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Related papers: High-ion absorption in the proximate damped Lyman-…

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Using a spectral stacking technique we searched for the average \lya emission from high-z Damped \lya (DLA) galaxies detected in the Sloan Digital Sky Survey QSO spectra. We used a sample of 341 DLAs of mean redshift <z>= 2.86 and log N(HI)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 H. Rahmani , R. Srianand , P. Noterdaeme , P. Petitjean

We present high signal-to-noise, 5 A resolution (FWHM) spectra of 66 z \ga 4 bright quasars obtained with the 4 m Cerro Tololo Inter-American Observatory and 4.2 m William Hershel telescopes. The primary goal of these observations was to…

A comprehensive analysis of 355 high-quality WSRT HI 21-cm line maps of nearby galaxies shows that the properties and incident rate of Damped Lyman-alpha (DLA) absorption systems observed in the spectra of high redshift QSOs are in good…

We present the observation of a new intermediate redshift damped Lyman-alpha absorption system candidate, discovered in the course of a spectroscopic follow-up for identifying the sources detected in a 150 A wide bandpass UV-imaging survey…

Astrophysics · Physics 2007-05-23 V. Le Brun , M. Viton , B. Milliard

We present a detailed analysis of a H$_2$-rich, extremely strong intervening Damped Ly-$\alpha$ Absorption system (DLA) at $z_{\rm abs}=2.786$ towards the quasar J$\,$0843+0221, observed with the Ultraviolet and Visual Echelle Spectrograph…

We report Keck/ESI and VLT/UVES observations of three super-damped Lyman-alpha quasar absorbers with H I column densities log N(HI) >= 21.7 at redshifts z=2-2.5. All three absorbers show similar metallicities (-1.3 to -1.5 dex), and dust…

Astrophysics of Galaxies · Physics 2015-12-09 Varsha P. Kulkarni , Debopam Som , Sean Morrison , Celine Peroux , Samuel Quiret , Donald G. York

The XQ-100 survey has provided high signal-noise spectra of 100 redshift 3-4.5 quasars with the X-Shooter spectrograph. The metal abundances for 13 elements in the 41 damped Lyman alpha systems (DLAs) identified in the XQ-100 sample are…

We present Keck/LRIS spectra of a candidate damped Lyman-alpha (DLA) galaxy toward the QSO 3C196 (z_em = 0.871). The DLA absorption system has a redshift of z_DLA = 0.437, and a galaxy at 1.5" from the QSO has been identified in high…

Astrophysics · Physics 2008-11-26 Soheila Gharanfoli , Varsha P. Kulkarni , Mark R. Chun , Marianne Takamiya

We present a spectroscopic investigation with VLT/X-shooter of seven candidate extremely strong damped Lyman-$\alpha$ absorption systems (ESDLAs, $N(\text{HI})\ge 5\times 10^{21}$ cm$^{-2}$) observed along quasar sightlines. We confirm the…

Astrophysics of Galaxies · Physics 2022-01-04 K. N. Telikova , S. A. Balashev , P. Noterdaeme , J. -K. Krogager , A. Ranjan

We report a detection of the 9.7 micrometer silicate absorption feature in a damped Lyman-alpha (DLA) system at z_{abs} = 0.524 toward AO0235+164, using the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. The feature shows…

Astrophysics · Physics 2009-06-23 Varsha P. Kulkarni , Donald G. York , Giovanni Vladilo , Daniel E. Welty

We present ten metallicity measurements for quasar absorbers near $z=1.2$ that were selected for having unusually significant ZnII absorption in their SDSS spectra. Follow-up UV space spectroscopy of the Ly$\alpha$ region shows that all ten…

Astrophysics of Galaxies · Physics 2018-12-19 Eric M. Monier , David A. Turnshek , Sandhya M. Rao , Gendith M. Sardane , Daniel Burdette

We present deep GMRT 21cm absorption spectra of 10 damped Lyman-$\alpha$ systems (DLAs), of which 8 are at redshifts $z \ga 1.3$. HI absorption was detected in only one DLA, the $z = 0.5318$ absorber toward PKS 1629+12, which has been…

Astrophysics · Physics 2008-11-26 Nissim Kanekar , Jayaram N Chengalur

We report results on the incidence and cosmological mass density of damped Lyman-alpha (DLA) systems at redshifts less that 1.65. We used HST and an efficient non-traditional (but unbiased) survey technique to discover DLA systems at…

Astrophysics · Physics 2009-10-31 Sandhya M. Rao , David A. Turnshek

We searched for star formation activity associated with high-z Damped Lyman-alpha systems (DLAs) with Subaru telescope. We used a set of narrow-band (NB) filters whose central wavelengths correspond to the redshifted Lyman-alpha emission…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Nobunari Kashikawa , Toru Misawa , Yosuke Minowa , Katsuya Okoshi , Takashi Hattori , Jun Toshikawa , Shogo Ishikawa , Masafusa Onoue

We calculate theoretical population ratios of the ground fine-structure levels of some atoms/ions which typically exhibit UV lines in the spectra of QSO absorbers redward the Ly-alpha forest: C0, C+, O0, Si+ and Fe+. The most reliable…

Astrophysics · Physics 2009-10-31 A. I. Silva , S. M. Viegas

The XQ-100 survey provides optical and near infrared coverage of 36 blindly selected, intervening damped Lyman alpha systems (DLAs) at 2 < z < 4, simultaneously covering the MgII doublet at 2796A, 2803A, and the Ly-alpha transition. Using…

We present the first detailed analysis of the chemical abundances, ionization state, and origin of a partial Lyman limit system (N(\hI) ~ 10^{16} \cmjj) at low redshift (z=0.167 towards PKS0405-1219). Two galaxies at ~ 70 h^{-1} kpc…

Astrophysics · Physics 2009-10-31 Hsiao-Wen Chen , Jason X. Prochaska

By combining our UVES-VLT spectra of a sample of four damped Ly-alpha systems (DLAs) toward the quasars Q0100+13, Q1331+17, Q2231-00 and Q2343+12 with the existing HIRES-Keck spectra, we covered the total spectral range from 3150 to 10000 A…

Astrophysics · Physics 2009-11-10 M. Dessauges-Zavadsky , F. Calura , J. X. Prochaska , S. D'Odorico , F. Matteucci

We report the detection of HI 21 cm absorption from the $z=2.289$ damped Lyman-$\alpha$ system (DLA) towards TXS 0311+430, with the Green Bank Telescope. The 21 cm absorption has a velocity spread (between nulls) of $\sim 110$ km s$^{-1}$…

Astrophysics · Physics 2009-11-13 Brian A. York , Nissim Kanekar , Sara L. Ellison , Max Pettini

(Abridged) We present the results of a systematic GBT and GMRT survey for 21-cm absorption in a sample of 10 DLAs at 2<z_abs<3.4. Analysis of L-band VLBA images of the background QSOs are also presented. We detect 21-cm absorption in only…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 R. Srianand , N. Gupta , P. Petitjean , P. Noterdaeme , C. Ledoux , C. J. Salter , D. J. Saikia