Are strong Mg II absorbers the signature of outflows?

N. Bouché, M. T. Murphy, C. Péroux, I. Csabai, V. Wild

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Background: Gas, and in particular, cold gas is seen locally in many different locations (disks, halos, merger tails, and even in outflows). Which one is traced by QSO absorption lines, and in particular by the Mg II metal line? Given that QSO absorption lines probe galaxy halos out to 100 kpc and have no bias on the host galaxy luminosity, they are crucial to our understanding of galaxy evolution in general and feedback in particular. Strong Mg II absorbers with equivalent width Wr2796 > 1 Å are in fact made of several (up to 20) sub-components or clouds. As a result, Wr is a measure of the line-of-sight velocity dispersion (Δv) of the clouds. Most models for QSO absorbers, except the outflow scenario, predict that the host-galaxy mass and the velocity dispersion Δv should correlate (by the Virial theorem). Goal: If one could measure the mass for QSO absorbers, one could test whether mass and Δv are correlated. Result: Using a statistical technique that does not require any spectroscopic follow-up, we find that the halo-mass Mh of the host-galaxy is anti-correlated with the equivalent width WΔv. This shows that the Mg II clouds are not virialized in the gaseous halos of the host-galaxies. If Mg II absorbers were virialized in galaxy halos, a positive mass-velocity correlation would have been observed. In addition, the kinematics of super-winds are most consistent with our Mh-Wr anti-correlation.

Original languageEnglish
Pages (from-to)131-134
Number of pages4
JournalNew Astronomy Reviews
Volume51
Issue number1-2
DOIs
Publication statusPublished - Feb 2007

Fingerprint

absorbers
outflow
signatures
galaxies
halos
quasars
gas
merger
virial theorem
cold gas
kinematics
probe
line of sight
metal
luminosity
probes
gases
metals

ASJC Scopus subject areas

  • Astronomy and Astrophysics

Cite this

Are strong Mg II absorbers the signature of outflows? / Bouché, N.; Murphy, M. T.; Péroux, C.; Csabai, I.; Wild, V.

In: New Astronomy Reviews, Vol. 51, No. 1-2, 02.2007, p. 131-134.

Research output: Contribution to journalArticle

Bouché, N, Murphy, MT, Péroux, C, Csabai, I & Wild, V 2007, 'Are strong Mg II absorbers the signature of outflows?', New Astronomy Reviews, vol. 51, no. 1-2, pp. 131-134. https://doi.org/10.1016/j.newar.2006.11.050
Bouché, N. ; Murphy, M. T. ; Péroux, C. ; Csabai, I. ; Wild, V. / Are strong Mg II absorbers the signature of outflows?. In: New Astronomy Reviews. 2007 ; Vol. 51, No. 1-2. pp. 131-134.
@article{5f7b6d984ac74e0b9544207db3c95e11,
title = "Are strong Mg II absorbers the signature of outflows?",
abstract = "Background: Gas, and in particular, cold gas is seen locally in many different locations (disks, halos, merger tails, and even in outflows). Which one is traced by QSO absorption lines, and in particular by the Mg II metal line? Given that QSO absorption lines probe galaxy halos out to 100 kpc and have no bias on the host galaxy luminosity, they are crucial to our understanding of galaxy evolution in general and feedback in particular. Strong Mg II absorbers with equivalent width Wr2796 > 1 {\AA} are in fact made of several (up to 20) sub-components or clouds. As a result, Wr is a measure of the line-of-sight velocity dispersion (Δv) of the clouds. Most models for QSO absorbers, except the outflow scenario, predict that the host-galaxy mass and the velocity dispersion Δv should correlate (by the Virial theorem). Goal: If one could measure the mass for QSO absorbers, one could test whether mass and Δv are correlated. Result: Using a statistical technique that does not require any spectroscopic follow-up, we find that the halo-mass Mh of the host-galaxy is anti-correlated with the equivalent width WΔv. This shows that the Mg II clouds are not virialized in the gaseous halos of the host-galaxies. If Mg II absorbers were virialized in galaxy halos, a positive mass-velocity correlation would have been observed. In addition, the kinematics of super-winds are most consistent with our Mh-Wr anti-correlation.",
author = "N. Bouch{\'e} and Murphy, {M. T.} and C. P{\'e}roux and I. Csabai and V. Wild",
year = "2007",
month = "2",
doi = "10.1016/j.newar.2006.11.050",
language = "English",
volume = "51",
pages = "131--134",
journal = "New Astronomy Reviews",
issn = "1387-6473",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Are strong Mg II absorbers the signature of outflows?

AU - Bouché, N.

AU - Murphy, M. T.

AU - Péroux, C.

AU - Csabai, I.

AU - Wild, V.

PY - 2007/2

Y1 - 2007/2

N2 - Background: Gas, and in particular, cold gas is seen locally in many different locations (disks, halos, merger tails, and even in outflows). Which one is traced by QSO absorption lines, and in particular by the Mg II metal line? Given that QSO absorption lines probe galaxy halos out to 100 kpc and have no bias on the host galaxy luminosity, they are crucial to our understanding of galaxy evolution in general and feedback in particular. Strong Mg II absorbers with equivalent width Wr2796 > 1 Å are in fact made of several (up to 20) sub-components or clouds. As a result, Wr is a measure of the line-of-sight velocity dispersion (Δv) of the clouds. Most models for QSO absorbers, except the outflow scenario, predict that the host-galaxy mass and the velocity dispersion Δv should correlate (by the Virial theorem). Goal: If one could measure the mass for QSO absorbers, one could test whether mass and Δv are correlated. Result: Using a statistical technique that does not require any spectroscopic follow-up, we find that the halo-mass Mh of the host-galaxy is anti-correlated with the equivalent width WΔv. This shows that the Mg II clouds are not virialized in the gaseous halos of the host-galaxies. If Mg II absorbers were virialized in galaxy halos, a positive mass-velocity correlation would have been observed. In addition, the kinematics of super-winds are most consistent with our Mh-Wr anti-correlation.

AB - Background: Gas, and in particular, cold gas is seen locally in many different locations (disks, halos, merger tails, and even in outflows). Which one is traced by QSO absorption lines, and in particular by the Mg II metal line? Given that QSO absorption lines probe galaxy halos out to 100 kpc and have no bias on the host galaxy luminosity, they are crucial to our understanding of galaxy evolution in general and feedback in particular. Strong Mg II absorbers with equivalent width Wr2796 > 1 Å are in fact made of several (up to 20) sub-components or clouds. As a result, Wr is a measure of the line-of-sight velocity dispersion (Δv) of the clouds. Most models for QSO absorbers, except the outflow scenario, predict that the host-galaxy mass and the velocity dispersion Δv should correlate (by the Virial theorem). Goal: If one could measure the mass for QSO absorbers, one could test whether mass and Δv are correlated. Result: Using a statistical technique that does not require any spectroscopic follow-up, we find that the halo-mass Mh of the host-galaxy is anti-correlated with the equivalent width WΔv. This shows that the Mg II clouds are not virialized in the gaseous halos of the host-galaxies. If Mg II absorbers were virialized in galaxy halos, a positive mass-velocity correlation would have been observed. In addition, the kinematics of super-winds are most consistent with our Mh-Wr anti-correlation.

UR - http://www.scopus.com/inward/record.url?scp=33846638255&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846638255&partnerID=8YFLogxK

U2 - 10.1016/j.newar.2006.11.050

DO - 10.1016/j.newar.2006.11.050

M3 - Article

AN - SCOPUS:33846638255

VL - 51

SP - 131

EP - 134

JO - New Astronomy Reviews

JF - New Astronomy Reviews

SN - 1387-6473

IS - 1-2

ER -