High‐Redshift Superwinds as the Source of the Strongest Mg<scp>ii</scp>Absorbers: A Feasibility Analysis

Bond, Nicholas A.; Churchill, Christopher W.; Charlton, Jane C.; Vogt, Steven S.

doi:10.1086/323876

Cited by 93 publications

(105 citation statements)

References 35 publications

Supporting

Mentioning

101

Contrasting

Order By: Relevance

“…The kinematics of high redshift DLAs are inconsistent with a large rotating disc scenario (Zwaan et al 2008). In order to explain the larger velocities of high redshift DLAs relative to local H i discs, there may be a population of DLAs that arise in starburst winds or from tidal interactions of galaxies, just as hypothesised for strong Mg ii systems (Bond et al 2001;Bouché et al 2007). …”

Section: Discussion and Summarymentioning

confidence: 99%

“…In most cases, no Lyα emission lines are found in the DLA trough, so whether the star formation activity and supernovae that produce the metals occur in situ (Wolfe et al 2004) at the time of the spectroscopic observation of the DLA, still has to be verified observationally. High redshift DLA systems might also be affected by galactic winds that remove the neutral gas from the galaxies in competition with accretion from the intergalactic medium (Bond et al 2001;Prochaska & Wolfe 2009;Tescari et al 2009). Combining measurements of star formation rates (SFRs) and impact parameters for the galaxies with metallicities and velocities determined from the absorption lines, is needed in order to disentangle these effects.…”

Section: Strong H I Absorption Lines With Column Densities In the Dampedmentioning

confidence: 99%

See 1 more Smart Citation

Uncovering strong MgII absorbing galaxies

Christensen

Noterdaeme

Petitjean

et al. 2009

A&A

View full text Add to dashboard Cite

Context. The nature of the galaxies that give rise to absorption lines, such as damped Lyman-α systems (DLAs) or strong Mg ii lines, in quasar spectra is difficult to investigate in emission. These galaxies can be very faint and located close to the lines of sight of the much brighter background quasars. Aims. Taking advantage of the total absorption of the QSO light bluewards of the Lyman limit of two DLAs at z > 3.4, we look for the continuum emission from intervening galaxies at z ≈ 2 that are identified via strong metal absorption lines. The Mg ii absorbers have equivalent width large enough to be potential DLA systems. Methods. Deep images are obtained with the FOcal Reducer and Spectrograph (FORS1) on the Very Large Telescope for the fields towards SDSS J110855+120953 and SDSS J140850+020522. These quasars have Mg ii absorption lines at z = 1.87 (W r (Mg ii) = 2.46 Å) and z = 1.98 (W r (Mg ii) = 1.89 Å), respectively, and each QSO has two intervening higher redshift DLAs at z > 3. The U and R bands of FORS1 lie blue and redwards of the Lyman limit of the background DLAs, allowing us to search for emission from the foreground galaxies directly along the lines of sight to the QSOs. Results. No galaxies are found close to the sight line of the QSO to a point source limit of U AB ∼ 28.0. In both fields, the closest objects lie at an impact parameter of ∼5 corresponding to ∼40 kpc in projection at z = 2, and have typical colours of star forming galaxies at that redshift. However, the currently available data do not allow us to confirm if the galaxies lie at the same redshifts as the absorption systems. A more extended structure is visible in the SDSS J14085+020522 field at an impact parameter of 0. 8 or 7 kpc. If these objects are at z ≈ 2 their luminosities are 0.03-0.04 L * in both fields. The star formation rates estimated from the UV flux are 0.5-0.6 M yr −1 , while the SFRs are half these values if the U band flux is due to Lyα emission alone. Conclusions. The non-detection of galaxies near to the line of sight is most likely explained by low metallicities and luminosities of the Mg ii galaxies. Alternatively, the Mg ii clouds are part of extended halos or in outflows from low-metallicity galaxies.

show abstract

Section: Discussion and Summarymentioning

confidence: 99%

Section: Strong H I Absorption Lines With Column Densities In the Dampedmentioning

confidence: 99%

Uncovering strong MgII absorbing galaxies

Christensen

Noterdaeme

Petitjean

et al. 2009

A&A

View full text Add to dashboard Cite

show abstract

“…This leaves the physical picture for this system uncertain. It may represent the chance interception of an unusually violent galactic outflow (Bond et al 2001), as has been seen in both QSO absorbers ) and galaxy spectra (Weiner et al 2009). Alternatively if a gravitational interpretation is invoked to explain the velocity spread, the associated potential must be somewhat large, up to galaxy group scales, unless the system is undergoing a merger or is otherwise out of dynamical equilibrium.…”

Section: Re-identifying a Reported High-z C Iv System As Mg Iimentioning

confidence: 90%

CONSTRAINTS ON THE UNIVERSAL C IV MASS DENSITY ATz∼ 6 FROM EARLY INFRARED SPECTRA OBTAINED WITH THE MAGELLAN FIRE SPECTROGRAPH

Simcoe

Cooksey

Matejek

et al. 2011

ApJ

View full text Add to dashboard Cite

We present a new determination of the intergalactic C iv mass density at 4.3 < z < 6.3. Our constraints are derived from high signal-to-noise spectra of seven quasars at z > 5.8 obtained with the newly commissioned Folded-Port Infrared Echellette (FIRE) spectrograph on the Magellan Baade telescope, coupled with six observations of northern objects taken from the literature. We confirm the presence of a downturn in the C iv abundance at z = 5.66 by a factor of 4.1 relative to its value at z = 4.96, as measured in the same sight lines. In the FIRE sample, a strong system previously reported in the literature as C iv at z = 5.82 is re-identified as Mg ii at z = 2.78, leading to a substantial downward revision in Ω C iv for these prior studies. Additionally, we confirm the presence of at least two systems with low-ionization C ii, Si ii, and O i absorption but relatively weak signal from C iv. The latter systems may be of interest if the downward trend in Ω C iv at high redshift is driven in part by ionization effects.

show abstract

“…It must be an evolution in systems more like S9, where the optical depth is highly variable and relatively large across the entire kinematic range of absorption. At even larger equivalent widths, '2 Å and greater, the evolution is likely dominated by systems with kinematics similar to those studied by Bond et al (2001). A sample of high-resolution Mg ii systems at z > 1 will be required to ultimately address these issues.…”

Section: Evolutionary Clues From Kinematicsmentioning

confidence: 96%

The Physical Conditions of Intermediate-Redshift M[CLC]g[/CLC] [CSC]ii[/CSC] Absorbing Clouds from Voigt Profile Analysis

Churchill

Vogt

Charlton

2003

The Astronomical Journal

Self Cite

116

145

View full text Add to dashboard Cite

We present a detailed and statistical analysis of the column densities and Doppler b parameters of Mg ii absorbing clouds at redshifts 0.4 z 1.2. We draw on the HIRES/Keck data (Dv ' 6.6 km s À1 ) and Voigt profile (VP) fitting results presented by Churchill & Vogt (Paper I). The sample comprises 175 clouds from 23 systems along 18 quasar lines of sight. In order to better understand whether the inferred physical conditions in the absorbing clouds could be '' false '' conditions, which can arise due to the nonuniqueness inherent in parameterizing complex absorption profiles, we performed extensive simulations of the VP analyses presented in this paper. In brief, we find the following: (1) The Fe ii and Mg ii column densities are correlated at the 9 level. There is a 5 anticorrelation between the Mg i/Mg ii column density ratio and the Mg ii column density. (2) Power-law fits to the column density distributions for Mg ii, Fe ii, and Mg i yielded power-law slopes of approximately À1.6, À1.7, and À2.0, respectively. (5) From photoionization models we find that the column density ratios are most consistent with being photoionized by the ultraviolet extragalactic ionizing background, as opposed to stellar radiation. Based on the Mg i to Mg ii column density ratios, it appears that at least two-phase ionization models are required to explain the data.

show abstract

High‐Redshift Superwinds as the Source of the Strongest MgiiAbsorbers: A Feasibility Analysis

Cited by 93 publications

References 35 publications

Uncovering strong MgII absorbing galaxies

Uncovering strong MgII absorbing galaxies

CONSTRAINTS ON THE UNIVERSAL C IV MASS DENSITY ATz∼ 6 FROM EARLY INFRARED SPECTRA OBTAINED WITH THE MAGELLAN FIRE SPECTROGRAPH

The Physical Conditions of Intermediate-Redshift M[CLC]g[/CLC] [CSC]ii[/CSC] Absorbing Clouds from Voigt Profile Analysis

Contact Info

Product

Resources

About