desert
• A complete sample of 21-cm absorbers at z~1.3: Giant Metrewave Radio Telescope Survey Using MgII Systems
• Cosmological constraints from 21cm surveys after reionization
• Search for cold gas in strong MgII absorbers at 0.5<z<1.5: nature and evolution of 21-cm absorbers
• The covering factor of high redshift damped Lyman-$\alpha$ systems
• GMRT mini-survey to search for 21-cm absorption in Quasar-Galaxy Pairs at z~0.1
• A metallicity-spin temperature relation in damped Lyman-$\alpha$ systems
• Discovery of 21cm absorption in a $z_{\mathrm{abs}}=2.289$ DLA towards TXS 0311+430: The first low spin temperature absorber at z > 1
• The geometry effects of an expanding Universe on the detection of cool neutral gas at high redshift
• New searches for HI 21-cm in damped Lyman-alpha absorption systems
• A cold component and the complex velocity structure of DLA1331+170
• New HI 21-cm absorbers at low and intermediate redshifts
• Relationships between the HI 21-cm line strength, MgII equivalent width and metallicity in damped Lyman-alpha absorption systems
• On the detectability of HI 21-cm in MgII absorption system
• Incidence of HI 21-cm absorption in strong FeII systems at $0.5<z<1.5$
• A survey for HI in the distant Universe: the detection of associated 21-cm absorption at z=1.28
• A Method to Measure the Mass of Damped Ly-alpha Absorber Host Galaxies Using Fluctuations in 21cm Emission
• Broad, weak 21 cm absorption in an early type galaxy: spectral-line finding and parametrization for future surveys
• The potential of tracing the star formation history with HI 21-cm in intervening absorption systems
• A fourth HI 21-cm absorption system in the sight-line of MG J0414+0534: a record for intervening absorbers
• A third HI 21-cm absorption system in the sight-line of MG J0414+0534: A redshift for Object X?