Constraints on the gas masses of low-z damped Lyman-$\alpha$ systems

Abstract

We report a deep search for redshifted HI 21 cm emission from three damped and sub-damped Lyman-$\alpha$ absorbers (DLAs) at $z\approx 0.1$ with the Green Bank Telescope (GBT). No evidence for a redshifted HI 21 cm emission signal was obtained in the GBT spectra of two absorbers, with the data on the third rendered unusable by terrestrial interference. The non-detections of HI 21 cm emission yield strong constraints on the HI masses of the associated galaxies, M${}_{\mathrm{HI}}<2.3\times 10^9\times (\Delta V/100{)}^{1/2}$ M${}_{\odot }$ for the sub-DLA at $z=0.0830$ towards J1553+3548, and M${}_{\mathrm{HI}}<2.7\times 10^9\times (\Delta V/100{)}^{1/2}$ M${}_{\odot }$ for the DLA at $z=0.0963$ towards J1619+3342, where $\Delta V$ is the HI 21 cm line width, in km s${}^{-1}$. This continues the trend of low HI masses found in all low-$z$ DLAs and sub-DLAs that have been searched for redshifted HI 21 cm emission. Low-redshift absorbers with relatively low HI column densities, $\lesssim few\times 10^{20}$ cm${}^{-2}$, thus do not typically arise in massive gas-rich galaxies.

5 pages, 4 figures; accepted for publication in MNRAS (Letters). Minor changes and added reference, to match the final version

References in corpus (10)

• The Mass-Metallicity Relation at z~2
• Metallicity Evolution of Damped Lyman-alpha Systems out to z~5
• Velocity-Metallicity Correlation for high-z DLA Galaxies: Evidence for a Mass-Metallicity Relation?
• Molecular hydrogen in high-redshift Damped Lyman-alpha systems: The VLT/UVES database
• On the Nature of Velocity Fields in High z Galaxies
• The Keck+Magellan Survey for Lyman Limit Absorption I: The Frequency Distribution of Super Lyman Limit Systems
• The nature of damped Lyman alpha and sub-damped Lyman alpha absorbers
• HI 21cm Absorption at $z\sim 2.347$ towards PKS B0438-436
• Revisiting the origin of the high metallicities of sub-damped Lyman-alpha systems
• HI 21cm observations of the PG1216+069 sub-DLy-alpha absorber field at z=0.00632

Cited by in corpus (2)

• ALMA + VLT observations of a Damped Lyman-α absorbing galaxy: Massive, wide CO emission, gas-rich but with very low SFR
• The gas and stellar mass of low-redshift damped Lyman-$\alpha$ absorbers